Effect of atropine or atenolol on cardiovascular responses to novelty stress in freely-moving rats.

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van den Buuse, Maarten

2002-09-01

Cardiac hemodynamic mechanisms involved in cardiovascular responses to stress were studied in conscious, freely-moving female spontaneously hypertensive rats exposed for 15 min to an open-field. When pretreated with saline, the rats displayed a rapid rise in blood pressure, heart rate, aortic dP/dt and locomotor activity. In rats pretreated with 0.5 mg/kg of methylatropine, the tachycardia was slightly, but significantly reduced. In rats pretreated with 1 mg/kg of atenolol, the tachycardis and rise in dP/dt were markedly reduced. These data suggest that the cardiac responses to stress include predominantly cardiac sympathetic activation and a minor component of vagal withdrawal.

Strain-dependent variations in spatial learning and in hippocampal synaptic plasticity in the dentate gyrus of freely behaving rats

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Denise eManahan-Vaughan

2011-03-01

Full Text Available Hippocampal synaptic plasticity is believed to comprise the cellular basis for spatial learning. Strain-dependent differences in synaptic plasticity in the CA1 region have been reported. However, it is not known whether these differences extend to other synapses within the trisynaptic circuit, although there is evidence for morphological variations within that path. We investigated whether Wistar and Hooded Lister (HL rat strains express differences in synaptic plasticity in the dentate gyrus in vivo. We also explored whether they exhibit differences in the ability to engage in spatial learning in an 8-arm radial maze. Basal synaptic transmission was stable over a 24h period in both rat strains, and the input-output relationship of both strains was not significantly different. Paired-pulse analysis revealed significantly less paired-pulse facilitation in the Hooded Lister strain when pulses were given 40-100 msec apart. Low frequency stimulation at 1Hz evoked long-term depression (>24h in Wistar and short-term depression (<2h in HL rats; 200Hz stimulation induced long-term potentiation (>24h in Wistar, and a transient, significantly smaller potentiation (<1h in HL rats, suggesting that HL rats have higher thresholds for expression of persistent synaptic plasticity. Training for 10d in an 8-arm radial maze revealed that HL rats master the working memory task faster than Wistar rats, although both strains show an equivalent performance by the end of the trial period. HL rats also perform more efficiently in a double working and reference memory task. On the other hand, Wistar rats show better reference memory performance on the final (8-10 days of training. Wistar rats were less active and more anxious than HL rats.These data suggest that strain-dependent variations in hippocampal synaptic plasticity occur in different hippocampal synapses. A clear correlation with differences in spatial learning is not evident however.

A new minimal-stress freely-moving rat model for preclinical studies on intranasal administration of CNS drugs.

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Stevens, Jasper; Suidgeest, Ernst; van der Graaf, Piet Hein; Danhof, Meindert; de Lange, Elizabeth C M

2009-08-01

To develop a new minimal-stress model for intranasal administration in freely moving rats and to evaluate in this model the brain distribution of acetaminophen following intranasal versus intravenous administration. Male Wistar rats received one intranasal cannula, an intra-cerebral microdialysis probe, and two blood cannulas for drug administration and serial blood sampling respectively. To evaluate this novel model, the following experiments were conducted. 1) Evans Blue was administered to verify the selectivity of intranasal exposure. 2) During a 1 min infusion 10, 20, or 40 microl saline was administered intranasally or 250 microl intravenously. Corticosterone plasma concentrations over time were compared as biomarkers for stress. 3) 200 microg of the model drug acetaminophen was given in identical setup and plasma, and brain pharmacokinetics were determined. In 96% of the rats, only the targeted nasal cavity was deeply colored. Corticosterone plasma concentrations were not influenced, neither by route nor volume of administration. Pharmacokinetics of acetaminophen were identical after intravenous and intranasal administration, although the Cmax in microdialysates was reached a little earlier following intravenous administration. A new minimal-stress model for intranasal administration in freely moving rats has been successfully developed and allows direct comparison with intravenous administration.

Sustained prejunctional facilitation of noradrenergic neurotransmission by adrenaline as a co-transmitter in the portal vein of freely moving rats

NARCIS (Netherlands)

COPPES, RP; Freie, I.; SMIT, J; ZAAGSMA, J

1994-01-01

1 The duration of the facilitatory effect of adrenaline on the electrically evoked overflow of noradrenaline was studied in the portal vein of permanently adreno-demedullated freely moving rats. 2 Rats were infused with adrenaline (20 or 100 ng min(-1)) for 2 h. After an interval of 1 h, when plasma

Afferent input selects NMDA receptor subtype to determine the persistency of hippocampal LTP in freely behaving mice

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Jesús Javier Ballesteros

2016-10-01

Full Text Available The glutamatergic N-methyl-D-aspartate receptor (NMDAR is critically involved in many forms of hippocampus-dependent memory that may be enabled by synaptic plasticity. Behavioral studies with NMDAR antagonists and NMDAR subunit (GluN2 mutants revealed distinct contributions from GluN2A- and GluN2B-containing NMDARs to rapidly and slowly acquired memory performance. Furthermore, studies of synaptic plasticity, in genetically modified mice in vitro, suggest that GluN2A and GluN2B may contribute in different ways to the induction and longevity of synaptic plasticity. In contrast to the hippocampal slice preparation, in behaving mice, the afferent frequencies that induce synaptic plasticity are very restricted and specific. In fact, it is the stimulus pattern, and not variations in afferent frequency that determine the longevity of long-term potentiation (LTP. Here, we explored the contribution of GluN2A and GluN2B to LTP of differing magnitudes and persistencies in freely behaving mice. We applied differing high-frequency stimulation (HFS patterns at 100 Hz to the hippocampal CA1 region, to induce NMDAR-dependent LTP in wild-type (WT mice, that endured for 24h (late (L-LTP. In GluN2A-KO mice, E-LTP (HFS, 50 pulses was significantly reduced in magnitude and duration, whereas LTP (HFS, 2 x 50 pulses and L-LTP (HFS, 4 x 50 pulses were unaffected compared to responses in WT animals. By contrast, pharmacological antagonism of GluN2B in WT had no effect on E-LTP but significantly prevented LTP. E- LTP and LTP were significantly impaired by GluN2B antagonism in GluN2A-KO mice. These data indicate that the pattern of afferent stimulation is decisive for the recruitment of distinct GluN2A and GluN2B signaling pathways that in turn determine the persistency of hippocampal LTP. Whereas brief bursts of patterned stimulation preferentially recruit GluN2A and lead to weak and short-lived forms of LTP, prolonged, more intense, afferent activation recruits GluN2B

Combined, but not individual, blockade of ASIC3, P2X, and EP4 receptors attenuates the exercise pressor reflex in rats with freely perfused hindlimb muscles

OpenAIRE

Stone, Audrey J.; Copp, Steven W.; Kim, Joyce S.; Kaufman, Marc P.

2015-01-01

In healthy humans, tests of the hypothesis that lactic acid, PGE2, or ATP plays a role in evoking the exercise pressor reflex proved controversial. The findings in humans resembled ours in decerebrate rats that individual blockade of the receptors to lactic acid, PGE2, and ATP had only small effects on the exercise pressor reflex provided that the muscles were freely perfused. This similarity between humans and rats prompted us to test the hypothesis that in rats with freely perfused muscles ...

A new rapid kindling variant for induction of cortical epileptogenesis in freely moving rats

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Juan Carlos Morales

2014-07-01

Full Text Available Kindling, one of the most used models of experimental epilepsy is based on daily electrical stimulation in several brain structures. Unlike the classic or slow kindling protocols (SK, the rapid kindling types (RK described until now require continuous stimulation at suprathreshold intensities applied directly to the same brain structure used for subsequent electrophysiological and inmunohistochemical studies, usually the hippocampus. However, the cellular changes observed in these rapid protocols, such as astrogliosis and neuronal loss, could be due to experimental manipulation more than to epileptogenesis-related alterations. Here, we developed a new RK protocol in order to generate an improved model of temporal lobe epilepsy (TLE which allows gradual progression of the epilepsy as well as obtaining an epileptic hippocampus, thus avoiding direct surgical manipulation and electric stimulation over this structure. This new protocol consists of basolateral amygdala (BLA stimulation with 10 trains of biphasic pulses (10s;50Hz per day with 20 minutes-intervals, during 3 consecutive days, using a subconvulsive and subthreshold intensity, which guarantees tissue integrity. The progression of epileptic activity was evaluated in freely moving rats through EEG recordings from cortex and amygdala, accompanied with synchronized video recordings. Moreover, we assessed the effectiveness of RK protocol and the establishment of epilepsy by evaluating cellular alterations of hippocampal slices from kindled rats. RK protocol induced convulsive states similar to SK protocols but in 3 days, with persistently lowered threshold to seizure induction and epileptogenic-dependent cellular changes in amygdala projection areas. We concluded that this novel RK protocol introduces a new variant of the chronic epileptogenesis models in freely moving rats, which is faster, highly reproducible and causes minimum cell damage with respect to that observed in other experimental

Continuous Force Decoding from Local Field Potentials of the Primary Motor Cortex in Freely Moving Rats.

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Khorasani, Abed; Heydari Beni, Nargess; Shalchyan, Vahid; Daliri, Mohammad Reza

2016-10-21

Local field potential (LFP) signals recorded by intracortical microelectrodes implanted in primary motor cortex can be used as a high informative input for decoding of motor functions. Recent studies show that different kinematic parameters such as position and velocity can be inferred from multiple LFP signals as precisely as spiking activities, however, continuous decoding of the force magnitude from the LFP signals in freely moving animals has remained an open problem. Here, we trained three rats to press a force sensor for getting a drop of water as a reward. A 16-channel micro-wire array was implanted in the primary motor cortex of each trained rat, and obtained LFP signals were used for decoding of the continuous values recorded by the force sensor. Average coefficient of correlation and the coefficient of determination between decoded and actual force signals were r = 0.66 and R 2  = 0.42, respectively. We found that LFP signal on gamma frequency bands (30-120 Hz) had the most contribution in the trained decoding model. This study suggests the feasibility of using low number of LFP channels for the continuous force decoding in freely moving animals resembling BMI systems in real life applications.

Strong activation of vascular prejunctional beta 2-adrenoceptors in freely moving rats by adrenaline released as a co-transmitter

NARCIS (Netherlands)

COPPES, RP; SMIT, J; KHALI, NN; Brouwer, F.; ZAAGSMA, J

1993-01-01

The effect of adrenaline on the electrically evoked noradrenaline overflow in the portal vein of adrenal demedullated freely moving rats was studied. Adrenaline (100 ng/min) was infused for 2 h into the portal vein. After a 1-h interval when plasma adrenaline had returned to pre-infusion

Prosthetic avian vocal organ controlled by a freely behaving bird based on a low dimensional model of the biomechanical periphery.

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Ezequiel M Arneodo

Full Text Available Because of the parallels found with human language production and acquisition, birdsong is an ideal animal model to study general mechanisms underlying complex, learned motor behavior. The rich and diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior has been understood by studying the physics of the avian vocal organ, particularly the syrinx. A mathematical model describing the complex periphery as a nonlinear dynamical system leads to the conclusion that nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth paths in a low dimensional parameter space. An analysis of the model provides insight into which parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited by a spontaneously singing muted bird and computing the model on a Digital Signal Processor in real-time, we produce realistic synthetic vocalizations that replace the bird's own auditory feedback. In this way, we build a bio-prosthetic avian vocal organ driven by a freely behaving bird via its physiologically coded motor commands. Since it is based on a low-dimensional nonlinear mathematical model of the peripheral effector, the emulation of the motor behavior requires light computation, in such a way that our bio-prosthetic device can be implemented on a portable platform.

Local field potentials in the ventral tegmental area during cocaine-induced locomotor activation: Measurements in freely moving rats.

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Harris Bozer, Amber L; Li, Ai-Ling; Sibi, Jiny E; Bobzean, Samara A M; Peng, Yuan B; Perrotti, Linda I

2016-03-01

The ventral tegmental area (VTA) has been established as a critical nucleus for processing behavioral changes that occur during psychostimulant use. Although it is known that cocaine induced locomotor activity is initiated in the VTA, not much is known about the electrical activity in real time. The use of our custom-designed wireless module for recording local field potential (LFP) activity provides an opportunity to confirm and identify changes in neuronal activity within the VTA of freely moving rats. The purpose of this study was to investigate the changes in VTA LFP activity in real time that underlie cocaine induced changes in locomotor behavior. Recording electrodes were implanted in the VTA of rats. Locomotor behavior and LFP activity were simultaneously recorded at baseline, and after saline and cocaine injections. Results indicate that cocaine treatment caused increases in both locomotor behavior and LFP activity in the VTA. Specifically, LFP activity was highest during the first 30 min following the cocaine injection and was most robust in Delta and Theta frequency bands; indicating the role of low frequency VTA activity in the initiation of acute stimulant-induced locomotor behavior. Our results suggest that LFP recording in freely moving animals can be used in the future to provide valuable information pertaining to drug induced changes in neural activity. Copyright © 2016 Elsevier Inc. All rights reserved.

Conditioned taste avoidance induced by forced and voluntary wheel running in rats.

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Forristall, J R; Hookey, B L; Grant, V L

2007-03-01

Voluntary exercise by rats running in a freely rotating wheel (free wheel) produces conditioned taste avoidance (CTA) of a flavored solution consumed before running [e.g., Lett, B.T., Grant, V.L., 1996. Wheel running induces conditioned taste aversion in rats trained while hungry and thirsty. Physiol. Behav. 59, 699-702]. Forced exercise, swimming or running, also produces CTA in rats [e.g., Masaki, T., Nakajima, S., 2006. Taste aversion induced by forced swimming, voluntary running, forced running, and lithium chloride injection treatments. Physiol. Behav. 88, 411-416]. Energy expenditure may be the critical factor in producing such CTA. If so, forced running in a motorized running wheel should produce CTA equivalent to that produced by a similar amount of voluntary running. In two experiments, we compared forced running in a motorized wheel with voluntary running in a free wheel. Mean distance run over 30 min was equated as closely as possible in the two apparatuses. Both types of exercise produced CTA relative to sedentary, locked-wheel controls. However, voluntary running produced greater CTA than forced running. We consider differences between running in the free and motorized wheels that may account for the differences in strength of CTA.

Combined, but not individual, blockade of ASIC3, P2X, and EP4 receptors attenuates the exercise pressor reflex in rats with freely perfused hindlimb muscles.

Science.gov (United States)

Stone, Audrey J; Copp, Steven W; Kim, Joyce S; Kaufman, Marc P

2015-12-01

In healthy humans, tests of the hypothesis that lactic acid, PGE2, or ATP plays a role in evoking the exercise pressor reflex proved controversial. The findings in humans resembled ours in decerebrate rats that individual blockade of the receptors to lactic acid, PGE2, and ATP had only small effects on the exercise pressor reflex provided that the muscles were freely perfused. This similarity between humans and rats prompted us to test the hypothesis that in rats with freely perfused muscles combined receptor blockade is required to attenuate the exercise pressor reflex. We first compared the reflex before and after injecting either PPADS (10 mg/kg), a P2X receptor antagonist, APETx2 (100 μg/kg), an activating acid-sensing ion channel 3 (ASIC) channel antagonist, or L161982 (2 μg/kg), an EP4 receptor antagonist, into the arterial supply of the hindlimb of decerebrated rats. We then examined the effects of combined blockade of P2X receptors, ASIC3 channels, and EP4 receptors on the exercise pressor reflex using the same doses, intra-arterial route, and time course of antagonist injections as those used for individual blockade. We found that neither PPADS (n = 5), APETx2 (n = 6), nor L161982 (n = 6) attenuated the reflex. In contrast, combined blockade of these receptors (n = 7) attenuated the peak (↓27%, P reflex. Combined blockade injected intravenously had no effect on the reflex. We conclude that combined blockade of P2X receptors, ASIC3 channels, and EP4 receptors on the endings of thin fiber muscle afferents is required to attenuate the exercise pressor reflex in rats with freely perfused hindlimbs. Copyright © 2015 the American Physiological Society.

Integrated wireless fast-scan cyclic voltammetry recording and electrical stimulation for reward-predictive learning in awake, freely moving rats

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Li, Yu-Ting; Wickens, Jeffery R.; Huang, Yi-Ling; Pan, Wynn H. T.; Chen, Fu-Yu Beverly; Chen, Jia-Jin Jason

2013-08-01

Objective. Fast-scan cyclic voltammetry (FSCV) is commonly used to monitor phasic dopamine release, which is usually performed using tethered recording and for limited types of animal behavior. It is necessary to design a wireless dopamine sensing system for animal behavior experiments. Approach. This study integrates a wireless FSCV system for monitoring the dopamine signal in the ventral striatum with an electrical stimulator that induces biphasic current to excite dopaminergic neurons in awake freely moving rats. The measured dopamine signals are unidirectionally transmitted from the wireless FSCV module to the host unit. To reduce electrical artifacts, an optocoupler and a separate power are applied to isolate the FSCV system and electrical stimulator, which can be activated by an infrared controller. Main results. In the validation test, the wireless backpack system has similar performance in comparison with a conventional wired system and it does not significantly affect the locomotor activity of the rat. In the cocaine administration test, the maximum electrically elicited dopamine signals increased to around 230% of the initial value 20 min after the injection of 10 mg kg-1 cocaine. In a classical conditioning test, the dopamine signal in response to a cue increased to around 60 nM over 50 successive trials while the electrically evoked dopamine concentration decreased from about 90 to 50 nM in the maintenance phase. In contrast, the cue-evoked dopamine concentration progressively decreased and the electrically evoked dopamine was eliminated during the extinction phase. In the histological evaluation, there was little damage to brain tissue after five months chronic implantation of the stimulating electrode. Significance. We have developed an integrated wireless voltammetry system for measuring dopamine concentration and providing electrical stimulation. The developed wireless FSCV system is proven to be a useful experimental tool for the continuous

Implantable fiber-optic interface for parallel multisite long-term optical dynamic brain interrogation in freely moving mice

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Doronina-Amitonova, L. V.; Fedotov, I. V.; Ivashkina, O. I.; Zots, M. A.; Fedotov, A. B.; Anokhin, K. V.; Zheltikov, A. M.

2013-01-01

Seeing the big picture of functional responses within large neural networks in a freely functioning brain is crucial for understanding the cellular mechanisms behind the higher nervous activity, including the most complex brain functions, such as cognition and memory. As a breakthrough toward meeting this challenge, implantable fiber-optic interfaces integrating advanced optogenetic technologies and cutting-edge fiber-optic solutions have been demonstrated, enabling a long-term optogenetic manipulation of neural circuits in freely moving mice. Here, we show that a specifically designed implantable fiber-optic interface provides a powerful tool for parallel long-term optical interrogation of distinctly separate, functionally different sites in the brain of freely moving mice. This interface allows the same groups of neurons lying deeply in the brain of a freely behaving mouse to be reproducibly accessed and optically interrogated over many weeks, providing a long-term dynamic detection of genome activity in response to a broad variety of pharmacological and physiological stimuli. PMID:24253232

Increased in vivo release of neuropeptide S in the amygdala of freely moving rats after local depolarisation and emotional stress.

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Ebner, Karl; Rjabokon, Alesja; Pape, Hans-Christian; Singewald, Nicolas

2011-10-01

Intracerebral microdialysis in conjunction with a highly sensitive radioimmunoassay was used to study the in vivo release of neuropeptide S (NPS) within the amygdala of freely moving rats. NPS was consistently detected in basolateral amygdala dialysates and the release considerably enhanced in response to local depolarisation as well as exposure to forced swim stress. Thus, our data demonstrate for the first time emotional stress-induced release of NPS in the amygdala supporting a functional role of endogenous NPS in stress/anxiety-related phenomena.

Neural activity in the prelimbic and infralimbic cortices of freely moving rats during social interaction: Effect of isolation rearing

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Minami, Chihiro; Shimizu, Tomoko

2017-01-01

Sociability promotes a sound daily life for individuals. Reduced sociability is a central symptom of various neuropsychiatric disorders, and yet the neural mechanisms underlying reduced sociability remain unclear. The prelimbic cortex (PL) and infralimbic cortex (IL) have been suggested to play an important role in the neural mechanisms underlying sociability because isolation rearing in rats results in impairment of social behavior and structural changes in the PL and IL. One possible mechanism underlying reduced sociability involves dysfunction of the PL and IL. We made a wireless telemetry system to record multiunit activity in the PL and IL of pairs of freely moving rats during social interaction and examined the influence of isolation rearing on this activity. In group-reared rats, PL neurons increased firing when the rat showed approaching behavior and also contact behavior, especially when the rat attacked the partner. Conversely, IL neurons increased firing when the rat exhibited leaving behavior, especially when the partner left on its own accord. In social interaction, the PL may be involved in active actions toward others, whereas the IL may be involved in passive relief from cautionary subjects. Isolation rearing altered social behavior and neural activity. Isolation-reared rats showed an increased frequency and decreased duration of contact behavior. The increased firing of PL neurons during approaching and contact behavior, observed in group-reared rats, was preserved in isolation-reared rats, whereas the increased firing of IL neurons during leaving behavior, observed in group-reared rats, was suppressed in isolation-reared rats. This result indicates that isolation rearing differentially alters neural activity in the PL and IL during social behavior. The differential influence of isolation rearing on neural activity in the PL and IL may be one of the neural bases of isolation rearing-induced behavior. PMID:28459875

Neural activity in the prelimbic and infralimbic cortices of freely moving rats during social interaction: Effect of isolation rearing.

Science.gov (United States)

Minami, Chihiro; Shimizu, Tomoko; Mitani, Akira

2017-01-01

Sociability promotes a sound daily life for individuals. Reduced sociability is a central symptom of various neuropsychiatric disorders, and yet the neural mechanisms underlying reduced sociability remain unclear. The prelimbic cortex (PL) and infralimbic cortex (IL) have been suggested to play an important role in the neural mechanisms underlying sociability because isolation rearing in rats results in impairment of social behavior and structural changes in the PL and IL. One possible mechanism underlying reduced sociability involves dysfunction of the PL and IL. We made a wireless telemetry system to record multiunit activity in the PL and IL of pairs of freely moving rats during social interaction and examined the influence of isolation rearing on this activity. In group-reared rats, PL neurons increased firing when the rat showed approaching behavior and also contact behavior, especially when the rat attacked the partner. Conversely, IL neurons increased firing when the rat exhibited leaving behavior, especially when the partner left on its own accord. In social interaction, the PL may be involved in active actions toward others, whereas the IL may be involved in passive relief from cautionary subjects. Isolation rearing altered social behavior and neural activity. Isolation-reared rats showed an increased frequency and decreased duration of contact behavior. The increased firing of PL neurons during approaching and contact behavior, observed in group-reared rats, was preserved in isolation-reared rats, whereas the increased firing of IL neurons during leaving behavior, observed in group-reared rats, was suppressed in isolation-reared rats. This result indicates that isolation rearing differentially alters neural activity in the PL and IL during social behavior. The differential influence of isolation rearing on neural activity in the PL and IL may be one of the neural bases of isolation rearing-induced behavior.

Systemic blockade of dopamine D2-like receptors increases high-voltage spindles in the globus pallidus and motor cortex of freely moving rats.

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Chen Yang

Full Text Available High-voltage spindles (HVSs have been reported to appear spontaneously and widely in the cortical-basal ganglia networks of rats. Our previous study showed that dopamine depletion can significantly increase the power and coherence of HVSs in the globus pallidus (GP and motor cortex of freely moving rats. However, it is unclear whether dopamine regulates HVS activity by acting on dopamine D₁-like receptors or D₂-like receptors. We employed local-field potential and electrocorticogram methods to simultaneously record the oscillatory activities in the GP and primary motor cortex (M1 in freely moving rats following systemic administration of dopamine receptor antagonists or saline. The results showed that the dopamine D₂-like receptor antagonists, raclopride and haloperidol, significantly increased the number and duration of HVSs, and the relative power associated with HVS activity in the GP and M1 cortex. Coherence values for HVS activity between the GP and M1 cortex area were also significantly increased by dopamine D₂-like receptor antagonists. On the contrary, the selective dopamine D₁-like receptor antagonist, SCH23390, had no significant effect on the number, duration, or relative power of HVSs, or HVS-related coherence between M1 and GP. In conclusion, dopamine D₂-like receptors, but not D₁-like receptors, were involved in HVS regulation. This supports the important role of dopamine D₂-like receptors in the regulation of HVSs. An siRNA knock-down experiment on the striatum confirmed our conclusion.

Systemic blockade of dopamine D2-like receptors increases high-voltage spindles in the globus pallidus and motor cortex of freely moving rats.

Science.gov (United States)

Yang, Chen; Ge, Shun-Nan; Zhang, Jia-Rui; Chen, Lei; Yan, Zhi-Qiang; Heng, Li-Jun; Zhao, Tian-Zhi; Li, Wei-Xin; Jia, Dong; Zhu, Jun-Ling; Gao, Guo-Dong

2013-01-01

High-voltage spindles (HVSs) have been reported to appear spontaneously and widely in the cortical-basal ganglia networks of rats. Our previous study showed that dopamine depletion can significantly increase the power and coherence of HVSs in the globus pallidus (GP) and motor cortex of freely moving rats. However, it is unclear whether dopamine regulates HVS activity by acting on dopamine D₁-like receptors or D₂-like receptors. We employed local-field potential and electrocorticogram methods to simultaneously record the oscillatory activities in the GP and primary motor cortex (M1) in freely moving rats following systemic administration of dopamine receptor antagonists or saline. The results showed that the dopamine D₂-like receptor antagonists, raclopride and haloperidol, significantly increased the number and duration of HVSs, and the relative power associated with HVS activity in the GP and M1 cortex. Coherence values for HVS activity between the GP and M1 cortex area were also significantly increased by dopamine D₂-like receptor antagonists. On the contrary, the selective dopamine D₁-like receptor antagonist, SCH23390, had no significant effect on the number, duration, or relative power of HVSs, or HVS-related coherence between M1 and GP. In conclusion, dopamine D₂-like receptors, but not D₁-like receptors, were involved in HVS regulation. This supports the important role of dopamine D₂-like receptors in the regulation of HVSs. An siRNA knock-down experiment on the striatum confirmed our conclusion.

Social transmission of Pavlovian fear: fear-conditioning by-proxy in related female rats.

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Jones, Carolyn E; Riha, Penny D; Gore, Andrea C; Monfils, Marie-H

2014-05-01

Pairing a previously neutral conditioned stimulus (CS; e.g., a tone) to an aversive unconditioned stimulus (US; e.g., a foot-shock) leads to associative learning such that the tone alone will elicit a conditioned response (e.g., freezing). Individuals can also acquire fear from a social context, such as through observing the fear expression of a conspecific. In the current study, we examined the influence of kinship/familiarity on social transmission of fear in female rats. Rats were housed in triads with either sisters or non-related females. One rat from each cage was fear conditioned to a tone CS+ shock US. On day two, the conditioned rat was returned to the chamber accompanied by one of her cage mates. Both rats were allowed to behave freely, while the tone was played in the absence of the foot-shock. The previously untrained rat is referred to as the fear-conditioned by-proxy (FCbP) animal, as she would freeze based on observations of her cage-mate's response rather than due to direct personal experience with the foot-shock. The third rat served as a cage-mate control. The third day, long-term memory tests to the CS were performed. Consistent with our previous application of this paradigm in male rats (Bruchey et al. in Behav Brain Res 214(1):80-84, 2010), our results revealed that social interactions between the fear conditioned and FCbP rats on day two contribute to freezing displayed by the FCbP rats on day three. In this experiment, prosocial behavior occurring at the termination of the cue on day two was significantly greater between sisters than their non-sister counterparts, and this behavior resulted in increased freezing on day three. Our results suggest that familiarity and/or kinship influences the social transmission of fear in female rats.

Freely accessible water does not decrease consumption of ethanol liquid diets.

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de Fiebre, NancyEllen C; de Fiebre, Christopher M

2003-02-01

In experimental studies, liquid ethanol diets are usually given as the sole source of nutrition and fluid. Two series of experiments were conducted to examine the effect of freely accessible water on the consumption of ethanol liquid diets in male Long-Evans rats. The consumption of diets and subsequent learning ability of rats were first examined in animals given twice-daily saline injections. One group received diet with no access to water for 12 weeks and was subsequently given free access to water with diets for an additional 12 weeks. A second group was given diet and water ad libitum for 24 weeks. Control animals received an isocaloric sucrose-containing diet (with or without ad libitum access to water). Subsequently, rats were tested for active avoidance learning. In the first 12 weeks, animals with ad libitum access to water drank more diet than did water-restricted animals, and previously water-restricted animals increased their diet consumption when access to water was freely available. All water-restricted animals, in both ethanol- and sucrose-treated groups, showed deficits in active avoidance learning, whereas only ethanol-treated animals in groups with ad libitum access to water showed learning deficits. In the second series of experiments, the effect of saline injections on diet consumption, both in the presence and absence of water, was examined. Although saline injections were associated with decreased diet consumption, there was no effect of free access to water. No differences in blood ethanol concentration were seen among groups. Findings obtained from both series of studies demonstrate that consumption of a Sustacal-based liquid ethanol diet does not decrease if access to water is freely available.

A wireless beta-microprobe based on pixelated silicon for in vivo brain studies in freely moving rats

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Märk, J.; Benoit, D.; Balasse, L.; Benoit, M.; Clémens, J. C.; Fieux, S.; Fougeron, D.; Graber-Bolis, J.; Janvier, B.; Jevaud, M.; Genoux, A.; Gisquet-Verrier, P.; Menouni, M.; Pain, F.; Pinot, L.; Tourvielle, C.; Zimmer, L.; Morel, C.; Laniece, P.

2013-07-01

The investigation of neurophysiological mechanisms underlying the functional specificity of brain regions requires the development of technologies that are well adjusted to in vivo studies in small animals. An exciting challenge remains the combination of brain imaging and behavioural studies, which associates molecular processes of neuronal communications to their related actions. A pixelated intracerebral probe (PIXSIC) presents a novel strategy using a submillimetric probe for beta+ radiotracer detection based on a pixelated silicon diode that can be stereotaxically implanted in the brain region of interest. This fully autonomous detection system permits time-resolved high sensitivity measurements of radiotracers with additional imaging features in freely moving rats. An application-specific integrated circuit (ASIC) allows for parallel signal processing of each pixel and enables the wireless operation. All components of the detector were tested and characterized. The beta+ sensitivity of the system was determined with the probe dipped into radiotracer solutions. Monte Carlo simulations served to validate the experimental values and assess the contribution of gamma noise. Preliminary implantation tests on anaesthetized rats proved PIXSIC's functionality in brain tissue. High spatial resolution allows for the visualization of radiotracer concentration in different brain regions with high temporal resolution.

Social exclusion intensifies anxiety-like behavior in adolescent rats.

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Lee, Hyunchan; Noh, Jihyun

2015-05-01

Social connection reduces the physiological reactivity to stressors, while social exclusion causes emotional distress. Stressful experiences in rats result in the facilitation of aversive memory and induction of anxiety. To determine the effect of social interaction, such as social connection, social exclusion and equality or inequality, on emotional change in adolescent distressed rats, the emotional alteration induced by restraint stress in individual rats following exposure to various social interaction circumstances was examined. Rats were assigned to one of the following groups: all freely moving rats, all rats restrained, rats restrained in the presence of freely moving rats and freely moving rats with a restrained rat. No significant difference in fear-memory and sucrose consumption between all groups was found. Change in body weight significantly increased in freely moving rats with a restrained rat, suggesting that those rats seems to share the stressful experience of the restrained rat. Interestingly, examination of the anxiety-like behavior revealed only rats restrained in the presence of freely moving rats to have a significant increase, suggesting that emotional distress intensifies in positions of social exclusion. These results demonstrate that unequally excluded social interaction circumstances could cause the amplification of distressed status and anxiety-related emotional alteration. Copyright © 2015 Elsevier B.V. All rights reserved.

Postnatal changes in local cerebral blood flow measured by the quantitative autoradiographic [14C]iodoantipyrine technique in freely moving rats

International Nuclear Information System (INIS)

Nehlig, A.; Pereira de Vasconcelos, A.; Boyet, S.

1989-01-01

The postnatal changes in local cerebral blood flow in freely moving rats were measured by means of the quantitative autoradiographic [ 14 C]iodoantipyrine method. The animals were studied at 10, 14, 17, 21 and 35 days and at the adult stage. At 10 days after birth, rates of blood flow were very low and quite homogeneous in most cerebral structures except in a few posterior areas. From these relatively uniform levels, values of local cerebral blood flow rose notably to reach a peak at 17 days in all brain regions studied. Rates of blood flow decreased between 17 and 21 days after birth and then increased from weaning time to reach the known characteristic distribution of the adult rat. The postnatal evolution of local cerebral blood in the rat is in good agreement with previous studies in other species such as dog and humans that also show higher rates of cerebral blood flow and glucose utilization at immature stages. However, in the rat, local cerebral blood flow and local cerebral glucose utilization are not coupled over the whole postnatal period studied, since blood flow rates reach peak values at 17 days whereas glucose utilization remains still quite low at that stage. The high rate of cerebral blood flow in the 17-day-old rat may reflect the energetic and biosynthetic needs of the actively developing brain that are completed by the summation of glucose and ketone body utilization

The relationship between gamma frequency and running speed differs for slow and fast gamma rhythms in freely behaving rats

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Zheng, Chenguang; Bieri, Kevin Wood; Trettel, Sean Gregory; Colgin, Laura Lee

2015-01-01

In hippocampal area CA1 of rats, the frequency of gamma activity has been shown to increase with running speed (Ahmed and Mehta, 2012). This finding suggests that different gamma frequencies simply allow for different timings of transitions across cell assemblies at varying running speeds, rather than serving unique functions. However, accumulating evidence supports the conclusion that slow (~25–55 Hz) and fast (~60–100 Hz) gamma are distinct network states with different functions. If slow and fast gamma constitute distinct network states, then it is possible that slow and fast gamma frequencies are differentially affected by running speed. In this study, we tested this hypothesis and found that slow and fast gamma frequencies change differently as a function of running speed in hippocampal areas CA1 and CA3, and in the superficial layers of the medial entorhinal cortex (MEC). Fast gamma frequencies increased with increasing running speed in all three areas. Slow gamma frequencies changed significantly less across different speeds. Furthermore, at high running speeds, CA3 firing rates were low, and MEC firing rates were high, suggesting that CA1 transitions from CA3 inputs to MEC inputs as running speed increases. These results support the hypothesis that slow and fast gamma reflect functionally distinct states in the hippocampal network, with fast gamma driven by MEC at high running speeds and slow gamma driven by CA3 at low running speeds. PMID:25601003

Dopamine Modulates Delta-Gamma Phase-Amplitude Coupling in the Prefrontal Cortex of Behaving Rats

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Andino-Pavlovsky, Victoria; Souza, Annie C.; Scheffer-Teixeira, Robson; Tort, Adriano B. L.; Etchenique, Roberto; Ribeiro, Sidarta

2017-01-01

Dopamine release and phase-amplitude cross-frequency coupling (CFC) have independently been implicated in prefrontal cortex (PFC) functioning. To causally investigate whether dopamine release affects phase-amplitude comodulation between different frequencies in local field potentials (LFP) recorded from the medial PFC (mPFC) of behaving rats, we used RuBiDopa, a light-sensitive caged compound that releases the neurotransmitter dopamine when irradiated with visible light. LFP power did not change in any frequency band after the application of light-uncaged dopamine, but significantly strengthened phase-amplitude comodulation between delta and gamma oscillations. Saline did not exert significant changes, while injections of dopamine and RuBiDopa produced a slow increase in comodulation for several minutes after the injection. The results show that dopamine release in the medial PFC shifts phase-amplitude comodulation from theta-gamma to delta-gamma. Although being preliminary results due to the limitation of the low number of animals present in this study, our findings suggest that dopamine-mediated modification of the frequencies involved in comodulation could be a mechanism by which this neurotransmitter regulates functioning in mPFC. PMID:28536507

Diltiazem Reduces Mortality and Breakdown of ATP in Red Blood Cell Induced by Isoproterenol in a Freely Moving Rat Model in Vivo

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Pollen K.F. Yeung

2014-09-01

Full Text Available The benefit of calcium channel blockers for cardiovascular prevention against heart attack and stroke has not been firmly supported. We investigated the possible cardiovascular protective effect of diltiazem (DTZ against injury induced by isoproterenol using a freely moving rat model in vivo. Sprague Dawley rats were injected subcutaneously (sc with either 5 or 10 mg/kg of DTZ, or saline as control, twice daily for five doses. One hour after the last injection, a single dose of isoproterenol (30 mg/kg was injected sc to each rat. Blood samples were collected serially for 6 h for measurement of adenine nucleotides (ATP, ADP and AMP in red blood cell (RBC by a validated HPLC. The study has shown isoproterenol induced 50% mortality and also increased RBC concentrations of AMP from 0.04 ± 0.02 to 0.29 ± 0.21 mM at the end of the experiment (p < 0.05. Treatment with 10 mg/kg of DTZ reduced mortality from 50% to <20% and attenuated the increase of RBC concentrations of AMP from +0.25 ± 0.22 in the control rats to +0.072 ± 0.092 mM (p < 0.05. The study concluded that 10 mg/kg of DTZ reduced mortality and breakdown of ATP induced by isoproterenol in rats.

The effect of minocycline on the masticatory movements following the inferior alveolar nerve transection in freely moving rats

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Mostafeezur Rahman

2012-04-01

Full Text Available Abstract Background To determine the effects of inferior alveolar nerve transection (IAN-X on masticatory movements in freely moving rats and to test if microglial cells in the trigeminal principal sensory nucleus (prV or motor nucleus (motV may be involved in modulation of mastication, the effects of microglial cell inhibitor minocycline (MC on masticatory jaw movements, microglia (Iba1 immunohistochemistry and the masticatory jaw movements and related masticatory muscle EMG activities were studied in IAN-X rats. Results The number of Iba1-immunoreactive (IR cells both in prV and motV was significantly larger in IAN-X rats compared with sham rats on day 3 after IAN-X. The intraperitoneal (i.p. administration of MC caused a significant reduction of the number of Iba1-IR cells both in prV and motV that was evident on day 14 after IAN-X. Furthermore, a significant reduction of the number of Iba1-IR cells could be observed in motV but not in prV after microinjection (m.i. of MC into the motV of IAN-X rats. The rats also exhibited a significant decrease in the head-withdrawal threshold on the side ipsilateral to the IAN-X compared to the threshold before IAN-X and it lasted to day 14. In addition, IAN-X markedly affected the ability to rat to carry out mastication. The number of complete masticatory sequences was significantly decreased. Furthermore, the total masticatory sequence time and food preparatory (PP period duration was significantly elongated in compared to sham rats. Although IAN-X significantly affected the total number of chewing cycles within the RC period of a masticatory sequence, it had no effect on the duration of the chewing cycles. On the other hand, systemic administration of MC (both i.p. and m.i. in IAN-X rats significantly improved decreased head-withdrawal threshold and the impaired masticatory jaw movements. Conclusions The present findings reveal that the strong modulation of masticatory jaw movements occurs following

Sleeping dendrites: fiber-optic measurements of dendritic calcium activity in freely moving and sleeping animals

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Julie Seibt

2014-03-01

Full Text Available Dendrites are the post-synaptic sites of most excitatory and inhibitory synapses in the brain, making them the main location of cortical information processing and synaptic plasticity. Although current hypotheses suggest a central role for sleep in proper cognitive function and brain plasticity, virtually nothing is known about changes in dendritic activity across the sleep-wake cycle and how waking experience modifies this activity. To start addressing these questions, we developed a method that allows long-term recordings of EEGs/EMG combined with in vivo cortical calcium (Ca2+ activity in freely moving and sleeping rats. We measured Ca2+ activity from populations of dendrites of layer (L 5 pyramidal neurons (n = 13 rats that we compared with Ca2+ activity from populations of neurons in L2/3 (n = 11 rats. L5 and L2/3 neurons were labelled using bolus injection of OGB1-AM or GCaMP6 (1. Ca2+ signals were detected using a fiber-optic system (cannula diameter = 400µm, transmitting the changes in fluorescence to a photodiode. Ca2+ fluctuations could then be correlated with ongoing changes in brain oscillatory activity during 5 major brain states: active wake [AW], quiet wake [QW], NREM, REM and NREM-REM transition (or intermediate state, [IS]. Our Ca2+ recordings show large transients in L5 dendrites and L2/3 neurons that oscillate predominantly at frequencies In summary, we show that this technique is successful in monitoring fluctuations in ongoing dendritic Ca2+ activity during natural brain states and allows, in principle, to combine behavioral measurement with imaging from various brain regions (e.g. deep structures in freely behaving animals. Using this method, we show that Ca2+ transients from populations of L2/3 neurons and L5 dendrites are deferentially regulated across the sleep/wake cycle, with dendritic activity being the highest during the IS sleep. Our correlation analysis suggests that specific sleep EEG activity during NREM and IS

Perifornical orexinergic neurons modulate REM sleep by influencing locus coeruleus neurons in rats.

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Choudhary, R C; Khanday, M A; Mitra, A; Mallick, B N

2014-10-24

Activation of the orexin (OX)-ergic neurons in the perifornical (PeF) area has been reported to induce waking and reduce rapid eye movement sleep (REMS). The activities of OX-ergic neurons are maximum during active waking and they progressively reduce during non-REMS (NREMS) and REMS. Apparently, the locus coeruleus (LC) neurons also behave in a comparable manner as that of the OX-ergic neurons particularly in relation to waking and REMS. Further, as PeF OX-ergic neurons send dense projections to LC, we argued that the former could drive the LC neurons to modulate waking and REMS. Studies in freely moving normally behaving animals where simultaneously neuro-chemo-anatomo-physio-behavioral information could be deciphered would significantly strengthen our understanding on the regulation of REMS. Therefore, in this study in freely behaving chronically prepared rats we stimulated the PeF neurons without or with simultaneous blocking of specific subtypes of OX-ergic receptors in the LC while electrophysiological recording characterizing sleep-waking was continued. Single dose of glutamate stimulation as well as sustained mild electrical stimulation of PeF (both bilateral) significantly increased waking and reduced REMS as compared to baseline. Simultaneous application of OX-receptor1 (OX1R) antagonist bilaterally into the LC prevented PeF stimulation-induced REMS suppression. Also, the effect of electrical stimulation of the PeF was long lasting as compared to that of the glutamate stimulation. Further, sustained electrical stimulation significantly decreased both REMS duration as well as REMS frequency, while glutamate stimulation decreased REMS duration only. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Dopamine depletion increases the power and coherence of high-voltage spindles in the globus pallidus and motor cortex of freely moving rats.

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Ge, Shunnan; Yang, Chen; Li, Min; Li, Jiang; Chang, Xiaozan; Fu, Jian; Chen, Lei; Chang, Chongwang; Wang, Xuelian; Zhu, Junling; Gao, Guodong

2012-07-17

Studies on patients with Parkinson's disease and in animal models have observed enhanced synchronization of oscillations in several frequency bands within and between the cortical-basal ganglia (BG) structures. Recent research has also shown that synchronization of high-voltage spindles (HVSs) in the cortex, striatum and substantia nigra pars reticulate is increased by dopamine depletion. However, more evidence is needed to determine whether HVS activity in the whole cortex-BG network represents homologous alteration following dopamine depletion. As the globus pallidus (GP) is in a central position to propagate and synchronize oscillations in the cortical-BG circuits, we employed local-field potentials and electrocorticogram to simultaneously record oscillations in the GP and primary (M1) and secondary (M2) motor cortices on freely moving 6-hydroxydopamine (6-OHDA) lesioned and control rats. Results showed that HVS episodes recorded from GP, and M2 and M1 cortex areas were more numerous and longer in 6-OHDA lesioned rats compared to controls. Relative power associated with HVS activity in the GP, and M2 and M1 cortices of 6-OHDA lesioned rats was significantly greater than that for control rats. Coherence values for HVS activity between the GP, and M2 and M1 cortex areas were significantly increased by dopamine depletion. Time lag between the M1 cortex HVS and GP HVS was significantly shorter for dopamine depleted than normal rats. Findings indicate a crucial rule for dopamine in the regulation of HVS activity in the whole cortical-BG circuit, and suggest a close relationship between abnormally synchronized HVS oscillations in the cortex-BG network and Parkinson's disease. Copyright © 2012 Elsevier B.V. All rights reserved.

[Conditions required for appearance of a double response to a single-shock stimulation of Schaffer collaterals in hippocampal field CA1 in freely moving rats].

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Zosimovskiĭ, V A; Korshunov, V A; Markevich, V A

2007-01-01

Schaffer collateral stimulation with a single current impulse can evoke a double response in hippocampal field CA1 of freely moving rats. The late response appears as a population excitatory postsynaptic potential with a preceding short-term potential (frequently biphasic) only after the early population spike and is time-locked to it. The wave shape and polarity of the late response, its latency with respect to the peak of the early population spike suggest that the excitation wave produced in the CA1 field by the stimulation of Schaffer collaterals passes across the entorhinal cortex and returns to the CA1 directly via the perforant path fibers. In waking rat, the medium-intensity stimulation of Schaffer collaterals (able to evoke in the CA1 an early population spike of sufficiently high amplitude) usually does not result in the appearance of the late response. However, similar stimulation becomes efficient after the tetanization of Schaffer collaterals, under conditions of the long-term potentiation of the early population spike. Moreover, the late response occurrence is facilitated in a rat falling asleep after the development in the CA1 of high-amplitude low-frequency EEG oscillations typical for the slow-wave sleep and in a sleeping rat independently of the EEG pattern.

Haloperidol-induced changes in neuronal activity in the striatum of the freely moving rat

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Dorin eYael

2013-12-01

Full Text Available The striatum is the main input structure of the basal ganglia, integrating input from the cerebral cortex and the thalamus, which is modulated by midbrain dopaminergic input. Dopamine modulators, including agonists and antagonists, are widely used to relieve motor and psychiatric symptoms in a variety of pathological conditions. Haloperidol, a dopamine D2 antagonist, is commonly used in multiple psychiatric conditions and motor abnormalities. This article reports the effects of haloperidol on the activity of three major striatal subpopulations: medium spiny projection neurons (MSNs, fast spiking interneurons (FSIs and tonically active neurons (TANs. We implanted multi-wire electrode arrays in the rat dorsal striatum and recorded the activity of multiple single units in freely moving animals before and after systemic haloperidol injection. Haloperidol decreased the firing rate of FSIs and MSNs while increasing their tendency to fire in an oscillatory manner in the high voltage spindle (HVS frequency range of 7-9 Hz. Haloperidol led to an increased firing rate of TANs but did not affect their non-oscillatory firing pattern and their typical correlated firing activity. Our results suggest that dopamine plays a key role in tuning both single unit activity and the interactions within and between different subpopulations in the striatum in a differential manner. These findings highlight the heterogeneous striatal effects of tonic dopamine regulation via D2 receptors which potentially enable the treatment of diverse pathological states associated with basal ganglia dysfunction.

Blockade of central vasopressin receptors reduces the cardiovascular response to acute stress in freely moving rats.

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Stojicić, S; Milutinović-Smiljanić, S; Sarenac, O; Milosavljević, S; Paton, J F R; Murphy, D; Japundzić-Zigon, N

2008-04-01

To investigate the contribution of central vasopressin receptors to blood pressure (BP) and heart rate (HR) response to stress we injected non-peptide selective V(1a) (SR49059), V(1b) (SSR149415), V(2) (SR121463) receptor antagonists, diazepam or vehicle in the lateral cerebral ventricle of conscious freely moving rats stressed by blowing air on their heads for 2 min. Cardiovascular effects of stress were evaluated by analyzing maximum increase of BP and HR (MAX), latency of maximum response (LAT), integral under BP and HR curve (integral), duration of their recovery and spectral parameters of BP and HR indicative of increased sympathetic outflow (LF(BP) and LF/HF(HR)). Moreover, the increase of serum corticosterone was measured. Exposure to air-jet stress induced simultaneous increase in BP and HR followed by gradual decline during recovery while LF(BP) oscillation remained increased as well as serum corticosterone level. Rats pre-treated with vasopressin receptor antagonists were not sedated while diazepam induced sedation that persisted during exposure to stress. V(1a), V(1b) and V(2) receptor antagonists applied separately did not modify basal values of cardiovascular parameters but prevented the increase in integral(BP). In addition, V(1b) and V(2) receptor antagonists reduced BP(MAX) whereas V(1a), V(1b) antagonist and diazepam reduced HR(MAX) induced by exposure to air-jet stress. All drugs shortened the recovery period, prevented the increase of LF(BP) without affecting the increase in serum corticosterone levels. Results indicate that vasopressin receptors located within the central nervous system mediate, in part, the cardiovascular response to air-jet stress without affecting either the neuroendocrine component or inducing sedation. They support the view that the V(1b) receptor antagonist may be of potential therapeutic value in reducing arterial pressure induced by stress-related disorders.

Comparative effects of organic and inorganic mercury on in vivo dopamine release in freely moving rats

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L.R.F. Faro

2007-10-01

Full Text Available The present study was carried out in order to compare the effects of administration of organic (methylmercury, MeHg and inorganic (mercury chloride, HgCl 2 forms of mercury on in vivo dopamine (DA release from rat striatum. Experiments were performed in conscious and freely moving female adult Sprague-Dawley (230-280 g rats using brain microdialysis coupled to HPLC with electrochemical detection. Perfusion of different concentrations of MeHg or HgCl 2 (2 µL/min for 1 h, N = 5-7/group into the striatum produced significant increases in the levels of DA. Infusion of 40 µM, 400 µM, or 4 mM MeHg increased DA levels to 907 ± 31, 2324 ± 156, and 9032 ± 70% of basal levels, respectively. The same concentrations of HgCl 2 increased DA levels to 1240 ± 66, 2500 ± 424, and 2658 ± 337% of basal levels, respectively. These increases were associated with significant decreases in levels of dihydroxyphenylacetic acid and homovallinic acid. Intrastriatal administration of MeHg induced a sharp concentration-dependent increase in DA levels with a peak 30 min after injection, whereas HgCl 2 induced a gradual, lower (for 4 mM and delayed increase in DA levels (75 min after the beginning of perfusion. Comparing the neurochemical profile of the two mercury derivatives to induce increases in DA levels, we observed that the time-course of these increases induced by both mercurials was different and the effect produced by HgCl 2 was not concentration-dependent (the effect was the same for the concentrations of 400 µM and 4 mM HgCl 2 . These results indicate that HgCl 2 produces increases in extracellular DA levels by a mechanism differing from that of MeHg.

Speed and accuracy of visual image discrimination by rats

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Pamela eReinagel

2013-12-01

Full Text Available The trade-off between speed and accuracy of sensory discrimination has most often been studying using sensory stimuli that evolve over time, such as random dot motion discrimination tasks. We previously reported that when rats perform motion discrimination, correct trials have longer reaction times than errors, accuracy increases with reaction time, and reaction time increases with stimulus ambiguity. In such experiments, new sensory information is continually presented, which could partly explain interactions between reaction time and accuracy. The present study shows that a changing physical stimulus is not essential to those findings. Freely behaving rats were trained to discriminate between two static visual images in a self-paced, 2-alternative forced-choice (2AFC reaction time task. Each trial was initiated by the rat, and the two images were presented simultaneously and persisted until the rat responded, with no time limit. Reaction times were longer in correct trials than in error trials, and accuracy increased with reaction time, comparable to results previously reported for rats performing motion discrimination. In the motion task, coherence has been used to vary discrimination difficulty. Here morphs between the previously learned images were used to parametrically vary the image similarity. In randomly interleaved trials, rats took more time on average to respond in trials in which they had to discriminate more similar stimuli. For both the motion and image tasks, the dependence of reaction time on ambiguity is weak, as if rats prioritized speed over accuracy. Therefore we asked whether rats can change the priority of speed and accuracy adaptively in response to a change in reward contingencies. For two rats, the penalty delay was increased from two to six seconds. When the penalty was longer, reaction times increased, and accuracy improved. This demonstrates that rats can flexibly adjust their behavioral strategy in response to the

Tetherless near-infrared control of brain activity in behaving animals using fully implantable upconversion microdevices.

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Wang, Ying; Lin, Xudong; Chen, Xi; Chen, Xian; Xu, Zhen; Zhang, Wenchong; Liao, Qinghai; Duan, Xin; Wang, Xin; Liu, Ming; Wang, Feng; He, Jufang; Shi, Peng

2017-10-01

Many nanomaterials can be used as sensors or transducers in biomedical research and they form the essential components of transformative novel biotechnologies. In this study, we present an all-optical method for tetherless remote control of neural activity using fully implantable micro-devices based on upconversion technology. Upconversion nanoparticles (UCNPs) were used as transducers to convert near-infrared (NIR) energy to visible light in order to stimulate neurons expressing different opsin proteins. In our setup, UCNPs were packaged in a glass micro-optrode to form an implantable device with superb long-term biocompatibility. We showed that remotely applied NIR illumination is able to reliably trigger spiking activity in rat brains. In combination with a robotic laser projection system, the upconversion-based tetherless neural stimulation technique was implemented to modulate brain activity in various regions, including the striatum, ventral tegmental area, and visual cortex. Using this system, we were able to achieve behavioral conditioning in freely moving animals. Notably, our microscale device was at least one order of magnitude smaller in size (∼100 μm in diameter) and two orders of magnitude lighter in weight (less than 1 mg) than existing wireless optogenetic devices based on light-emitting diodes. This feature allows simultaneous implantation of multiple UCNP-optrodes to achieve modulation of brain function to control complex animal behavior. We believe that this technology not only represents a novel practical application of upconversion nanomaterials, but also opens up new possibilities for remote control of neural activity in the brains of behaving animals. Copyright © 2017 Elsevier Ltd. All rights reserved.

A truncated conical beam model for analysis of the vibration of rat whiskers.

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Yan, Wenyi; Kan, Qianhua; Kergrene, Kenan; Kang, Guozheng; Feng, Xi-Qiao; Rajan, Ramesh

2013-08-09

A truncated conical beam model is developed to study the vibration behaviour of a rat whisker. Translational and rotational springs are introduced to better represent the constraint conditions at the base of the whiskers in a living rat. Dimensional analysis shows that the natural frequency of a truncated conical beam with generic spring constraints at its ends is inversely proportional to the square root of the mass density. Under all the combinations of the classical free, pinned, sliding or fixed boundary conditions of a truncated conical beam, it is proved that the natural frequency can be expressed as f = α(rb/L(2))E/ρ and the frequency coefficient α only depends on the ratio of the radii at the two ends of the beam. The natural frequencies of a representative rat whisker are predicted for two typical situations: freely whisking in air and the tip touching an object. Our numerical results show that there exists a window where the natural frequencies of a rat whisker are very sensitive to the change of the rotational constraint at the base. This finding is also confirmed by the numerical results of 18 whiskers with their data available from literature. It can be concluded that the natural frequencies of a rat whisker can be adjusted within a wide range through manipulating the constraints of the follicle on the rat base by a behaving animal. Copyright © 2013 Elsevier Ltd. All rights reserved.

Conditions required for the appearance of double responses in hippocampal field CA1 to application of single stimuli to Shäffer collaterals in freely moving rats.

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Zosimovskii, V A; Korshunov, V A; Markevich, V A

2008-03-01

Stimulation of Shäffer collaterals with single current impulses could evoke double responses in hippocampal field CA1 in freely moving rats. The late response - the population excitatory postsynaptic potential with a preceding transient potential, often biphasic - occurred only after an early population spike and was time-locked to it. The shape characteristics of the late response, its polarity, and its latent period relative to the early population spike suggest that stimulation of Shäffer collaterals gives rise, in CA1, to a wave of excitation which passes through the entorhinal cortex and returns to CA1 directly via fibers of the perforant path. In conscious rats, medium-strength stimulation of Shäffer collaterals, sufficient to evoke a quite early population spike in CA1, did not usually lead to the appearance of a late response; the same stimulation became effective after tetanization of Shäffer collaterals in conditions of long-term potentiation of the early population spike. Furthermore, the appearance of the late response was facilitated in rats falling asleep on the background of high-amplitude, low-frequency EEG oscillations in CA1 characteristic of slow-wave sleep, as well as in sleeping rats, regardless of the EEG pattern.

Alteration of striatal dopamine levels under various partial pressure of oxygen in pre-convulsive and convulsive phases in freely-moving rats.

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Lavoute, Cécile; Weiss, Michel; Risso, Jean-Jacques; Rostain, Jean-Claude

2014-02-01

The purpose of this study was to investigate the change in the striatal dopamine (DA) level in freely-moving rat exposed to different partial pressure of oxygen (from 1 to 5 ATA). Some works have suggested that DA release by the substantia nigra pars compacta (SNc) neurons in the striatum could be disturbed by hyperbaric oxygen (HBO) exposure, altering therefore the basal ganglia activity. Such changes could result in a change in glutamatergic and GABAergic control of the dopaminergic neurons into the SNc. Such alterations could provide more information about the oxygen-induced seizures observed at 5 ATA in rat. DA-sensitive electrodes were implanted into the striatum under general anesthesia. After 1 week rest, awaked rats were exposed to oxygen-nitrogen mixture at a partial pressure of oxygen of 1, 2, 3, 4 and 5 ATA. DA level was monitored continuously (every 3 min) by in vivo voltammetry before and during HBO exposure. HBO induced a decrease in DA level in relationship to the increase in partial pressure of oxygen from 1 ATA to 4 ATA (-15 % at 1 ATA, -30 % at 2 ATA, -40 % at 3 ATA, -45 % at 4 ATA), without signs of oxygen toxicity. At 5 ATA, DA level strongly decreases (-75 %) before seizure which occurred after 27 min ± 7 HBO exposure. After the epileptic seizure the decrease in DA level disappeared. These changes and the biphasic effect of HBO were discussed in function of HBO action on neurochemical regulations of the nigro striatal pathway.

Pupils' reasons for learning and behaving and for not learning and behaving in English and maths lessons in a secondary school.

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Norwich, B

1999-12-01

There is renewed interest in motivation and school learning, though there has been relatively little theory-linked research in English schools. In the first stage, to explore pupils' reasons for learning and behaving and for not learning and behaving in English, maths and other subjects. In the second stage, to examine differences in reasons across subjects, for learning and behaving and for not learning and behaving for boys and girls in two year groups in one secondary school. Stage 1, 16 pupils in years 7, 8 and 9 in two London secondary schools; Stage 2, 267 pupils in years 7 and 9 in one of these schools. Stage 1--semi-structured interviews were conducted to elicit different kinds of reasons conceptualised in terms of the Deci & Ryan's (1985) framework of self-determination. From these elicited reasons, an inventory 'Why I Learn' was designed. Stage 2--the inventory was administered to identify reasons for learning and behaving and for not learning and behaving in English and maths. Parent introjected reasons were the highest for learning and behaving while teacher introjected and intrinsic reasons were the lowest. Intrinsic reasons were highest for not learning and behaving. Year group differences in reason levels were more significant than gender or subject differences. Reasons for learning and behaving were more differentiated from each other than reasons for not learning and behaving. The results are discussed in terms of their significance for self-determination theory, research into the conditions promoting greater self-determination in school learning and further development of the inventory for programme evaluation.

The R-enantiomer of citalopram counteracts escitalopram-induced increase in extracellular 5-HT in the frontal cortex of freely moving rats

DEFF Research Database (Denmark)

Mørk, A; Kreilgaard, Mads; Sánchez, C

2003-01-01

The selective serotonin (5-HT) reuptake inhibitor, citalopram, is a racemic mixture of an S(+)- and R(-)-enantiomer, escitalopram and R-citalopram, respectively. The present study compares the effects of escitalopram, R-citalopram and citalopram on extracellular levels of 5-HT in the frontal cortex...... of freely moving rats. In addition, co-injection of escitalopram and R-citalopram (ratios 1:2 and 1:4) were assessed. In some experiments escitalopram and R-citalopram were infused into the frontal cortex by reverse microdialysis. Finally, the extracellular level of escitalopram in the frontal cortex...... was studied after administration of escitalopram alone or in combination with R-citalopram. Escitalopram (1.0-3.9 mg/kg, s.c.) produced a greater maximal increase in extracellular 5-HT than citalopram (2.0-8.0 mg/kg, s.c.). R-citalopram (15.6 mg/kg s.c.) did not affect the 5-HT levels. When co-injected, R...

Supradural inflammatory soup in awake and freely moving rats induces facial allodynia that is blocked by putative immune modulators.

Science.gov (United States)

Wieseler, Julie; Ellis, Amanda; McFadden, Andrew; Stone, Kendra; Brown, Kimberley; Cady, Sara; Bastos, Leandro F; Sprunger, David; Rezvani, Niloofar; Johnson, Kirk; Rice, Kenner C; Maier, Steven F; Watkins, Linda R

2017-06-01

Facial allodynia is a migraine symptom that is generally considered to represent a pivotal point in migraine progression. Treatment before development of facial allodynia tends to be more successful than treatment afterwards. As such, understanding the underlying mechanisms of facial allodynia may lead to a better understanding of the mechanisms underlying migraine. Migraine facial allodynia is modeled by applying inflammatory soup (histamine, bradykinin, serotonin, prostaglandin E2) over the dura. Whether glial and/or immune activation contributes to such pain is unknown. Here we tested if trigeminal nucleus caudalis (Sp5C) glial and/or immune cells are activated following supradural inflammatory soup, and if putative glial/immune inhibitors suppress the consequent facial allodynia. Inflammatory soup was administered via bilateral indwelling supradural catheters in freely moving rats, inducing robust and reliable facial allodynia. Gene expression for microglial/macrophage activation markers, interleukin-1β, and tumor necrosis factor-α increased following inflammatory soup along with robust expression of facial allodynia. This provided the basis for pursuing studies of the behavioral effects of 3 diverse immunomodulatory drugs on facial allodynia. Pretreatment with either of two compounds broadly used as putative glial/immune inhibitors (minocycline, ibudilast) prevented the development of facial allodynia, as did treatment after supradural inflammatory soup but prior to the expression of facial allodynia. Lastly, the toll-like receptor 4 (TLR4) antagonist (+)-naltrexone likewise blocked development of facial allodynia after supradural inflammatory soup. Taken together, these exploratory data support that activated glia and/or immune cells may drive the development of facial allodynia in response to supradural inflammatory soup in unanesthetized male rats. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of stress-induced suppression of long-term potentiation in the hippocampal CA1 field of freely moving rats.

Science.gov (United States)

Hirata, Riki; Togashi, Hiroko; Matsumoto, Machiko; Yamaguchi, Taku; Izumi, Takeshi; Yoshioka, Mitsuhiro

2008-08-21

Several lines of evidence have shown that exposure to stress impairs long-term potentiation (LTP) in the CA1 field of the hippocampus, but the detailed mechanisms for this effect remain to be clarified. The present study elucidated the synaptic mechanism of stress-induced LTP suppression in conscious, freely moving rats using electrophysiological approaches. Open field stress (i.e., novel environment stress) and elevated platform stress (i.e., uncontrollable stress) were employed. Basal synaptic transmission was significantly reduced during exposure to elevated platform stress but not during exposure to open field stress. LTP induction was blocked by elevated platform stress but not influenced by open field stress. Significant increases in serum corticosterone levels were observed in the elevated platform stress group compared with the open field stress group. Furthermore, LTP suppression induced by elevated platform stress was prevented by pretreatment with an anxiolytic drug diazepam (1 mg/kg, i.p.). These results suggest that stress-induced LTP suppression depends on the relative intensity of the stressor. The inhibitory synaptic response induced by an intense psychological stress, such as elevated platform stress, may be attributable to LTP impairment in the CA1 field of the hippocampus.

Freely oriented portable superconducting magnet

Science.gov (United States)

Schmierer, Eric N [Los Alamos, NM; Prenger, F Coyne [Los Alamos, NM; Hill, Dallas D [Los Alamos, NM

2010-01-12

A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.

Production of freely-migrating defects during irradiation

International Nuclear Information System (INIS)

Rehn, L.E.; Okamoto, P.R.

1986-09-01

During irradiation at elevated temperatures, vacancy and interstitial defects that escape can produce several different types of microstructural changes. Hence the production rate of freely-migrating defects must be known as a function of irradiating particle species and energy before quantitative correlations can be made between microstructural changes. Our fundamental knowledge of freely-migrating defect production has increased substantially in recent years. Critical experimental findings that led to the improved understanding are reviewed in this paper. A strong similarity is found for the dependence of freely-migrating defect production on primary recoil energy as measured in a variety of metals and alloys by different authors. The efficiency for producing freely-migrating defects decreases much more strongly with increasing primary recoil energy than does the efficiency for creating stable defects at liquid helium temperatures. The stronger decrease can be understood in terms of additional intracascade recombination that results from the nonrandom distribution of defects existing in the primary damage state for high primary recoil energies. Although the existing data base is limited to fcc materials, the strong similarity in the reported investigations suggests that the same dependence of freely-migrating defect production on primary recoil energy may be characteristic of a wide variety of other alloy systems as well. 52 refs., 4 figs

Wireless multi-channel single unit recording in freely moving and vocalizing primates.

Science.gov (United States)

Roy, Sabyasachi; Wang, Xiaoqin

2012-01-15

The ability to record well-isolated action potentials from individual neurons in naturally behaving animals is crucial for understanding neural mechanisms underlying natural behaviors. Traditional neurophysiology techniques, however, require the animal to be restrained which often restricts natural behavior. An example is the common marmoset (Callithrix jacchus), a highly vocal New World primate species, used in our laboratory to study the neural correlates of vocal production and sensory feedback. When restrained by traditional neurophysiological techniques marmoset vocal behavior is severely inhibited. Tethered recording systems, while proven effective in rodents pose limitations in arboreal animals such as the marmoset that typically roam in a three-dimensional environment. To overcome these obstacles, we have developed a wireless neural recording technique that is capable of collecting single-unit data from chronically implanted multi-electrodes in freely moving marmosets. A lightweight, low power and low noise wireless transmitter (headstage) is attached to a multi-electrode array placed in the premotor cortex of the marmoset. The wireless headstage is capable of transmitting 15 channels of neural data with signal-to-noise ratio (SNR) comparable to a tethered system. To minimize radio-frequency (RF) and electro-magnetic interference (EMI), the experiments were conducted within a custom designed RF/EMI and acoustically shielded chamber. The individual electrodes of the multi-electrode array were periodically advanced to densely sample the cortical layers. We recorded single-unit data over a period of several months from the frontal cortex of two marmosets. These recordings demonstrate the feasibility of using our wireless recording method to study single neuron activity in freely roaming primates. Copyright © 2011 Elsevier B.V. All rights reserved.

BehavePlus fire modeling system, version 5.0: Variables

Science.gov (United States)

Patricia L. Andrews

2009-01-01

This publication has been revised to reflect updates to version 4.0 of the BehavePlus software. It was originally published as the BehavePlus fire modeling system, version 4.0: Variables in July, 2008.The BehavePlus fire modeling system is a computer program based on mathematical models that describe wildland fire behavior and effects and the...

Involvement of serotonin in the ventral tegmental area in thermoregulation of freely moving rats.

Science.gov (United States)

Ishiwata, Takayuki; Hasegawa, Hiroshi; Greenwood, Benjamin N

2017-07-13

We have recently reported that the serotonin (5-HT) projections from the midbrain's raphe nuclei that contains 5-HT cell bodies may play a role both in heat production and in heat loss. The purpose of the present study was to clarify the involvement of 5-HT in the ventral tegmental area (VTA), where 5-HT is suggested to participate in thermoregulation, using the combined methods of telemetry, microdialysis, and high performance liquid chromatography, with a special emphasis on regulation of the body temperature (T b ) in freely moving rats. First, we measured changes in T b , tail skin temperature (T tail ; an index of heat loss), heart rate (HR; an index of heat production), locomotor activity (Act), and levels of extracellular monoamines in the VTA during cold (5°C) or heat (35°C) exposure. Subsequently, we perfused citalopram (5-HT re-uptake inhibitor) into the VTA and measured the thermoregulatory parameters and monoamines release. Although T b , T tail , and HR changed during both exposures, significant changes in extracellular level of 5-HT (138.7±12.7% baseline, p<0.01), but not dopamine (DA) or noradrenaline (NA) were noted in the VTA only during heat exposure. In addition, perfusion of citalopram into the VTA increased extracellular 5-HT levels (221.0±52.2% baseline, p<0.01), but not DA or NA, while T b decreased from 37.4±0.1°C to 36.8±0.2°C (p<0.001),T tail increased from 26.3±0.4°C to 28.4±0.4°C (p<0.001), and HR and Act remained unchanged. Our results suggest that the VTA is a key area for thermoregulation, and 5-HT, but not DA or NA, modulates the heat loss system through action in the VTA. Copyright © 2017 Elsevier B.V. All rights reserved.

Stress and Sucrose Intake Modulate Neuronal Activity in the Anterior Hypothalamic Area in Rats.

Science.gov (United States)

Mitra, Arojit; Guèvremont, Geneviève; Timofeeva, Elena

2016-01-01

The anterior hypothalamic area (AHA) is an important integrative relay structure for a variety of autonomic, endocrine, and behavioral responses including feeding behavior and response to stress. However, changes in the activity of the AHA neurons during stress and feeding in freely moving rats are not clear. The present study investigated the firing rate and burst activity of neurons in the central nucleus of the AHA (cAHA) during sucrose intake in non-stressful conditions and after acute stress in freely behaving rats. Rats were implanted with micro-electrodes into the cAHA, and extracellular multi-unit activity was recorded during 1-h access to 10% sucrose in non-stressful conditions or after acute foot shock stress. Acute stress significantly reduced sucrose intake, total sucrose lick number, and lick frequency in licking clusters, and increased inter-lick intervals. At the cluster start (CS) of sucrose licking, the cAHA neurons increased (CS-excited, 20% of the recorded neurons), decreased (CS-inhibited, 42% of the neurons) or did not change (CS-nonresponsive, 38% of the neurons) their firing rate. Stress resulted in a significant increase in the firing rate of the CS-inhibited neurons by decreasing inter-spike intervals within the burst firing of these neurons. This increase in the stress-induced firing rate of the CS-inhibited neurons was accompanied by a disruption of the correlation between the firing rate of CS-inhibited and CS-nonresponsive neurons that was observed in non-stressful conditions. Stress did not affect the firing rate of the CS-excited and CS-nonresponsive neurons. However, stress changed the pattern of burst firing of the CS-excited and CS-nonresponsive neurons by decreasing and increasing the burst number in the CS-excited and CS-nonresponsive neurons, respectively. These results suggest that the cAHA neurons integrate the signals related to stress and intake of palatable food and play a role in the stress- and eating-related circuitry.

Effects of GABA-B receptor positive modulator on ketamine-induced psychosis-relevant behaviors and hippocampal electrical activity in freely moving rats.

Science.gov (United States)

Ma, Jingyi; Stan Leung, L

2017-10-01

Decreased GABA B receptor function is proposed to mediate some symptoms of schizophrenia. In this study, we tested the effect of CGP7930, a GABA B receptor positive allosteric modulator, on ketamine-induced psychosis-relevant behaviors and hippocampal electrical activity in behaving rats. Electrodes were bilaterally implanted into the hippocampus, and cannulae were placed into the lateral ventricles of Long-Evans rats. CGP7930 or vehicle was injected intraperitoneally (i.p.) or intracerebroventricularly (i.c.v.), alone or 15 min prior to ketamine (3 mg/kg, subcutaneous) injection. Paired click auditory evoked potentials in the hippocampus (AEP), prepulse inhibition (PPI), and locomotor activity were recorded before and after drug injection. CGP7930 at doses of 1 mg/kg (i.p.) prevented ketamine-induced deficit of PPI. CGP7930 (1 mg/kg i.p.) also prevented the decrease in gating of hippocampal AEP and the increase in hippocampal gamma (65-100 Hz) waves induced by ketamine. Unilateral i.c.v. infusion of CGP7930 (0.3 mM/1 μL) also prevented the decrease in gating of hippocampal AEP induced by ketamine. Ketamine-induced behavioral hyperlocomotion was suppressed by 5 mg/kg i.p. CGP7930. CGP7930 alone, without ketamine, did not significantly affect integrated PPI, locomotion, gating of hippocampal AEP, or gamma waves. CGP7930 (1 mg/kg i.p.) increased heterosynaptically mediated paired pulse depression in the hippocampus, a measure of GABA B receptor function in vivo. CGP7930 reduces the behavioral and electrophysiological disruptions induced by ketamine in animals, and the hippocampus may be one of the neural targets where CGP7930 exerts its actions.

Changes in Sensory Responsiveness in Behaving Primates.

Science.gov (United States)

1986-07-14

controlled behavioral training and monitoring, and electrophysiological recording in awake , behaving monkeys. All I, research equipment listed in the original...recording from the sensorimotor cortices was conducted on May 21. Under general anesthesia, a craniotomy was performed over the pre- and postcentral cortices...Department of Neurosurgery at U.T. Dr. Klein is somewhat unusual in that he has had previous experience recording from awake , behaving monkeys. The experience

Hypocretin/orexin antagonism enhances sleep-related adenosine and GABA neurotransmission in rat basal forebrain.

Science.gov (United States)

Vazquez-DeRose, Jacqueline; Schwartz, Michael D; Nguyen, Alexander T; Warrier, Deepti R; Gulati, Srishti; Mathew, Thomas K; Neylan, Thomas C; Kilduff, Thomas S

2016-03-01

Hypocretin/orexin (HCRT) neurons provide excitatory input to wake-promoting brain regions including the basal forebrain (BF). The dual HCRT receptor antagonist almorexant (ALM) decreases waking and increases sleep. We hypothesized that HCRT antagonists induce sleep, in part, through disfacilitation of BF neurons; consequently, ALM should have reduced efficacy in BF-lesioned (BFx) animals. To test this hypothesis, rats were given bilateral IgG-192-saporin injections, which predominantly targets cholinergic BF neurons. BFx and intact rats were then given oral ALM, the benzodiazepine agonist zolpidem (ZOL) or vehicle (VEH) at lights-out. ALM was less effective than ZOL at inducing sleep in BFx rats compared to controls. BF adenosine (ADO), γ-amino-butyric acid (GABA), and glutamate levels were then determined via microdialysis from intact, freely behaving rats following oral ALM, ZOL or VEH. ALM increased BF ADO and GABA levels during waking and mixed vigilance states, and preserved sleep-associated increases in GABA under low and high sleep pressure conditions. ALM infusion into the BF also enhanced cortical ADO release, demonstrating that HCRT input is critical for ADO signaling in the BF. In contrast, oral ZOL and BF-infused ZOL had no effect on ADO levels in either BF or cortex. ALM increased BF ADO (an endogenous sleep-promoting substance) and GABA (which is increased during normal sleep), and required an intact BF for maximal efficacy, whereas ZOL blocked sleep-associated BF GABA release, and required no functional contribution from the BF to induce sleep. ALM thus induces sleep by facilitating the neural mechanisms underlying the normal transition to sleep.

behaved particle swarm optimization (QPSO)

African Journals Online (AJOL)

Administrator

2011-06-13

Jun 13, 2011 ... experiment results of L-glutamic acid fermentation process showed that our ... Key words: Soft-sensing model, quantum-behaved particle swarm optimization ... information about such biochemical variables is, in most practical ...

GABAergic inhibition of leg motoneurons is required for normal walking behavior in freely moving Drosophila.

Science.gov (United States)

Gowda, Swetha B M; Paranjpe, Pushkar D; Reddy, O Venkateswara; Thiagarajan, Devasena; Palliyil, Sudhir; Reichert, Heinrich; VijayRaghavan, K

2018-02-27

Walking is a complex rhythmic locomotor behavior generated by sequential and periodical contraction of muscles essential for coordinated control of movements of legs and leg joints. Studies of walking in vertebrates and invertebrates have revealed that premotor neural circuitry generates a basic rhythmic pattern that is sculpted by sensory feedback and ultimately controls the amplitude and phase of the motor output to leg muscles. However, the identity and functional roles of the premotor interneurons that directly control leg motoneuron activity are poorly understood. Here we take advantage of the powerful genetic methodology available in Drosophila to investigate the role of premotor inhibition in walking by genetically suppressing inhibitory input to leg motoneurons. For this, we have developed an algorithm for automated analysis of leg motion to characterize the walking parameters of wild-type flies from high-speed video recordings. Further, we use genetic reagents for targeted RNAi knockdown of inhibitory neurotransmitter receptors in leg motoneurons together with quantitative analysis of resulting changes in leg movement parameters in freely walking Drosophila Our findings indicate that targeted down-regulation of the GABA A receptor Rdl (Resistance to Dieldrin) in leg motoneurons results in a dramatic reduction of walking speed and step length without the loss of general leg coordination during locomotion. Genetically restricting the knockdown to the adult stage and subsets of motoneurons yields qualitatively identical results. Taken together, these findings identify GABAergic premotor inhibition of motoneurons as an important determinant of correctly coordinated leg movements and speed of walking in freely behaving Drosophila . Copyright © 2018 the Author(s). Published by PNAS.

Functional magnetic resonance imaging in awake transgenic fragile X rats: evidence of dysregulation in reward processing in the mesolimbic/habenular neural circuit.

Science.gov (United States)

Kenkel, W M; Yee, J R; Moore, K; Madularu, D; Kulkarni, P; Gamber, K; Nedelman, M; Ferris, C F

2016-03-22

Anxiety and social deficits, often involving communication impairment, are fundamental clinical features of fragile X syndrome. There is growing evidence that dysregulation in reward processing is a contributing factor to the social deficits observed in many psychiatric disorders. Hence, we hypothesized that transgenic fragile X mental retardation 1 gene (fmr1) KO (FX) rats would display alterations in reward processing. To this end, awake control and FX rats were imaged for changes in blood oxygen level dependent (BOLD) signal intensity in response to the odor of almond, a stimulus to elicit the innate reward response. Subjects were 'odor naive' to this evolutionarily conserved stimulus. The resulting changes in brain activity were registered to a three-dimensional segmented, annotated rat atlas delineating 171 brain regions. Both wild-type (WT) and FX rats showed robust brain activation to a rewarding almond odor, though FX rats showed an altered temporal pattern and tended to have a higher number of voxels with negative BOLD signal change from baseline. This pattern of greater negative BOLD was especially apparent in the Papez circuit, critical to emotional processing and the mesolimbic/habenular reward circuit. WT rats showed greater positive BOLD response in the supramammillary area, whereas FX rats showed greater positive BOLD response in the dorsal lateral striatum, and greater negative BOLD response in the retrosplenial cortices, the core of the accumbens and the lateral preoptic area. When tested in a freely behaving odor-investigation paradigm, FX rats failed to show the preference for almond odor which typifies WT rats. However, FX rats showed investigation profiles similar to WT when presented with social odors. These data speak to an altered processing of this highly salient novel odor in the FX phenotype and lend further support to the notion that altered reward systems in the brain may contribute to fragile X syndrome symptomology.

Numerical investigation for one bad-behaved flow in a Pelton turbine

International Nuclear Information System (INIS)

Wei, X Z; Yang, K; Wang, H J; Gong, R Z; Li, D Y

2015-01-01

The gas-liquid two-phase flow in pelton turbines is very complicated, there are many kinds of bad-behaved flow in pelton turbines. In this paper, CFD numerical simulation for the pelton turbine was conducted using VOF two-phase model. One kind of bad-behaved flow caused by the two jets was captured, and the bad-behaved flow was analysed by torque on buckets. It can be concluded that the angle between the two jets and the value of ratio of runner diameter and jet diameter are important parameters for the bad-behaved flow. Furthermore, the reason why the efficiency of some multi-jet type turbines is very low can be well explained by the analysis of bad-behaved flow. Finally, some suggestions for improvement were also provided in present paper

Numerical investigation for one bad-behaved flow in a Pelton turbine

Science.gov (United States)

Wei, X. Z.; Yang, K.; Wang, H. J.; Gong, R. Z.; Li, D. Y.

2015-01-01

The gas-liquid two-phase flow in pelton turbines is very complicated, there are many kinds of bad-behaved flow in pelton turbines. In this paper, CFD numerical simulation for the pelton turbine was conducted using VOF two-phase model. One kind of bad-behaved flow caused by the two jets was captured, and the bad-behaved flow was analysed by torque on buckets. It can be concluded that the angle between the two jets and the value of ratio of runner diameter and jet diameter are important parameters for the bad-behaved flow. Furthermore, the reason why the efficiency of some multi-jet type turbines is very low can be well explained by the analysis of bad-behaved flow. Finally, some suggestions for improvement were also provided in present paper.

Freely tunable broadband polarization rotator for terahertz waves.

Science.gov (United States)

Fan, Ren-Hao; Zhou, Yu; Ren, Xiao-Ping; Peng, Ru-Wen; Jiang, Shang-Chi; Xu, Di-Hu; Xiong, Xiang; Huang, Xian-Rong; Wang, Mu

2015-02-18

A freely tunable polarization rotator for broadband terahertz waves is demonstrated using a three-rotating-layer metallic grating structure, which can conveniently rotate the polarization of a linearly polarized terahertz wave to any desired direction with nearly perfect conversion efficiency. This low-cost, high-efficiency, and freely tunable device has potential applications as material analysis, wireless communication, and THz imaging. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improved quantum-behaved particle swarm optimization with local search strategy

Directory of Open Access Journals (Sweden)

Maolong Xi

2017-03-01

Full Text Available Quantum-behaved particle swarm optimization, which was motivated by analysis of particle swarm optimization and quantum system, has shown compared performance in finding the optimal solutions for many optimization problems to other evolutionary algorithms. To address the problem of premature, a local search strategy is proposed to improve the performance of quantum-behaved particle swarm optimization. In proposed local search strategy, a super particle is presented which is a collection body of randomly selected particles’ dimension information in the swarm. The selected probability of particles in swarm is different and determined by their fitness values. To minimization problems, the fitness value of one particle is smaller; the selected probability is more and will contribute more information in constructing the super particle. In addition, in order to investigate the influence on algorithm performance with different local search space, four methods of computing the local search radius are applied in local search strategy and propose four variants of local search quantum-behaved particle swarm optimization. Empirical studies on a suite of well-known benchmark functions are undertaken in order to make an overall performance comparison among the proposed methods and other quantum-behaved particle swarm optimization. The simulation results show that the proposed quantum-behaved particle swarm optimization variants have better advantages over the original quantum-behaved particle swarm optimization.

Freely flowing conversations

DEFF Research Database (Denmark)

Aakjær, Marie Kirstejn; Andrade, David; Dexters, Peter

and in regards to rehabilitation efforts. In the context of prisons UDI is inspired by the complexity approach (Stacey 2005). We seek to facilitate freely flowing conversations between inmates, staff and managers – pushing the boundaries of existing norms, roles and beliefs. In the end however we rely...... relations by changing conversations. Through the theoretical framework of the complexity approach, we discuss how this may lead to organizational change. Finally we suggest that inviting inmates to take part in conversations about core organizational development may be a fundamental strategy in trying...

Zolpidem Reduces Hippocampal Neuronal Activity in Freely Behaving Mice: A Large Scale Calcium Imaging Study with Miniaturized Fluorescence Microscope

Science.gov (United States)

Berdyyeva, Tamara; Otte, Stephani; Aluisio, Leah; Ziv, Yaniv; Burns, Laurie D.; Dugovic, Christine; Yun, Sujin; Ghosh, Kunal K.; Schnitzer, Mark J.; Lovenberg, Timothy; Bonaventure, Pascal

2014-01-01

Therapeutic drugs for cognitive and psychiatric disorders are often characterized by their molecular mechanism of action. Here we demonstrate a new approach to elucidate drug action on large-scale neuronal activity by tracking somatic calcium dynamics in hundreds of CA1 hippocampal neurons of pharmacologically manipulated behaving mice. We used an adeno-associated viral vector to express the calcium sensor GCaMP3 in CA1 pyramidal cells under control of the CaMKII promoter and a miniaturized microscope to observe cellular dynamics. We visualized these dynamics with and without a systemic administration of Zolpidem, a GABAA agonist that is the most commonly prescribed drug for the treatment of insomnia in the United States. Despite growing concerns about the potential adverse effects of Zolpidem on memory and cognition, it remained unclear whether Zolpidem alters neuronal activity in the hippocampus, a brain area critical for cognition and memory. Zolpidem, when delivered at a dose known to induce and prolong sleep, strongly suppressed CA1 calcium signaling. The rate of calcium transients after Zolpidem administration was significantly lower compared to vehicle treatment. To factor out the contribution of changes in locomotor or physiological conditions following Zolpidem treatment, we compared the cellular activity across comparable epochs matched by locomotor and physiological assessments. This analysis revealed significantly depressive effects of Zolpidem regardless of the animal’s state. Individual hippocampal CA1 pyramidal cells differed in their responses to Zolpidem with the majority (∼65%) significantly decreasing the rate of calcium transients, and a small subset (3%) showing an unexpected and significant increase. By linking molecular mechanisms with the dynamics of neural circuitry and behavioral states, this approach has the potential to contribute substantially to the development of new therapeutics for the treatment of CNS disorders. PMID:25372144

Zolpidem reduces hippocampal neuronal activity in freely behaving mice: a large scale calcium imaging study with miniaturized fluorescence microscope.

Directory of Open Access Journals (Sweden)

Tamara Berdyyeva

Full Text Available Therapeutic drugs for cognitive and psychiatric disorders are often characterized by their molecular mechanism of action. Here we demonstrate a new approach to elucidate drug action on large-scale neuronal activity by tracking somatic calcium dynamics in hundreds of CA1 hippocampal neurons of pharmacologically manipulated behaving mice. We used an adeno-associated viral vector to express the calcium sensor GCaMP3 in CA1 pyramidal cells under control of the CaMKII promoter and a miniaturized microscope to observe cellular dynamics. We visualized these dynamics with and without a systemic administration of Zolpidem, a GABAA agonist that is the most commonly prescribed drug for the treatment of insomnia in the United States. Despite growing concerns about the potential adverse effects of Zolpidem on memory and cognition, it remained unclear whether Zolpidem alters neuronal activity in the hippocampus, a brain area critical for cognition and memory. Zolpidem, when delivered at a dose known to induce and prolong sleep, strongly suppressed CA1 calcium signaling. The rate of calcium transients after Zolpidem administration was significantly lower compared to vehicle treatment. To factor out the contribution of changes in locomotor or physiological conditions following Zolpidem treatment, we compared the cellular activity across comparable epochs matched by locomotor and physiological assessments. This analysis revealed significantly depressive effects of Zolpidem regardless of the animal's state. Individual hippocampal CA1 pyramidal cells differed in their responses to Zolpidem with the majority (∼ 65% significantly decreasing the rate of calcium transients, and a small subset (3% showing an unexpected and significant increase. By linking molecular mechanisms with the dynamics of neural circuitry and behavioral states, this approach has the potential to contribute substantially to the development of new therapeutics for the treatment of CNS disorders.

Freely-migrating defects: Their production and interaction with cascade remnants

International Nuclear Information System (INIS)

Rehn, L.E.; Wiedersich, H.

1991-05-01

Many microstructural changes that occur during irradiation are driven primarily by freely-migrating defects, i.e. those defects which escape from nascent cascades to migrate over distances that are large relative to typical cascade dimensions. Several measurements during irradiation at elevated temperatures have shown that the survival rate of freely-migrating defects decreases much more strongly with increasing primary recoil energy than does the survival rate for defects generated at liquid helium temperatures. For typical fission or fusion recoil spectra, and for heavy-ion bombardment, the fraction of defects that migrate long-distances is apparently only ∼1% of the calculated dpa. This small surviving fraction of freely-migrating defects results at least partially from additional intracascade recombination at elevated temperatures. However, cascade remnants, e.g., vacancy and interstitial clusters, also contribute by enhancing intercascade defect annihilation. A recently developed rate-theory approach is used to discuss the relative importance of intra- and intercascade recombination to the survival rate of freely-migrating defects. Within the validity of certain simplifying assumptions, the additional sink density provided by defect clusters produced directly within individual cascades can explain the difference between a defect survival rate of about 30% for low dose, low temperature irradiations with heavy ions, and a survival rate of only ∼1% for freely-migrating defects at elevated temperatures. The status of our current understanding of freely-migrating defects, including remaining unanswered questions, is also discussed. 33 refs., 5 figs

Quantum Behaved Particle Swarm Optimization Algorithm Based on Artificial Fish Swarm

OpenAIRE

Yumin, Dong; Li, Zhao

2014-01-01

Quantum behaved particle swarm algorithm is a new intelligent optimization algorithm; the algorithm has less parameters and is easily implemented. In view of the existing quantum behaved particle swarm optimization algorithm for the premature convergence problem, put forward a quantum particle swarm optimization algorithm based on artificial fish swarm. The new algorithm based on quantum behaved particle swarm algorithm, introducing the swarm and following activities, meanwhile using the a...

Increased hepatic glycogen synthetase and decreased phosphorylase in trained rats

DEFF Research Database (Denmark)

Galbo, H; Saugmann, P; Richter, Erik

1979-01-01

Rats were either physically trained by a 12 wk swimming program or were freely eating or weight matched, sedentary controls. Trained rats had a higher relative liver weight and total hepatic glycogen synthetase (EC 2.4.1.11) activity and a lower phosphorylase (EC 2.4.1.1) activity than the other...

Gravitational waves from freely precessing neutron stars

International Nuclear Information System (INIS)

Jones, D.I.

2001-01-01

The purpose of this study is to assess the likely detectability of gravitational waves from freely precessing neutron stars. We begin by presenting a neutron star model of sufficient complexity to take into account both the elasticity and fluidity of a realistic neutron star. We then examine the effect of internal dissipation (i.e. heat generation within the star) and gravitational radiation reaction on the wobble. This is followed by an examination of various astrophysical scenarios where some mechanism might pump the precessional motion. We estimate the gravitational wave amplitude in these situations. Finally, we conclude that gravitational radiation from freely precessing neutron stars is almost certainly limited to a level undetectable by a LIGO II detector by internal dissipation. (author)

Engagement of the Rat Hindlimb Motor Cortex across Natural Locomotor Behaviors

OpenAIRE

DiGiovanna, J.; Dominici, N.; Friedli, L.; Rigosa, J.; Duis, S.; Kreider, J.; Beauparlant, J.; van den Brand, R.; Schieppati, M.; Micera, S.; Courtine, G.

2016-01-01

Contrary to cats and primates, cortical contribution to hindlimb locomotor movements is not critical in rats. However, the importance of the motor cortex to regain locomotion after neurological disorders in rats suggests that cortical engagement in hindlimb motor control may depend on the behavioral context. To investigate this possibility, we recorded whole-body kinematics, muscle synergies, and hindlimb motor cortex modulation in freely moving rats performing a range of natural locomotor pr...

Hepatic portal vein cannulation for infusion and blood sampling in freely moving rats

NARCIS (Netherlands)

Strubbe, J.H.; Bruggink, J.E; Steffens, A.B

1999-01-01

Chronic portal vein cannulation in the rat is an important technique to study secretory rates of hormones from the endocrine pancreas. Moreover, it can be used for studying the effects of enteric hormones and pharmaca on behavioral and physiological processes. This article contains an extensive

In vitro assessment of the agonist properties of the novel 5-HT1A receptor ligand, CUMI-101 (MMP), in rat brain tissue

International Nuclear Information System (INIS)

Hendry, Nicola; Christie, Isabel; Rabiner, Eugenii Alfredovich; Laruelle, Marc; Watson, Jeannette

2011-01-01

Introduction: Development of agonist positron emission tomography (PET) radioligands for the 5-HT neurotransmitter system is an important target to enable the understanding of human 5-HT function in vivo. [ 11 C]CUMI-101, proposed as the first 5-HT 1A receptor agonist PET ligand, has been reported to behave as a potent 5-HT 1A agonist in a cellular system stably expressing human recombinant 5-HT 1A receptors. In this study, we investigate the agonist properties of CUMI-101 in rat brain tissue. Methods: [ 35 S]-GTPγS binding studies were used to determine receptor function in HEK (human embryonic kidney) 293 cells transfected with human recombinant 5-HT 1A receptors and in rat cortex and rat hippocampal tissue, following administration of CUMI-101 and standard 5-HT1A antagonists (5-HT, 5-CT and 8-OH-DPAT). Results: CUMI-101 behaved as an agonist at human recombinant 5-HT 1A receptors (pEC 50 9.2). However, CUMI-101 did not show agonist activity in either rat cortex or hippocampus at concentrations up to 10 μM. In these tissues, CUMI-behaved as an antagonist with pK B s of 9.2 and 9.3, respectively. Conclusions: Our studies demonstrate that as opposed to its behavior in human recombinant system, in rat brain tissue CUMI-101 behaves as a potent 5-HT 1A receptor antagonist.

Electrocorticographic activity over sensorimotor cortex and motor function in awake behaving rats.

Science.gov (United States)

Boulay, Chadwick B; Chen, Xiang Yang; Wolpaw, Jonathan R

2015-04-01

Sensorimotor cortex exerts both short-term and long-term control over the spinal reflex pathways that serve motor behaviors. Better understanding of this control could offer new possibilities for restoring function after central nervous system trauma or disease. We examined the impact of ongoing sensorimotor cortex (SMC) activity on the largely monosynaptic pathway of the H-reflex, the electrical analog of the spinal stretch reflex. In 41 awake adult rats, we measured soleus electromyographic (EMG) activity, the soleus H-reflex, and electrocorticographic activity over the contralateral SMC while rats were producing steady-state soleus EMG activity. Principal component analysis of electrocorticographic frequency spectra before H-reflex elicitation consistently revealed three frequency bands: μβ (5-30 Hz), low γ (γ1; 40-85 Hz), and high γ (γ2; 100-200 Hz). Ongoing (i.e., background) soleus EMG amplitude correlated negatively with μβ power and positively with γ1 power. In contrast, H-reflex size correlated positively with μβ power and negatively with γ1 power, but only when background soleus EMG amplitude was included in the linear model. These results support the hypothesis that increased SMC activation (indicated by decrease in μβ power and/or increase in γ1 power) simultaneously potentiates the H-reflex by exciting spinal motoneurons and suppresses it by decreasing the efficacy of the afferent input. They may help guide the development of new rehabilitation methods and of brain-computer interfaces that use SMC activity as a substitute for lost or impaired motor outputs. Copyright © 2015 the American Physiological Society.

The relationship between hippocampal EEG theta activity and locomotr behaviour in freely moving rats: effects of vigabatrin

NARCIS (Netherlands)

Bouwman, B.M.; Lier, H. van; Nitert, H.E.J.; Drinkenburg, W.H.I.M.; Coenen, A.M.L.; Rijn, C.M. van

2005-01-01

The relationship between hippocampal electroencephalogram (EEG) theta activity and locomotor speed in both spontaneous and forced walking conditions was studied in rats after vigabatrin injection (500 mg/kg i.p.). Vigabatrin increased the percentage of time that rats spent being immobile. During

Responsiveness in Behaving Monkeys and Human Subjects

Science.gov (United States)

1993-07-31

Status of Current Research - Statement of Work Each study involving awake , behaving monkey neurophysiological recording used a behavioral paradigm that...anesthesia. A craniotomy was performed at approximately A+ 14.5mm. The recording chamber then was fixed to the skull at a lateral angle of 8’ from

Cardiovascular response to acute stress in freely moving rats: time-frequency analysis.

Science.gov (United States)

Loncar-Turukalo, Tatjana; Bajic, Dragana; Japundzic-Zigon, Nina

2008-01-01

Spectral analysis of cardiovascular series is an important tool for assessing the features of the autonomic control of the cardiovascular system. In this experiment Wistar rats ecquiped with intraarterial catheter for blood pressure (BP) recording were exposed to stress induced by blowing air. The problem of non stationary data was overcomed applying the Smoothed Pseudo Wigner Villle (SPWV) time-frequency distribution. Spectral analysis was done before stress, during stress, immediately after stress and later in recovery. The spectral indices were calculated for both systolic blood pressure (SBP) and pulse interval (PI) series. The time evolution of spectral indices showed perturbed sympathovagal balance.

Age differences in how consumers behave following exposure to DTC advertising.

Science.gov (United States)

DeLorme, Denise E; Huh, Jisu; Reid, Leonard N

2006-01-01

This study was conducted to provide additional evidence on how consumers behave following direct-to-consumer (DTC) advertising exposure and to determine if there are differences in ad-prompted acts (drug inquiry and drug requests) between different age groups (i.e., older, mature, and younger adults). The results suggest that younger, mature, and older consumers are all moved to act by DTC drug ads, but that each age group behaves in different ways. Somewhat surprisingly, age was not predictive of ad-prompted behavior. DTC advertising was no more effective at moving older consumers to behave than their younger counterparts. These results suggest that age does not matter that much when it comes to the "moving power" of prescription drug advertising, even though research indicates that older consumers are more vulnerable to the persuasive effects of communication.

Hippocampal network activity is transiently altered by induction of long-term potentiation in the dentate gyrus of freely behaving rats

Directory of Open Access Journals (Sweden)

Arthur Bikbaev

2007-12-01

Full Text Available A role for oscillatory activity in hippocampal neuronal networks has been proposed in sensory encoding, cognitive functions and synaptic plasticity. In the hippocampus, theta (5–10 Hz and gamma (30–100 Hz oscillations may provide a mechanism for temporal encoding of information, and the basis for formation and retrieval of memory traces. Long-term potentiation (LTP of synaptic transmission, a candidate cellular model of synaptic information storage, is typically induced by high-frequency tetanisation (HFT of afferent pathways. Taking into account the role of oscillatory activity in the processing of information, dynamic changes may occur in hippocampal network activity in the period during HFT and/or soon after it. These changes in rhythmic activity may determine or, at least, contribute to successful potentiation and, in general, to formation of memory. We have found that short-term potentiation (STP and LTP as well LTPfailure are characterised with different profiles of changes in theta and gamma frequencies. Potentiation of synaptic transmission was associated with a significant increase in the relative theta power and mean amplitude of theta cycles in the period encompassing 300 seconds after HFT. Where LTP or STP, but not failure of potentiation, occurred, this facilitation of theta was accompanied by transient increases in gamma power and in the mean amplitude of gamma oscillations within a single theta cycle. Our data support that specific, correlated changes in these parameters are associated with successful synaptic potentiation. These findings suggest that changes in theta-gamma activity associated with induction of LTP may enable synaptic information storage in the hippocampus.

Soot Formation in Freely-Propagating Laminar Premixed Flames

Science.gov (United States)

Lin, K.-C.; Hassan, M. I.; Faeth, G. M.

1997-01-01

Soot formation within hydrocarbon-fueled flames is an important unresolved problem of combustion science. Thus, the present study is considering soot formation in freely-propagating laminar premixed flames, exploiting the microgravity environment to simplify measurements at the high-pressure conditions of interest for many practical applications. The findings of the investigation are relevant to reducing emissions of soot and continuum radiation from combustion processes, to improving terrestrial and spacecraft fire safety, and to developing methods of computational combustion, among others. Laminar premixed flames are attractive for studying soot formation because they are simple one-dimensional flows that are computationally tractable for detailed numerical simulations. Nevertheless, studying soot-containing burner-stabilized laminar premixed flames is problematical: spatial resolution and residence times are limited at the pressures of interest for practical applications, flame structure is sensitive to minor burner construction details so that experimental reproducibility is not very good, consistent burner behavior over the lengthy test programs needed to measure soot formation properties is hard to achieve, and burners have poor durability. Fortunately, many of these problems are mitigated for soot-containing, freely-propagating laminar premixed flames. The present investigation seeks to extend work in this laboratory for various soot processes in flames by observing soot formation in freely-propagating laminar premixed flames. Measurements are being made at both Normal Gravity (NG) and MicroGravity (MG), using a short-drop free-fall facility to provide MG conditions.

A Novel Distributed Quantum-Behaved Particle Swarm Optimization

Directory of Open Access Journals (Sweden)

Yangyang Li

2017-01-01

Full Text Available Quantum-behaved particle swarm optimization (QPSO is an improved version of particle swarm optimization (PSO and has shown superior performance on many optimization problems. But for now, it may not always satisfy the situations. Nowadays, problems become larger and more complex, and most serial optimization algorithms cannot deal with the problem or need plenty of computing cost. Fortunately, as an effective model in dealing with problems with big data which need huge computation, MapReduce has been widely used in many areas. In this paper, we implement QPSO on MapReduce model and propose MapReduce quantum-behaved particle swarm optimization (MRQPSO which achieves parallel and distributed QPSO. Comparisons are made between MRQPSO and QPSO on some test problems and nonlinear equation systems. The results show that MRQPSO could complete computing task with less time. Meanwhile, from the view of optimization performance, MRQPSO outperforms QPSO in many cases.

Freely Accessible Chemical Database Resources of Compounds for in Silico Drug Discovery.

Science.gov (United States)

Yang, JingFang; Wang, Di; Jia, Chenyang; Wang, Mengyao; Hao, GeFei; Yang, GuangFu

2018-05-07

In silico drug discovery has been proved to be a solidly established key component in early drug discovery. However, this task is hampered by the limitation of quantity and quality of compound databases for screening. In order to overcome these obstacles, freely accessible database resources of compounds have bloomed in recent years. Nevertheless, how to choose appropriate tools to treat these freely accessible databases are crucial. To the best of our knowledge, this is the first systematic review on this issue. The existed advantages and drawbacks of chemical databases were analyzed and summarized based on the collected six categories of freely accessible chemical databases from literature in this review. Suggestions on how and in which conditions the usage of these databases could be reasonable were provided. Tools and procedures for building 3D structure chemical libraries were also introduced. In this review, we described the freely accessible chemical database resources for in silico drug discovery. In particular, the chemical information for building chemical database appears as attractive resources for drug design to alleviate experimental pressure. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Freely migrating defects in ion-irradiated Cu3Au

International Nuclear Information System (INIS)

Wei, L.C.; Lang, E.; Flynn, C.P.; Averback, R.S.

1999-01-01

The efficiency of producing freely migrating vacancy defects in irradiated Cu 3 Au was examined using electrical resistivity measurements of radiation-induced ordering on highly perfect single-crystal films. Relative efficiencies for He, Ne, and Ar bombardments at different ion energy and specimen temperature were obtained. The ratio of the efficiencies of 0.6 MeV Ne to He increased with temperature from ∼0.25 at 340 K to a saturation value of ∼0.40 at 520 K. For Ar and He, the ratio increased from ∼0.11 at 360 K to ∼0.18 at 540 K. Estimates indicate that about half of all defects created in cascades are freely migrating. copyright 1999 American Institute of Physics

Operant conditioning of neural activity in freely behaving monkeys with intracranial reinforcement.

Science.gov (United States)

Eaton, Ryan W; Libey, Tyler; Fetz, Eberhard E

2017-03-01

Operant conditioning of neural activity has typically been performed under controlled behavioral conditions using food reinforcement. This has limited the duration and behavioral context for neural conditioning. To reward cell activity in unconstrained primates, we sought sites in nucleus accumbens (NAc) whose stimulation reinforced operant responding. In three monkeys, NAc stimulation sustained performance of a manual target-tracking task, with response rates that increased monotonically with increasing NAc stimulation. We recorded activity of single motor cortex neurons and documented their modulation with wrist force. We conditioned increased firing rates with the monkey seated in the training booth and during free behavior in the cage using an autonomous head-fixed recording and stimulating system. Spikes occurring above baseline rates triggered single or multiple electrical pulses to the reinforcement site. Such rate-contingent, unit-triggered stimulation was made available for periods of 1-3 min separated by 3-10 min time-out periods. Feedback was presented as event-triggered clicks both in-cage and in-booth, and visual cues were provided in many in-booth sessions. In-booth conditioning produced increases in single neuron firing probability with intracranial reinforcement in 48 of 58 cells. Reinforced cell activity could rise more than five times that of non-reinforced activity. In-cage conditioning produced significant increases in 21 of 33 sessions. In-cage rate changes peaked later and lasted longer than in-booth changes, but were often comparatively smaller, between 13 and 18% above non-reinforced activity. Thus intracranial stimulation reinforced volitional increases in cortical firing rates during both free behavior and a controlled environment, although changes in the latter were more robust. NEW & NOTEWORTHY Closed-loop brain-computer interfaces (BCI) were used to operantly condition increases in muscle and neural activity in monkeys by delivering activity-dependent stimuli to an intracranial reinforcement site (nucleus accumbens). We conditioned increased firing rates with the monkeys seated in a training booth and also, for the first time, during free behavior in a cage using an autonomous head-fixed BCI. Copyright © 2017 the American Physiological Society.

Anticipating and Resisting the Temptation to Behave Unethically.

Science.gov (United States)

Sheldon, Oliver J; Fishbach, Ayelet

2015-07-01

Ethical dilemmas pose a self-control conflict between pursuing immediate benefits through behaving dishonestly and pursuing long-term benefits through acts of honesty. Therefore, factors that facilitate self-control for other types of goals (e.g., health and financial) should also promote ethical behavior. Across four studies, we find support for this possibility. Specifically, we find that only under conditions that facilitate conflict identification--including the consideration of several decisions simultaneously (i.e., a broad decision frame) and perceived high connectedness to the future self--does anticipating a temptation to behave dishonestly in advance promote honesty. We demonstrate these interaction patterns between conflict identification and temptation anticipation in negotiation situations (Study 1), lab tasks (Study 2), and ethical dilemmas in the workplace (Studies 3-4). We conclude that identifying a self-control conflict and anticipating a temptation are two necessary preconditions for ethical decision making. © 2015 by the Society for Personality and Social Psychology, Inc.

Chemogenetic manipulation of ventral pallidal neurons impairs acquisition of sign-tracking in rats.

Science.gov (United States)

Chang, Stephen E; Todd, Travis P; Bucci, David J; Smith, Kyle S

2015-12-01

Cues associated with rewarding events acquire value themselves as a result of the incentive value of the reward being transferred to the cue. Consequently, presentation of a reward-paired cue can trigger reward-seeking behaviours towards the cue itself (i.e. sign-tracking). The ventral pallidum (VP) has been demonstrated to be involved in a number of motivated behaviours, both conditioned and unconditioned. However, its contribution to the acquisition of incentive value is unknown. Using a discriminative autoshaping procedure with levers, the effects of disrupting VP activity in rats on the emergence of sign-tracking was investigated using chemogenetics, i.e. Designer Receptors Exclusively Activated by Designer Drugs (DREADDs). Transient disruption of VP neurons [activation of the inhibitory hM4D(Gi) DREADD through systemic injections of clozapine N-oxide (CNO) prior to each autoshaping session] impaired acquisition of sign-tracking (lever press rate) without having any effect on approach to the site of reward delivery (i.e. goal-tracking) or on the expression of sign-tracking after it was acquired. In addition, electrophysiological recordings were conducted in freely behaving rats following VP DREADD activation. The majority of VP units that were responsive to CNO injections exhibited rapid inhibition relative to baseline, a subset of CNO-responsive units showed delayed excitation, and a smaller subset displayed a mixed response of inhibition and excitation following CNO injections. It is argued that disruption of VP during autoshaping specifically disrupted the transfer of incentive value that was attributed to the lever cue, suggesting a surprisingly fundamental role for the VP in acquiring, compared with expressing, Pavlovian incentive values. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Purinergic 2X receptors play a role in evoking the exercise pressor reflex in rats with peripheral artery insufficiency.

Science.gov (United States)

Stone, Audrey J; Yamauchi, Katsuya; Kaufman, Marc P

2014-02-01

Purinergic 2X (P2X) receptors on the endings of thin fiber afferents have been shown to play a role in evoking the exercise pressor reflex in cats. In this study, we attempted to extend this finding to decerebrated, unanesthetized rats whose femoral arteries were either freely perfused or were ligated 72 h before the start of the experiment. We first established that our dose of pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS; 10 mg/kg), a P2X receptor antagonist, attenuated the pressor response to α,β-methylene ATP (10 μg/kg), a P2X receptor agonist. We then compared the exercise pressor reflex before and after infusing PPADS into the arterial supply of the hindlimb muscles that were statically contracted. In rats with freely perfused femoral arteries, the peak pressor responses to contraction were not significantly attenuated by PPADS (before PPADS: 19 ± 2 mmHg, 13 min after PPADS: 17 ± 2 mmHg, and 25 min after PPADS: 17 ± 3 mmHg). Likewise, the cardioaccelerator and renal sympathetic nerve responses were not significantly attenuated. In contrast, we found that in rats whose femoral arteries were ligated PPADS significantly attenuated the peak pressor responses to contraction (before PPADS: 37 ± 5 mmHg, 13 min after PPADS: 27 ± 6 mmHg, and 25 min after PPADS: 25 ± 5 mmHg; P reflex in rats whose femoral arteries were ligated but play only a minimal role in evoking the reflex in rats whose femoral arteries were freely perfused.

Impairment of decision making and disruption of synchrony between basolateral amygdala and anterior cingulate cortex in the maternally separated rat.

Science.gov (United States)

Cao, Bing; Wang, Jun; Zhang, Xu; Yang, Xiangwei; Poon, David Chun-Hei; Jelfs, Beth; Chan, Rosa H M; Wu, Justin Che-Yuen; Li, Ying

2016-12-01

There is considerable evidence to suggest early life experiences, such as maternal separation (MS), play a role in the prevalence of emotional dysregulation and cognitive impairment. At the same time, optimal decision making requires functional integrity between the amygdala and anterior cingulate cortex (ACC), and any dysfunction of this system is believed to induce decision-making deficits. However, the impact of MS on decision-making behavior and the underlying neurophysiological mechanisms have not been thoroughly studied. As such, we consider the impact of MS on the emotional and cognitive functions of rats by employing the open-field test, elevated plus-maze test, and rat gambling task (RGT). Using multi-channel recordings from freely behaving rats, we assessed the effects of MS on the large scale synchrony between the basolateral amygdala (BLA) and the ACC; while also characterizing the relationship between neural spiking activity and the ongoing oscillations in theta frequency band across the BLA and ACC. The results indicated that the MS rats demonstrated anxiety-like behavior. While the RGT showed a decrease in the percentage of good decision-makers, and an increase in the percentage of poor decision-makers. Electrophysiological data revealed an increase in the total power in the theta band of the LFP in the BLA and a decrease in theta power in the ACC in MS rats. MS was also found to disrupt the spike-field coherence of the ACC single unit spiking activity to the ongoing theta oscillations in the BLA and interrupt the synchrony in the BLA-ACC pathway. We provide specific evidence that MS leads to decision-making deficits that are accompanied by alteration of the theta band LFP in the BLA-ACC circuitries and disruption of the neural network integrity. These observations may help revise fundamental notions regarding neurophysiological biomarkers to treat cognitive impairment induced by early life stress. Copyright © 2016 Elsevier Inc. All rights

Emotions in freely varying and mono-pitched vowels, acoustic and EGG analyses.

Science.gov (United States)

Waaramaa, Teija; Palo, Pertti; Kankare, Elina

2015-12-01

Vocal emotions are expressed either by speech or singing. The difference is that in singing the pitch is predetermined while in speech it may vary freely. It was of interest to study whether there were voice quality differences between freely varying and mono-pitched vowels expressed by professional actors. Given their profession, actors have to be able to express emotions both by speech and singing. Electroglottogram and acoustic analyses of emotional utterances embedded in expressions of freely varying vowels [a:], [i:], [u:] (96 samples) and mono-pitched protracted vowels (96 samples) were studied. Contact quotient (CQEGG) was calculated using 35%, 55%, and 80% threshold levels. Three different threshold levels were used in order to evaluate their effects on emotions. Genders were studied separately. The results suggested significant gender differences for CQEGG 80% threshold level. SPL, CQEGG, and F4 were used to convey emotions, but to a lesser degree, when F0 was predetermined. Moreover, females showed fewer significant variations than males. Both genders used more hypofunctional phonation type in mono-pitched utterances than in the expressions with freely varying pitch. The present material warrants further study of the interplay between CQEGG threshold levels and formant frequencies, and listening tests to investigate the perceptual value of the mono-pitched vowels in the communication of emotions.

The effect of acute swim stress and training in the water maze on hippocampal synaptic activity as well as plasticity in the dentate gyrus of freely moving rats: revisiting swim-induced LTP reinforcement.

Science.gov (United States)

Tabassum, Heena; Frey, Julietta U

2013-12-01

Hippocampal long-term potentiation (LTP) is a cellular model of learning and memory. An early form of LTP (E-LTP) can be reinforced into its late form (L-LTP) by various behavioral interactions within a specific time window ("behavioral LTP-reinforcement"). Depending on the type and procedure used, various studies have shown that stress differentially affects synaptic plasticity. Under low stress, such as novelty detection or mild foot shocks, E-LTP can be transformed into L-LTP in the rat dentate gyrus (DG). A reinforcing effect of a 2-min swim, however, has only been shown in (Korz and Frey (2003) J Neurosci 23:7281-7287; Korz and Frey (2005) J Neurosci 25:7393-7400; Ahmed et al. (2006) J Neurosci 26:3951-3958; Sajikumar et al., (2007) J Physiol 584.2:389-400) so far. We have reinvestigated these studies using the same as well as an improved recording technique which allowed the recording of field excitatory postsynaptic potentials (fEPSP) and the population spike amplitude (PSA) at their places of generation in freely moving rats. We show that acute swim stress led to a long-term depression (LTD) in baseline values of PSA and partially fEPSP. In contrast to earlier studies a LTP-reinforcement by swimming could never be reproduced. Our results indicate that 2-min swim stress influenced synaptic potentials as well as E-LTP negatively. Copyright © 2013 Wiley Periodicals, Inc.

MICRODIALYSIS OF MELATONIN IN THE RAT PINEAL-GLAND - METHODOLOGY AND PHARMACOLOGICAL APPLICATIONS

NARCIS (Netherlands)

DRIJFHOUT, WJ; GROL, CJ; WESTERINK, BHC

The present study describes the development of a new technique to measure melatonin contents in the pineal gland of freely moving rats, by means of on-line microdialysis. The transcerebral cannula was modified, and a sensitive assay of melatonin, using HPLC with fluorimetric detection, was set up.

Influence of a multideficient diet from northeastern Brazil on resting blood pressure and baroreflex sensitivity in conscious, freely moving rats

Directory of Open Access Journals (Sweden)

F.M.F. Monteiro

2001-02-01

Full Text Available The "regional basic diet" or RBD is a multideficient diet (providing 8% protein which is known to produce dietary deficiencies in some populations in northeastern Brazil. The present study investigated the effects of RBD-induced malnutrition on resting blood pressure and baroreflex sensitivity in conscious rats. Malnourished rats were obtained by feeding dams the RBD during mating and pregnancy (RBD-1 group or during nursing and a 10-day period after weaning (RBD-2 group. At 90 days of age, only RBD-2 rats weighed significantly (P<0.001 less than control rats born to dams fed a standard commercial diet (23% protein during pregnancy and nursing. Baseline mean arterial pressure and heart rate of both RBD-1 and RBD-2 rats were comparable to those of controls. The slopes for both reflex bradycardia and tachycardia (bpm/mmHg induced by intravenous phenylephrine and sodium nitroprusside, respectively, were unchanged in either RBD-1 (-2.08 ± 0.11 and -3.10 ± 0.43, respectively or RBD-2 (-2.32 ± 0.30 and -3.73 ± 0.53, respectively rats, when compared to controls (-2.09 ± 0.10 and -3.17 ± 0.33, respectively. This study shows that, after a prolonged period of nutritional recovery, the patterns of resting blood pressure and baroreflex sensitivity of both pre- and postnatally malnourished rats were similar to those of controls. The decreased body weight and the tendency to increased reflex tachycardia in RBD-2 rats may suggest that this type of maternal malnutrition during lactation is more critical than during pregnancy.

Use of microdialysis for monitoring sympathetic and parasympathetic innervation of heart in conscious rats

NARCIS (Netherlands)

Cremers, T.I.F.H.; Teisman, A.C H; van Gilst, W.H; Westerink, B.H.C.

1997-01-01

A microdialysis method was developed to sample norepinephrine and acetylcholine from the heart of freely moving rats. A flexible dialysis fiber (length 14 mm), with a copper wire inserted inside, was implanted into the heart. Extracellular norepinephrine was detectable for at least 72 h after

A charged anisotropic well-behaved Adler-Finch-Skea solution satisfying Karmarkar condition

Science.gov (United States)

Bhar, Piyali; Singh, Ksh. Newton; Rahaman, Farook; Pant, Neeraj; Banerjee, Sumita

In the present paper, we discover a new well-behaved charged anisotropic solution of Einstein-Maxwell’s field equations. We ansatz the metric potential g00 of the form given by Maurya et al. (Eur. Phys. J. C 76(12) (2016) 693) with n = 2. In their paper, it is mentioned that for n = 2, the solution is not well-behaved for neutral configuration as the speed of sound is nondecreasing radially outward. However, the solution can represent a physically possible configuration with the inclusion of some net electric charge, i.e. the solution can become a well-behaved solution with decreasing sound speed radially outward for a charged configuration. Due to the inclusion of electric charge, the solution leads to a very stiff equation-of-state (EoS) with the velocity of sound at the center vr02 = 0.819, vt02 = 0.923 and the compactness parameter u = 0.823 is close to the Buchdahl limit 0.889. This stiff EoS support a compact star configuration of mass 5.418M⊙ and radius of 10.1km.

Mass distribution and rotational inertia of "microtype" and "freely mobile" middle ear ossicles in rodents.

Science.gov (United States)

Lavender, Danielle; Taraskin, Sergei N; Mason, Matthew J

2011-12-01

The middle ears of seven species of rodents, including four hamster species, were examined under light microscopy and through micro-CT imaging. Hamsters were found to possess a spectrum of ossicular morphologies ranging from something approaching "freely mobile" (Mesocricetus) to something nearer the "microtype" (Cricetulus), although no hamster has an orbicular apophysis of the malleus. Rats, mice and Calomyscus were found to have typically microtype ossicles. To explore the functional effects of these morphological differences, CT scan data were used to calculate the magnitudes of the moments of inertia and positions of the centres of mass and principal rotational axes for the malleus-incus complexes. Microtype species were found to have much greater ossicular inertias, relative to size, about the "anatomical axis" extending between anterior process of the malleus and short process of the incus; ossicular centres of mass were displaced further from this axis. Calculated inertial values were then put into an existing model of middle ear function (Hemilä et al., 1995), in order to see whether the more accurate data would improve predictions of upper hearing limits. For the rat and mouse they did, but this was not so for the hamster Mesocricetus. This might indicate that the inner rather than the middle ear limits hearing in this species, or might simply reflect other shortcomings of the model. Functional differences appear to exist even among rodent ears of the same general type, but the adaptive significance of these differences remains enigmatic. Copyright © 2011 Elsevier B.V. All rights reserved.

BEHAVE: fire behavior prediction and fuel modeling system--FUEL subsystem

Science.gov (United States)

Robert E. Burgan; Richard C. Rothermel

1984-01-01

This manual documents the fuel modeling procedures of BEHAVE--a state-of-the-art wildland fire behavior prediction system. Described are procedures for collecting fuel data, using the data with the program, and testing and adjusting the fuel model.

How are we behaving?

CERN Multimedia

2012-01-01

It’s almost two years since CERN introduced a Code of Conduct. The results may not be immediately measurable, but I’d like to think it’s made the lab a better place to be. The Code of Conduct is based on values that most of us immediately identify with, and so implementing it comes as second nature. Nevertheless, in an organisation of over 10,000 people, it’s useful to have a set of guidelines and there have been occasions on which it’s been necessary to remind people of them.   I use the figure of 10,000 advisedly since the Code of Conduct applies to us all, those on the CERN payroll as well as users of the lab’s facilities and people working for CERN contractors, as long as they are acting on CERN’s behalf. The Code also applies to us whether we are on the CERN site or anywhere else. CERN is a major presence in the region. The way we behave can have a significant influence on how our neighbours perceive us, and how the la...

Clustering impact regime with shocks in freely evolving granular gas

Science.gov (United States)

Isobe, Masaharu

2017-06-01

A freely cooling granular gas without any external force evolves from the initial homogeneous state to the inhomogeneous clustering state, at which the energy decay deviates from the Haff's law. The asymptotic behavior of energy in the inelastic hard sphere model have been predicted by several theories, which are based on the mode coupling theory or extension of inelastic hard rods gas. In this study, we revisited the clustering regime of freely evolving granular gas via large-scale molecular dynamics simulation with up to 16.7 million inelastic hard disks. We found novel regime regarding on collisions between "clusters" spontaneously appearing after clustering regime, which can only be identified more than a few million particles system. The volumetric dilatation pattern of semicircular shape originated from density shock propagation are well characterized on the appearing of "cluster impact" during the aggregation process of clusters.

An investigation of the challenges in reconstructing PET images of a freely moving animal

International Nuclear Information System (INIS)

Akhtar, Mahmood; Kyme, Andre; Meikle, Steven; Zhou, Victor; Fulton, Roger

2013-01-01

Imaging the brain of a freely moving small animal using positron emission tomography (PET) while simultaneously observing its behaviour is an important goal for neuroscience. While we have successfully demonstrated the use of line-of-response (LOR) rebinning to correct the head motion of confined animals, a large proportion of events may need to be discarded because they either 'miss' the detector array after transformation or fall out of the acceptance range of a sinogram. The proportion of events that would have been measured had motion not occurred, so-called 'lost events', is expected to be even larger for freely moving animals. Moreover, the data acquisition in the case of a freely moving animal is further complicated by a complex attenuation field. The aims of this study were (a) to characterise the severity of 'lost events' problem for the freely moving animal scenario, and (b) to investigate the relative impact of attenuation correction errors on quantitative accuracy of reconstructed images. A phantom study was performed to simulate the uncorrelated motion of a target and non-target source volume. A small animal PET scanner was used to acquire list-mode data for different sets of phantom positions. The list-mode data were processed using the standard LOR rebinning approach, and multiple frame variants of this designed to reduce discarded events. We found that LOR rebinning caused up to 86 % 'lost events', and artifacts that we attribute to incomplete projections, when applied to a freely moving target. This fraction was reduced by up to 18 % using the variant approaches, resulting in slightly reduced image artifacts. The effect of the non-target compartment on attenuation correction of the target volume was surprisingly small. However, for certain poses where the target and non-target volumes are aligned transaxially in the field-of-view, the attenuation problem becomes more complex and sophisticated correction methods will be required. We conclude that

Synaptic plasticity and the analysis of the field-EPSP as well as the population spike using separate recording electrodes in the dentate gyrus in freely moving rats.

Science.gov (United States)

Frey, Sabine; Frey, Julietta U

2009-10-30

Commonly, synaptic plasticity events such as long-term potentiation (LTP) are investigated by using a stimulation electrode and a single, monopolar field recording electrode in the dentate gyrus in intact, freely moving rats. The recording electrode is mostly positioned in the granular cell layer, or the hilar region of the dentate gyrus, i.e. far away from the place of generation of monosynaptic postsynaptic excitatory potentials (EPSP). Since LTP is a synaptic phenomenon and field recordings far away from the activated synapses do not guarantee a specific interpretation of the overlaid, mixture of complex potentials of several different electrical fields it is often difficult or even impossible to interpret the data obtained by such a single recording electrode. Therefore, at least a separate or two recording electrodes should be used to record the EPSP as well as the spike, respectively, ideally at their places of generation. Here, we describe a method by implanting a chronic bipolar recording electrode which fulfils the above requirements by recording the field-EPSP as well as the population spike at their places of generation and describe the time course of LTP measured using this "double-recording" electrode. We show that different tetanization protocols resulted in EPSP- or population spike-LTP but only if the potentials were recorded by electrodes positioned within adequate places of potential generation. Interestingly, the commonly used recording in the hilus of a distinct part of a potential, mistakenly analyzed as an "EPSP" did not reveal any LTP.

Fear Expression Suppresses Medial Prefrontal Cortical Firing in Rats.

Directory of Open Access Journals (Sweden)

Thomas F Giustino

Full Text Available The medial prefrontal cortex (mPFC plays a crucial role in emotional learning and memory in rodents and humans. While many studies suggest a differential role for the prelimbic (PL and infralimbic (IL subdivisions of mPFC, few have considered the relationship between neural activity in these two brain regions recorded simultaneously in behaving animals. Importantly, how concurrent PL and IL activity relate to conditioned freezing behavior is largely unknown. Here we used single-unit recordings targeting PL and IL in awake, behaving rats during the acquisition and expression of conditioned fear. On Day 1, rats received either signaled or unsignaled footshocks in the recording chamber; an auditory conditioned stimulus (CS preceded signaled footshocks. Twenty-four hours later, animals were returned to the recording chamber (modified to create a novel context where they received 5 CS-alone trials. After fear conditioning, both signaled and unsignaled rats exhibited high levels of post-shock freezing that was associated with an enduring suppression of mPFC spontaneous firing, particularly in the IL of signaled rats. Twenty-four hours later, CS presentation produced differential conditioned freezing in signaled and unsignaled rats: freezing increased in rats that had received signaled shocks, but decreased in animals in the unsignaled condition (i.e., external inhibition. This group difference in CS-evoked freezing was mirrored in the spontaneous firing rate of neurons in both PL and IL. Interestingly, differences in PL and IL firing rate highly correlated with freezing levels. In other words, in the signaled group IL spontaneous rates were suppressed relative to PL, perhaps limiting IL-mediated suppression of fear and allowing PL activity to dominate performance, resulting in high levels of freezing. This was not observed in the unsignaled group, which exhibited low freezing. These data reveal that the activity of mPFC neurons is modulated by both

Extraction of motor activity from the cervical spinal cord of behaving rats

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Prasad, Abhishek; Sahin, Mesut

2006-12-01

Injury at the cervical region of the spinal cord results in the loss of the skeletal muscle control from below the shoulders and hence causes quadriplegia. The brain-computer interface technique is one way of generating a substitute for the lost command signals in these severely paralyzed individuals using the neural signals from the brain. In this study, we are investigating the feasibility of an alternative method where the volitional signals are extracted from the cervical spinal cord above the point of injury. A microelectrode array assembly was implanted chronically at the C5-C6 level of the spinal cord in rats. Neural recordings were made during the face cleaning behavior with forelimbs as this task involves cyclic forelimb movements and does not require any training. The correlation between the volitional motor signals and the elbow movements was studied. Linear regression technique was used to reconstruct the arm movement from the rectified-integrated version of the principal neural components. The results of this study demonstrate the feasibility of extracting the motor signals from the cervical spinal cord and using them for reconstruction of the elbow movements.

A wirelessly-powered homecage with animal behavior analysis and closed-loop power control.

Science.gov (United States)

Yaoyao Jia; Zheyuan Wang; Canales, Daniel; Tinkler, Morgan; Chia-Chun Hsu; Madsen, Teresa E; Mirbozorgi, S Abdollah; Rainnie, Donald; Ghovanloo, Maysam

2016-08-01

This paper presents a new EnerCage-homecage system, EnerCage-HC2, for longitudinal electrophysiology data acquisition experiments on small freely moving animal subjects, such as rodents. EnerCage-HC2 is equipped with multi-coil wireless power transmission (WPT), closed-loop power control, bidirectional data communication via Bluetooth Low Energy (BLE), and Microsoft Kinect® based animal behavior tracking and analysis. The EnerCage-HC2 achieves a homogeneous power transfer efficiency (PTE) of 14% on average, with ~42 mW power delivered to the load (PDL) at a nominal height of 7 cm by the closed-loop power control mechanism. The Microsoft Kinect® behavioral analysis algorithm can not only track the animal position in real-time but also classify 5 different types of rodent behaviors: standstill, walking, grooming, rearing, and rotating. A proof-of-concept in vivo experiment was conducted on two awake freely behaving rats while successfully operating a one-channel stimulator and generating an ethogram.

Freely-migrating-defect production during irradiation at elevated temperatures

Science.gov (United States)

Hashimoto, T.; Rehn, L. E.; Okamoto, P. R.

1988-12-01

Radiation-induced segregation in a Cu-1 at. % Au alloy was investigated using in situ Rutherford backscattering spectrometry. The amount of Au atom depletion in the near surface region was measured as a function of dose during irradiation at 350 °C with four ions of substantially different masses. Relative efficiencies for producing freely migrating defects were evaluated for 1.8-MeV 1H, 4He, 20Ne, and 84Kr ions by determining beam current densities that gave similar radiation-induced segregation rates. Irradiations with primary knock-on atom median energies of 1.7, 13, and 79 keV yielded relative efficiencies of 53, 7, and 6 %, respectively, compared to the irradiation with a 0.83-keV median energy. Despite quite different defect and host alloy properties, the relative efficiencies for producing freely migrating defects determined in Cu-Au are remarkably similar to those found previously in Ni-Si alloys. Hence, the reported efficiencies appear to offer a reliable basis for making quantitative correlations of microstructural changes induced in different alloy systems by a wide variety of irradiation particles.

Sensory and cognitive neurophysiology in rats, Part 1: Controlled tactile stimulation and micro-ECoG recordings in freely moving animals.

Science.gov (United States)

Dimitriadis, George; Fransen, Anne M M; Maris, Eric

2014-07-30

We have developed a setup for rats that allows for controlled sensory input to an animal engaged in a task while recording both electrophysiological signals and behavioral output. We record electrophysiological signals using a novel high-density micro-electrocorticography (micro-ECoG) grid that covers almost the whole somatosensory system. We dealt with the well-known difficulty that the rat uses its whisker system in an active (motor-controlled) way to explore its environment by designing a head-mounted device that stimulates the rat's snout in a way unaffected by whisker movements. We replicate the spatial specificity of early evoked responses in somatosensory and auditory cortex. In a companion paper (Cognitive Neurophysiology in Rats, Part 2: Validation and Demonstration) we validate our setup and show for the first time that the ECoG can be used to record evoked responses in a signal that reflects neural output (spiking activity). Compared with high-density wire recordings, micro-ECoG offers a much more stable signal without readjustments, and a much better scalability. Compared with head-fixed preparations, our head-mounted stimulator allows to stay closer to the rat's natural way of collecting sensory information. For perceptual and cognitive research, our setup provides a unique combination of possibilities that cannot be achieved in other setups for rodents. Copyright © 2014 Elsevier B.V. All rights reserved.

Quantification of extracellular levels of corticosterone in the basolateral amygdaloid complex of freely-moving rats: a dialysis study of circadian variation and stress-induced modulation.

Science.gov (United States)

Bouchez, Gaëlle; Millan, Mark J; Rivet, Jean-Michel; Billiras, Rodolphe; Boulanger, Raphaël; Gobert, Alain

2012-05-03

Corticosterone influences emotion and cognition via actions in a diversity of corticolimbic structures, including the amygdala. Since extracellular levels of corticosterone in brain have rarely been studied, we characterized a specific and sensitive enzymatic immunoassay for microdialysis quantification of corticosterone in the basolateral amygdaloid complex of freely-moving rats. Corticosterone levels showed marked diurnal variation with an evening (dark phase) peak and stable, low levels during the day (light phase). The "anxiogenic agents", FG7142 (20 mg/kg) and yohimbine (10 mg/kg), and an environmental stressor, 15-min forced-swim, induced marked and sustained (1-3 h) increases in dialysis levels of corticosterone in basolateral amygdaloid complex. They likewise increased dialysis levels of dopamine and noradrenaline, but not serotonin and GABA. As compared to basal corticosterone levels of ~200-300 pg/ml, the elevation provoked by forced-swim was ca. 20-fold and this increase was abolished by adrenalectomy. Interestingly, stress-induced rises of corticosterone levels in basolateral amygdaloid complex were abrogated by combined but not separate administration of the corticotrophin releasing factor(1) (CRF(1)) receptor antagonist, CP154,526, and the vasopressin(1b) (V(1b)) receptor antagonist, SSR149,415. Underpinning their specificity, they did not block forced-swim-induced elevations in dopamine and noradrenaline. In conclusion, extracellular levels of corticosterone in the basolateral amygdaloid complex display marked diurnal variation. Further, they are markedly elevated by acute stressors, the effects of which are mediated (in contrast to concomitant elevations in levels of monoamines) by co-joint recruitment of CRF(1) and V(1b) receptors. Copyright © 2012 Elsevier B.V. All rights reserved.

Wave fronts, pulses and wave trains in photoexcited superlattices behaving as excitable or oscillatory media

International Nuclear Information System (INIS)

Arana, J I; Bonilla, L L; Grahn, H T

2011-01-01

Undoped and strongly photoexcited semiconductor superlattices with field-dependent recombination behave as excitable or oscillatory media with spatially discrete nonlinear convection and diffusion. Infinitely long, dc-current-biased superlattices behaving as excitable media exhibit wave fronts with increasing or decreasing profiles, whose velocities can be calculated by means of asymptotic methods. These superlattices can also support pulses of the electric field. Pulses moving downstream with the flux of electrons can be constructed from their component wave fronts, whereas pulses advancing upstream do so slowly and experience saltatory motion: they change slowly in long intervals of time separated by fast transitions during which the pulses jump to the previous superlattice period. Photoexcited superlattices can also behave as oscillatory media and exhibit wave trains. (paper)

Rats demonstrate helping behavior toward a soaked conspecific.

Science.gov (United States)

Sato, Nobuya; Tan, Ling; Tate, Kazushi; Okada, Maya

2015-09-01

Helping behavior is a prosocial behavior whereby an individual helps another irrespective of disadvantages to him or herself. In the present study, we examined whether rats would help distressed, conspecific rats that had been soaked with water. In Experiment 1, rats quickly learned to liberate a soaked cagemate from the water area by opening the door to allow the trapped rat into a safe area. Additional tests showed that the presentation of a distressed cagemate was necessary to induce rapid door-opening behavior. In addition, it was shown that rats dislike soaking and that rats that had previously experienced a soaking were quicker to learn how to help a cagemate than those that had never been soaked. In Experiment 2, the results indicated that rats did not open the door to a cagemate that was not distressed. In Experiment 3, we tested behavior when rats were forced to choose between opening the door to help a distressed cagemate and opening a different door to obtain a food reward. Irrespective of how they learned to open the door, in most test trials, rats chose to help the cagemate before obtaining a food reward, suggesting that the relative value of helping others is greater than the value of a food reward. These results suggest that rats can behave prosocially and that helper rats may be motivated by empathy-like feelings toward their distressed cagemate.

Blockade of acid sensing ion channels attenuates the augmented exercise pressor reflex in rats with chronic femoral artery occlusion.

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Tsuchimochi, Hirotsugu; Yamauchi, Katsuya; McCord, Jennifer L; Kaufman, Marc P

2011-12-15

We found previously that static contraction of the hindlimb muscles of rats whose femoral artery was ligated evoked a larger reflex pressor response (i.e. exercise pressor reflex) than did static contraction of the contralateral hindlimb muscles which were freely perfused. Ligating a femoral artery in rats results in blood flow patterns to the muscles that are remarkably similar to those displayed by humans with peripheral artery disease. Using decerebrated rats, we tested the hypothesis that the augmented exercise pressor reflex in rats with a ligated femoral artery is attenuated by blockade of the acid sensing ion channel (ASIC) 3. We found that femoral arterial injection of either amiloride (5 and 50 μg kg(-1)) or APETx2 (100 μg kg(-1)) markedly attenuated the reflex in rats with a ligated femoral artery. In contrast, these ASIC antagonists had only modest effects on the reflex in rats with freely perfused hindlimbs. Tests of specificity of the two antagonists revealed that the low dose of amiloride and APETx2 greatly attenuated the pressor response to lactic acid, an ASIC agonist, but did not attenuate the pressor response to capsaicin, a TRPV1 agonist. In contrast, the high dose of amiloride attenuated the pressor responses to lactic acid, but also attenuated the pressor response to capsaicin. We conclude that ASIC3 on thin fibre muscle afferents plays an important role in evoking the exercise pressor reflex in rats with a compromised arterial blood supply to the working muscles.

Learning history and cholinergic modulation in the dorsal hippocampus are necessary for rats to infer the status of a hidden event.

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Fast, Cynthia D; Flesher, M Melissa; Nocera, Nathanial A; Fanselow, Michael S; Blaisdell, Aaron P

2016-06-01

Identifying statistical patterns between environmental stimuli enables organisms to respond adaptively when cues are later observed. However, stimuli are often obscured from detection, necessitating behavior under conditions of ambiguity. Considerable evidence indicates decisions under ambiguity rely on inference processes that draw on past experiences to generate predictions under novel conditions. Despite the high demand for this process and the observation that it deteriorates disproportionately with age, the underlying mechanisms remain unknown. We developed a rodent model of decision-making during ambiguity to examine features of experience that contribute to inference. Rats learned either a simple (positive patterning) or complex (negative patterning) instrumental discrimination between the illumination of one or two lights. During test, only one light was lit while the other relevant light was blocked from physical detection (covered by an opaque shield, rendering its status ambiguous). We found experience with the complex negative patterning discrimination was necessary for rats to behave sensitively to the ambiguous test situation. These rats behaved as if they inferred the presence of the hidden light, responding differently than when the light was explicitly absent (uncovered and unlit). Differential expression profiles of the immediate early gene cFos indicated hippocampal involvement in the inference process while localized microinfusions of the muscarinic antagonist, scopolamine, into the dorsal hippocampus caused rats to behave as if only one light was present. That is, blocking cholinergic modulation prevented the rat from inferring the presence of the hidden light. Collectively, these results suggest cholinergic modulation mediates recruitment of hippocampal processes related to past experiences and transfer of these processes to make decisions during ambiguous situations. Our results correspond with correlations observed between human brain

The relationship between hippocampal EEG theta activity and locomotor behaviour in freely moving rats: effects of vigabatrin.

Science.gov (United States)

Bouwman, B M; van Lier, H; Nitert, H E J; Drinkenburg, W H I M; Coenen, A M L; van Rijn, C M

2005-01-30

The relationship between hippocampal electroencephalogram (EEG) theta activity and locomotor speed in both spontaneous and forced walking conditions was studied in rats after vigabatrin injection (500 mg/kg i.p.). Vigabatrin increased the percentage of time that rats spent being immobile. During spontaneous walking in the open field, the speed of locomotion was increased by vigabatrin, while theta peak frequency was decreased. Vigabatrin also reduced the theta peak frequency during forced (speed controlled) walking. There was only a weak positive correlation (r=0.22) between theta peak frequency and locomotor speed for the saline condition. Furthermore, vigabatrin abolishes the weak relationship between speed of locomotion and theta peak frequency. Vigabatrin and saline did not differ in the slope of the regression line, but showed different offset points at the theta peak frequency axis. Thus, other factors than speed of locomotion seem to be involved in determination of the theta peak frequency.

Effects of fasting on plasma catecholamine, corticosterone and glucose concentrations under basal and stress conditions in individual rats

NARCIS (Netherlands)

de Boer, S.F.; Koopmans, S.J.; Slangen, J L; Van der Gugten, J

Plasma noradrenaline (NA), adrenaline (A), corticosterone (CS) and glucose concentrations were determined in blood sampled via a cardiac catheter from freely moving male rats under ad lib fed and 24 hr food deprived conditions using a repeated measures within-subject design. Resting plasma NA and

The role of the intrinsic cholinergic system of the striatum: What have we learned from TAN recordings in behaving animals?

Science.gov (United States)

Apicella, Paul

2017-09-30

Cholinergic interneurons provide rich local innervation of the striatum and play an important role in controlling behavior, as evidenced by the variety of movement and psychiatric disorders linked to disrupted striatal cholinergic transmission. Much progress has been made in recent years regarding our understanding of how these interneurons contribute to the processing of information in the striatum. In particular, investigation of the activity of presumed striatal cholinergic interneurons, identified as tonically active neurons or TANs in behaving animals, has pointed to their role in the signaling and learning of the motivational relevance of environmental stimuli. Although the bulk of this work has been conducted in monkeys, several studies have also been carried out in behaving rats, but information remains rather disparate across studies and it is still questionable whether rodent TANs correspond to TANs described in monkeys. Consequently, our current understanding of the function of cholinergic transmission in the striatum is challenged by the rapidly growing, but often confusing literature on the relationship between TAN activity and specific behaviors. As regards the precise nature of the information conveyed by the cholinergic TANs, a recent influential view emphasized that these local circuit neurons may play a special role in the processing of contextual information that is important for reinforcement learning and selection of appropriate actions. This review provides a summary of recent progress in TAN physiology from which it is proposed that striatal cholinergic interneurons are crucial elements for flexible switching of behaviors under changing environmental conditions. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Stimulation of accumbal GABAA receptors inhibits delta2-, but not delta1-, opioid receptor-mediated dopamine efflux in the nucleus accumbens of freely moving rats.

Science.gov (United States)

Aono, Yuri; Kiguchi, Yuri; Watanabe, Yuriko; Waddington, John L; Saigusa, Tadashi

2017-11-15

The nucleus accumbens contains delta-opioid receptors that may reduce inhibitory neurotransmission. Reduction in GABA A receptor-mediated inhibition of accumbal dopamine release due to delta-opioid receptor activation should be suppressed by stimulating accumbal GABA A receptors. As delta-opioid receptors are divided into delta2- and delta1-opioid receptors, we analysed the effects of the GABA A receptor agonist muscimol on delta2- and delta1-opioid receptor-mediated accumbal dopamine efflux in freely moving rats using in vivo microdialysis. Drugs were administered intracerebrally through the dialysis probe. Doses of compounds indicate total amount administered (mol) during 25-50min infusions. The delta2-opioid receptor agonist deltorphin II (25.0nmol)- and delta1-opioid receptor agonist DPDPE (5.0nmol)-induced increases in dopamine efflux were inhibited by the delta2-opioid receptor antagonist naltriben (1.5nmol) and the delta1-opioid receptor antagonist BNTX (150.0pmol), respectively. Muscimol (250.0pmol) inhibited deltorphin II (25.0nmol)-induced dopamine efflux. The GABA A receptor antagonist bicuculline (50.0pmol), which failed to affect deltorphin II (25.0nmol)-induced dopamine efflux, counteracted the inhibitory effect of muscimol on deltorphin II-induced dopamine efflux. Neither muscimol (250.0pmol) nor bicuculline (50.0 and 500.0pmol) altered DPDPE (5.0nmol)-induced dopamine efflux. The present results show that reduction in accumbal GABA A receptor-mediated inhibition of dopaminergic activity is necessary to produce delta2-opioid receptor-induced increase in accumbal dopamine efflux. This study indicates that activation of delta2- but not delta1-opioid receptors on the cell bodies and/or terminals of accumbal GABAergic interneurons inhibits GABA release and, accordingly, decreases GABA A receptor-mediated inhibition of dopaminergic terminals, resulting in enhanced accumbal dopamine efflux. Copyright © 2017 Elsevier B.V. All rights reserved.

The Naked Mole Rat Genome Resource: facilitating analyses of cancer and longevity-related adaptations.

Science.gov (United States)

Keane, Michael; Craig, Thomas; Alföldi, Jessica; Berlin, Aaron M; Johnson, Jeremy; Seluanov, Andrei; Gorbunova, Vera; Di Palma, Federica; Lindblad-Toh, Kerstin; Church, George M; de Magalhães, João Pedro

2014-12-15

The naked mole rat (Heterocephalus glaber) is an exceptionally long-lived and cancer-resistant rodent native to East Africa. Although its genome was previously sequenced, here we report a new assembly sequenced by us with substantially higher N50 values for scaffolds and contigs. We analyzed the annotation of this new improved assembly and identified candidate genomic adaptations which may have contributed to the evolution of the naked mole rat's extraordinary traits, including in regions of p53, and the hyaluronan receptors CD44 and HMMR (RHAMM). Furthermore, we developed a freely available web portal, the Naked Mole Rat Genome Resource (http://www.naked-mole-rat.org), featuring the data and results of our analysis, to assist researchers interested in the genome and genes of the naked mole rat, and also to facilitate further studies on this fascinating species. © The Author 2014. Published by Oxford University Press.

Schlieren photography on freely flying hawkmoth.

Science.gov (United States)

Liu, Yun; Roll, Jesse; Van Kooten, Stephen; Deng, Xinyan

2018-05-01

The aerodynamic force on flying insects results from the vortical flow structures that vary both spatially and temporally throughout flight. Due to these complexities and the inherent difficulties in studying flying insects in a natural setting, a complete picture of the vortical flow has been difficult to obtain experimentally. In this paper, Schlieren , a widely used technique for highspeed flow visualization, was adapted to capture the vortex structures around freely flying hawkmoth ( Manduca ). Flow features such as leading-edge vortex, trailing-edge vortex, as well as the full vortex system in the wake were visualized directly. Quantification of the flow from the Schlieren images was then obtained by applying a physics-based optical flow method, extending the potential applications of the method to further studies of flying insects. © 2018 The Author(s).

ChemoPy: freely available python package for computational biology and chemoinformatics.

Science.gov (United States)

Cao, Dong-Sheng; Xu, Qing-Song; Hu, Qian-Nan; Liang, Yi-Zeng

2013-04-15

Molecular representation for small molecules has been routinely used in QSAR/SAR, virtual screening, database search, ranking, drug ADME/T prediction and other drug discovery processes. To facilitate extensive studies of drug molecules, we developed a freely available, open-source python package called chemoinformatics in python (ChemoPy) for calculating the commonly used structural and physicochemical features. It computes 16 drug feature groups composed of 19 descriptors that include 1135 descriptor values. In addition, it provides seven types of molecular fingerprint systems for drug molecules, including topological fingerprints, electro-topological state (E-state) fingerprints, MACCS keys, FP4 keys, atom pairs fingerprints, topological torsion fingerprints and Morgan/circular fingerprints. By applying a semi-empirical quantum chemistry program MOPAC, ChemoPy can also compute a large number of 3D molecular descriptors conveniently. The python package, ChemoPy, is freely available via http://code.google.com/p/pychem/downloads/list, and it runs on Linux and MS-Windows. Supplementary data are available at Bioinformatics online.

Pan-neuronal calcium imaging with cellular resolution in freely swimming zebrafish.

Science.gov (United States)

Kim, Dal Hyung; Kim, Jungsoo; Marques, João C; Grama, Abhinav; Hildebrand, David G C; Gu, Wenchao; Li, Jennifer M; Robson, Drew N

2017-11-01

Calcium imaging with cellular resolution typically requires an animal to be tethered under a microscope, which substantially restricts the range of behaviors that can be studied. To expand the behavioral repertoire amenable to imaging, we have developed a tracking microscope that enables whole-brain calcium imaging with cellular resolution in freely swimming larval zebrafish. This microscope uses infrared imaging to track a target animal in a behavior arena. On the basis of the predicted trajectory of the animal, we applied optimal control theory to a motorized stage system to cancel brain motion in three dimensions. We combined this motion-cancellation system with differential illumination focal filtering, a variant of HiLo microscopy, which enabled us to image the brain of a freely swimming larval zebrafish for more than an hour. This work expands the repertoire of natural behaviors that can be studied with cellular-resolution calcium imaging to potentially include spatial navigation, social behavior, feeding and reward.

Effects of swimming training and free mobilization on bone mineral densities of rats with the immobilization-induced osteopenia

International Nuclear Information System (INIS)

Karatosun, H.; Erdogan, A.; Akgun, C.; Cetin, C.; Yeldiz, M.

2006-01-01

To investigate the possible effects of regular swimming exercise on bone mineral density (BMD) compared with free activity after cast immobilization of rats. We carried out the study from April 2005 to June 2005 at the Department of Sports Medicine, Medical School of Suleyman Demirel University, Isparta, Turkey. The study included a total of 24 female Wistar rats. The rats were randomized to control (n = 6), swimming training (ST) n = 9, and free mobilization (FM) n = 9 groups. We measured Bone mineral densities of femur and vertebra of all rats with a total body scanner using software specifically designed for small animals, before study started and at weeks 3 and 7. Timepoints corresponded to basal, after cast removal (ACIM), and after 3 weeks of free mobilization (AFM) or swimming training (AST). We immobilized the right hindlimb of each ST and FM animal with a cast while the left hindlimbs were kept free. After 3 weeks, the casts were removed. Then we allowed the rats to move freely in their cage for one week, after which the animals in ST group started to swim for 5 days a week for 3 weeks for 30 minutes per day. The group FM rats moved freely in the cage. Bone mineral density of the femur and vertebra after cast immobilization was significantly decreased compared with both their basal and age-matched control group. After mobilization, significant increases occurred in both groups according to ACIM. Similar but milder changes were observed in free limbs femur BMD of rats. Interestingly, vertebra BMD of swimming group was also higher than its age-matched control group (p<0.05). Our study showed that swimming exercise had a significant rehabilitative effect on BMD loss associated with immobilization. Further studies are needed to investigate the effects of swimming on other bone properties. (author)

An Inductively-Powered Wireless Neural Recording System with a Charge Sampling Analog Front-End.

Science.gov (United States)

Lee, Seung Bae; Lee, Byunghun; Kiani, Mehdi; Mahmoudi, Babak; Gross, Robert; Ghovanloo, Maysam

2016-01-15

An inductively-powered wireless integrated neural recording system (WINeR-7) is presented for wireless and battery less neural recording from freely-behaving animal subjects inside a wirelessly-powered standard homecage. The WINeR-7 system employs a novel wide-swing dual slope charge sampling (DSCS) analog front-end (AFE) architecture, which performs amplification, filtering, sampling, and analog-to-time conversion (ATC) with minimal interference and small amount of power. The output of the DSCS-AFE produces a pseudo-digital pulse width modulated (PWM) signal. A circular shift register (CSR) time division multiplexes (TDM) the PWM pulses to create a TDM-PWM signal, which is fed into an on-chip 915 MHz transmitter (Tx). The AFE and Tx are supplied at 1.8 V and 4.2 V, respectively, by a power management block, which includes a high efficiency active rectifier and automatic resonance tuning (ART), operating at 13.56 MHz. The 8-ch system-on-a-chip (SoC) was fabricated in a 0.35-μm CMOS process, occupying 5.0 × 2.5 mm 2 and consumed 51.4 mW. For each channel, the sampling rate is 21.48 kHz and the power consumption is 19.3 μW. In vivo experiments were conducted on freely behaving rats in an energized homecage by continuously delivering 51.4 mW to the WINeR-7 system in a closed-loop fashion and recording local field potentials (LFP).

Combinatorial Clustering Algorithm of Quantum-Behaved Particle Swarm Optimization and Cloud Model

Directory of Open Access Journals (Sweden)

Mi-Yuan Shan

2013-01-01

Full Text Available We propose a combinatorial clustering algorithm of cloud model and quantum-behaved particle swarm optimization (COCQPSO to solve the stochastic problem. The algorithm employs a novel probability model as well as a permutation-based local search method. We are setting the parameters of COCQPSO based on the design of experiment. In the comprehensive computational study, we scrutinize the performance of COCQPSO on a set of widely used benchmark instances. By benchmarking combinatorial clustering algorithm with state-of-the-art algorithms, we can show that its performance compares very favorably. The fuzzy combinatorial optimization algorithm of cloud model and quantum-behaved particle swarm optimization (FCOCQPSO in vague sets (IVSs is more expressive than the other fuzzy sets. Finally, numerical examples show the clustering effectiveness of COCQPSO and FCOCQPSO clustering algorithms which are extremely remarkable.

Freely floating structures trapping time-harmonic water waves (revisited)

OpenAIRE

Kuznetsov, Nikolay; Motygin, Oleg

2014-01-01

We study the coupled small-amplitude motion of the mechanical system consisting of infinitely deep water and a structure immersed in it. The former is bounded above by a free surface, whereas the latter is formed by an arbitrary finite number of surface-piercing bodies floating freely. The mathematical model of time-harmonic motion is a spectral problem in which the frequency of oscillations serves as the spectral parameter. It is proved that there exist axisymmetric structures consisting of ...

A Review of Freely Available Quantum Computer Simulation Software

OpenAIRE

Brandhorst-Satzkorn, Johan

2012-01-01

A study has been made of a few different freely available Quantum Computer simulators. All the simulators tested are available online on their respective websites. A number of tests have been performed to compare the different simulators against each other. Some untested simulators of various programming languages are included to show the diversity of the quantum computer simulator applications. The conclusion of the review is that LibQuantum is the best of the simulators tested because of ea...

Angiotensin II and CRF Receptors in the Central Nucleus of the Amygdala Mediate Hemodynamic Response Variability to Cocaine in Conscious Rats

OpenAIRE

Watanabe, Mari A.; Kucenas, Sarah; Bowman, Tamara A.; Ruhlman, Melissa; Knuepfer, Mark M.

2009-01-01

Stress or cocaine evokes either a large increase in systemic vascular resistance (SVR) or a smaller increase in SVR accompanied by an increase in cardiac output (designated vascular and mixed responders, respectively) in Sprague-Dawley rats. We hypothesized that the central nucleus of the amygdala (CeA) mediates this variability. Conscious, freely-moving rats, instrumented for measurement of arterial pressure and cardiac output and for drug delivery into the CeA, were given cocaine (5 mg/kg, ...

Concentration of frequencies of trapped waves in problems on freely floating bodies

Energy Technology Data Exchange (ETDEWEB)

Nazarov, Sergei A [Institute of Problems of Mechanical Engineering, Russian Academy of Sciences, St.-Petersburg (Russian Federation)

2012-09-30

It is shown that by choosing the shape of two identical bodies floating freely in a channel with symmetric cross-section it is possible to form any pre-assigned number of linearly independent trapped waves (localized solutions). Bibliography: 27 titles.

Chaos Quantum-Behaved Cat Swarm Optimization Algorithm and Its Application in the PV MPPT

Directory of Open Access Journals (Sweden)

Xiaohua Nie

2017-01-01

Full Text Available Cat Swarm Optimization (CSO algorithm was put forward in 2006. Despite a faster convergence speed compared with Particle Swarm Optimization (PSO algorithm, the application of CSO is greatly limited by the drawback of “premature convergence,” that is, the possibility of trapping in local optimum when dealing with nonlinear optimization problem with a large number of local extreme values. In order to surmount the shortcomings of CSO, Chaos Quantum-behaved Cat Swarm Optimization (CQCSO algorithm is proposed in this paper. Firstly, Quantum-behaved Cat Swarm Optimization (QCSO algorithm improves the accuracy of the CSO algorithm, because it is easy to fall into the local optimum in the later stage. Chaos Quantum-behaved Cat Swarm Optimization (CQCSO algorithm is proposed by introducing tent map for jumping out of local optimum in this paper. Secondly, CQCSO has been applied in the simulation of five different test functions, showing higher accuracy and less time consumption than CSO and QCSO. Finally, photovoltaic MPPT model and experimental platform are established and global maximum power point tracking control strategy is achieved by CQCSO algorithm, the effectiveness and efficiency of which have been verified by both simulation and experiment.

Chaos Quantum-Behaved Cat Swarm Optimization Algorithm and Its Application in the PV MPPT.

Science.gov (United States)

Nie, Xiaohua; Wang, Wei; Nie, Haoyao

2017-01-01

Cat Swarm Optimization (CSO) algorithm was put forward in 2006. Despite a faster convergence speed compared with Particle Swarm Optimization (PSO) algorithm, the application of CSO is greatly limited by the drawback of "premature convergence," that is, the possibility of trapping in local optimum when dealing with nonlinear optimization problem with a large number of local extreme values. In order to surmount the shortcomings of CSO, Chaos Quantum-behaved Cat Swarm Optimization (CQCSO) algorithm is proposed in this paper. Firstly, Quantum-behaved Cat Swarm Optimization (QCSO) algorithm improves the accuracy of the CSO algorithm, because it is easy to fall into the local optimum in the later stage. Chaos Quantum-behaved Cat Swarm Optimization (CQCSO) algorithm is proposed by introducing tent map for jumping out of local optimum in this paper. Secondly, CQCSO has been applied in the simulation of five different test functions, showing higher accuracy and less time consumption than CSO and QCSO. Finally, photovoltaic MPPT model and experimental platform are established and global maximum power point tracking control strategy is achieved by CQCSO algorithm, the effectiveness and efficiency of which have been verified by both simulation and experiment.

Early radiation effects on muscarinic receptor-induced secretory responsiveness of the parotid gland in the freely moving rat

NARCIS (Netherlands)

Coppes, RP; Roffel, AF; Zeilstra, LJW; Vissink, A; Konings, AWT

Although the salivary glands have a low rate of cell turnover, they are relatively radiosensitive. To study the possible mechanism behind this inherent radiosensitivity, a rat model was developed in which saliva can be collected after local irradiation of the parotid gland without the use of

BEHAVE: fire behavior prediction and fuel modeling system-BURN Subsystem, part 1

Science.gov (United States)

Patricia L. Andrews

1986-01-01

Describes BURN Subsystem, Part 1, the operational fire behavior prediction subsystem of the BEHAVE fire behavior prediction and fuel modeling system. The manual covers operation of the computer program, assumptions of the mathematical models used in the calculations, and application of the predictions.

Two-Photon Functional Imaging of the Auditory Cortex in Behaving Mice: From Neural Networks to Single Spines

Directory of Open Access Journals (Sweden)

Ruijie Li

2018-04-01

Full Text Available In vivo two-photon Ca2+ imaging is a powerful tool for recording neuronal activities during perceptual tasks and has been increasingly applied to behaving animals for acute or chronic experiments. However, the auditory cortex is not easily accessible to imaging because of the abundant temporal muscles, arteries around the ears and their lateral locations. Here, we report a protocol for two-photon Ca2+ imaging in the auditory cortex of head-fixed behaving mice. By using a custom-made head fixation apparatus and a head-rotated fixation procedure, we achieved two-photon imaging and in combination with targeted cell-attached recordings of auditory cortical neurons in behaving mice. Using synthetic Ca2+ indicators, we recorded the Ca2+ transients at multiple scales, including neuronal populations, single neurons, dendrites and single spines, in auditory cortex during behavior. Furthermore, using genetically encoded Ca2+ indicators (GECIs, we monitored the neuronal dynamics over days throughout the process of associative learning. Therefore, we achieved two-photon functional imaging at multiple scales in auditory cortex of behaving mice, which extends the tool box for investigating the neural basis of audition-related behaviors.

Prey capture by freely swimming flagellates

Science.gov (United States)

Andersen, Anders; Dolger, Julia; Nielsen, Lasse Tor; Kiorboe, Thomas

2017-11-01

Flagellates are unicellular microswimmers that propel themselves using one or several beating flagella. Here, we explore the dependence of swimming kinematics and prey clearance rate on flagellar arrangement and determine optimal flagellar arrangements and essential trade-offs. To describe near-cell flows around freely swimming flagellates we consider a model in which the cell is represented by a no-slip sphere and each flagellum by a point force. For uniflagellates pulled by a single flagellum the model suggests that a long flagellum favors fast swimming, whereas high clearance rate is favored by a very short flagellum. For biflagellates with both a longitudinal and a transversal flagellum we explore the helical swimming kinematics and the prey capture sites. We compare our predictions with observations of swimming kinematics, prey capture, and flows around common marine flagellates. The Centre for Ocean Life is a VKR Centre of Excellence supported by the Villum Foundation.

Virtual reality for freely moving animals.

Science.gov (United States)

Stowers, John R; Hofbauer, Maximilian; Bastien, Renaud; Griessner, Johannes; Higgins, Peter; Farooqui, Sarfarazhussain; Fischer, Ruth M; Nowikovsky, Karin; Haubensak, Wulf; Couzin, Iain D; Tessmar-Raible, Kristin; Straw, Andrew D

2017-10-01

Standard animal behavior paradigms incompletely mimic nature and thus limit our understanding of behavior and brain function. Virtual reality (VR) can help, but it poses challenges. Typical VR systems require movement restrictions but disrupt sensorimotor experience, causing neuronal and behavioral alterations. We report the development of FreemoVR, a VR system for freely moving animals. We validate immersive VR for mice, flies, and zebrafish. FreemoVR allows instant, disruption-free environmental reconfigurations and interactions between real organisms and computer-controlled agents. Using the FreemoVR platform, we established a height-aversion assay in mice and studied visuomotor effects in Drosophila and zebrafish. Furthermore, by photorealistically mimicking zebrafish we discovered that effective social influence depends on a prospective leader balancing its internally preferred directional choice with social interaction. FreemoVR technology facilitates detailed investigations into neural function and behavior through the precise manipulation of sensorimotor feedback loops in unrestrained animals.

Biological activities caused by far-infrared radiation

Science.gov (United States)

Inoué, Shojiro; Kabaya, Morihiro

1989-09-01

Contrary to previous presumption, accumulated evidence indicates that far-infrared rays are biologically active. A small ceramic disk that emist far-infrared rays (4 16 μm) has commonly been applied to a local spot or a whole part of the body for exposure. Pioneering attempts to experimentally analyze an effect of acute and chronic radiation of far-infrared rays on living organisms have detected a growth-promoting effect in growing rats, a sleep-modulatory effect in freely behaving rats and an insomiac patient, and a blood circulation-enhancing effect in human skin. Question-paires to 542 users of far-infrared radiator disks embedded in bedelothes revealed that the majority of the users subjectively evaluated an improvement of their health. These effects on living organisms appear to be non-specifically triggered by an exposure to far-infrared rays, which eventually induce an increase in temperature of the body tissues or, more basically, an elevated motility of body fluids due to decrease in size of water clusters.

Navier-Stokes hydrodynamics of thermal collapse in a freely cooling granular gas.

Science.gov (United States)

Kolvin, Itamar; Livne, Eli; Meerson, Baruch

2010-08-01

We show that, in dimension higher than one, heat diffusion and viscosity cannot arrest thermal collapse in a freely evolving dilute granular gas, even in the absence of gravity. Thermal collapse involves a finite-time blowup of the gas density. It was predicted earlier in ideal, Euler hydrodynamics of dilute granular gases in the absence of gravity, and in nonideal, Navier-Stokes granular hydrodynamics in the presence of gravity. We determine, analytically and numerically, the dynamic scaling laws that characterize the gas flow close to collapse. We also investigate bifurcations of a freely evolving dilute granular gas in circular and wedge-shaped containers. Our results imply that, in general, thermal collapse can only be arrested when the gas density becomes comparable with the close-packing density of grains. This provides a natural explanation to the formation of densely packed clusters of particles in a variety of initially dilute granular flows.

Oxytocin Differentially Affects Sucrose Taking and Seeking in Male and Female Rats

OpenAIRE

Zhou, Luyi; Ghee, Shannon M.; See, Ronald E.; Reichel, Carmela M.

2015-01-01

Oxytocin has a modulatory role in natural and drug reward processes. While the role of oxytocin in pair bonding and reproduction has been extensively studied, sex differences in conditioned and unconditioned behavioral responses to oxytocin treatment have not been fully characterized. Here, we determined whether male and female rats would show similar dose response curves in response to acute oxytocin on measures of locomotor activity, sucrose seeking, and sucrose intake. Male and freely cycl...

Freely Chosen Index Finger Tapping Frequency Is Increased in Repeated Bouts of Tapping.

Science.gov (United States)

Hansen, Ernst Albin; Ebbesen, Brian Duborg; Dalsgaard, Ane; Mora-Jensen, Mark Holten; Rasmussen, Jakob

2015-01-01

Healthy individuals (n = 40) performed index finger tapping at freely chosen frequency during repeated bouts and before and after near-maximal muscle action consisting of 3 intense flexions of the index finger metacarpal phalangeal joint. One experiment showed, unexpectedly, that a bout of tapping increased the tapping frequency in the subsequent bout. Thus, a cumulating increase of 8.2 ± 5.4% (p tapping frequency was still increased in consecutive bouts when rest periods were extended to 20 min. Besides, near-maximal muscle activation, followed by 5 min rest, did not affect the tapping frequency. In conclusion, freely chosen tapping frequency was increased in repeated bouts of tapping, which were separated by 10-20 min rest periods. The observed phenomenon is suggested to be termed repeated bout rate enhancement.

A method for unit recording in the lumbar spinal cord during locomotion of the conscious adult rat

DEFF Research Database (Denmark)

Berg, Rune W; Chen, Ming-Teh; Huang, Hsueh-Chen

2009-01-01

Extracellular recordings from single units in the brain, for example the neocortex, have proven feasible in moving, awake rats, but have not yet been possible in the spinal cord. Single-unit activity during locomotor-like activity in reduced preparations from adult cats and rats have provided...... valuable insights for the development of hypotheses about the organization of functional networks in the spinal cord. However, since reduced preparations could result in spurious conclusions, it is crucial to test these hypotheses in animals that are awake and behaving. Furthermore, unresolved issues...

Studies on the different forms of material reacting with antiinsulin antibodies in the fetal and adult rat

International Nuclear Information System (INIS)

Felix, J.M.; Sutter-Dub, M.T.; Legrele, C.; Reims Univ., 51

1975-01-01

The nature of peak B (MW = 10-12,000, proinsulin) and peak C (MW = 50-100,000, 'big big' insulin) materials detected by the double antibody (DA) procedure in elution profiles of rat sera after Sephadex G 50 or G 100 chromatography (cf. preceding companion paper) is further investigated. Peak B is converted by mild tryptic digestion in an immunoreactive material behaving in rechromatography exactly like insulin monomer. Peak C is less easily detected by the dextran coated charcoal (DCC) method; it resists 8 M urea 37 0 C for 1 hr, is not an artifact due to the complement system; its relative importance is very much reduced in pancreatic extracts or perifusates. Incubation of biologically active 125 I labelled insulin in rat sera results in appearance of labelled material behaving on chromatography like peak C natural material, having the electrophoretic mobility of rat α 1 globulins and albumin, and resisting 8 M urea, acidic pHs and 0.5 M NaCl. Similar incubation in buffer supplemented with bovine albumin results in appearance of a labelled material having the electrophoretic mobility of beef albumin; N-ethyl-maleimide provides against this binding, which might result from (S-S)-(SH) interchanges. Rat α globulins and albumin (but not beef albumin) cross-react with the DA procedure; they do not react with the DCC method. Insulin bound to plasma proteins react with both methods. It is suggested that peak C material, as detected by the DA method in rat serum, consists both of insulin covalently bound to plasma proteins and of certain plasma proteins; the DCC method detects only bound insulin. In streptozotocin treated rats, peak C material persists after the complete disappearance of insulin and proinsulin when detected by the (DA) procedure, but disappears when detected by the DCC procedure. (orig.) [de

Studies on the different forms of material reacting with antiinsulin antibodies in the fetal and adult rat

Energy Technology Data Exchange (ETDEWEB)

Felix, J M; Sutter-Dub, M T; Legrele, C [Reims Univ., 51 (France). Lab. de Physiologie Animale; Reims Univ., 51 (France). Centre de Biologie et de Biochimie du Developpement)

1975-09-01

The nature of peak B (MW = 10-12,000, proinsulin) and peak C (MW = 50-100,000, 'big big' insulin) materials detected by the double antibody (DA) procedure in elution profiles of rat sera after Sephadex G 50 or G 100 chromatography (cf. preceding companion paper) is further investigated. Peak B is converted by mild tryptic digestion in an immunoreactive material behaving in rechromatography exactly like insulin monomer. Peak C is less easily detected by the dextran coated charcoal (DCC) method; it resists 8 M urea 37/sup 0/C for 1 hr, is not an artifact due to the complement system; its relative importance is very much reduced in pancreatic extracts or perifusates. Incubation of biologically active /sup 125/I labelled insulin in rat sera results in appearance of labelled material behaving on chromatography like peak C natural material, having the electrophoretic mobility of rat ..cap alpha../sub 1/ globulins and albumin, and resisting 8 M urea, acidic pHs and 0.5 M NaCl. Similar incubation in buffer supplemented with bovine albumin results in appearance of a labelled material having the electrophoretic mobility of beef albumin; N-ethyl-maleimide provides against this binding, which might result from (S-S)-(SH) interchanges. Rat ..cap alpha.. globulins and albumin (but not beef albumin) cross-react with the DA procedure; they do not react with the DCC method. Insulin bound to plasma proteins react with both methods. It is suggested that peak C material, as detected by the DA method in rat serum, consists both of insulin covalently bound to plasma proteins and of certain plasma proteins; the DCC method detects only bound insulin. In streptozotocin treated rats, peak C material persists after the complete disappearance of insulin and proinsulin when detected by the (DA) procedure, but disappears when detected by the DCC procedure.

Water-avoidance stress enhances gastric contractions in freely moving conscious rats: role of peripheral CRF receptors.

Science.gov (United States)

Nozu, Tsukasa; Kumei, Shima; Takakusaki, Kaoru; Okumura, Toshikatsu

2014-05-01

Stress alters gastrointestinal motility through central and peripheral corticotropin-releasing factor (CRF) pathways. Accumulating evidence has demonstrated that peripheral CRF is deeply involved in the regulation of gastric motility, and enhances gastric contractions through CRF receptor type 1 (CRF1) and delays gastric emptying (GE) through CRF receptor type 2 (CRF2). Since little is known whether water-avoidance stress (WAS) alters gastric motility, the present study tried to clarify this question and the involvement of peripheral CRF receptor subtypes in the mechanisms. We recorded intraluminal gastric pressure waves using a perfused manometric method. The rats were anesthetized and the manometric catheter was inserted into the stomach 4-6 days before the experiments. We assessed the area under the manometric trace as the motor index (MI), and compared this result with those obtained 1 h before and after initiation of WAS in nonfasted conscious rats. Solid GE for 1 h was also measured. WAS significantly increased gastric contractions. Intraperitoneal (ip) administration of astressin (100 μg/kg, 5 min prior to stress), a nonselective CRF antagonist, blocked the response to WAS. On the other hand, pretreatment (5 min prior to stress) with neither astressin2-B (200 μg/kg, ip), a selective CRF2 antagonist, nor urocortin 2 (30 μg/kg, ip), a selective CRF2 agonist, modified the response to WAS. These drugs did not alter the basal MI. WAS did not change GE. WAS may activate peripheral CRF1 but not CRF2 signaling and stimulates gastric contractions without altering GE.

Evolving Models of Pavlovian Conditioning: Cerebellar Cortical Dynamics in Awake Behaving Mice

Directory of Open Access Journals (Sweden)

Michiel M. ten Brinke

2015-12-01

Full Text Available Three decades of electrophysiological research on cerebellar cortical activity underlying Pavlovian conditioning have expanded our understanding of motor learning in the brain. Purkinje cell simple spike suppression is considered to be crucial in the expression of conditional blink responses (CRs. However, trial-by-trial quantification of this link in awake behaving animals is lacking, and current hypotheses regarding the underlying plasticity mechanisms have diverged from the classical parallel fiber one to the Purkinje cell synapse LTD hypothesis. Here, we establish that acquired simple spike suppression, acquired conditioned stimulus (CS-related complex spike responses, and molecular layer interneuron (MLI activity predict the expression of CRs on a trial-by-trial basis using awake behaving mice. Additionally, we show that two independent transgenic mouse mutants with impaired MLI function exhibit motor learning deficits. Our findings suggest multiple cerebellar cortical plasticity mechanisms underlying simple spike suppression, and they implicate the broader involvement of the olivocerebellar module within the interstimulus interval.

Assessment of Mining Extent and Expansion in Myanmar Based on Freely-Available Satellite Imagery

Directory of Open Access Journals (Sweden)

Katherine J. LaJeunesse Connette

2016-11-01

Full Text Available Using freely-available data and open-source software, we developed a remote sensing methodology to identify mining areas and assess recent mining expansion in Myanmar. Our country-wide analysis used Landsat 8 satellite data from a select number of mining areas to create a raster layer of potential mining areas. We used this layer to guide a systematic scan of freely-available fine-resolution imagery, such as Google Earth, in order to digitize likely mining areas. During this process, each mining area was assigned a ranking indicating our certainty in correct identification of the mining land use. Finally, we identified areas of recent mining expansion based on the change in albedo, or brightness, between Landsat images from 2002 and 2015. We identified 90,041 ha of potential mining areas in Myanmar, of which 58% (52,312 ha was assigned high certainty, 29% (26,251 ha medium certainty, and 13% (11,478 ha low certainty. Of the high-certainty mining areas, 62% of bare ground was disturbed (had a large increase in albedo since 2002. This four-month project provides the first publicly-available database of mining areas in Myanmar, and it demonstrates an approach for large-scale assessment of mining extent and expansion based on freely-available data.

Cocaine action on peripheral, non-monoamine neural substrates as a trigger of electroencephalographic desynchronization and electromyographic activation following i.v. administration in freely moving rats.

Science.gov (United States)

Smirnov, M S; Kiyatkin, E A

2010-01-20

Many important physiological, behavioral and subjective effects of i.v. cocaine (COC) are exceptionally rapid and transient, suggesting a possible involvement of peripheral neural substrates in their triggering. In the present study, we used high-speed electroencephalographic (EEG) and electromyographic (EMG) recordings (4-s resolution) in freely moving rats to characterize the central electrophysiological effects of i.v. COC at low doses within a self-administration range (0.25-1.0 mg/kg). We found that COC induces rapid, strong, and prolonged desynchronization of cortical EEG (decrease in alpha and increase in beta and gamma activity) and activation of the neck EMG that begin within 2-6 s following the start of a 10-s injection; immediate components of both effects were dose-independent. The rapid effects of COC were mimicked by i.v. COC methiodide (COC-MET), a derivative that cannot cross the blood-brain barrier. At equimolar doses (0.33-1.33 mg/kg), COC-MET had equally fast and strong effects on EEG and EMG total powers, decreasing alpha and increasing beta and gamma activities. Rapid EEG desynchronization and EMG activation was also induced by i.v. procaine, a structurally similar, short-acting local anesthetic with virtually no effects on monoamine uptake; at equipotential doses (1.25-5.0 mg/kg), these effects were weaker and shorter in duration than those of COC. Surprisingly, i.v. saline injection delivered during slow-wave sleep (but not during quiet wakefulness) also induced a transient EEG desynchronization but without changes in EMG and motor activity; these effects were significantly weaker and much shorter than those induced by all tested drugs. These data suggest that in awake animals, i.v. COC induces rapid cortical activation and a subsequent motor response via its action on peripheral non-monoamine neural elements, involving neural transmission via visceral sensory pathways. By providing a rapid neural signal and triggering neural activation, such

An Abstract Coalgebraic Approach to Process Equivalence for Well- Behaved Operational Semantics

DEFF Research Database (Denmark)

Klin, Bartek

This thesis is part of the programme aimed at finding a mathematical theory of well-behaved structural operational semantics. General and basic results shown in 1997 in a seminal paper by Turi and Plotkin are extended in two directions, aiming at greater expressivity of the framework. The so-call...

Effect of whole-body gamma radiation on tissue sulfhydryl contents in experimental rats

International Nuclear Information System (INIS)

Sarkar, S.R.; Singh, L.R.; Uniyal, B.P.

1985-01-01

It has been postulated that vital constituents of cell membranes concerned with the maintenance of cellular integrity are affected by ionizing radiation. Sulfhydryl contents, which form an integral component of cell membranes play vital roles in maintaining cellular integrity. The purpose was to evaluate non-protein and protein sulfhydryl contents in tissues of irradiated rats. Adult male Sprague Dawley rats were exposed to whole-body gamma irradiation of 4 Gy and 10 Gy and non-protein and protein sulfhydryl contents of blood, heart and spleen were studied on postirradiation day 1, 3 and 6. Both groups of experimental rats exhibited unchanged blood non-protein sulfhydryl contents on first day after irradiation with significant diminution subsequently. In contrast, blood protein sulfhydryl groups of both groups of rats were increased on first day post exposure, which became normal on sixth day. Myocardial non-protein and protein sulfhydryl contents of both groups of rats remained unchanged in the initial stage of radiation exposure indicating radioresistance nature of rat heart. Both groups of rats demonstrated biphasic nature of non-protein sulfhydryl contents in spleen, asrevealed by initial increase with subsequent decrease. Protein sulfhydryl contents of rats of 4 Gy group showed significant diminution post exposure throughout, while the same of 10 Gy behaved in opposite way. (author)

Intra-accumbens baclofen, but not muscimol, increases second order instrumental responding for food reward in rats.

Directory of Open Access Journals (Sweden)

Kim G T Pulman

Full Text Available Stimulation of either GABA(A or GABA(B receptors within the nucleus accumbens shell strongly enhances food intake in rats. However the effects of subtype-selective stimulation of GABA receptors on instrumental responses for food reward are less well characterized. Here we contrast the effects of the GABA(A receptor agonist muscimol and GABA(B receptor agonist baclofen on instrumental responding for food using a second order reinforcement schedule. Bilateral intra-accumbens administration of baclofen (220-440 pmol stimulated responding but a higher dose (660 pmol induced stereotyped oral behaviour that interfered with responding. Baclofen (220-660 pmol also stimulated intake of freely available chow. Muscimol (220-660 pmol was without effect on responding for food on this schedule but did stimulate intake of freely available chow. Unilateral administration of either baclofen or muscimol (220 pmol induced similar patterns of c-fos immunoreactivity in several hypothalamic sites but differed in its induction in the central nucleus of the amygdala. We conclude that stimulation of GABA(A or GABA(B receptors in the nucleus accumbens shell of rats produces clearly distinguishable effects on operant responding for food.

Intra-accumbens baclofen, but not muscimol, increases second order instrumental responding for food reward in rats.

Science.gov (United States)

Pulman, Kim G T; Somerville, Elizabeth M; Clifton, Peter G

2012-01-01

Stimulation of either GABA(A) or GABA(B) receptors within the nucleus accumbens shell strongly enhances food intake in rats. However the effects of subtype-selective stimulation of GABA receptors on instrumental responses for food reward are less well characterized. Here we contrast the effects of the GABA(A) receptor agonist muscimol and GABA(B) receptor agonist baclofen on instrumental responding for food using a second order reinforcement schedule. Bilateral intra-accumbens administration of baclofen (220-440 pmol) stimulated responding but a higher dose (660 pmol) induced stereotyped oral behaviour that interfered with responding. Baclofen (220-660 pmol) also stimulated intake of freely available chow. Muscimol (220-660 pmol) was without effect on responding for food on this schedule but did stimulate intake of freely available chow. Unilateral administration of either baclofen or muscimol (220 pmol) induced similar patterns of c-fos immunoreactivity in several hypothalamic sites but differed in its induction in the central nucleus of the amygdala. We conclude that stimulation of GABA(A) or GABA(B) receptors in the nucleus accumbens shell of rats produces clearly distinguishable effects on operant responding for food.

A wireless recording system that utilizes Bluetooth technology to transmit neural activity in freely moving animals

Science.gov (United States)

Hampson, Robert E.; Collins, Vernell; Deadwyler, Sam A.

2009-01-01

A new wireless transceiver is described for recording individual neuron firing from behaving rats utilizing Bluetooth transmission technology and a processor onboard for discrimination of neuronal waveforms and associated time stamps. This universal brain activity transmitter (UBAT) is attached to rodents via a backpack and amplifier headstage and can transmit 16 channels of captured neuronal firing data via a Bluetooth transceiver chip over very large and unconstrained distances. The onboard microprocessor of the UBAT allows flexible online control over waveform isolation criteria via transceiver instruction and the two-way communication capacity allows for closed-loop applications between neural events and behavioral or physiological processes which can be modified by transceiver instructions. A detailed description of the multiplexer processing of channel data as well as examples of neuronal recordings in different behavioral testing contexts is provided to demonstrate the capacity for robust transmission within almost any laboratory environment. A major advantage of the UBAT is the long transmission range and lack of object-based line of sight interference afforded by Bluetooth technology, allowing flexible recording capabilities within multiple experimental paradigms without interruption. Continuous recordings over very large distance separations from the monitor station are demonstrated providing experimenters with recording advantages not previously available with other telemetry devices. PMID:19524612

A wireless recording system that utilizes Bluetooth technology to transmit neural activity in freely moving animals.

Science.gov (United States)

Hampson, Robert E; Collins, Vernell; Deadwyler, Sam A

2009-09-15

A new wireless transceiver is described for recording individual neuron firing from behaving rats utilizing Bluetooth transmission technology and a processor onboard for discrimination of neuronal waveforms and associated time stamps. This universal brain activity transmitter (UBAT) is attached to rodents via a backpack and amplifier headstage and can transmit 16 channels of captured neuronal firing data via a Bluetooth transceiver chip over very large and unconstrained distances. The onboard microprocessor of the UBAT allows flexible online control over waveform isolation criteria via transceiver instruction and the two-way communication capacity allows for closed-loop applications between neural events and behavioral or physiological processes which can be modified by transceiver instructions. A detailed description of the multiplexer processing of channel data as well as examples of neuronal recordings in different behavioral testing contexts is provided to demonstrate the capacity for robust transmission within almost any laboratory environment. A major advantage of the UBAT is the long transmission range and lack of object-based line of sight interference afforded by Bluetooth technology, allowing flexible recording capabilities within multiple experimental paradigms without interruption. Continuous recordings over very large distance separations from the monitor station are demonstrated providing experimenters with recording advantages not previously available with other telemetry devices.

Naltrexone potentiates 4-aminopyridine seizures in the rat.

Science.gov (United States)

Mihály, A; Bencsik, K; Solymosi, T

1990-01-01

The effects of a pharmacological blockade of the mu opiate receptors on the manifestation of tonic-clonic seizures were investigated in freely moving animals. 4-aminopyridine, a specific blocker of the neuronal K+ channels was used to produce generalized convulsions. After pretreatment of adult rats with 1 mg/kg naltrexone HCl, 3, 5, 7, 9, 14 mg/kg 4-aminopyridine was injected intraperitoneally, and the latencies of the symptoms generated by 4-aminopyridine were measured. Naltrexone HCl decreased these latencies and enhanced the seizures significantly. The experiments provided further evidence for the existence of a tonic anticonvulsant opioid system in the brain.

Effects of dissolved organic matter from a eutrophic lake on the freely dissolved concentrations of emerging organic contaminants.

Science.gov (United States)

Xiao, Yi-Hua; Huang, Qing-Hui; Vähätalo, Anssi V; Li, Fei-Peng; Chen, Ling

2014-08-01

The authors studied the effects of dissolved organic matter (DOM) on the bioavailability of bisphenol A (BPA) and chloramphenicol by measuring the freely dissolved concentrations of the contaminants in solutions containing DOM that had been isolated from a mesocosm in a eutrophic lake. The abundance and aromaticity of the chromophoric DOM increased over the 25-d mesocosm experiment. The BPA freely dissolved concentration was 72.3% lower and the chloramphenicol freely dissolved concentration was 56.2% lower using DOM collected on day 25 than using DOM collected on day 1 of the mesocosm experiment. The freely dissolved concentrations negatively correlated with the ultraviolent absorption coefficient at 254 nm and positively correlated with the spectral slope of chromophoric DOM, suggesting that the bioavailability of these emerging organic contaminants depends on the characteristics of the DOM present. The DOM-water partition coefficients (log KOC ) for the emerging organic contaminants positively correlated with the aromaticity of the DOM, measured as humic acid-like fluorescent components C1 (excitation/emission=250[313]/412 nm) and C2 (excitation/emission=268[379]/456 nm). The authors conclude that the bioavailability of emerging organic contaminants in eutrophic lakes can be affected by changes in the DOM. © 2014 SETAC.

An Adaptive Cultural Algorithm with Improved Quantum-behaved Particle Swarm Optimization for Sonar Image Detection.

Science.gov (United States)

Wang, Xingmei; Hao, Wenqian; Li, Qiming

2017-12-18

This paper proposes an adaptive cultural algorithm with improved quantum-behaved particle swarm optimization (ACA-IQPSO) to detect the underwater sonar image. In the population space, to improve searching ability of particles, iterative times and the fitness value of particles are regarded as factors to adaptively adjust the contraction-expansion coefficient of the quantum-behaved particle swarm optimization algorithm (QPSO). The improved quantum-behaved particle swarm optimization algorithm (IQPSO) can make particles adjust their behaviours according to their quality. In the belief space, a new update strategy is adopted to update cultural individuals according to the idea of the update strategy in shuffled frog leaping algorithm (SFLA). Moreover, to enhance the utilization of information in the population space and belief space, accept function and influence function are redesigned in the new communication protocol. The experimental results show that ACA-IQPSO can obtain good clustering centres according to the grey distribution information of underwater sonar images, and accurately complete underwater objects detection. Compared with other algorithms, the proposed ACA-IQPSO has good effectiveness, excellent adaptability, a powerful searching ability and high convergence efficiency. Meanwhile, the experimental results of the benchmark functions can further demonstrate that the proposed ACA-IQPSO has better searching ability, convergence efficiency and stability.

Recombinase-driver rat lines: tools, techniques, and optogenetic application to dopamine-mediated reinforcement.

Science.gov (United States)

Witten, Ilana B; Steinberg, Elizabeth E; Lee, Soo Yeun; Davidson, Thomas J; Zalocusky, Kelly A; Brodsky, Matthew; Yizhar, Ofer; Cho, Saemi L; Gong, Shiaoching; Ramakrishnan, Charu; Stuber, Garret D; Tye, Kay M; Janak, Patricia H; Deisseroth, Karl

2011-12-08

Currently there is no general approach for achieving specific optogenetic control of genetically defined cell types in rats, which provide a powerful experimental system for numerous established neurophysiological and behavioral paradigms. To overcome this challenge we have generated genetically restricted recombinase-driver rat lines suitable for driving gene expression in specific cell types, expressing Cre recombinase under the control of large genomic regulatory regions (200-300 kb). Multiple tyrosine hydroxylase (Th)::Cre and choline acetyltransferase (Chat)::Cre lines were produced that exhibited specific opsin expression in targeted cell types. We additionally developed methods for utilizing optogenetic tools in freely moving rats and leveraged these technologies to clarify the causal relationship between dopamine (DA) neuron firing and positive reinforcement, observing that optical stimulation of DA neurons in the ventral tegmental area (VTA) of Th::Cre rats is sufficient to support vigorous intracranial self-stimulation (ICSS). These studies complement existing targeting approaches by extending the generalizability of optogenetics to traditionally non-genetically-tractable but vital animal models. Copyright © 2011 Elsevier Inc. All rights reserved.

Columnar transmitter based wireless power delivery system for implantable device in freely moving animals.

Science.gov (United States)

Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Lee, Sung Eun; Jun, Sang Bum; Kim, Sung June

2013-01-01

A wireless power delivery system is developed to deliver electrical power to the neuroprosthetic devices that are implanted into animals freely moving inside the cage. The wireless powering cage is designed for long-term animal experiments without cumbersome wires for power supply or the replacement of batteries. In the present study, we propose a novel wireless power transmission system using resonator-based inductive links to increase power efficiency and to minimize the efficiency variations. A columnar transmitter coil is proposed to provide lateral uniformity of power efficiency. Using this columnar transmitter coil, only 7.2% efficiency fluctuation occurs from the maximum transmission efficiency of 25.9%. A flexible polymer-based planar type receiver coil is fabricated and assembled with a neural stimulator and an electrode. Using the designed columnar transmitter coil, the implantable device successfully operates while it moves freely inside the cage.

Sensory and cognitive neurophysiology in rats, Part 1: Controlled tactile stimulation and micro-ECoG recordings in freely moving animals

NARCIS (Netherlands)

Dimitriadis, G.; Fransen, A.M.M.; Maris, E.G.G.

2014-01-01

Background: We have developed a setup for rats that allows for controlled sensory input to an animal engaged in a task while recording both electrophysiological signals and behavioral output. New method: We record electrophysiological signals using a novel high-density micro-electrocorticography

Passive sampling methods for contaminated sediments: Scientific rationale supporting use of freely dissolved concentrations

DEFF Research Database (Denmark)

Mayer, Philipp; Parkerton, Thomas F.; Adams, Rachel G.

2014-01-01

Passive sampling methods (PSMs) allow the quantification of the freely dissolved concentration (Cfree ) of an organic contaminant even in complex matrices such as sediments. Cfree is directly related to a contaminant's chemical activity, which drives spontaneous processes including diffusive upta...

Vibration transmission characteristics of the legs of freely standing honeybees

DEFF Research Database (Denmark)

Rohrseitz, Kristin; Kilpinen, Ole

1997-01-01

as the stimulator. This was also the case in freely standing honeybees, except around 400 Hz, where an average attenuation of approximately 6 dB was observed. In the fixed bee preparation, the vertical movements of the legs were also measured during horizontal stimulation. The vertical vibration amplitude...... of the legs was 15-20 dB lower than the horizontal stimulation amplitude. The electrophysiologically and behaviourally determined thresholds for vibration stimulation increased by approximately 10 dB, when the stimulus direction was changed from vertical to horizontal. These observations support the notion...

The diffusion permeability to water of the rat blood-brain barrier

DEFF Research Database (Denmark)

Bolwig, T G; Lassen, N A

1975-01-01

The diffusion permeability to water of the rat blood-brain-barrier (BBB) was studied. Preliminary data obtained with the Oldendorf tissue uptake method (Oldendorf 1970) in seizure experiments suggested that the transfer from blood to brain of labelled water is diffusion-limited. More definite...... passage increased from 0.26 to 0.67 when the arterial carbon dioxide tension was changed from 15 to 85 mm Hg, a change increasing the cerebral blood flow about sixfold. This finding suggests that water does not pass the blood-brain barrier as freely as lipophilic gases....

Dynamic changes in extracellular release of GABA and glutamate in the lateral septum during social play behavior in juvenile rats: Implications for sex-specific regulation of social play behavior

Science.gov (United States)

Bredewold, Remco; Schiavo, Jennifer K.; van der Hart, Marieke; Verreij, Michelle; Veenema, Alexa H.

2015-01-01

Social play is a motivated and rewarding behavior that is displayed by nearly all mammals and peaks in the juvenile period. Moreover, social play is essential for the development of social skills and is impaired in social disorders like autism. We recently showed that the lateral septum (LS) is involved in the regulation of social play behavior in juvenile male and female rats. The LS is largely modulated by GABA and glutamate neurotransmission, but their role in social play behavior is unknown. Here, we determined whether social play behavior is associated with changes in the extracellular release of GABA and glutamate in the LS and to what extent such changes modulate social play behavior in male and female juvenile rats. Using intracerebral microdialysis in freely behaving rats, we found no sex difference in extracellular GABA concentrations, but extracellular glutamate concentrations are higher in males than in females under baseline condition and during social play. This resulted in a higher glutamate/GABA concentration ratio in males versus females and thus, an excitatory predominance in the LS of males. Furthermore, social play behavior in both sexes is associated with significant increases in extracellular release of GABA and glutamate in the LS. Pharmacological blockade of GABA-A receptors in the LS with bicuculline (100 ng/0.5 µl, 250 ng/0.5 µl) dose-dependently decreased the duration of social play behavior in both sexes. In contrast, pharmacological blockade of ionotropic glutamate receptors (NMDA and AMPA/kainate receptors) in the LS with AP-5 + CNQX (2 mM+0.4 mM/0.5 µl, 30 mM+3 mM/0.5 µl) dose-dependently decreased the duration of social play behavior in females, but did not alter social play behavior in males. Together, these data suggest a role for GABA neurotransmission in the LS in the regulation of juvenile social play behavior in both sexes, while glutamate neurotransmission in the LS is involved in the sex-specific regulation of juvenile

Effect of chain wheel shape on crank torque, freely chosen pedal rate, and physiological responses during submaximal cycling

DEFF Research Database (Denmark)

Hansen, Ernst Albin; Jensen, Kurt; Hallen, Jostein

2009-01-01

at preset pedal rates as well as resulting in lower pedal rate and metabolic response at freely chosen pedal rate. Ten trained cyclists (mean+/-SD: 27+/-3 years of age, 182+/-4 cm tall, 77.5+/-7.0 kg of body mass, and peak oxygen uptake of 61.7+/-4.4 ml kg(-1) min(-1)) cycled with a Biopace and a circular...... chain wheel at 180 W at 65 and 90 rpm for recording of crank torque profiles, and at their freely chosen pedal rate for recording of pedal rate and metabolic response, including oxygen uptake and blood lactate concentration. Crank torque profiles were similar between the two chain wheels during cycling...... at preset pedal rates. During cycling at the freely chosen pedal rate (being 93+/-6 and 93+/-4 rpm for the Biopace and circular chain wheel, respectively), blood lactate concentration was significantly different between the two chain wheels, being on average 0.2 mmol l(-1) lower with the Biopace chain wheel...

NR2B antagonist CP-101,606 abolishes pitch-mediated deviance detection in awake rats

Directory of Open Access Journals (Sweden)

Siva eDigavalli

2014-08-01

Full Text Available Schizophrenia patients exhibit a decreased ability to detect change in their auditory environment as measured by auditory event related potentials such as mismatch negativity. This deficit has been linked to abnormal NMDA neurotransmission since, among other observations, non-selective channel blockers of NMDA reliably diminish deviance detection in human subjects as well as in animal models. Recent molecular and functional evidence link NR2B receptor subtype to aberrant NMDA transmission in schizophrenia. However, it is unknown if NR2B receptors participate in pre-attentive deviance detection. We recorded event related potentials from the vertex of freely behaving rats in response to frequency mismatch protocols. We saw a robust increase in N1 response to deviants compared to standard as well as control stimuli indicating true deviance detection. Moreover, the increased negativity was highly sensitive to deviant probability. Next, we tested the effect of a non-selective NMDA channel blocker (ketamine, 30 mg/kg and a highly selective NR2B antagonist, CP-101,606 (10 or 30 mg/kg on deviance detection. Ketamine attenuated deviance mainly by increasing the amplitude of the standard ERP. Amplitude and/or latency of several ERP components were also markedly affected. In contrast, CP-101,606 robustly and dose-dependently inhibited the deviant’s N1 amplitude and as a consequence, completely abolished deviance detection. No other ERPs or components were affected. Thus, we report first evidence that NR2B receptors robustly participate in processes of automatic deviance detection in a rodent model. Lastly, our model demonstrates a path forward to test specific pharmacological hypotheses using translational endpoints relevant to aberrant sensory processing in schizophrenia.

Physiological Fluctuations in Brain Temperature as a Factor Affecting Electrochemical Evaluations of Extracellular Glutamate and Glucose in Behavioral Experiments

Science.gov (United States)

2013-01-01

The rate of any chemical reaction or process occurring in the brain depends on temperature. While it is commonly believed that brain temperature is a stable, tightly regulated homeostatic parameter, it fluctuates within 1–4 °C following exposure to salient arousing stimuli and neuroactive drugs, and during different behaviors. These temperature fluctuations should affect neural activity and neural functions, but the extent of this influence on neurochemical measurements in brain tissue of freely moving animals remains unclear. In this Review, we present the results of amperometric evaluations of extracellular glutamate and glucose in awake, behaving rats and discuss how naturally occurring fluctuations in brain temperature affect these measurements. While this temperature contribution appears to be insignificant for glucose because its extracellular concentrations are large, it is a serious factor for electrochemical evaluations of glutamate, which is present in brain tissue at much lower levels, showing smaller phasic fluctuations. We further discuss experimental strategies for controlling the nonspecific chemical and physical contributions to electrochemical currents detected by enzyme-based biosensors to provide greater selectivity and reliability of neurochemical measurements in behaving animals. PMID:23448428

Critical evaluation of colon submucosal microdialysis in awake, mobile rats.

Directory of Open Access Journals (Sweden)

Norbert Cibicek

Full Text Available Sensors able to record large bowel physiology and biochemistry in situ in awake rodents are lacking. Microdialysis is a mini-invasive technique that may be utilized to continuously deliver or recover low-molecular substances from various tissues. In this experiment we evaluated the feasibility of in vivo microdialysis to monitor extracellular fluid chemistry in the descending colon submucosa of conscious, freely moving rodents. Following surgical implantation of a microdialysis probe, male Wistar rats were housed in metabolic cages where they were analgized and clinically followed for four days with free access to standard diet and water. To assess local microcirculation and probe function, glucose, lactate, glucose-to-lactate ratio and urea clearance were determined in the dialysates from the three postoperative days with focus on the final 24-h period. In an attempt to mitigate the expected tissue inflammatory response, one group of animals had the catheters perfused with 5-aminosalicylic acid-enriched medium with final concentration 1 μmol/L. For verification of probe position and the assessment of the surrounding foreign body reaction, standard histological and immunohistochemical methods were employed. Microdialysis of rat gut is associated with considerable technical challenges that may lead to the loss of probe function and high drop-out rate. In this setting, limited data did not allow to draw any firm conclusion regarding local anti-inflammatory effectiveness of 5-aminosalicylic acid perfusion. Although intestinal microdialysis may be suitable for larger anesthetized animals, low reproducibility of the presented method compromises its routine experimental use in awake and freely moving small-sized rodents.

Downhole instrument including a flexible probe which can travel freely around bends in a borehole

International Nuclear Information System (INIS)

Dickinson III, B. W. O.

1985-01-01

Bore hole instrument and methods of manufacturing and using the same. The instrument includes an elongated flexible probe which is inserted into a bore hole and can travel freely around bends of relatively short radius in the hole. The probe includes a plurality of sensors, explosive charges or the like which are spaced apart and embedded in a flexible body comprising a mass of cushioning material, with a flexible outer casing of fabric having a high tensile strength. The probe is driven into a bore hole in piston-like fashion, and the flexible body enables the probe to travel freely around bends of relatively short radius. Instrumentation for processing signals from the probe is located at the surface of the earth, and a flexible cable interconnects the instrumentation with the probe

Differential effects of centrally-active antihypertensives on 5-HT1A receptors in rat dorso-lateral septum, rat hippocampus and guinea-pig hippocampus.

Science.gov (United States)

Leishman, D J; Boeijinga, P H; Galvan, M

1994-01-01

1. The electrophysiological responses elicited by 5-hydroxytryptamine1A-(5-HT1A) receptor agonists in rat and guinea-pig CA1 pyramidal neurones and rat dorso-lateral septal neurones were compared in vitro by use of conventional intracellular recording techniques. 2. In the presence of 1 microM tetrodotoxin (TTX), to prevent indirect effects, 5-HT, N,N-dipropyl-5-carboxamidotryptamine (DP-5-CT) and 8-hydroxy-2(di-n-propylamino) tetralin (8-OH-DPAT) hyperpolarized the neurones from rat and guinea-pig brain. 3. The hypotensive drug flesinoxan, a selective 5-HT1A receptor agonist, hyperpolarized neurones in all three areas tested; however, another hypotensive agent with high affinity at 5-HT1A-receptors, 5-methyl-urapidil, hyperpolarized only the neurones in rat hippocampus and septum. 4. In guinea-pig hippocampal neurones, 5-methyl-urapidil behaved as a 5-HT1A-receptor antagonist. 5. The relative efficacies (5-HT = 1) of DP-5-CT, 8-OH-DPAT, flesinoxan and 5-methyl-urapidil at the three sites were: rat hippocampus, 1.09, 0.7, 0.5 and 0.24; rat septum, 0.88, 0.69, 0.82 and 0.7; guinea-pig hippocampus, 1.0, 0.69, 0.89 and 0, respectively. 6. It is concluded that the hypotensive agents flesinoxan and 5-methyl-urapidil appear to have different efficacies at 5-HT1A receptors located in different regions of the rodent brain. Whether these regional and species differences arise from receptor plurality or variability in intracellular transduction mechanisms remains to be elucidated.

Flutter instability of freely hanging articulated pipes conveying fluid

Science.gov (United States)

Schouveiler, Lionel; Chermette, Félix

2018-03-01

We experimentally investigate the stability of freely hanging articulated pipes made of rigid segments connected by flexible joints and with their displacements constrained in a vertical plane. When the velocity of the fluid conveyed by the pipe is increased, flutter-type instability occurs above a critical value. The critical velocity and the characteristics of the flutter modes (frequency, amplitude, and shape) are determined as a function of the number n of segments into the pipe which is varied from 2 to 5. Experimental results are compared to predictions from linear stability analysis extending previous studies by taking into account damping due to the dissipation in the joints. Qualitative agreement is found and the limits of the analysis are discussed.

Implanting Glioblastoma Spheroids into Rat Brains and Monitoring Tumor Growth by MRI Volumetry.

Science.gov (United States)

Löhr, Mario; Linsenmann, Thomas; Jawork, Anna; Kessler, Almuth F; Timmermann, Nils; Homola, György A; Ernestus, Ralf-Ingo; Hagemann, Carsten

2017-01-01

The outcome of patients suffering from glioblastoma multiforme (GBM) remains poor with a median survival of less than 15 months. To establish innovative therapeutical approaches or to analyze the effect of protein overexpression or protein knockdown by RNA interference in vivo, animal models are mandatory. Here, we describe the implantation of C6 glioma spheroids into the rats' brain and how to follow tumor growth by MRI scans. We show that C6 cells grown in Sprague-Dawley rats share several morphologic features of human glioblastoma like pleomorphic cells, areas of necrosis, vascular proliferation, and tumor cell invasion into the surrounding brain tissue. In addition, we describe a method for tumor volumetry utilizing the CISS 3D- or contrast-enhanced T1-weighted 3D sequence and freely available post-processing software.

Biopython: freely available Python tools for computational molecular biology and bioinformatics

DEFF Research Database (Denmark)

Cock, Peter J A; Antao, Tiago; Chang, Jeffrey T

2009-01-01

SUMMARY: The Biopython project is a mature open source international collaboration of volunteer developers, providing Python libraries for a wide range of bioinformatics problems. Biopython includes modules for reading and writing different sequence file formats and multiple sequence alignments......, dealing with 3D macro molecular structures, interacting with common tools such as BLAST, ClustalW and EMBOSS, accessing key online databases, as well as providing numerical methods for statistical learning. AVAILABILITY: Biopython is freely available, with documentation and source code at (www...

An Improved Quantum-Behaved Particle Swarm Optimization Algorithm with Elitist Breeding for Unconstrained Optimization.

Science.gov (United States)

Yang, Zhen-Lun; Wu, Angus; Min, Hua-Qing

2015-01-01

An improved quantum-behaved particle swarm optimization with elitist breeding (EB-QPSO) for unconstrained optimization is presented and empirically studied in this paper. In EB-QPSO, the novel elitist breeding strategy acts on the elitists of the swarm to escape from the likely local optima and guide the swarm to perform more efficient search. During the iterative optimization process of EB-QPSO, when criteria met, the personal best of each particle and the global best of the swarm are used to generate new diverse individuals through the transposon operators. The new generated individuals with better fitness are selected to be the new personal best particles and global best particle to guide the swarm for further solution exploration. A comprehensive simulation study is conducted on a set of twelve benchmark functions. Compared with five state-of-the-art quantum-behaved particle swarm optimization algorithms, the proposed EB-QPSO performs more competitively in all of the benchmark functions in terms of better global search capability and faster convergence rate.

Mass and heat transfer between a fluidized bed and a freely moving submerged sphere

NARCIS (Netherlands)

Prins, W.; Valk, M.

1995-01-01

For fluidized bed combustion and gasification of solid fuels, but also for various other fluidized bed processes such as drying, granulation and evaporation, mass and heat transport to (or from) a particle freely moving in the fluidized bed is of great importance. The combustion rate of a

OptoZIF Drive: a 3D printed implant and assembly tool package for neural recording and optical stimulation in freely moving mice

Science.gov (United States)

Freedman, David S.; Schroeder, Joseph B.; Telian, Gregory I.; Zhang, Zhengyang; Sunil, Smrithi; Ritt, Jason T.

2016-12-01

Objective. Behavioral neuroscience studies in freely moving rodents require small, light-weight implants to facilitate neural recording and stimulation. Our goal was to develop an integrated package of 3D printed parts and assembly aids for labs to rapidly fabricate, with minimal training, an implant that combines individually positionable microelectrodes, an optical fiber, zero insertion force (ZIF-clip) headstage connection, and secondary recording electrodes, e.g. for electromyography (EMG). Approach. Starting from previous implant designs that position recording electrodes using a control screw, we developed an implant where the main drive body, protective shell, and non-metal components of the microdrives are 3D printed in parallel. We compared alternative shapes and orientations of circuit boards for electrode connection to the headstage, in terms of their size, weight, and ease of wire insertion. We iteratively refined assembly methods, and integrated additional assembly aids into the 3D printed casing. Main results. We demonstrate the effectiveness of the OptoZIF Drive by performing real time optogenetic feedback in behaving mice. A novel feature of the OptoZIF Drive is its vertical circuit board, which facilities direct ZIF-clip connection. This feature requires angled insertion of an optical fiber that still can exit the drive from the center of a ring of recording electrodes. We designed an innovative 2-part protective shell that can be installed during the implant surgery to facilitate making additional connections to the circuit board. We use this feature to show that facial EMG in mice can be used as a control signal to lock stimulation to the animal’s motion, with stable EMG signal over several months. To decrease assembly time, reduce assembly errors, and improve repeatability, we fabricate assembly aids including a drive holder, a drill guide, an implant fixture for microelectode ‘pinning’, and a gold plating fixture. Significance. The

Reduced ghrelin secretion in the hypothalamus of rats due to cisplatin-induced anorexia.

Science.gov (United States)

Yakabi, Koji; Sadakane, Chiharu; Noguchi, Masamichi; Ohno, Shino; Ro, Shoki; Chinen, Katsuya; Aoyama, Toru; Sakurada, Tomoya; Takabayashi, Hideaki; Hattori, Tomohisa

2010-08-01

Although chemotherapy with cisplatin is a widely used and effective cancer treatment, the undesirable gastrointestinal side effects associated with it, such as nausea, vomiting, and anorexia, markedly decrease patients' quality of life. To elucidate the mechanism underlying chemotherapy-induced anorexia, focusing on the hypothalamic ghrelin secretion-anorexia association, we measured hypothalamic ghrelin secretion in fasted and cisplatin-treated rats. Hypothalamic ghrelin secretion changes after vagotomy or administration of cisplatin. Cisplatin + rikkunshito, a serotonin 2C receptor antagonist or serotonin 3 receptor antagonist, was investigated. The effects of intracerebroventricular (icv) administration of ghrelin or the serotonin 2C receptor antagonist SB242084 on food intake were also evaluated in cisplatin-treated rats. Hypothalamic ghrelin secretion significantly increased in 24-h-fasted rats compared to freely fed rats and was markedly reduced 24 and 48 h after cisplatin treatment in cisplatin-treated rats compared to saline-treated rats, although their plasma ghrelin levels were comparable. In cisplatin-treated rats, icv ghrelin administration reversed the decrease in food intake, vagotomy partially restored hypothalamic ghrelin secretion, and hypothalamic serotonin 2C receptor mRNA expression increased significantly. Administration of rikkunshito (an endogenous ghrelin enhancer) or a serotonin 2C receptor antagonist reversed the decrease in hypothalamic ghrelin secretion and food intake 24 h after cisplatin treatment. Cisplatin-induced anorexia is mediated through reduced hypothalamic ghrelin secretion. Cerebral serotonin 2C receptor activation partially induces decrease in hypothalamic ghrelin secretion, and rikkunshito suppresses cisplatin-induced anorexia by enhancing this secretion.

Thermoregulatory responses to acute heat loads in rats following spontaneous running.

Science.gov (United States)

Sugimoto, N; Shido, O; Sakurada, S; Nagasaka, T

1999-02-01

Earlier studies showed that spontaneous exercise training in rodents shifted their core temperature and thermoeffector thresholds to high levels. The present study investigated heat loss and heat production responses to acute heat loads of exercise-trained rats. The exercise-trained rats were allowed to run in a running wheel freely for 6 months, while the sedentary controls were denied access to the wheel during the same period. Then, they were loosely restrained and put in a direct calorimeter. After thermal equilibrium had been attained, they were warmed for 30 min with an intraperitoneal electric heater (internal heating). At least 2 h later, the rats were externally warmed for 90 min by raising the ambient temperature from 24 to 38C (external warming). Hypothalamic temperature (Thy), evaporative and nonevaporative heat loss (R+C+K) and heat production were measured. Internal and external heating significantly increased Thy. During internal heating, the magnitude of the increase in Thy was significantly smaller and the amount of increase in (R+C+K) was significantly greater in the exercise-trained rats than in the controls. The slope showing the relationship between Thy and (R+C+K) in the trained rats was significantly steeper than that in the controls. During external warming, the magnitude of increase in Thy of the exercise-trained rats was significantly greater than that of the controls. The slope showing the relationship between Thy and (R+C+K) in the trained rats was not different from that in the controls. Changes in evaporative heat loss and heat production during the two types of heat load did not differ between the two groups. The results suggest that, in rats, exercise training with voluntary running improves heat tolerance through enhancing nonevaporative heat loss response. However, this may be the case only when the rats are subjected to a direct internal heat load.

Anticonvulsant treatment of sarin-induced seizures with nasal midazolam: An electrographic, behavioral, and histological study in freely moving rats

International Nuclear Information System (INIS)

Gilat, E.; Kadar, T.; Levy, A.; Rabinovitz, I.; Cohen, G.; Kapon, Y.; Sahar, R.; Brandeis, R.

2005-01-01

Centrally mediated seizures and convulsions are common consequences of exposure to organophosphates (OPs). These seizures rapidly progress to status epilepticus (SE) and contribute to profound brain injury. Effective management of these seizures is critical for minimization of brain damage. Nasal application of midazolam (1.5 mg/kg) after 5 min of sarin-induced electrographic seizure activity (EGSA) ameliorated EGSA and convulsive behavior (238 ± 90 s). Identical treatment after 30 min was not sufficient to ameliorate ECoG paradoxical activity and convulsive behavior. Nasal midazolam (1.5 mg/kg), together with scopolamine (1 mg/kg, im) after 5 min of EGSA, exerted a powerful and rapid anticonvulsant effect (53 ± 10 s). Delaying the same treatment to 30 min of EGSA leads to attenuation of paroxysmal ECoG activity in all cases but total cessation of paroxysmal activity was not observed in most animals tested. Cognitive tests utilizing the Morris Water Maze demonstrated that nasal midazolam alone or together with scopolamine (im), administered after 5 min of convulsions, abolished the effect of sarin on learning. Both these treatments, when given after 30 min of convulsions, only decreased the sarin-induced learning impairments. Whereas rats which were not subject to the anticonvulsant agents did not show any memory for the platform location, both treatments (at 5 min as well as at 30 min) completely abolished the memory deficits. Both treatments equally blocked the impairment of reversal learning when given at 5 min. However, when administered after 30 min, midazolam alone reversed the impairments in reversal learning, while midazolam with scopolamine did not. Rats exposed to sarin and treated with the therapeutic regimen with the exclusion of midazolam exhibited severe brain lesions that encountered the hippocampus, pyriform cortex, and thalamus. Nasal midazolam at 5 min prevented brain damage, while delaying the midazolam treatment to 30 min of EGSA resulted in

Anticonvulsant treatment of sarin-induced seizures with nasal midazolam: An electrographic, behavioral, and histological study in freely moving rats

Energy Technology Data Exchange (ETDEWEB)

Gilat, E [Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100 (Israel); Kadar, T [Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100 (Israel); Levy, A [Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100 (Israel); Rabinovitz, I [Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100 (Israel); Cohen, G [Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100 (Israel); Kapon, Y [Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100 (Israel); Sahar, R [Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100 (Israel); Brandeis, R [Department of Pharmacology, Israel Institute for Biological Research, Ness Ziona, 74100 (Israel)

2005-11-15

Centrally mediated seizures and convulsions are common consequences of exposure to organophosphates (OPs). These seizures rapidly progress to status epilepticus (SE) and contribute to profound brain injury. Effective management of these seizures is critical for minimization of brain damage. Nasal application of midazolam (1.5 mg/kg) after 5 min of sarin-induced electrographic seizure activity (EGSA) ameliorated EGSA and convulsive behavior (238 {+-} 90 s). Identical treatment after 30 min was not sufficient to ameliorate ECoG paradoxical activity and convulsive behavior. Nasal midazolam (1.5 mg/kg), together with scopolamine (1 mg/kg, im) after 5 min of EGSA, exerted a powerful and rapid anticonvulsant effect (53 {+-} 10 s). Delaying the same treatment to 30 min of EGSA leads to attenuation of paroxysmal ECoG activity in all cases but total cessation of paroxysmal activity was not observed in most animals tested. Cognitive tests utilizing the Morris Water Maze demonstrated that nasal midazolam alone or together with scopolamine (im), administered after 5 min of convulsions, abolished the effect of sarin on learning. Both these treatments, when given after 30 min of convulsions, only decreased the sarin-induced learning impairments. Whereas rats which were not subject to the anticonvulsant agents did not show any memory for the platform location, both treatments (at 5 min as well as at 30 min) completely abolished the memory deficits. Both treatments equally blocked the impairment of reversal learning when given at 5 min. However, when administered after 30 min, midazolam alone reversed the impairments in reversal learning, while midazolam with scopolamine did not. Rats exposed to sarin and treated with the therapeutic regimen with the exclusion of midazolam exhibited severe brain lesions that encountered the hippocampus, pyriform cortex, and thalamus. Nasal midazolam at 5 min prevented brain damage, while delaying the midazolam treatment to 30 min of EGSA resulted

"Just Google It"--The Scope of Freely Available Information Sources for Doctoral Thesis Writing

Science.gov (United States)

Grigas, Vincas; Juzeniene, Simona; Velickaite, Jone

2017-01-01

Introduction: Recent developments in the field of scientific information resource provision lead us to the key research question, namely,what is the coverage of freely available information sources when writing doctoral theses, and whether the academic library can assume the leading role as a direct intermediator for information users. Method:…

The games economists play: Why economics students behave more selfishly than other students.

Directory of Open Access Journals (Sweden)

Philipp Gerlach

Full Text Available Do economics students behave more selfishly than other students? Experiments involving monetary allocations suggest so. This article investigates the underlying motives for the economic students' more selfish behavior by separating three potential explanatory mechanisms: economics students are less concerned with fairness when making allocation decisions; have a different notion of what is fair in allocations; or are more skeptical about other people's allocations, which in turn makes them less willing to comply with a shared fairness norm. The three mechanisms were tested by inviting students from various disciplines to participate in a relatively novel experimental game and asking all participants to give reasons for their choices. Compared with students of other disciplines, economics students were about equally likely to mention fairness in their comments; had a similar notion of what was fair in the situation; however, they expected lower offers, made lower offers, and were less willing to enforce compliance with a fair allocation at a cost to themselves. The economics students' lower expectations mediated their allocation decisions, suggesting that economics students behaved more selfishly because they expected others not to comply with the shared fairness norm.

Cardiovascular effects of intrathecally administered bradykinin in the rat: characterization of receptors with antagonists.

OpenAIRE

Lopes, P.; Regoli, D.; Couture, R.

1993-01-01

1. The effects of intrathecal (i.t.) pretreatment with selective B1 or B2 kinin receptor antagonists were studied on the cardiovascular response to i.t. injection of bradykinin (BK) in conscious freely moving rats. 2. BK (81 pmol) produced an increase in mean arterial pressure (MAP: 9-13 mmHg) and decrease in heart rate (HR: 20-30 beats min-1) that reached a maximum 2 min after injection. 3. The BK-induced cardiovascular responses were dose-dependently and reversibly reduced by four antagonis...

Food Neophobia in Wild Rats (Rattus norvegicus Inhabiting a Changeable Environment-A Field Study.

Directory of Open Access Journals (Sweden)

Klaudia Modlinska

Full Text Available Food neophobia is a reaction to novel food observed in many animal species, particularly omnivores, including Rattus norvegicus. A neophobic reaction is typically characterised by avoidance of novel food and the necessity to assess both its potential value and toxicity by the animal. It has been hypothesised that this reaction is not observed in rats inhabiting a changeable environment with a high level of variability with regard to food and food sources. This study was conducted in such changeable conditions and it aims to demonstrate the behaviour of wild rats R. norvegicus in their natural habitat. The rats were studied in a farm setting, and the experimental arena was demarcated by a specially constructed pen which was freely accessible to the rats. At regular intervals, the rats were given new flavour- and smell-altered foods, while their behaviour was video-recorded. The results obtained in the study seem to confirm the hypothesis that rats inhabiting a highly changeable environment do not exhibit food neophobia. The observed reaction to novel food may be connected with a reaction to a novel object to a larger extent than to food neophobia. The value of the results obtained lies primarily in the fact that the study was conducted in the animals' natural habitat, and that it investigated their spontaneous behaviours.

Using the Visualization Software Evaluation Rubric to explore six freely available visualization applications

Directory of Open Access Journals (Sweden)

Thea P. Atwood

2018-01-01

Full Text Available Objective: As a variety of visualization tools become available to librarians and researchers, it can be challenging to select a tool that is robust and flexible enough to provide the desired visualization outcomes for work or personal use. In this article, the authors provide guidance on several freely available tools, and offer a rubric for use in evaluating visualization tools. Methods: A rubric was generated to assist the authors in assessing the selected six freely available visualization tools. Each author analyzed three tools, and discussed the differences, similarities, challenges, and successes of each. Results: Of the six visualization tools, two tools emerged with high marks. The authors found that the rubric was a successful evaluation tool, and facilitated discussion on the strengths and weaknesses of the six selected visualization pieces of software. Conclusions: Of the six different visualization tools analyzed, all had different functions and features available to best meet the needs of users. In a situation where there are many options available, and it is difficult at first glance to determine a clear winner, a rubric can be useful in providing a method to quickly assess and communicate the effectiveness of a tool.

Decoding bipedal locomotion from the rat sensorimotor cortex

Science.gov (United States)

Rigosa, J.; Panarese, A.; Dominici, N.; Friedli, L.; van den Brand, R.; Carpaneto, J.; DiGiovanna, J.; Courtine, G.; Micera, S.

2015-10-01

Objective. Decoding forelimb movements from the firing activity of cortical neurons has been interfaced with robotic and prosthetic systems to replace lost upper limb functions in humans. Despite the potential of this approach to improve locomotion and facilitate gait rehabilitation, decoding lower limb movement from the motor cortex has received comparatively little attention. Here, we performed experiments to identify the type and amount of information that can be decoded from neuronal ensemble activity in the hindlimb area of the rat motor cortex during bipedal locomotor tasks. Approach. Rats were trained to stand, step on a treadmill, walk overground and climb staircases in a bipedal posture. To impose this gait, the rats were secured in a robotic interface that provided support against the direction of gravity and in the mediolateral direction, but behaved transparently in the forward direction. After completion of training, rats were chronically implanted with a micro-wire array spanning the left hindlimb motor cortex to record single and multi-unit activity, and bipolar electrodes into 10 muscles of the right hindlimb to monitor electromyographic signals. Whole-body kinematics, muscle activity, and neural signals were simultaneously recorded during execution of the trained tasks over multiple days of testing. Hindlimb kinematics, muscle activity, gait phases, and locomotor tasks were decoded using offline classification algorithms. Main results. We found that the stance and swing phases of gait and the locomotor tasks were detected with accuracies as robust as 90% in all rats. Decoded hindlimb kinematics and muscle activity exhibited a larger variability across rats and tasks. Significance. Our study shows that the rodent motor cortex contains useful information for lower limb neuroprosthetic development. However, brain-machine interfaces estimating gait phases or locomotor behaviors, instead of continuous variables such as limb joint positions or speeds

Protective Effect of ECQ on Rat Reflux Esophagitis Model.

Science.gov (United States)

Jang, Hyeon-Soon; Han, Jeong Hoon; Jeong, Jun Yeong; Sohn, Uy Dong

2012-12-01

This study was designed to determine the protective effect of Rumex Aquaticus Herba extracts containing quercetin-3-β-D-glucuronopyranoside (ECQ) on experimental reflux esophagitis. Reflux esophagitis was induced by surgical procedure. The rats were divided into seven groups, namely normal group, control group, ECQ (1, 3, 10, 30 mg/kg) group and omeprazole (30 mg/kg) group. ECQ and omeprazole groups received intraduodenal administration. The Rats were starved for 24 hours before the experiments, but were freely allowed to drink water. ECQ group attenuated the gross esophagitis significantly compared to that treated with omeprazole in a dose-dependent manner. ECQ decreased the volume of gastric juice and increased the gastric pH, which are similar to those of omeprazole group. In addition, ECQ inhibited the acid output effectively in reflux esophagitis. Significantly increased amounts of malondialdehyde (MDA), myeloperoxidase (MPO) activity and the mucosal depletion of reduced glutathione (GSH) were observed in the reflux esophagitis. ECQ administration attenuated the decrement of the GSH levels and affected the MDA levels and MPO activity. These results suggest that the ECQ has a protective effect which may be attributed to its multiple effects including anti-secretory, anti-oxidative and anti-inflammatory actions on reflux esophagitis in rats.

Flood Inundation Modelling Under Uncertainty Using Globally and Freely Available Remote Sensing Data

Science.gov (United States)

Yan, K.; Di Baldassarre, G.; Giustarini, L.; Solomatine, D. P.

2012-04-01

The extreme consequences of recent catastrophic events have highlighted that flood risk prevention still needs to be improved to reduce human losses and economic damages, which have considerably increased worldwide in recent years. Flood risk management and long term floodplain planning are vital for living with floods, which is the currently proposed approach to cope with floods. To support the decision making processes, a significant issue is the availability of data to build appropriate and reliable models, from which the needed information could be obtained. The desirable data for model building, calibration and validation are often not sufficient or available. A unique opportunity is offered nowadays by globally available data which can be freely downloaded from internet. This might open new opportunities for filling the gap between available and needed data, in order to build reliable models and potentially lead to the development of global inundation models to produce floodplain maps for the entire globe. However, there remains the question of what is the real potential of those global remote sensing data, characterized by different accuracy, for global inundation monitoring and how to integrate them with inundation models. This research aims at contributing to understand whether the current globally and freely available remote sensing data (e.g. SRTM, SAR) can be actually used to appropriately support inundation modelling. In this study, the SRTM DEM is used for hydraulic model building, while ENVISAT-ASAR satellite imagery is used for model validation. To test the usefulness of these globally and freely available data, a model based on the high resolution LiDAR DEM and ground data (high water marks) is used as benchmark. The work is carried out on a data-rich test site: the River Alzette in the north of Luxembourg City. Uncertainties are estimated for both SRTM and LiDAR based models. Probabilistic flood inundation maps are produced under the framework of

[Effects of excess folic acid on growth and metabolism of water-soluble vitamins in weaning rats].

Science.gov (United States)

Fukuwatari, Tsutomu; Shibata, Katsumi

2008-02-01

In order to determine the tolerable upper intake level of folic acid in humans, we investigated the effects of excessive folic acid administration on the body weight gain, food intake, tissue weight, and metabolism of B-group vitamins in weaning rats. The rats were freely fed ordinary diet containing 0.0002% folic acid (control diet) or the same diet with 0.01%, 0.1%, or 1.0% folic acid for 29 days. The body weight gains and food intakes did not differ among the four groups. Diarrhea was not seen even in the 1.0% group. Excess folic acid did not affect the tissue weights of the brain, heart, liver, kidney, spleen, lung, or testis, or urinary excretion of other B-group vitamins. These results clearly showed that feeding a diet containing up to 1.0% folic acid did not affect the food intake, body weight gain, tissue weight, or urinary excretion of B-group vitamins in weaning rats.

A neurorobotic platform for locomotor prosthetic development in rats and mice

Science.gov (United States)

von Zitzewitz, Joachim; Asboth, Leonie; Fumeaux, Nicolas; Hasse, Alexander; Baud, Laetitia; Vallery, Heike; Courtine, Grégoire

2016-04-01

Objectives. We aimed to develop a robotic interface capable of providing finely-tuned, multidirectional trunk assistance adjusted in real-time during unconstrained locomotion in rats and mice. Approach. We interfaced a large-scale robotic structure actuated in four degrees of freedom to exchangeable attachment modules exhibiting selective compliance along distinct directions. This combination allowed high-precision force and torque control in multiple directions over a large workspace. We next designed a neurorobotic platform wherein real-time kinematics and physiological signals directly adjust robotic actuation and prosthetic actions. We tested the performance of this platform in both rats and mice with spinal cord injury. Main Results. Kinematic analyses showed that the robotic interface did not impede locomotor movements of lightweight mice that walked freely along paths with changing directions and height profiles. Personalized trunk assistance instantly enabled coordinated locomotion in mice and rats with severe hindlimb motor deficits. Closed-loop control of robotic actuation based on ongoing movement features enabled real-time control of electromyographic activity in anti-gravity muscles during locomotion. Significance. This neurorobotic platform will support the study of the mechanisms underlying the therapeutic effects of locomotor prosthetics and rehabilitation using high-resolution genetic tools in rodent models.

Differential changes of metabolic brain activity and interregional functional coupling in prefronto-limbic pathways during different stress conditions: Functional imaging in freely behaving rodent pups

Directory of Open Access Journals (Sweden)

Joerg eBock

2012-05-01

Full Text Available The trumpet-tailed rat or degu (Octodon degus is an established model to investigate the consequences of early stress on the development of emotional brain circuits and behaviour. The aim of this study was to identify brain circuits, that respond to different stress conditions and to test if acute stress alters functional coupling of brain activity among prefrontal and limbic regions. Using functional imaging (2-Fluoro-deoxyglucose method in 8 day old male degu pups the following stress conditions were compared: (A pups together with parents and siblings (control, (B separation of the litter from the parents, (C individual separation from parents and siblings, (D individual separation and presentation of maternal calls. Condition (B significantly downregulated brain activity in the prefrontal cortex, hippocampus, nucleus accumbens and sensory areas compared to controls. Activity decrease was even more pronounced during condition (C, where, in contrast to all other regions, activity in the PAG was increased. Interestingly, brain activity in stress-associated brain regions such as the amygdala and habenula was not affected. In condition (D maternal vocalizations reactivated brain activity in the cingulate and precentral medial cortex, nucleus accumbens and striatum and in sensory areas. In contrast, reduced activity was measured in the prelimbic and infralimbic cortex and in the hippocampus and amygdala. Correlation analysis revealed complex, region- and situation-specific changes of interregional functional coupling among prefrontal and limbic brain regions during stress exposure. We show here for the first time that early life stress results in a widespread reduction of brain activity in the infant brain and changes interregional functional coupling. Moreover, maternal vocalizations can partly buffer stress-induced decrease in brain activity in some regions and evoked very different functional coupling patterns compared to the three other

Pareto-Ranking Based Quantum-Behaved Particle Swarm Optimization for Multiobjective Optimization

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Na Tian

2015-01-01

Full Text Available A study on pareto-ranking based quantum-behaved particle swarm optimization (QPSO for multiobjective optimization problems is presented in this paper. During the iteration, an external repository is maintained to remember the nondominated solutions, from which the global best position is chosen. The comparison between different elitist selection strategies (preference order, sigma value, and random selection is performed on four benchmark functions and two metrics. The results demonstrate that QPSO with preference order has comparative performance with sigma value according to different number of objectives. Finally, QPSO with sigma value is applied to solve multiobjective flexible job-shop scheduling problems.

Activity changes of the cat paraventricular hypothalamus during phasic respiratory events

DEFF Research Database (Denmark)

Kristensen, Morten Pilgaard; Poe, G R; Rector, D M

1997-01-01

We monitored the spatiotemporal organization of cellular activity in the medial paraventricular hypothalamus during spontaneously-occurring periods of increased inspiratory effort followed by prolonged respiratory pauses (sigh/apnea) in the freely-behaving cat. Paraventricular hypothalamic activity...

An Ambulatory Electroencephalography System for Freely Moving Horses: An Innovating Approach

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Hugo Cousillas

2017-05-01

Full Text Available Electroencephalography (EEG that has been extensively studied in humans presents also a large interest for studies on animal brain processes. However, since the quality of the recordings is altered by muscular activity, most EEG recordings on animals are obtained using invasive methods with deeply implanted electrodes. This requires anesthesia and can thus only be used in laboratory or clinical settings. As EEG is a very useful tool both for detecting brain alterations due to diseases or accidents and to evaluate the arousal and attentional state of the animal, it seemed crucial to develop a tool that would make such recordings possible in the horse’s home environment, with a freely moving horse. Such a tool should neither be invasive nor cause discomforts to the horse as the usual other practice which consists, after shaving the zone, in gluing the electrodes to the skin. To fulfill these requirements, we developed a novel EEG headset adapted to the horse’s head that allows an easy and fast positioning of the electrodes and that can be used in the home environment on a freely moving horse. In this study, we show that this EEG headset allows to obtain reliable recordings, and we propose an original evaluation of an animal’s “EEG profile” that allows comparisons between individuals and situations. This EEG headset opens new possibilities of investigation on horse cognition, and it can also become a useful tool for veterinarians to evaluate cerebral disorders or check the anesthesia level during a surgery.

Evaluation of cellular viability by quantitative autoradiographic study of myocardial uptake of a fatty acid analogue in isoproterenol-induced focal rat heart necrosis

International Nuclear Information System (INIS)

Humbert, T.; Luu-Duc, C.; Comet, M.; Demenge, P.

1991-01-01

Previous studies led us to hypothesize that a fatty acid analogue, 15-p-iodophenyl-β-methyl pentadecanoic acid (IMPPA or BMIPP), which is taken up but not quickly metabolized by heart cells, would be a more suitable tracer of cellular viability that 201 Tl. Biodistribution studies of 1- 14 C-IMPPA in conscious, freely moving rats showed that the concentration ratio of radioactivity in the heart with respect to the blood was about 8 for at least 60 min after intravenous administration, permitting its use as a putative tracer in these conscious, freely moving rats. Thereafter, the myocardial uptake of 14 C-IMPPA was studied in isoproterenol-treated rats (daily treatment for 10 days in order to induce cardiac hypertrophy and necrotic foci) with respect to control ones. Comparison of myocardial localizations by quantitative autoradiography of the uptake of 201 Tl and 14 C-IMPPA with that of triphenyltetrazolium chloride (TTC) staining enabled comparative evaluation of nutritional blood flow, localization and uptake of 14 C-IMPPA and necrotic foci size. Distributions of 14 C-IMPPA and 201 Tl in control rats' hearts were homogenous, like TTC staining. In infarcted hearts, areas of decreased 14 C-IMPPA uptake were nearly the same (100%±5%) as those unstained by TTC. These areas were larger than those showing a decrease in thallium uptake (about 70%±5% of the total scar size). Therefore, IMPPA seems to be a more accurate and sensitive indicator of necrosis localization compared with thallium. It may be a useful agent for assessment of myocardial viability by single photon emission tomography (SPET) imaging. (orig.)

Calculating Puerto Rico’s Ecological Footprint (1970–2010 Using Freely Available Data

Directory of Open Access Journals (Sweden)

Matthew E. Hopton

2015-07-01

Full Text Available Ecological Footprint Analysis (EFA is appealing as a metric of sustainability because it is straightforward in theory and easy to conceptualize. However, EFA is difficult to implement because it requires extensive data. A simplified approach to EFA that requires fewer data can serve as a perfunctory analysis allowing researchers to examine a system with relatively little cost and effort. We examined whether a simplified approach using freely available data could be applied to Puerto Rico, a densely populated island with limited land resources. Forty-one years of data were assembled to compute the ecological footprint from 1970 to 2010. According to EFA, individuals in Puerto Rico were moving toward sustainability over time, as the per capita ecological footprint decreased from 3.69 ha per capita (ha/ca in 1970 to 3.05 ha/ca in 2010. However, due to population growth, the population’s footprint rose from 1.00 × 107 ha in 1970 to 1.14 × 107 ha in 2010, indicating Puerto Rico as a whole was moving away from sustainability. Our findings demonstrate the promise for conducting EFA using a simplified approach with freely available data, and we discuss potential limitations on data quality and availability that should be addressed to further improve the science.

Do Students Behave Rationally in Multiple Choice Tests? Evidence from a Field Experiment

OpenAIRE

María Paz Espinosa; Javier Gardeazabal

2013-01-01

A disadvantage of multiple choice tests is that students have incentives to guess. To discourage guessing, it is common to use scoring rules that either penalize wrong answers or reward omissions. In psychometrics, penalty and reward scoring rules are considered equivalent. However, experimental evidence indicates that students behave differently under penalty or reward scoring rules. These differences have been attributed to the different framing (penalty versus reward). In this paper, we mo...

ECG-ViEW II, a freely accessible electrocardiogram database

Science.gov (United States)

Park, Man Young; Lee, Sukhoon; Jeon, Min Seok; Yoon, Dukyong; Park, Rae Woong

2017-01-01

The Electrocardiogram Vigilance with Electronic data Warehouse II (ECG-ViEW II) is a large, single-center database comprising numeric parameter data of the surface electrocardiograms of all patients who underwent testing from 1 June 1994 to 31 July 2013. The electrocardiographic data include the test date, clinical department, RR interval, PR interval, QRS duration, QT interval, QTc interval, P axis, QRS axis, and T axis. These data are connected with patient age, sex, ethnicity, comorbidities, age-adjusted Charlson comorbidity index, prescribed drugs, and electrolyte levels. This longitudinal observational database contains 979,273 electrocardiograms from 461,178 patients over a 19-year study period. This database can provide an opportunity to study electrocardiographic changes caused by medications, disease, or other demographic variables. ECG-ViEW II is freely available at http://www.ecgview.org. PMID:28437484

Single whole-body exposure to sarin vapor in rats: Long-term neuronal and behavioral deficits

International Nuclear Information System (INIS)

Grauer, Ettie; Chapman, Shira; Rabinovitz, Ishai; Raveh, Lily; Weissman, Ben-Avi; Kadar, Tamar; Allon, Nahum

2008-01-01

Freely moving rats were exposed to sarin vapor (34.2 ± 0.8 μg/l) for 10 min. Mortality at 24 h was 35% and toxic sings in the surviving rats ranged from sever (prolonged convulsions) through moderate to almost no overt signs. Some of the surviving rats developed delayed, intermittent convulsions. All rats were evaluated for long-term functional deficits in comparison to air-exposed control rats. Histological analysis revealed typical cell loss at 1 week post inhalation exposure. Neuronal inflammation was demonstrated by a 20-fold increase in prostaglandin (PGE 2 ) levels 24 h following exposure that markedly decreased 6 days later. An additional, delayed increase in PGE 2 was detected at 1 month and continued to increase for up to 6 months post exposure. Glial activation following neural damage was demonstrated by an elevated level of peripheral benzodiazepine receptors (PBR) seen in the brain 4 and 6 months after exposure. At the same time muscarinic receptors were unaffected. Six weeks, four and six months post exposure behavioral evaluations were performed. In the open field, sarin-exposed rats showed a significant increase in overall activity with no habituation over days. In a working memory paradigm in the water maze, these same rats showed impaired working and reference memory processes with no recovery. Our data suggest long lasting impairment of brain functions in surviving rats following a single sarin exposure. Animals that seem to fully recover from the exposure, and even animals that initially show no toxicity signs, developed some adverse neural changes with time

Effect of lead exposure on serum estradiol and certain haematological indices in female rats

International Nuclear Information System (INIS)

Abd El-Moneim, A.E.; El-Abiad, N.M.

1996-01-01

In this study, graded dosages of lead acetate (Pb Ac) 0,100,200 and 500 mg/liter were dissolved in tap water and offered freely to four groups of female rats to show the effect of lead (Pb) ingestion on serum estradiol (E 2 ) concentration. Changes in body weight (B.wt), relative liver, kidney, spleen weights were recorded. Blood lead content, red blood cells (RBC), white blood cells (WBC) counts, blood hemoglobin (Hb) content and hematocrit values were measured as indicators of elevated Pb exposure. After three months of treatment, as compared to control animals, all lead-treated rats showed a significant decrease in B.wt and significant increase in relative weights of liver and spleen. Kidney relative weight did not indicate significant differences between rats given tap water with or without Pb Ac. Blood Pb content and WBC count were higher and RBC count was lower in rats given leaded water. Both Hb and Hct values were insignificantly reduced in lead exposed rats. The treatment with 500 mg Pb Ac/liter of drinking water resulted in significant fall of serum E 2 to reach about half its value control group at end of the experiment, while, the decrease in serum E 2 was less significant in the group received 200 mg Pb Ac/liter tap water. 2 tabs

3D-e-Chem-VM: Structural Cheminformatics Research Infrastructure in a Freely Available Virtual Machine

NARCIS (Netherlands)

McGuire, R.; Verhoeven, S.; Vass, M.; Vriend, G.; Esch, I.J. de; Lusher, S.J.; Leurs, R.; Ridder, L.; Kooistra, A.J.; Ritschel, T.; Graaf, C. de

2017-01-01

3D-e-Chem-VM is an open source, freely available Virtual Machine ( http://3d-e-chem.github.io/3D-e-Chem-VM/ ) that integrates cheminformatics and bioinformatics tools for the analysis of protein-ligand interaction data. 3D-e-Chem-VM consists of software libraries, and database and workflow tools

3D-e-Chem-VM : Structural Cheminformatics Research Infrastructure in a Freely Available Virtual Machine

NARCIS (Netherlands)

McGuire, Ross; Verhoeven, Stefan; Vass, Márton; Vriend, Gerrit; De Esch, Iwan J P; Lusher, Scott J.; Leurs, Rob; Ridder, Lars; Kooistra, Albert J.; Ritschel, Tina; de Graaf, C.

2017-01-01

3D-e-Chem-VM is an open source, freely available Virtual Machine ( http://3d-e-chem.github.io/3D-e-Chem-VM/ ) that integrates cheminformatics and bioinformatics tools for the analysis of protein-ligand interaction data. 3D-e-Chem-VM consists of software libraries, and database and workflow tools

Eight-Week Remote Monitoring Using a Freely Worn Device Reveals Unstable Gait Patterns in Older Fallers.

Science.gov (United States)

Brodie, Matthew A; Lord, Stephen R; Coppens, Milou J; Annegarn, Janneke; Delbaere, Kim

2015-11-01

Develop algorithms to detect gait impairments remotely using data from freely worn devices during long-term monitoring. Identify statistical models that describe how gait performances are distributed over several weeks. Determine the data window required to reliably assess an increased propensity for falling. 1085 days of walking data were collected from eighteen independent-living older people (mean age 83 years) using a freely worn pendant sensor (housing a triaxial accelerometer and pressure sensor). Statistical distributions from several accelerometer-derived gait features (encompassing quantity, exposure, intensity, and quality) were compared for those with and without a history of falling. Participants completed more short walks relative to long walks, as approximated by a power law. Walks less than 13.1 s comprised 50% of exposure to walking-related falls. Daily-life cadence was bimodal and step-time variability followed a log-normal distribution. Fallers took significantly fewer steps per walk and had relatively more exposure from short walks and greater mode of step-time variability. Using a freely worn device and wavelet-based analysis tools allowed long-term monitoring of walks greater than or equal to three steps. In older people, short walks constitute a large proportion of exposure to falls. To identify fallers, mode of variability may be a better measure of central tendency than mean of variability. A week's monitoring is sufficient to reliably assess the long-term propensity for falling. Statistical distributions of gait performances provide a reference for future wearable device development and research into the complex relationships between daily-life walking patterns, morbidity, and falls.

Brain state-dependence of electrically evoked potentials monitored with head-mounted electronics.

Science.gov (United States)

Richardson, Andrew G; Fetz, Eberhard E

2012-11-01

Inferring changes in brain connectivity is critical to studies of learning-related plasticity and stimulus-induced conditioning of neural circuits. In addition, monitoring spontaneous fluctuations in connectivity can provide insight into information processing during different brain states. Here, we quantified state-dependent connectivity changes throughout the 24-h sleep-wake cycle in freely behaving monkeys. A novel, head-mounted electronic device was used to electrically stimulate at one site and record evoked potentials at other sites. Electrically evoked potentials (EEPs) revealed the connectivity pattern between several cortical sites and the basal forebrain. We quantified state-dependent changes in the EEPs. Cortico-cortical EEP amplitude increased during slow-wave sleep, compared to wakefulness, while basal-cortical EEP amplitude decreased. The results demonstrate the utility of using portable electronics to document state-dependent connectivity changes in freely behaving primates.

Diminished epinephrine response to hypoglycemia despite enlarged adrenal medulla in trained rats

DEFF Research Database (Denmark)

Stallknecht, B; Kjaer, M; Mikines, K J

1990-01-01

/day or served as controls being either sedentary freely eating (C), food restricted (FR), sham swim trained (ST), or cold stressed (CS). Adrenal glands were weighted and cross sectioned for light microscopic determination of size of the adrenal medulla. Endurance-trained compared with control rats had heavier...... adrenal glands (P less than 0.05), higher catecholamine content in the glands (P less than 0.05), and higher adrenal medulla volumes (P less than 0.05) [males: 2.74 +/- 0.16 (T) vs. 2.05 +/- 0.16 (C), 1.90 +/- 0.10 (ST), and 2.21 +/- 0.08 mm3 (CS)] [females: 2.55 +/- 0.11 (T) vs. 1.92 +/- 0.06 mm3 (C......)]. Cold stress or sham swim training did not increase adrenal weight or volume of adrenal medulla (P greater than 0.05). To stimulate adrenal medulla secretion, rats had an insulin-induced hypoglycemia. Insulin dose needed to suppress plasma glucose below 4.0 mM was four times greater in sedentary...

Activity changes of the cat paraventricular hypothalamus during stressor exposure

DEFF Research Database (Denmark)

Kristensen, Morten Pilgaard; Rector, David M; Poe, Gina R

2004-01-01

Dorso-medial paraventricular hypothalamus (PVH) activity was assessed by light scattering procedures in freely behaving cats during auditory stressor exposure. Acoustic noise (> 95dB) raised plasma ACTH concentrations, somatic muscle tonus, respiratory frequency and cardiac rates; PVH activity...

Preoperative diagnosis and radiographic findings of a freely movable mucocele of the vermiform appendix

Energy Technology Data Exchange (ETDEWEB)

Shukunami, K.-I.; Kaneshima, M.; Kotsuji, F. [Fukui Medical Univ., Dept. of Obstetrics and Gynecology, Matsuoka-Cho, Yoshida-Gun, Fukui (Japan)

2000-10-01

Mucocele of the vermiform appendix is rarely diagnosed before surgery, although radiologic and ultrasonographic (US) findings have been reported. To our knowledge, there have been no previous reports of 2 different radiologic images of the cyst in the same patient during the preoperative period. We present 2 different shapes and locations of a freely movable mucocele of the appendix as it appeared before surgery. (author)

A comparison of Lewis and Fischer rat strains on autoshaping (sign-tracking), discrimination reversal learning and negative auto-maintenance.

Science.gov (United States)

Kearns, David N; Gomez-Serrano, Maria A; Weiss, Stanley J; Riley, Anthony L

2006-05-15

Lewis (LEW) and Fischer (F344) rat strains differ on a number of physiological characteristics, such as hypothalamic-pituitary-adrenal (HPA) axis activity, as well as on behavioral tasks, including those that measure impulsivity and drug reward. Since autoshaping, the phenomenon where animals approach and contact reward-paired conditioned stimuli, has been linked to HPA axis functioning, impulsivity and drug taking, the present study compared LEW and F344 rats on the rate of acquisition and performance of the autoshaping response. Rats were trained on an autoshaping procedure where insertions of one retractable lever (CS(+)) were paired response-independently with food, while insertions of another lever (CS(-)) were not paired with food. LEW rats acquired the autoshaping response more rapidly and also performed the autoshaping response at a higher rate than F344 rats. No differences between the strains were observed when rats were trained on a discrimination reversal where the CS(+) and CS(-) levers were reversed or during a negative auto-maintenance phase where CS(+) lever contacts cancelled food delivery. Potential physiological mechanisms that might mediate the present results, including strain differences in HPA axis and monoamine neurotransmitter activity, are discussed. The finding that LEW (as compared to F344 rats) more readily acquire autoshaping and perform more responses is consistent with research indicating that LEW rats behave more impulsively and more readily self-administer drugs of abuse.

Manganese-Enhanced Magnetic Resonance Imaging and Studies of Rat Behavior: Transient Motor Deficit in Skilled Reaching, Rears, and Activity in Rats After a Single Dose of MnCl

Directory of Open Access Journals (Sweden)

Mariam Alaverdashvili

2017-05-01

Full Text Available Manganese-enhanced magnetic resonance imaging (MEMRI has been suggested to be a useful tool to visualize and map behavior-relevant neural populations at large scale in freely behaving rodents. A primary concern in MEMRI applications is Mn 2+ toxicity. Although a few studies have specifically examined toxicity on gross motor behavior, Mn 2+ toxicity on skilled motor behavior was not explored. Thus, the objective of this study was to combine manganese as a functional contrast agent with comprehensive behavior evaluation. We evaluated Mn 2+ effect on skilled reach-to-eat action, locomotion, and balance using a single pellet reaching task, activity cage, and cylinder test, respectively. The tests used are sensitive to the pathophysiology of many neurological and neurodegenerative disorders of the motor system. The behavioral testing was done in combination with a moderate dose of manganese. Behavior was studied before and after a single, intravenous infusion of MnCl 2 (48 mg/kg. The rats were imaged at 1, 3, 5, 7, and 14 days following infusion. The results show that MnCl 2 infusion resulted in detectable abnormalities in skilled reaching, locomotion, and balance that recovered within 3 days compared with the infusion of saline. Because some tests and behavioral measures could not detect motor abnormalities of skilled movements, comprehensive evaluation of motor behavior is critical in assessing the effects of MnCl 2 . The relaxation mapping results suggest that the transport of Mn 2+ into the brain is through the choroid plexus-cerebrospinal fluid system with the primary entry point and highest relaxation rates found in the pituitary gland. Relaxation rates in the pituitary gland correlated with measures of motor skill, suggesting that altered motor ability is related to the level of Mn circulating in the brain. Thus, combined MEMRI and behavioral studies that both achieve adequate image enhancement and are also free of motor skills deficits are

Eavesdropping on the "Ping-Pong" Quantum Communication Protocol Freely in a Noise Channel

OpenAIRE

Deng, Fu-Guo; Li, Xi-Han; Li, Chun-Yan; Zhou, Ping; Zhou, Hong-Yu

2005-01-01

We introduce an attack scheme for eavesdropping the ping-pong quantum communication protocol proposed by Bostr$\\ddot{o}$m and Felbinger [Phys. Rev. Lett. \\textbf{89}, 187902 (2002)] freely in a noise channel. The vicious eavesdropper, Eve, intercepts and measures the travel photon transmitted between the sender and the receiver. Then she replaces the quantum signal with a multi-photon signal in a same state, and measures the photons return with the measuring basis with which Eve prepares the ...

Tritium metabolism in rat tissues

International Nuclear Information System (INIS)

Takeda, H.

1982-01-01

As part of a series of studies designed to evaluate the relative radiotoxicity of various tritiated compounds, metabolism of tritium in rat tissues was studied after administration of tritiated water, leucine, thymidine, and glucose. The distribution and retention of tritium varied widely, depending on the chemical compound administered. Tritium introduced as tritiated water behaved essentially as body water and became uniformly distributed among the tissues. However, tritium administered as organic compounds resulted in relatively high incorporation into tissue constituents other than water, and its distribution differed among the various tissues. Moreover, the excretion rate of tritium from tissues was slower for tritiated organic compounds than for tritiated water. Administrationof tritiated organic compounds results in higher radiation doses to the tissues than does administration of tritiated water. Among the tritiated compounds examined, for equal radioactivity administered, leucine gave the highest radiation dose, followed in turn by thymidine, glucose, and water. (author)

Automatic Moving Object Segmentation for Freely Moving Cameras

Directory of Open Access Journals (Sweden)

Yanli Wan

2014-01-01

Full Text Available This paper proposes a new moving object segmentation algorithm for freely moving cameras which is very common for the outdoor surveillance system, the car build-in surveillance system, and the robot navigation system. A two-layer based affine transformation model optimization method is proposed for camera compensation purpose, where the outer layer iteration is used to filter the non-background feature points, and the inner layer iteration is used to estimate a refined affine model based on the RANSAC method. Then the feature points are classified into foreground and background according to the detected motion information. A geodesic based graph cut algorithm is then employed to extract the moving foreground based on the classified features. Unlike the existing global optimization or the long term feature point tracking based method, our algorithm only performs on two successive frames to segment the moving foreground, which makes it suitable for the online video processing applications. The experiment results demonstrate the effectiveness of our algorithm in both of the high accuracy and the fast speed.

Central estrogenic pathways protect against the depressant action of acute nicotine on reflex tachycardia in female rats

International Nuclear Information System (INIS)

El-Mas, Mahmoud M.; Fouda, Mohamed A.; El-gowilly, Sahar M.; Saad, Evan I.

2012-01-01

We have previously shown that acute exposure of male rats to nicotine preferentially attenuates baroreceptor-mediated control of reflex tachycardia in contrast to no effect on reflex bradycardia. Here, we investigated whether female rats are as sensitive as their male counterparts to the baroreflex depressant effect of nicotine and whether this interaction is modulated by estrogen. Baroreflex curves relating reflex chronotropic responses evoked by i.v. doses (1–16 μg/kg) of phenylephrine (PE) or sodium nitroprusside (SNP), were constructed in conscious freely moving proestrus, ovariectomized (OVX), and estrogen (50 μg/kg/day s.c., 5 days)-replaced OVX (OVXE 2 ) rats. Slopes of the curves were taken as a measure of baroreflex sensitivity (BRS PE and BRS SNP ). Nicotine (100 μg/kg i.v.) reduced BRS SNP in OVX rats but not in proestrus or OVXE 2 rats. The attenuation of reflex tachycardia by nicotine was also evident in diestrus rats, which exhibited plasma estrogen levels similar to those of OVX rats. BRS PE was not affected by nicotine in all rat preparations. Experiments were then extended to determine whether central estrogenic receptors modulate the nicotine–BRS SNP interaction. Intracisteral (i.c.) treatment of OVX rats with estrogen sulfate (0.2 μg/rat) abolished the BRS SNP attenuating effect of i.v. nicotine. This protective effect of estrogen disappeared when OVX rats were pretreated with i.c. ICI 182,780 (50 μg/rat, selective estrogen receptor antagonist). Together, these findings suggest that central neural pools of estrogen receptors underlie the protection offered by E 2 against nicotine-induced baroreceptor dysfunction in female rats. -- Highlights: ► Estrogen protects against the depressant effect of nicotine on reflex tachycardia. ► The baroreflex response and estrogen status affect the nicotine–BRS interaction. ► The protection offered by estrogen is mediated via central estrogen receptors.

The effect of honey compared to sucrose, mixed sugars, and a sugar-free diet on weight gain in young rats.

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Chepulis, L M

2007-04-01

To determine whether honey, sucrose, and mixed sugars as in honey have different effects on weight gain, 40 6-wk-old Sprague-Dawley rats were fed a powdered diet that was either sugar free or contained 8% sucrose, 8% mixed sugars as in honey, or 10% honey freely for 6 wk. Weight gain and food intake were assessed weekly, and at completion of the study blood samples were removed for measurement of blood sugar (HbA1c) and a fasting lipid profile. The animals were then minced and total percentage body fat and protein measured. Overall percentage weight gain was significantly lower in honey-fed rats than those fed sucrose or mixed sugars, despite a similar food intake. Weight gains were comparable for rats fed honey and a sugar free diet although food intake was significantly higher in honey-fed rats. HbA1c and triglyceride levels were significantly higher in all sugar treatments compared with rats fed a sugar free diet, but no other differences in lipid profiles were reported. No differences in percentage body fat or protein levels were reported.

The olfactory tubercle encodes odor valence in behaving mice.

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Gadziola, Marie A; Tylicki, Kate A; Christian, Diana L; Wesson, Daniel W

2015-03-18

Sensory information acquires meaning to adaptively guide behaviors. Despite odors mediating a number of vital behaviors, the components of the olfactory system responsible for assigning meaning to odors remain unclear. The olfactory tubercle (OT), a ventral striatum structure that receives monosynaptic input from the olfactory bulb, is uniquely positioned to transform odor information into behaviorally relevant neural codes. No information is available, however, on the coding of odors among OT neurons in behaving animals. In recordings from mice engaged in an odor discrimination task, we report that the firing rate of OT neurons robustly and flexibly encodes the valence of conditioned odors over identity, with rewarded odors evoking greater firing rates. This coding of rewarded odors occurs before behavioral decisions and represents subsequent behavioral responses. We predict that the OT is an essential region whereby odor valence is encoded in the mammalian brain to guide goal-directed behaviors. Copyright © 2015 the authors 0270-6474/15/354515-13$15.00/0.

Possible relationship between the stress-induced synaptic response and metaplasticity in the hippocampal CA1 field of freely moving rats.

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Hirata, Riki; Matsumoto, Machiko; Judo, Chika; Yamaguchi, Taku; Izumi, Takeshi; Yoshioka, Mitsuhiro; Togashi, Hiroko

2009-07-01

Hippocampal long-term potentiation (LTP) is suppressed not only by stress paradigms but also by low frequency stimulation (LFS) prior to LTP-inducing high frequency stimulation (HFS; tetanus), termed metaplasticity. These synaptic responses are dependent on N-methyl-D-aspartate receptors, leading to speculations about the possible relationship between metaplasticity and stress-induced LTP impairment. However, the functional significance of metaplasticity has been unclear. The present study elucidated the electrophysiological and neurochemical profiles of metaplasticity in the hippocampal CA1 field, with a focus on the synaptic response induced by the emotional stress, contextual fear conditioning (CFC). The population spike amplitude in the CA1 field was decreased during exposure to CFC, and LTP induction was suppressed after CFC in conscious rats. The synaptic response induced by CFC was mimicked by LFS, i.e., LFS impaired the synaptic transmission and subsequent LTP. Plasma corticosterone levels were increased by both CFC and LFS. Extracellular levels of gamma-aminobutyric acid (GABA), but not glutamate, in the hippocampus increased during exposure to CFC or LFS. Furthermore, electrical stimulation of the medial prefrontal cortex (mPFC), which caused decreases in freezing behavior during exposure to CFC, counteracted the LTP impairment induced by LFS. These findings suggest that metaplasticity in the rat hippocampal CA1 field is related to the neural basis of stress experience-dependent fear memory, and that hippocampal synaptic response associated stress-related processes is under mPFC regulation.

The influence of aripiprazole and olanzapine on neurotransmitters level in frontal cortex of prenatally stressed rats.

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Ratajczak, P; Kus, K; Gołembiowska, K; Noworyta-Sokołowska, K; Woźniak, A; Zaprutko, T; Nowakowska, E

2016-09-01

The study aims to verify whether alterations in the level of neurotransmitters have occurred in prenatally stressed rats (animal model of schizophrenia), and whether aripiprazole (ARI) and olanzapine (OLA) modify this level. The effects of ARI (1.5mg/kg) and OLA (0.5mg/kg) were studied by means of microdialysis in freely moving rats (observation time 120min). The level of neurotransmitters (DA, 5-HT, NA) and their metabolites (DOPAC, HVA, 5-HIAA) was analyzed by HPLC with coulochemical detection. Obtained results indicate that after a single administration of ARI and OLA in the prenatally stressed rats the increase of DA, DOPAC, and 5-HT was observed. In turn ARI administration increase the level of HVA and 5-HIAA and also decrease the level of NA. After OLA administration the level of NA and HVA increased and no significant change in 5-HIAA was observed. Alterations observed as a result of ARI and OLA administration may be pivotal in identifying animal models of mental disorders and in the analysis of neuroleptics effectiveness. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of hindlimb unloading on stereological parameters of the motor cortex and hippocampus in male rats.

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Salehi, Mohammad Saied; Mirzaii-Dizgah, Iraj; Vasaghi-Gharamaleki, Behnoosh; Zamiri, Mohammad Javad

2016-11-09

Hindlimb unloading (HU) can cause motion and cognition dysfunction, although its cellular and molecular mechanisms are not well understood. The aim of the present study was to determine the stereological parameters of the brain areas involved in motion (motor cortex) and spatial learning - memory (hippocampus) under an HU condition. Sixteen adult male rats, kept under a 12 : 12 h light-dark cycle, were divided into two groups of freely moving (n=8) and HU (n=8) rats. The volume of motor cortex and hippocampus, the numerical cell density of neurons in layers I, II-III, V, and VI of the motor cortex, the entire motor cortex as well as the primary motor cortex, and the numerical density of the CA1, CA3, and dentate gyrus subregions of the hippocampus were estimated. No significant differences were observed in the evaluated parameters. Our results thus indicated that motor cortical and hippocampal atrophy and cell loss may not necessarily be involved in the motion and spatial learning memory impairment in the rat.

Change of cholinergic transmission and memory deficiency induced by injection of b-amyloid protein into NBM of rats

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

The change of cholinergic transmission of b-amyloid protein (b-AP) treated rats was studied by intracerebral microdialysis sampling combined with HPLC analysis. b-AP1-40 was injected into nucleus basalis magnocellularis (NBM). Passive avoidance response test (step-down test) and delayed alternation task were used for memory testing. The impairment of memory after injection of b-AP1-40 into NBM exhibited mainly the deficiency of short-term working memory. One week after injection of b-AP1-40 the release of acetylcholine (ACh) from frontal cortex of freely-moving rats decreased significantly, and the response of cholinergic nerve ending to the action of high [K+] solution was rather weak. In control animals the percentage of increase of ACh- release during behavioral performance was 57%, while in b-AP1-40 - treated rats it was 34%. The temporary in-crease of the ACh-release of the rat put into a new place was also significantly diminished in b-AP1-40 -treated rats. The results show that the injection of b-AP1-40 into NBM impairs the cholinergic transmission in frontal cortex, and the impairment of cholinergic transmission may be the main cause of the deficit of working memory.

Engagement of the Rat Hindlimb Motor Cortex across Natural Locomotor Behaviors.

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DiGiovanna, Jack; Dominici, Nadia; Friedli, Lucia; Rigosa, Jacopo; Duis, Simone; Kreider, Julie; Beauparlant, Janine; van den Brand, Rubia; Schieppati, Marco; Micera, Silvestro; Courtine, Grégoire

2016-10-05

Contrary to cats and primates, cortical contribution to hindlimb locomotor movements is not critical in rats. However, the importance of the motor cortex to regain locomotion after neurological disorders in rats suggests that cortical engagement in hindlimb motor control may depend on the behavioral context. To investigate this possibility, we recorded whole-body kinematics, muscle synergies, and hindlimb motor cortex modulation in freely moving rats performing a range of natural locomotor procedures. We found that the activation of hindlimb motor cortex preceded gait initiation. During overground locomotion, the motor cortex exhibited consistent neuronal population responses that were synchronized with the spatiotemporal activation of hindlimb motoneurons. Behaviors requiring enhanced muscle activity or skilled paw placement correlated with substantial adjustment in neuronal population responses. In contrast, all rats exhibited a reduction of cortical activity during more automated behavior, such as stepping on a treadmill. Despite the facultative role of the motor cortex in the production of locomotion in rats, these results show that the encoding of hindlimb features in motor cortex dynamics is comparable in rats and cats. However, the extent of motor cortex modulations appears linked to the degree of volitional engagement and complexity of the task, reemphasizing the importance of goal-directed behaviors for motor control studies, rehabilitation, and neuroprosthetics. We mapped the neuronal population responses in the hindlimb motor cortex to hindlimb kinematics and hindlimb muscle synergies across a spectrum of natural locomotion behaviors. Robust task-specific neuronal population responses revealed that the rat motor cortex displays similar modulation as other mammals during locomotion. However, the reduced motor cortex activity during more automated behaviors suggests a relationship between the degree of engagement and task complexity. This relationship

Hypothesis: solid tumours behave as systemic metabolic dictators.

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Lee, Yang-Ming; Chang, Wei-Chun; Ma, Wen-Lung

2016-06-01

Current knowledge regarding mechanisms of carcinogenesis in human beings centres around the accumulation of genetic instability, amplified cellular signalling, disturbed cellular energy metabolism and microenvironmental regulation governed by complicated cell-cell interactions. In this article, we provide an alternative view of cancer biology. We propose that cancer behaves as a systemic dictator that interacts with tissues throughout the body to control their metabolism and eventually homeostasis. The mechanism of development of this endocrine organ-like tumour (EOLT) tissue might be the driving force for cancer progression. Here, we review the literature that led to the development of this hypothesis. The EOLT phenotype can be defined as a tumour that alters systemic homeostasis. The literature indicates that the EOLT phenotype is present throughout cancer progression. The feedback mechanism that governs the interaction between tumours and various organs is unknown. We believe that investigating the mechanism of EOLT development may advance the current knowledge of regulation within the tumour macroenvironment and consequently lead to new diagnostic methods and therapy. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Electropharmacogram of Sceletium tortuosum extract based on spectral local field power in conscious freely moving rats.

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Dimpfel, Wilfried; Schombert, Leonie; Gericke, Nigel

2016-01-11

The endemic succulent South African plant, Sceletium tortuosum (L.) N.E. Br. (synonym Mesembryanthemum tortuosum L.), of the family Mesembryathemaceae, has an ancient oral tradition history of use by San and Khoikhoi people as an integral part of the indigenous culture and materia medica. A special standardized extract of Sceletium tortuosum (Zembrin®) has been developed and tested pre-clinically in rats, and clinically in healthy subjects. The present investigation aimed at the construction of electropharmacograms of Zembrin® in the presence of three dosages (2.5, 5.0 and 10.0 mg/kg), and comparative electropharmacograms and discriminatory analyses for other herbal extracts, citicoline and rolipram. Seventeen adult Fischer rats were each implanted with a set consisting of four bipolar concentric steel electrodes fixed by dental cement and three screws driven into the scalp. After two weeks of recovery from surgery the animals were adapted to oral administration by gavage and to experimental conditions (45 min pre-drug period and 5h of recording after a rest of 5 min for calming down). Data were transmitted wirelessly and processed using a Fast Fourier Transformation (FFT). Spectral power was evaluated for 8 frequency ranges, namely delta, theta, alpha1, alpha2, beta1a, beta1b, beta2 and gamma power. Zembrin® dose dependently attenuated all frequency ranges, to varying degrees. The most prominent was the statistically significant reduction in alpha2 and beta1a waves, correlated with activation of the dopaminergic and glutamatergic transmitter systems respectively. This feature is common to all synthetic and herbal stimulants tested to date. The second strongest effects were reduction in both the delta and the theta frequency ranges, correlated with changes in the cholinergic and norepinephrine systems respectively, a pattern seen in preparations prescribed for neurodegenerative diseases. Theta wave reduction in common with the delta, alpha2 and beta1 attenuation

Anti-inflammatory and organ protective effect of insulin in scalded MODS rats without controlling hyperglycemia.

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Zhu, Zhongzhen; Hu, Tian; Wang, Zhanke; Wang, Jin; Liu, Rui; Yang, Qianyong; Zhang, Xiaoyun; Xiong, Yuanyuan

2018-02-01

Insulin, as an anti-inflammatory drug, could not be freely used in patients who experienced trauma according to the degree of inflammation, because of the side effect of hypoglycemia. In vivo experimental evidence is lacking concerning whether the effect is dosage dependent and whether it relies on controlling hyperglycemia. By adjusting the dosage ratio of glucose and insulin, different dosages of insulin were used to treat severely scalded MODS rats to achieve uncontrolled or controlled hyperglycemia. One hundred forty rats with severe scalded were randomly divided into a hyperglycemia-controlled group, hyperglycemia-uncontrolled group, and control group. The levels of inflammation response indexes and major organ dysfunction indexes were measured and compared between groups. The blood indexes of inflammatory response and major organ dysfunction did not show statistical difference between hyperglycemia-controlled groups (A) and uncontrolled groups (B) in the same dosage of insulin (all P>0.05). The blood indexes of inflammatory response and major organ dysfunction demonstrated statistical difference in different dosages of insulin with hyperglycemia-controlled groups (A1-A3 groups) and hyperglycemia-uncontrolled groups (B1-B3 groups) (all Pcontrolling hyperglycemia. The effect of anti-inflammation and organ protection of insulin is dosage dependent in vivo; it does not rely on controlling hyperglycemia. Temporary traumatic hyperglycemia itself might not be detrimental to the body. Adjusting the ratio of insulin and glucose could provide a novel train of thought for freely treating patients with severe traumatic injury with different dosages of insulin according to the degree of inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

Motion makes sense: an adaptive motor-sensory strategy underlies the perception of object location in rats.

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Saraf-Sinik, Inbar; Assa, Eldad; Ahissar, Ehud

2015-06-10

Tactile perception is obtained by coordinated motor-sensory processes. We studied the processes underlying the perception of object location in freely moving rats. We trained rats to identify the relative location of two vertical poles placed in front of them and measured at high resolution the motor and sensory variables (19 and 2 variables, respectively) associated with this whiskers-based perceptual process. We found that the rats developed stereotypic head and whisker movements to solve this task, in a manner that can be described by several distinct behavioral phases. During two of these phases, the rats' whiskers coded object position by first temporal and then angular coding schemes. We then introduced wind (in two opposite directions) and remeasured their perceptual performance and motor-sensory variables. Our rats continued to perceive object location in a consistent manner under wind perturbations while maintaining all behavioral phases and relatively constant sensory coding. Constant sensory coding was achieved by keeping one group of motor variables (the "controlled variables") constant, despite the perturbing wind, at the cost of strongly modulating another group of motor variables (the "modulated variables"). The controlled variables included coding-relevant variables, such as head azimuth and whisker velocity. These results indicate that consistent perception of location in the rat is obtained actively, via a selective control of perception-relevant motor variables. Copyright © 2015 the authors 0270-6474/15/358777-13$15.00/0.

Optimasi Penempatan Menara BTS Menggunakan Quantum-Behaved Particle Swarm Optimization

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Mohamad Fatkhur Rohman

2016-11-01

Full Text Available Universal Mobile Telecomunication System (UMTS saat ini dipandang sebagai sebuah sistem impian yang menggantikan Global System for Mobile Communication (GSM dan merupakan salah satu evolusi generasi ketiga (3G dari jaringan mobile. Salah satu komponen pendukung jaringan UMTS adalah Node B, Node B dapat dianalogikan sebagai BTS. Seiring perkembangan kebutuhan pelanggan yang semakin meningkat, kebutuhan akan BTS(Node B semakin bertambah, hal ini menyebabkan banyaknya jumlah menara BTS da menyebabkan pemandangan yang kurang bagus bagi visualisasi kota.oleh karena itu perlu dilakukan optimisasi penempatan menara BTS. Salah satu metode untuk mengoptimasi adalah Quantum-behaved Particle Swarm Optimization. Maka dalam penelitian ini akan dirancang simulasi optimasi penempatan BTS menggunakan QPSO dengan parameter yang akan dioptimasi adalah Coverage Area dan Trafik. Dari hasil penelitian yang dilakukan, Algoritma QPSO mampu mengurangi jumlah BTS dari 55 BTS menjadi 43 BTS.

High channel count microphone array accurately and precisely localizes ultrasonic signals from freely-moving mice.

Science.gov (United States)

Warren, Megan R; Sangiamo, Daniel T; Neunuebel, Joshua P

2018-03-01

An integral component in the assessment of vocal behavior in groups of freely interacting animals is the ability to determine which animal is producing each vocal signal. This process is facilitated by using microphone arrays with multiple channels. Here, we made important refinements to a state-of-the-art microphone array based system used to localize vocal signals produced by freely interacting laboratory mice. Key changes to the system included increasing the number of microphones as well as refining the methodology for localizing and assigning vocal signals to individual mice. We systematically demonstrate that the improvements in the methodology for localizing mouse vocal signals led to an increase in the number of signals detected as well as the number of signals accurately assigned to an animal. These changes facilitated the acquisition of larger and more comprehensive data sets that better represent the vocal activity within an experiment. Furthermore, this system will allow more thorough analyses of the role that vocal signals play in social communication. We expect that such advances will broaden our understanding of social communication deficits in mouse models of neurological disorders. Copyright © 2018 Elsevier B.V. All rights reserved.

Analysis of glucose and lactate in hippocampal dialysates of rats during the operant conditioned reflex using microdialysis.

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Dong, Yu; Wang, Lei; Shangguan, Dihua; Yu, Xiao; Zhao, Rui; Han, Huiwan; Liu, Guoquan

2003-07-01

Changes of extracellular glucose and lactate in hippocampus for freely moving rats during the operant conditioned reflex were examined simultaneously. Samples of the dialysate were assayed for both glucose and lactate using in vivo microdialysis and a microbore flow injection analysis-immobilized enzyme reactor-electrochemical detection (FIA-IMER-ECD) system. Microdialysis samplings were conducted in a Skinner box where lights were delivered as conditioned stimuli (CS) paired with foot shocks as unconditioned stimuli (US). In the treatment group the concentration of glucose and lactate showed no fluctuations during the whole process. However, in the control group in which the rats were exposed to many foot shocks, lactate levels decreased by 19% below baseline during the behavioral session and glucose showed a delayed decrease (by 18%). Compared with glucose, lactate can immediately indicate the dynamic changes in brain.

A Wireless EEG Recording Method for Rat Use inside the Water Maze.

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Richard C Pinnell

Full Text Available With the continued miniaturisation of portable embedded systems, wireless EEG recording techniques are becoming increasingly prevalent in animal behavioural research. However, in spite of their versatility and portability, they have seldom been used inside water-maze tasks designed for rats. As such, a novel 3D printed implant and waterproof connector is presented, which can facilitate wireless water-maze EEG recordings in freely-moving rats, using a commercial wireless recording system (W32; Multichannel Systems. As well as waterproofing the wireless system, battery, and electrode connector, the implant serves to reduce movement-related artefacts by redistributing movement-related forces away from the electrode connector. This implant/connector was able to successfully record high-quality LFP in the hippocampo-striatal brain regions of rats as they undertook a procedural-learning variant of the double-H water-maze task. Notably, there were no significant performance deficits through its use when compared with a control group across a number of metrics including number of errors and speed of task completion. Taken together, this method can expand the range of measurements that are currently possible in this diverse area of behavioural neuroscience, whilst paving the way for integration with more complex behaviours.

One-electron densities of freely rotating Wigner molecules

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Cioslowski, Jerzy

2017-12-01

A formalism enabling computation of the one-particle density of a freely rotating assembly of identical particles that vibrate about their equilibrium positions with amplitudes much smaller than their average distances is presented. It produces densities as finite sums of products of angular and radial functions, the length of the expansion being determined by the interplay between the point-group and permutational symmetries of the system in question. Obtaining from a convolution of the rotational and bosonic components of the parent wavefunction, the angular functions are state-dependent. On the other hand, the radial functions are Gaussians with maxima located at the equilibrium lengths of the position vectors of individual particles and exponents depending on the scalar products of these vectors and the eigenvectors of the corresponding Hessian as well as the respective eigenvalues. Although the new formalism is particularly useful for studies of the Wigner molecules formed by electrons subject to weak confining potentials, it is readily adaptable to species (such as ´balliums’ and Coulomb crystals) composed of identical particles with arbitrary spin statistics and permutational symmetry. Several examples of applications of the present approach to the harmonium atoms within the strong-correlation regime are given.

The mechano-gated channel inhibitor GsMTx4 reduces the exercise pressor reflex in rats with ligated femoral arteries.

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Copp, Steven W; Kim, Joyce S; Ruiz-Velasco, Victor; Kaufman, Marc P

2016-05-01

Mechanical and metabolic stimuli arising from contracting muscles evoke the exercise pressor reflex. This reflex is greater in a rat model of simulated peripheral arterial disease in which a femoral artery is chronically ligated than it is in rats with freely perfused femoral arteries. The role played by the mechanically sensitive component of the exaggerated exercise pressor reflex in ligated rats is unknown. We tested the hypothesis that the mechano-gated channel inhibitor GsMTx4, a relatively selective inhibitor of mechano-gated Piezo channels, reduces the exercise pressor reflex in decerebrate rats with ligated femoral arteries. Injection of 10 μg of GsMTx4 into the arterial supply of the hindlimb reduced the pressor response to Achilles tendon stretch (a purely mechanical stimulus) but had no effect on the pressor responses to intra-arterial injection of α,β-methylene ATP or lactic acid (purely metabolic stimuli). Moreover, injection of 10 μg of GsMTx4 into the arterial supply of the hindlimb reduced both the integrated pressor area (control 535 ± 21, GsMTx4 218 ± 24 mmHg·s; P reflex contributes to the exaggerated exercise pressor reflex during intermittent hindlimb muscle contractions in rats with ligated femoral arteries. Copyright © 2016 the American Physiological Society.

Plasma growth hormone response to human growth hormone releasing factor in rats administered with chlorpromazine and antiserum against somatostatin. Effects of hypo- and hyperthyroidism.

Science.gov (United States)

Wakabayashi, I; Tonegawa, Y; Ihara, T; Hattori, M; Shibasaki, T; Ling, N

1985-10-01

The effect of hypo- and hyperthyroidism on the plasma growth hormone (GH) response to synthetic human growth hormone releasing factor (GRF) was determined in conscious, freely moving rats pretreated with chlorpromazine and antiserum against somatostatin. Chlorpromazine plus somatostatin antiserum pretreated rats gave consistent response to GRF which was not observed in untreated rats. Chlorpromazine alone has no effect on GH secretion induced by GRF in rat pituitary monolayer culture. In rats made hypothyroid by thyroidectomy, both basal and peak plasma GH responses to a small (0.25 microgram/kg bw) and a moderate dose of GRF (1 microgram/kg bw) were significantly reduced as compared to controls. In rats made hyperthyroid by the administration of thyroxine, basal and peak plasma GH responses to a small but not to a moderate dose of GRF were significantly reduced as compared to controls. A reduced plasma GH response to a small dose of GRF was observed 8 days after the cessation of thyroxine administration. The pituitary GH reserve was markedly reduced in hypothyroid but not in hyperthyroid rats as compared to their respective controls. These results indicate that plasma GH response to GRF is reduced both in hypo- and hyperthyroidism. The mechanism involved in the phenomenon appears to be different between the two conditions.

Spectrum of relativistic radiation from electric charges and dipoles as they fall freely into a black hole

Energy Technology Data Exchange (ETDEWEB)

Shatskiy, A. A., E-mail: shatskiy@asc.rssi.ru; Novikov, I. D.; Lipatova, L. N. [Russian Academy of Sciences, Astrospace Center, Lebedev Physical Institute (Russian Federation)

2013-06-15

The motion of electric charges and dipoles falling radially and freely into a Schwarzschild black hole is considered. The inverse effect of the electromagnetic fields on the black hole is neglected. Since the dipole is assumed to be a point particle, the deformation due to the action of tidal forces on it is neglected. According to the theorem stating that 'black holes have no hair', the multipole electromagnetic fields should be completely radiated as a multipole falls into a black hole. The electromagnetic radiation power spectrum for these multipoles (a monopole and a dipole) has been found. Differences have been found in the spectra for different orientations of the falling dipole. A general method has been developed to find the radiated multipole electromagnetic fields for multipoles (including higher-order multipoles-quadrupoles, etc.) falling freely into a black hole. The calculated electromagnetic spectra can be compared with observational data from stellar-mass and smaller black holes.

Solving Bilevel Multiobjective Programming Problem by Elite Quantum Behaved Particle Swarm Optimization

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Tao Zhang

2012-01-01

Full Text Available An elite quantum behaved particle swarm optimization (EQPSO algorithm is proposed, in which an elite strategy is exerted for the global best particle to prevent premature convergence of the swarm. The EQPSO algorithm is employed for solving bilevel multiobjective programming problem (BLMPP in this study, which has never been reported in other literatures. Finally, we use eight different test problems to measure and evaluate the proposed algorithm, including low dimension and high dimension BLMPPs, as well as attempt to solve the BLMPPs whose theoretical Pareto optimal front is not known. The experimental results show that the proposed algorithm is a feasible and efficient method for solving BLMPPs.

Mechanical mandible competence in rats with nutritional growth retardation.

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Lezón, Christian Esteban; Pintos, Patricia Mabel; Bozzini, Clarisa; Romero, Alan Agüero; Casavalle, Patricia; Friedman, Silvia María; Boyer, Patricia Mónica

2017-08-01

In order to provide a better understanding of the sympathetic nervous system as a negative regulator of bone status, the aim of the study was to establish the biomechanical mandible response to different doses of a β-adrenergic antagonist such as propranolol (P) in a stress-induced food restriction model of growth retardation. Rats were assigned to eight groups: Control (C), C+P3.5 (CP3.5), C+P7 (CP7), C+P14 (CP14), NGR, NGR+P3.5 (NGRP3.5), NGR+P7 (NGRP7) and NGR+P14 (NGRP14). C, CP3.5, CP7 and CP14 rats were freely fed with the standard diet. NGR, NGRP3.5, NGRP7 and NGRP14 rats received, for 4 weeks (W4), 80% of the amount of controls food consumed. Propranolol 3.5, 7 and 14mg/kg/day was injected ip 5days per week in CP3.5 and NGRP3.5, CP7 and NGRP7, CP14 and NGRP14, respectively. At W4, zoometry, mandible morphometry, static histomorphometric and biomechanical competence were performed. A dose of Propranolol 7mg/kg/day induced interradicular bone volume accretion reaching a mandible stiffness according to chronological age. These findings evidenced that sympathetic nervous system activity is a negative regulator of mandible mechanical competence in the nutritional growth retardation model. Propranolol 7mg/kg/day, under the regimen usage, seems to be appropriate to blockade SNS activity on mandible mechanical performance in NGR rats, probably associated to an effect on bone mechanostat system ability to detect disuse mode as an error. Copyright © 2017 Elsevier Ltd. All rights reserved.

Motor tics evoked by striatal disinhibition in the rat

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Bronfeld, Maya; Yael, Dorin; Belelovsky, Katya; Bar-Gad, Izhar

2013-01-01

Motor tics are sudden, brief, repetitive movements that constitute the main symptom of Tourette syndrome (TS). Multiple lines of evidence suggest the involvement of the cortico-basal ganglia system, and in particular the basal ganglia input structure—the striatum in tic formation. The striatum receives somatotopically organized cortical projections and contains an internal GABAergic network of interneurons and projection neurons' collaterals. Disruption of local striatal GABAergic connectivity has been associated with TS and was found to induce abnormal movements in model animals. We have previously described the behavioral and neurophysiological characteristics of motor tics induced in monkeys by local striatal microinjections of the GABAA antagonist bicuculline. In the current study we explored the abnormal movements induced by a similar manipulation in freely moving rats. We targeted microinjections to different parts of the dorsal striatum, and examined the effects of this manipulation on the induced tic properties, such as latency, duration, and somatic localization. Tics induced by striatal disinhibition in monkeys and rats shared multiple properties: tics began within several minutes after microinjection, were expressed solely in the contralateral side, and waxed and waned around a mean inter-tic interval of 1–4 s. A clear somatotopic organization was observed only in rats, where injections to the anterior or posterior striatum led to tics in the forelimb or hindlimb areas, respectively. These results suggest that striatal disinhibition in the rat may be used to model motor tics such as observed in TS. Establishing this reliable and accessible animal model could facilitate the study of the neural mechanisms underlying motor tics, and the testing of potential therapies for tic disorders. PMID:24065893

Pressor response to L-cysteine injected into the cisterna magna of conscious rats involves recruitment of hypothalamic vasopressinergic neurons.

Science.gov (United States)

Takemoto, Yumi

2013-03-01

The sulfur-containing non-essential amino acid L-cysteine injected into the cisterna magna of adult conscious rats produces an increase in blood pressure. The present study examined if the pressor response to L-cysteine is stereospecific and involves recruitment of hypothalamic vasopressinergic neurons and medullary noradrenergic A1 neurons. Intracisternally injected D-cysteine produced no cardiovascular changes, while L-cysteine produced hypertension and tachycardia in freely moving rats, indicating the stereospecific hemodynamic actions of L-cysteine via the brain. The double labeling immunohistochemistry combined with c-Fos detection as a marker of neuronal activation revealed significantly higher numbers of c-Fos-positive vasopressinergic neurons both in the supraoptic and paraventricular nuclei and tyrosine hydroxylase containing medullary A1 neurons, of L-cysteine-injected rats than those injected with D-cysteine as iso-osmotic control. The results indicate that the cardiovascular responses to intracisternal injection of L-cysteine in the conscious rat are stereospecific and include recruitment of hypothalamic vasopressinergic neurons both in the supraoptic and paraventricular nuclei, as well as of medullary A1 neurons. The findings may suggest a potential function of L-cysteine as an extracellular signal such as neuromodulators in central regulation of blood pressure.

The Effects of Spaceflight on the Rat Circadian Timing System

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Fuller, Charles A.; Murakami, Dean M.; Hoban-Higgins, Tana M.; Fuller, Patrick M.; Robinson, Edward L.; Tang, I.-Hsiung

2003-01-01

Two fundamental environmental influences that have shaped the evolution of life on Earth are gravity and the cyclic changes occurring over the 24-hour day. Light levels, temperature, and humidity fluctuate over the course of a day, and organisms have adapted to cope with these variations. The primary adaptation has been the evolution of a biological timing system. Previous studies have suggested that this system, named the circadian (circa - about; dies - a day) timing system (CTS), may be sensitive to changes in gravity. The NASA Neurolab spaceflight provided a unique opportunity to evaluate the effects of microgravity on the mammalian CTS. Our experiment tested the hypotheses that microgravity would affect the period, phasing, and light sensitivity of the CTS. Twenty-four Fisher 344 rats were exposed to 16 days of microgravity on the Neurolab STS-90 mission, and 24 Fisher 344 rats were also studied on Earth as one-G controls. Rats were equipped with biotelemetry transmitters to record body temperature (T(sub b)) and heart rate (HR) continuously while the rats moved freely. In each group, 18 rats were exposed to a 24-hour light-dark (LD 12:12) cycle, and six rats were exposed to constant dim red-light (LL). The ability of light to induce a neuronal activity marker (c-fos) in the circadian pacemaker of the brain, the suprachiasmatic nucleus (SCN), was examined in rats studied on flight days two (FD2) and 14 (FD14), and postflight days two (R+1) and 14 (R+13). The flight rats in LD remained synchronized with the LD cycle. However, their T(sub b), rhythm was markedly phase-delayed relative to the LD cycle. The LD flight rats also had a decreased T(sub b) and a change in the waveform of the T(sub b) rhythm compared to controls. Rats in LL exhibited free-running rhythms of T(sub b), and HR; however, the periods were longer in microgravity. Circadian period returned to preflight values after landing. The internal phase angle between rhythms was different in flight than

A Novel and Freely Available Interactive 3d Model of the Internal Carotid Artery.

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Valera-Melé, Marc; Puigdellívol-Sánchez, Anna; Mavar-Haramija, Marija; Juanes-Méndez, Juan A; San-Román, Luis; de Notaris, Matteo; Prats-Galino, Alberto

2018-03-05

We describe a new and freely available 3D interactive model of the intracranial internal carotid artery (ICA) and the skull base that also allows to display and compare its main segment classifications. High-resolution 3D human angiography (isometric voxel's size 0.36 mm) and Computed Tomography angiography images were exported to Virtual Reality Modeling Language (VRML) format for processing in a 3D software platform and embedding in a 3D Portable Document Format (PDF) document that can be freely downloaded at http://diposit.ub.edu/dspace/handle/2445/112442 and runs under Acrobat Reader on Mac and Windows computers and Windows 10 tablets. The 3D-PDF allows for visualisation and interaction through JavaScript-based functions (including zoom, rotation, selective visualization and transparentation of structures or a predefined sequence view of the main segment classifications if desired). The ICA and its main branches and loops, the Gasserian ganglion, the petrolingual ligament and the proximal and distal dural rings within the skull base environment (anterior and posterior clinoid processes, silla turcica, ethmoid and sphenoid bones, orbital fossae) may be visualized from different perspectives. This interactive 3D-PDF provides virtual views of the ICA and becomes an innovative tool to improve the understanding of the neuroanatomy of the ICA and surrounding structures.

Targeted, noninvasive blockade of cortical neuronal activity

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McDannold, Nathan; Zhang, Yongzhi; Power, Chanikarn; Arvanitis, Costas D.; Vykhodtseva, Natalia; Livingstone, Margaret

2015-11-01

Here we describe a novel method to noninvasively modulate targeted brain areas through the temporary disruption of the blood-brain barrier (BBB) via focused ultrasound, enabling focal delivery of a neuroactive substance. Ultrasound was used to locally disrupt the BBB in rat somatosensory cortex, and intravenous administration of GABA then produced a dose-dependent suppression of somatosensory-evoked potentials in response to electrical stimulation of the sciatic nerve. No suppression was observed 1-5 days afterwards or in control animals where the BBB was not disrupted. This method has several advantages over existing techniques: it is noninvasive; it is repeatable via additional GABA injections; multiple brain regions can be affected simultaneously; suppression magnitude can be titrated by GABA dose; and the method can be used with freely behaving subjects. We anticipate that the application of neuroactive substances in this way will be a useful tool for noninvasively mapping brain function, and potentially for surgical planning or novel therapies.

Freely chosen cadence during a covert manipulation of ambient temperature.

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Hartley, Geoffrey L; Cheung, Stephen S

2013-01-01

The present study investigated relationships between changes in power output (PO) to torque (TOR) or freely chosen cadence (FCC) during thermal loading. Twenty participants cycled at a constant rating of perceived exertion while ambient temperature (Ta) was covertly manipulated at 20-min intervals of 20 °C, 35 °C, and 20 °C. The magnitude responses of PO, FCC and TOR were analyzed using repeated-measures ANOVA, while the temporal correlations were analyzed using Auto-Regressive Integrated Moving Averages (ARIMA). Increases in Ta caused significant thermal strain (p FCC remained unchanged (p = .51). ARIMA indicates that changes in PO were highly correlated to TOR (stationary r2 = .954, p = .04), while FCC was moderately correlated (stationary r2 = .717, p = .01) to PO. In conclusion, changes in PO are caused by a modulation in TOR, whereas FCC remains unchanged and therefore, unaffected by thermal stressors.

Central estrogenic pathways protect against the depressant action of acute nicotine on reflex tachycardia in female rats

Energy Technology Data Exchange (ETDEWEB)

El-Mas, Mahmoud M., E-mail: mahelm@hotmail.com; Fouda, Mohamed A.; El-gowilly, Sahar M.; Saad, Evan I.

2012-02-01

We have previously shown that acute exposure of male rats to nicotine preferentially attenuates baroreceptor-mediated control of reflex tachycardia in contrast to no effect on reflex bradycardia. Here, we investigated whether female rats are as sensitive as their male counterparts to the baroreflex depressant effect of nicotine and whether this interaction is modulated by estrogen. Baroreflex curves relating reflex chronotropic responses evoked by i.v. doses (1–16 μg/kg) of phenylephrine (PE) or sodium nitroprusside (SNP), were constructed in conscious freely moving proestrus, ovariectomized (OVX), and estrogen (50 μg/kg/day s.c., 5 days)-replaced OVX (OVXE{sub 2}) rats. Slopes of the curves were taken as a measure of baroreflex sensitivity (BRS{sub PE} and BRS{sub SNP}). Nicotine (100 μg/kg i.v.) reduced BRS{sub SNP} in OVX rats but not in proestrus or OVXE{sub 2} rats. The attenuation of reflex tachycardia by nicotine was also evident in diestrus rats, which exhibited plasma estrogen levels similar to those of OVX rats. BRS{sub PE} was not affected by nicotine in all rat preparations. Experiments were then extended to determine whether central estrogenic receptors modulate the nicotine–BRS{sub SNP} interaction. Intracisteral (i.c.) treatment of OVX rats with estrogen sulfate (0.2 μg/rat) abolished the BRS{sub SNP} attenuating effect of i.v. nicotine. This protective effect of estrogen disappeared when OVX rats were pretreated with i.c. ICI 182,780 (50 μg/rat, selective estrogen receptor antagonist). Together, these findings suggest that central neural pools of estrogen receptors underlie the protection offered by E{sub 2} against nicotine-induced baroreceptor dysfunction in female rats. -- Highlights: ► Estrogen protects against the depressant effect of nicotine on reflex tachycardia. ► The baroreflex response and estrogen status affect the nicotine–BRS interaction. ► The protection offered by estrogen is mediated via central estrogen receptors.

Optical cuff for optogenetic control of the peripheral nervous system

Science.gov (United States)

Michoud, Frédéric; Sottas, Loïc; Browne, Liam E.; Asboth, Léonie; Latremoliere, Alban; Sakuma, Miyuki; Courtine, Grégoire; Woolf, Clifford J.; Lacour, Stéphanie P.

2018-02-01

Objective. Nerves in the peripheral nervous system (PNS) contain axons with specific motor, somatosensory and autonomic functions. Optogenetics offers an efficient approach to selectively activate axons within the nerve. However, the heterogeneous nature of nerves and their tortuous route through the body create a challenging environment to reliably implant a light delivery interface. Approach. Here, we propose an optical peripheral nerve interface—an optocuff—, so that optogenetic modulation of peripheral nerves become possible in freely behaving mice. Main results. Using this optocuff, we demonstrate orderly recruitment of motor units with epineural optical stimulation of genetically targeted sciatic nerve axons, both in anaesthetized and in awake, freely behaving animals. Behavioural experiments and histology show the optocuff does not damage the nerve thus is suitable for long-term experiments. Significance. These results suggest that the soft optocuff might be a straightforward and efficient tool to support more extensive study of the PNS using optogenetics.

Education based thinking and behaving? Towards an identity perspective for studying education differentials in public opinion and political participation

NARCIS (Netherlands)

Spruyt, Bram; Kuppens, Toon

2015-01-01

Education based thinking and behaving? Towards and identity perspective for studying education differentials in public opinion and political participation Abstract Ever since scholars started studying public opinion and political behaviour, they have reported substantial educational differences.

Critical comparison of hydrodynamic models for gas-solid fluidized beds - Part II: freely bubbling gas-solid fluidized beds

NARCIS (Netherlands)

Patil, D.J.; van Sint Annaland, M.; Kuipers, J.A.M.

2005-01-01

Correct prediction of spontaneous bubble formation in freely bubbling gas¿solid fluidized beds using Eulerian models, strongly depends on the description of the internal momentum transfer in the particulate phase. In this part, the comparison of the simple classical model, describing the solid phase

Recovery time after intra-abdominal transmitter placement for telemetric (neuro)physiological measurement in freely moving common marmosets (Callitrix jacchus).

NARCIS (Netherlands)

Bakker, Jaco; Arndt, Saskia; Klomp, Rianne; Rijnbeek, Milene, W.M.; Philippens, Ingrid, H.C.H.M.; Langermans, Jan, A.

2014-01-01

Background Telemetry is very important for monitoring physiological functions in awake and freely moving laboratory animals. Although implantable transmitters reduce stress resulting from daily handling and restraint, the procedure requires invasive surgery, which affects behaviour and wellbeing of

Synthetic tactile perception induced by transcranial alternating-current stimulation can substitute for natural sensory stimulus in behaving rabbits.

Science.gov (United States)

Márquez-Ruiz, Javier; Ammann, Claudia; Leal-Campanario, Rocío; Ruffini, Giulio; Gruart, Agnès; Delgado-García, José M

2016-01-21

The use of brain-derived signals for controlling external devices has long attracted the attention from neuroscientists and engineers during last decades. Although much effort has been dedicated to establishing effective brain-to-computer communication, computer-to-brain communication feedback for "closing the loop" is now becoming a major research theme. While intracortical microstimulation of the sensory cortex has already been successfully used for this purpose, its future application in humans partly relies on the use of non-invasive brain stimulation technologies. In the present study, we explore the potential use of transcranial alternating-current stimulation (tACS) for synthetic tactile perception in alert behaving animals. More specifically, we determined the effects of tACS on sensory local field potentials (LFPs) and motor output and tested its capability for inducing tactile perception using classical eyeblink conditioning in the behaving animal. We demonstrated that tACS of the primary somatosensory cortex vibrissa area could indeed substitute natural stimuli during training in the associative learning paradigm.

Behavioral Phenotyping of Juvenile Long-Evans and Sprague-Dawley Rats: Implications for Preclinical Models of Autism Spectrum Disorders.

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Katherine M Ku

Full Text Available The laboratory rat is emerging as an attractive preclinical animal model of autism spectrum disorder (ASD, allowing investigators to explore genetic, environmental and pharmacological manipulations in a species exhibiting complex, reciprocal social behavior. The present study was carried out to compare two commonly used strains of laboratory rats, Sprague-Dawley (SD and Long-Evans (LE, between the ages of postnatal day (PND 26-56 using high-throughput behavioral phenotyping tools commonly used in mouse models of ASD that we have adapted for use in rats. We detected few differences between young SD and LE strains on standard assays of exploration, sensorimotor gating, anxiety, repetitive behaviors, and learning. Both SD and LE strains also demonstrated sociability in the 3-chamber social approach test as indexed by spending more time in the social chamber with a constrained age/strain/sex matched novel partner than in an identical chamber without a partner. Pronounced differences between the two strains were, however, detected when the rats were allowed to freely interact with a novel partner in the social dyad paradigm. The SD rats in this particular testing paradigm engaged in play more frequently and for longer durations than the LE rats at both juvenile and young adult developmental time points. Results from this study that are particularly relevant for developing preclinical ASD models in rats are threefold: (i commonly utilized strains exhibit unique patterns of social interactions, including strain-specific play behaviors, (ii the testing environment may profoundly influence the expression of strain-specific social behavior and (iii simple, automated measures of sociability may not capture the complexities of rat social interactions.

BADAL: A Culture of Revenge, The Impact of Collateral Damage on Taliban Insurgency

Science.gov (United States)

2008-03-01

residents’ (on both side of the border) point of view, Durand Line is a virtual border and is trespassed across freely, without any legal document or... Positiv e Perception of Coalition Behav ior Kill Rate ~ Attrition Rate ~ Attritions Rate 2 ~ Collateral Damage Civ ilian Deaths ~ Death Rate Madrassa

Nicotine intake and problem solving strategies are modified during a cognitively demanding water maze task in rats.

Science.gov (United States)

Nesil, Tanseli; Kanit, Lutfiye; Pogun, Sakire

2015-11-01

Nicotine is the major addictive component in tobacco, and despite well-established adverse health effects of tobacco addiction, some smokers have difficulty quitting. The acute cognitive enhancement and/or the amelioration of the cognitive disruption during withdrawal that some smokers experience after smoking are among important factors that hinder quit attempts. The animal model presented in the current study is comparable to the human smoking condition although nicotine intake routes are different. Rats were exposed to a free choice of oral nicotine starting at adolescence, and given a water maze (WM) task as adults. This design allowed us to see if rats alter their nicotine intake during the WM task and if nicotine preference and intake modify abilities and strategies rats use for problem solving. Male and female rats were exposed to a free choice of oral nicotine/water for 24weeks, starting at five weeks of age. After this period, they were selected based on their nicotine intake and, together with control animals that received only water, were subjected to a place-learning task in the WM. Free-choice nicotine exposure continued during WM testing. Following acquisition, the probe trial presented the rats with a choice between using two different strategies for problem solving. Nicotine supported acquisition and rats increased their nicotine intake during WM testing; this effect was more pronounced in male rats with minimum nicotine preference and intake. Furthermore, nicotine modified the "female type" strategy in solving the place-learning task and nicotine treated female rats, unlike control females, behaved like males. The increase in nicotine intake during mental engagement, and the sexually dimorphic effect of nicotine on problem solving strategies that we have observed in rats, may suggest that implementing sex-specific smoking cessation approaches, especially under stressful and cognitively demanding conditions, may be useful in helping smokers quit

Academic Achievement and Classification of Students from the Freely Associated States in Guam Schools. REL 2017-260

Science.gov (United States)

Stewart, Joshua; Stringer, Katie; Arens, Sheila A.; Cicchinelli, Louis F.; San Nicolas, Heidi; Flores, Nieves

2017-01-01

Guam is home to the largest population of migrants from the Freely Associated States (FAS): the Federated States of Micronesia, the Republic of the Marshall Islands, and the Republic of Palau. FAS students made up 22 percent of total student enrollment in Guam public schools in 2012. FAS students face a number of challenges when they enter Guam…

Sex differences in methamphetamine seeking in rats: impact of oxytocin.

Science.gov (United States)

Cox, Brittney M; Young, Amy B; See, Ronald E; Reichel, Carmela M

2013-10-01

Previous evidence in an animal model of drug self-administration and drug seeking showed that acute oxytocin decreased methamphetamine (meth) seeking in male rats, suggesting potential clinical efficacy for the treatment of psychostimulant addiction. However, based on the well-established role of oxytocin in reproduction and pair bond formation, it is important to know how this effect extrapolates to females. Here, we tested whether oxytocin (1mg/kg, IP) would decrease meth seeking in female rats across various stages of the estrous cycle (Experiment 1). Freely cycling Long Evans female rats self-administered meth (IV) in 2-h daily sessions, followed by daily extinction sessions. Following extinction, rats received oxytocin (0, 0.3, or 1mg/kg, IP) 30min before a meth priming injection (1mg/kg, IP) to assess reinstatement of meth seeking. Next, we examined the effects of oxytocin on motivated meth- and sucrose-taking and seeking in male and female rats. In separate experiments, males and females self-administered meth (Experiment 2) or sucrose (Experiment 3) until responding was stabilized along a fixed ratio (FR) 5 schedule of reinforcement. Subsequently, rats received either oxytocin or vehicle prior to self-administration along a progressive ratio (PR) schedule of reinforcement. Rats were subsequently tested for cue-, meth-, and stress-induced reinstatement after pretreatment with oxytocin or vehicle. While oxytocin reduced meth seeking in females, we found that estrous cycle stage (as determined from vaginal cytology) did not influence meth-primed reinstatement or the ability of oxytocin to decrease reinstatement of meth seeking. Oxytocin reduced PR responding for meth only in females. Females responded more than males during cue-induced reinstatement of meth and sucrose seeking, and oxytocin reduced this responding only in meth females. In both sexes, oxytocin attenuated meth seeking in response to a meth prime and yohimbine (a pharmacological stressor). The

Influence of Secondary Hyperparathyroidism Induced by Low Dietary Calcium, Vitamin D Deficiency, and Renal Failure on Circulating Rat PTH Molecular Forms.

Science.gov (United States)

D'Amour, Pierre; Rousseau, Louise; Hornyak, Stephen; Yang, Zan; Cantor, Tom

2011-01-01

Rats(r) with secondary hyperparathyroidism were studied to define the relationship between vitamin D metabolites and rPTH levels measured by 3 different rat ELISAs. Controls and renal failure (RF) rats were on a normal diet, while 2 groups on a low-calcium (-Ca) or a vitamin D-deficient (-D) diet. RF was induced surgically. Mild RF rats had normal calcium and 25(OH)D but reduced 1,25(OH)(2)D levels (P < .001) with a 2.5-fold increased in rPTH (P < .001). Severe RF rats and those on a -Ca or -D diet had reduced calcium (P < .01) and 25(OH)D levels (P < .05), with rPTH increased by 2 (-Ca diet; P < .05), 4 (-D diet; P < .001), and 20-folds (RF; P < .001) while 1,25(OH)(2)D was high (-Ca diet: P < .001) or low (-D diet, RF: P < .001). 25(OH)D and 1,25(OH)(2)D were positively and negatively related on the -Ca and -D diets, respectively. rPTH molecular forms behaved as expected in RF and on -Ca diet, but not on -D diet with more C-rPTH fragments when less were expected. This may be related to the short-time course of this study compared to prior studies.

Neurotoxic effects of levobupivacaine and fentanyl on rat spinal cord

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Yesim Cokay Abut

2015-02-01

Full Text Available BACKGROUND: The purpose of the study was to compare the neurotoxic effects of intrathecally administered levobupivacaine, fentanyl and their mixture on rat spinal cord. METHODS: In experiment, there were four groups with medication and a control group. Rats were injected 15 µL saline or fentanyl 0.0005 µg/15 µL, levobupivacaine 0.25%/15 µL and fentanyl 0.0005 µg + levobupivacaine 0.25%/15 µL intrathecally for four days. Hot plate test was performed to assess neurologic function after each injection at 5th, 30th and 60th min. Five days after last lumbal injection, spinal cord sections between the T5 and T6 vertebral levels were obtained for histologic analysis. A score based on subjective assessment of number of eosinophilic neurons - Red neuron - which means irreversible neuronal degeneration. They reflect the approximate number of degenerating neurons present in the affected neuroanatomic areas as follows: 1, none; 2, 1-20%; 3, 21-40%; 4, 41-60%; and 5, 61-100% dead neurons. An overall neuropathologic score was calculated for each rat by summating the pathologic scores for all spinal cord areas examined. RESULTS: In the results of HPT, comparing the control group, analgesic latency statistically prolonged for all four groups.In neuropathologic investment, the fentanyl and fentanyl + levobupivacaine groups have statistically significant high degenerative neuron counts than control and saline groups. CONCLUSIONS: These results suggest that, when administered intrathecally in rats, fentanyl and levobupivacaine behave similar for analgesic action, but fentanyl may be neurotoxic for spinal cord. There was no significant degeneration with levobupivacaine, but fentanyl group has had significant degeneration.

Neural responses in the primary auditory cortex of freely behaving cats while discriminating fast and slow click-trains.

Science.gov (United States)

Dong, Chao; Qin, Ling; Liu, Yongchun; Zhang, Xinan; Sato, Yu

2011-01-01

Repeated acoustic events are ubiquitous temporal features of natural sounds. To reveal the neural representation of the sound repetition rate, a number of electrophysiological studies have been conducted on various mammals and it has been proposed that both the spike-time and firing rate of primary auditory cortex (A1) neurons encode the repetition rate. However, previous studies rarely examined how the experimental animals perceive the difference in the sound repetition rate, and a caveat to these experiments is that they compared physiological data obtained from animals with psychophysical data obtained from humans. In this study, for the first time, we directly investigated acoustic perception and the underlying neural mechanisms in the same experimental animal by examining spike activities in the A1 of free-moving cats while performing a Go/No-go task to discriminate the click-trains at different repetition rates (12.5-200 Hz). As reported by previous studies on passively listening animals, A1 neurons showed both synchronized and non-synchronized responses to the click-trains. We further found that the neural performance estimated from the precise temporal information of synchronized units was good enough to distinguish all 16.7-200 Hz from the 12.5 Hz repetition rate; however, the cats showed declining behavioral performance with the decrease of the target repetition rate, indicating an increase of difficulty in discriminating two slower click-trains. Such behavioral performance was well explained by the firing rate of some synchronized and non-synchronized units. Trial-by-trial analysis indicated that A1 activity was not affected by the cat's judgment of behavioral response. Our results suggest that the main function of A1 is to effectively represent temporal signals using both spike timing and firing rate, while the cats may read out the rate-coding information to perform the task in this experiment.

Neural responses in the primary auditory cortex of freely behaving cats while discriminating fast and slow click-trains.

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Chao Dong

Full Text Available Repeated acoustic events are ubiquitous temporal features of natural sounds. To reveal the neural representation of the sound repetition rate, a number of electrophysiological studies have been conducted on various mammals and it has been proposed that both the spike-time and firing rate of primary auditory cortex (A1 neurons encode the repetition rate. However, previous studies rarely examined how the experimental animals perceive the difference in the sound repetition rate, and a caveat to these experiments is that they compared physiological data obtained from animals with psychophysical data obtained from humans. In this study, for the first time, we directly investigated acoustic perception and the underlying neural mechanisms in the same experimental animal by examining spike activities in the A1 of free-moving cats while performing a Go/No-go task to discriminate the click-trains at different repetition rates (12.5-200 Hz. As reported by previous studies on passively listening animals, A1 neurons showed both synchronized and non-synchronized responses to the click-trains. We further found that the neural performance estimated from the precise temporal information of synchronized units was good enough to distinguish all 16.7-200 Hz from the 12.5 Hz repetition rate; however, the cats showed declining behavioral performance with the decrease of the target repetition rate, indicating an increase of difficulty in discriminating two slower click-trains. Such behavioral performance was well explained by the firing rate of some synchronized and non-synchronized units. Trial-by-trial analysis indicated that A1 activity was not affected by the cat's judgment of behavioral response. Our results suggest that the main function of A1 is to effectively represent temporal signals using both spike timing and firing rate, while the cats may read out the rate-coding information to perform the task in this experiment.

An image-free opto-mechanical system for creating virtual environments and imaging neuronal activity in freely moving Caenorhabditis elegans.

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Serge Faumont

Full Text Available Non-invasive recording in untethered animals is arguably the ultimate step in the analysis of neuronal function, but such recordings remain elusive. To address this problem, we devised a system that tracks neuron-sized fluorescent targets in real time. The system can be used to create virtual environments by optogenetic activation of sensory neurons, or to image activity in identified neurons at high magnification. By recording activity in neurons of freely moving C. elegans, we tested the long-standing hypothesis that forward and reverse locomotion are generated by distinct neuronal circuits. Surprisingly, we found motor neurons that are active during both types of locomotion, suggesting a new model of locomotion control in C. elegans. These results emphasize the importance of recording neuronal activity in freely moving animals and significantly expand the potential of imaging techniques by providing a mean to stabilize fluorescent targets.

[Effects of excess vitamin B1 or vitamin B2 on growth and urinary excretion of water-soluble vitamins in weaning rats].

Science.gov (United States)

Fukuwatari, Tsutomu; Kuzuya, Mako; Satoh, Shiori; Shibata, Katsumi

2009-04-01

To determine the tolerable upper intake levels of vitamin B(1) and vitamin B(2) in humans, we investigated the effects of excess thiamin or riboflavin administration on body weight gain, food intake, tissue weights, and urinary excretion of B-group vitamins in weaning rats. The weaning rats were freely fed ordinary diet containing 0.0006% thiamin-HCl or the same diet with 0.006%, 0.03%, 0.18% or 1.0% thiamin-HCl for 30 days, or the diet containing 0.0006% riboflavin or the same diet with 0.1%, 0.5 or 1.0% riboflavin for 22 days. Mild diarrhea was seen only in the rats fed with 1.0% thiamin-HCl diet. Excess thiamin-HCl or riboflavin did not affect body weight gains, food intake or tissue weights. The urinary excretions of water-soluble vitamins also did not differ among the diets. These results clearly showed that feeding a diet containing up to 1.0% thiamin-HCl or 1.0% riboflavin did not induce apparent adverse effects, and the no-observed-adverse-effect-levels (NOAELs) for thiamin-HCl and riboflavin in rats might be 1.0% in diet, corresponding to 900 mg/kg body weight/day.

Ionic liquids behave as dilute electrolyte solutions

Science.gov (United States)

Gebbie, Matthew A.; Valtiner, Markus; Banquy, Xavier; Fox, Eric T.; Henderson, Wesley A.; Israelachvili, Jacob N.

2013-01-01

We combine direct surface force measurements with thermodynamic arguments to demonstrate that pure ionic liquids are expected to behave as dilute weak electrolyte solutions, with typical effective dissociated ion concentrations of less than 0.1% at room temperature. We performed equilibrium force–distance measurements across the common ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) using a surface forces apparatus with in situ electrochemical control and quantitatively modeled these measurements using the van der Waals and electrostatic double-layer forces of the Derjaguin–Landau–Verwey–Overbeek theory with an additive repulsive steric (entropic) ion–surface binding force. Our results indicate that ionic liquids screen charged surfaces through the formation of both bound (Stern) and diffuse electric double layers, where the diffuse double layer is comprised of effectively dissociated ionic liquid ions. Additionally, we used the energetics of thermally dissociating ions in a dielectric medium to quantitatively predict the equilibrium for the effective dissociation reaction of [C4mim][NTf2] ions, in excellent agreement with the measured Debye length. Our results clearly demonstrate that, outside of the bound double layer, most of the ions in [C4mim][NTf2] are not effectively dissociated and thus do not contribute to electrostatic screening. We also provide a general, molecular-scale framework for designing ionic liquids with significantly increased dissociated charge densities via judiciously balancing ion pair interactions with bulk dielectric properties. Our results clear up several inconsistencies that have hampered scientific progress in this important area and guide the rational design of unique, high–free-ion density ionic liquids and ionic liquid blends. PMID:23716690

A freely-available authoring system for browser-based CALL with speech recognition

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Myles O'Brien

2017-06-01

Full Text Available A system for authoring browser-based CALL material incorporating Google speech recognition has been developed and made freely available for download. The system provides a teacher with a simple way to set up CALL material, including an optional image, sound or video, which will elicit spoken (and/or typed answers from the user and check them against a list of specified permitted answers, giving feedback with hints when necessary. The teacher needs no HTML or Javascript expertise, just the facilities and ability to edit text files and upload to the Internet. The structure and functioning of the system are explained in detail, and some suggestions are given for practical use. Finally, some of its limitations are described.

Effect of ginseng saponina on nicotine-induced dopamine release in the rat nucleus accumbens and striatum

International Nuclear Information System (INIS)

Kim, Sang Eun; Shim, In Sop; Chung, June Key; Lee, Myung Chul

2002-01-01

We investigated the effect of ginseng total saponin (GTS) on nicotine-induced dopamine (DA) release in the striatum and nucleus accumbens of freely moving rats using in vivo microdialysis technique. Systemic pretreatment with GTS decreased striatal DA release induced by local infusion of nicotine into the striatum. However, GTS had no effect on the resting levels of extracellular DA in the striatum. GTS also blocked nicotine-induced DA release in the nucleus accumbens. The results of the present study suggest that GTS acts on the DA terminals to prevent DA release induced by nicotine. This may reflect the blocking effect of GTS on behavioral hyperactivity induced by psychostimulants

Effect of ginseng saponina on nicotine-induced dopamine release in the rat nucleus accumbens and striatum

Energy Technology Data Exchange (ETDEWEB)

Kim, Sang Eun [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Shim, In Sop [Kyunghee University, Seoul (Korea, Republic of); Chung, June Key; Lee, Myung Chul [Seoul National University College of Medicine, Seoul (Korea, Republic of)

2002-10-01

We investigated the effect of ginseng total saponin (GTS) on nicotine-induced dopamine (DA) release in the striatum and nucleus accumbens of freely moving rats using in vivo microdialysis technique. Systemic pretreatment with GTS decreased striatal DA release induced by local infusion of nicotine into the striatum. However, GTS had no effect on the resting levels of extracellular DA in the striatum. GTS also blocked nicotine-induced DA release in the nucleus accumbens. The results of the present study suggest that GTS acts on the DA terminals to prevent DA release induced by nicotine. This may reflect the blocking effect of GTS on behavioral hyperactivity induced by psychostimulants.

DNA polymerases in the rat pituitary gland. Effect of oestrogens and sulpiride.

Science.gov (United States)

Jahn, G A; Kalbermann, L E; Machiavelli, G; Szijan, I; Burdman, J A

1980-06-01

Changes in the activity of DNA polymerase and [3H]thymidine incorporation into the DNA of the anterior pituitary gland were studied in oestrogenized male and pregnant rats. The activities of DNA polymerases alpha and beta, extracted in Tris--HCl or in sodium phosphate buffer were characterized according to their optimum pH and sensitivity to N-ethyl-maleimide. In the Tris-soluble fraction DNA polymerase activity is almost exclusively alpha, while in the phosphate soluble fraction it is a mixture of alpha and beta. The administration of oestrogens to male rats increases [3H]thymidine incorporation and enhances the activity of DNA polymerases in the Tris-soluble fraction, while the activity of the phosphate-soluble enzyme does not change. Sulpiride administration results in a further increment of [3H]thymidine incorporation and of DNA polymerase activity in the Tris-soluble fraction. In pregnant rats sulpiride also produces an increment of DNA polymerase activity only in the Tris-soluble fraction. Thus, the activity of the Tris-soluble fraction from APG behaves as DNA polymerase alpha. This activity changes in parallel with [3H]thymidine incorporation into DNA which is an indication of cell proliferation in the gland. This is discussed with respect to a negative feedback mechanism between intracellular prolactin concentration and DNA synthesis in the APG.

Firing properties of dopamine neurons in freely moving dopamine-deficient mice: Effects of dopamine receptor activation and anesthesia

OpenAIRE

Robinson, Siobhan; Smith, David M.; Mizumori, Sheri J. Y.; Palmiter, Richard D.

2004-01-01

To examine the regulation of midbrain dopamine neurons, recordings were obtained from single neurons of freely moving, genetically engineered dopamine-deficient (DD) mice. DD mice were tested without dopamine signaling (basal state) and with endogenous dopamine signaling (after L-dopa administration). In the basal state, when dopamine concentration in DD mice is

Deletion of Type 2 Metabotropic Glutamate Receptor Decreases Sensitivity to Cocaine Reward in Rats.

Science.gov (United States)

Yang, Hong-Ju; Zhang, Hai-Ying; Bi, Guo-Hua; He, Yi; Gao, Jun-Tao; Xi, Zheng-Xiong

2017-07-11

Cocaine users show reduced expression of the metabotropic glutamate receptor (mGluR2), but it is not clear whether this is a predisposing trait for addiction or a consequence of drug exposure. In this study, we found that a nonsense mutation at the mGluR2 gene decreased mGluR2 expression and altered the seeking and taking of cocaine. mGluR2 mutant rats show reduced sensitivity to cocaine reward, requiring more cocaine to reach satiation when it was freely available and ceasing their drug-seeking behavior sooner than controls when the response requirement was increased. mGluR2 mutant rats also show a lower propensity to relapse after a period of cocaine abstinence, an effect associated with reduced cocaine-induced dopamine and glutamate overflow in the nucleus accumbens. These findings suggest that mGluR2 polymorphisms or reduced availability of mGluR2 might be risk factors for the initial development of cocaine use but could actually protect against addiction by reducing sensitivity to cocaine reward. Published by Elsevier Inc.

An Age-Dependent Physiologically-Based Pharmacokinetic/Pharmacodynamic Model for the Organophosphorus Insecticide Chlorpyrifos in the Preweanling Rat

Energy Technology Data Exchange (ETDEWEB)

Timchalk, Chuck; Kousba, Ahmed A.; Poet, Torka S.

2007-08-01

Juvenile rats are more susceptible than adults to the acute toxicity of organophosphorus insecticides like chlorpyrifos (CPF). Age- and dose-dependent differences in metabolism may be responsible. Of importance is CYP450 activation and detoxification of CPF to chlorpyrifos-oxon (CPF-oxon) and trichloropyridinol (TCP), as well as B-esterase (cholinesterase; ChE) and A-esterase (PON-1) detoxification of CPF-oxon to TCP. In the current study, a modified physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model incorporating age-dependent changes in CYP450, PON-1, and tissue ChE levels for rats was developed. In this model, age was used as a dependent function to estimate body weight which was then used to allometrically scale both metabolism and tissue ChE levels. Model simulations suggest that preweanling rats are particularly sensitive to CPF toxicity, with levels of CPF-oxon in blood and brain disproportionately increasing, relative to the response in adult rats. This age-dependent non-linear increase in CPF-oxon concentration may potentially result from the depletion of non-target B-esterases, and a lower PON-1 metabolic capacity in younger animals. These results indicate that the PBPK/PD model behaves consistently with the general understanding of CPF toxicity, pharmacokinetics and tissue ChE inhibition in neonatal and adult rats. Hence, this model represents an important starting point for developing a computational model to assess the neurotoxic potential of environmentally relevant organophosphate exposures in infants and children.

Addition of biochar to sewage sludge decreases freely dissolved PAHs content and toxicity of sewage sludge-amended soil.

Science.gov (United States)

Stefaniuk, Magdalena; Oleszczuk, Patryk

2016-11-01

Due to an increased content of polycyclic aromatic hydrocarbons (PAHs) frequently found in sewage sludges, it is necessary to find solutions that will reduce the environmental hazard associated with their presence. The aim of this study was to determine changes of total and freely dissolved concentration of PAHs in sewage sludge-biochar-amended soil. Two different sewage sludges and biochars with varying properties were tested. Biochars (BC) were produced from biogas residues at 400 °C or 600 °C and from willow at 600 °C. The freely dissolved PAH concentration was determined by means of passive sampling using polyoxymethylene (POM). Total and freely dissolved PAH concentration was monitored at the beginning of the experiment and after 90 days of aging of the sewage sludge with the biochar and soil. Apart from chemical evaluation, the effect of biochar addition on the toxicity of the tested materials on bacteria - Vibrio fischeri (Microtox ® ), plants - Lepidium sativum (Phytotestkit F, Phytotoxkit F), and Collembola - Folsomia candida (Collembolan test) was evaluated. The addition of biochar to the sewage sludges decreased the content of C free PAHs. A reduction from 11 to 43% of sewage sludge toxicity or positive effects on plants expressed by root growth stimulation from 6 to 25% to the control was also found. The range of reduction of C free PAHs and toxicity was dependent on the type of biochar. After 90 days of incubation of the biochars with the sewage sludge in the soil, C free PAHs and toxicity were found to further decrease compared to the soil with sewage sludge alone. The obtained results show that the addition of biochar to sewage sludges may significantly reduce the risk associated with their environmental use both in terms of PAH content and toxicity of the materials tested. Copyright © 2016 Elsevier Ltd. All rights reserved.

Neuronal Activity in the Subthalamic Cerebrovasodilator Area under Partial-Gravity Conditions in Rats

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Zeredo L Zeredo

2014-03-01

Full Text Available The reduced-gravity environment in space is known to cause an upward shift in body fluids and thus require cardiovascular adaptations in astronauts. In this study, we recorded in rats the neuronal activity in the subthalamic cerebrovasodilator area (SVA, a key area that controls cerebral blood flow (CBF, in response to partial gravity. “Partial gravity” is the term that defines the reduced-gravity levels between 1 g (the unit gravity acceleration on Earth and 0 g (complete weightlessness in space. Neuronal activity was recorded telemetrically through chronically implanted microelectrodes in freely moving rats. Graded levels of partial gravity from 0.4 g to 0.01 g were generated by customized parabolic-flight maneuvers. Electrophysiological signals in each partial-gravity phase were compared to those of the preceding 1 g level-flight. As a result, SVA neuronal activity was significantly inhibited by the partial-gravity levels of 0.15 g and lower, but not by 0.2 g and higher. Gravity levels between 0.2–0.15 g could represent a critical threshold for the inhibition of neurons in the rat SVA. The lunar gravity (0.16 g might thus trigger neurogenic mechanisms of CBF control. This is the first study to examine brain electrophysiology with partial gravity as an experimental parameter.

ABC gene-ranking for prediction of drug-induced cholestasis in rats

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Yauheniya Cherkas

Full Text Available As legacy toxicogenomics databases have become available, improved data mining approaches are now key to extracting and visualizing subtle relationships between toxicants and gene expression. In the present study, a novel “aggregating bundles of clusters” (ABC procedure was applied to separate cholestatic from non-cholestatic drugs and model toxicants in the Johnson & Johnson (Janssen rat liver toxicogenomics database [3]. Drug-induced cholestasis is an important issue, particularly when a new compound enters the market with this liability, with standard preclinical models often mispredicting this toxicity. Three well-characterized cholestasis-responsive genes (Cyp7a1, Mrp3 and Bsep were chosen from a previous in-house Janssen gene expression signature; these three genes show differing, non-redundant responses across the 90+ paradigm compounds in our database. Using the ABC procedure, extraneous contributions were minimized in comparisons of compound gene responses. All genes were assigned weights proportional to their correlations with Cyp7a1, Mrp3 and Bsep, and a resampling technique was used to derive a stable measure of compound similarity. The compounds that were known to be associated with rat cholestasis generally had small values of this measure relative to each other but also had large values of this measure relative to non-cholestatic compounds. Visualization of the data with the ABC-derived signature showed a very tight, essentially identically behaving cluster of robust human cholestatic drugs and experimental cholestatic toxicants (ethinyl estradiol, LPS, ANIT and methylene dianiline, disulfiram, naltrexone, methapyrilene, phenacetin, alpha-methyl dopa, flutamide, the NSAIDs–—indomethacin, flurbiprofen, diclofenac, flufenamic acid, sulindac, and nimesulide, butylated hydroxytoluene, piperonyl butoxide, and bromobenzene, some slightly less active compounds (3′-acetamidofluorene, amsacrine, hydralazine, tannic acid, some

Design and validation of Segment - freely available software for cardiovascular image analysis

International Nuclear Information System (INIS)

Heiberg, Einar; Sjögren, Jane; Ugander, Martin; Carlsson, Marcus; Engblom, Henrik; Arheden, Håkan

2010-01-01

Commercially available software for cardiovascular image analysis often has limited functionality and frequently lacks the careful validation that is required for clinical studies. We have already implemented a cardiovascular image analysis software package and released it as freeware for the research community. However, it was distributed as a stand-alone application and other researchers could not extend it by writing their own custom image analysis algorithms. We believe that the work required to make a clinically applicable prototype can be reduced by making the software extensible, so that researchers can develop their own modules or improvements. Such an initiative might then serve as a bridge between image analysis research and cardiovascular research. The aim of this article is therefore to present the design and validation of a cardiovascular image analysis software package (Segment) and to announce its release in a source code format. Segment can be used for image analysis in magnetic resonance imaging (MRI), computed tomography (CT), single photon emission computed tomography (SPECT) and positron emission tomography (PET). Some of its main features include loading of DICOM images from all major scanner vendors, simultaneous display of multiple image stacks and plane intersections, automated segmentation of the left ventricle, quantification of MRI flow, tools for manual and general object segmentation, quantitative regional wall motion analysis, myocardial viability analysis and image fusion tools. Here we present an overview of the validation results and validation procedures for the functionality of the software. We describe a technique to ensure continued accuracy and validity of the software by implementing and using a test script that tests the functionality of the software and validates the output. The software has been made freely available for research purposes in a source code format on the project home page (http://segment.heiberg.se). Segment

Pre-existing differences in motivation for food and sensitivity to cocaine-induced locomotion in obesity-prone rats.

Science.gov (United States)

Vollbrecht, Peter J; Nobile, Cameron W; Chadderdon, Aaron M; Jutkiewicz, Emily M; Ferrario, Carrie R

2015-12-01

Obesity is a significant problem in the United States, with roughly one third of adults having a body mass index (BMI) over thirty. Recent evidence from human studies suggests that pre-existing differences in the function of mesolimbic circuits that mediate motivational processes may promote obesity and hamper weight loss. However, few preclinical studies have examined pre-existing neurobehavioral differences related to the function of mesolimbic systems in models of individual susceptibility to obesity. Here, we used selectively bred obesity-prone and obesity-resistant rats to examine 1) the effect of a novel "junk-food" diet on the development of obesity and metabolic dysfunction, 2) over-consumption of "junk-food" in a free access procedure, 3) motivation for food using instrumental procedures, and 4) cocaine-induced locomotor activity as an index of general mesolimbic function. As expected, eating a sugary, fatty, "junk-food" diet exacerbated weight gain and increased fasted insulin levels only in obesity-prone rats. In addition, obesity-prone rats continued to over-consume junk-food during discrete access testing, even when this same food was freely available in the home cage. Furthermore, when asked to press a lever to obtain food in an instrumental task, rates of responding were enhanced in obesity-prone versus obesity-resistant rats. Finally, obesity-prone rats showed a stronger locomotor response to 15 mg/kg cocaine compared to obesity-resistant rats prior to any diet manipulation. This enhanced sensitivity to this dose of cocaine is indicative of basal differences in the function of mesolimbic circuits in obesity-prone rats. We speculate that pre-existing differences in motivational systems may contribute to over-consumption and enhanced motivation in susceptible individuals. Copyright © 2015 Elsevier Inc. All rights reserved.

Pre-existing differences in motivation for food and sensitivity to cocaine-induced locomotion in obesity-prone rats

Science.gov (United States)

Vollbrecht, Peter J.; Nobile, Cameron W.; Chadderdon, Aaron M.; Jutkiewicz, Emily M.; Ferrario, Carrie R.

2015-01-01

Obesity is a significant problem in the United States, with roughly one third of adults having a body mass index (BMI) over thirty. Recent evidence from human studies suggests that pre-existing differences in the function of mesolimbic circuits that mediate motivational processes may promote obesity and hamper weight loss. However, few preclinical studies have examined pre-existing neurobehavioral differences related to the function of mesolimbic systems in models of individual susceptibility to obesity. Here, we used selectively bred obesity-prone and obesity-resistant rats to examine 1) the effect of a novel “junk-food” diet on the development of obesity and metabolic dysfunction, 2) over-consumption of “junk-food” in a free access procedure, 3) motivation for food using instrumental procedures, and 4) cocaine-induced locomotor activity as an index of general mesolimbic function. As expected, eating a sugary, fatty, “junk-food” diet exacerbated weight gain and increased fasted insulin levels only in obesity-prone rats. In addition, obesity-prone rats continued to over-consume junk-food during discrete access testing, even when this same food was freely available in the home cage. Furthermore, when asked to press a lever to obtain food in an instrumental task, rates of responding were enhanced in obesity-prone versus obesity-resistant rats. Finally, obesity-prone rats showed a stronger locomotor response to 15 mg/kg cocaine compared to obesity-resistant rats prior to any diet manipulation. This enhanced sensitivity to this dose of cocaine is indicative of basal differences in the function of mesolimbic circuits in obesity-prone rats. We speculate that pre-existing differences in motivational systems may contribute to over-consumption and enhanced motivation in susceptible individuals. PMID:26423787

Cortico-pontine theta carrier frequency phase shift across sleep/wake states following monoaminergic lesion in rat.

Science.gov (United States)

Kalauzi, Aleksandar; Spasic, Sladjana; Petrovic, Jelena; Ciric, Jelena; Saponjic, Jelena

2012-06-01

This study was aimed to explore the sleep/wake states related cortico-pontine theta carrier frequency phase shift following a systemically induced chemical axotomy of the monoaminergic afferents within a brain of the freely moving rats. Our experiments were performed in 14 adult, male Sprague Dawley rats, chronically implanted for sleep recording. We recorded sleep during baseline condition, following sham injection (saline i.p. 1 ml/kg), and every week for 5 weeks following injection of the systemic neurotoxins (DSP-4 or PCA; 1 ml/kg, i.p.) for chemical axotomy of the locus coeruleus (LC) and dorsal raphe (DR) axon terminals. After sleep/wake states identification, FFT analysis was performed on 5 s epochs. Theta carrier frequency phase shift (∆Φ) was calculated for each epoch by averaging theta Fourier component phase shifts, and the ∆Φ values were plotted for each rat in control condition and 28 days following the monoaminergic lesions, as a time for permanently established DR or LC chemical axotomy. Calculated group averages have shown that ∆Φ increased between pons and cortex significantly in all sleep/wake states (Wake, NREM and REM) following the monoaminergic lesions, with respect to controls. Monoaminergic lesions established the pontine leading role in the brain theta oscillations during all sleep/wake states.

Brain maps 4.0—Structure of the rat brain: An open access atlas with global nervous system nomenclature ontology and flatmaps

Science.gov (United States)

2018-01-01

Abstract The fourth edition (following editions in 1992, 1998, 2004) of Brain maps: structure of the rat brain is presented here as an open access internet resource for the neuroscience community. One new feature is a set of 10 hierarchical nomenclature tables that define and describe all parts of the rat nervous system within the framework of a strictly topographic system devised previously for the human nervous system. These tables constitute a global ontology for knowledge management systems dealing with neural circuitry. A second new feature is an aligned atlas of bilateral flatmaps illustrating rat nervous system development from the neural plate stage to the adult stage, where most gray matter regions, white matter tracts, ganglia, and nerves listed in the nomenclature tables are illustrated schematically. These flatmaps are convenient for future development of online applications analogous to “Google Maps” for systems neuroscience. The third new feature is a completely revised Atlas of the rat brain in spatially aligned transverse sections that can serve as a framework for 3‐D modeling. Atlas parcellation is little changed from the preceding edition, but the nomenclature for rat is now aligned with an emerging panmammalian neuroanatomical nomenclature. All figures are presented in Adobe Illustrator vector graphics format that can be manipulated, modified, and resized as desired, and freely used with a Creative Commons license. PMID:29277900

An improved strategy for evaluating the extent of chronic arterial baroreceptor denervation in conscious rats

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M. Rodríguez-Martínez

2010-11-01

Full Text Available There is no index or criterion of aortic barodenervation, nor can we differentiate among rats that have suffered chronic sham, aortic or sino-aortic denervation. The objective of this study was to develop a procedure to generate at least one quantitative, reproducible and validated index that precisely evaluates the extent of chronic arterial barodenervation performed in conscious rats. Data from 79 conscious male Wistar rats of about 65-70 days of age with diverse extents of chronic arterial barodenervation and used in previous experiments were reanalyzed. The mean arterial pressure (MAP and the heart rate (HR of all rats were measured systematically before (over 1 h and after three consecutive iv bolus injections of phenylephrine (PHE and sodium nitroprusside (SNP. Four expressions of the effectiveness of barodenervation (MAP lability, PHE ratio, SNP ratio, and SNP-PHE slope were assessed with linear fixed models, three-level average variance, average separation among levels, outlier box plot analysis, and overlapping graphic analysis. The analysis indicated that a neither MAP lability nor SNP-PHE slope was affected by the level of chronic sodium intake; b even though the Box-Cox transformations of both MAP lability [transformed lability index (TLI] and SNP-PHE slope [transformed general sensitivity index (TGSI, {((3-(ΔHRSNP-ΔHRPHE/ΔMAPSNP-ΔMAPPHE-0.4-1/-0.04597}] could be two promising indexes, TGSI proved to be the best index; c TLI and TGSI were not freely interchangeable indexes for this purpose. TGSI ranges that permit differentiation between sham (10.09 to 11.46, aortic (8.40 to 9.94 and sino-aortic (7.68 to 8.24 barodenervated conscious rats were defined.

A simple miniature device for wireless stimulation of neural circuits in small behaving animals.

Science.gov (United States)

Zhang, Yisi; Langford, Bruce; Kozhevnikov, Alexay

2011-10-30

The use of wireless neural stimulation devices offers significant advantages for neural stimulation experiments in behaving animals. We demonstrate a simple, low-cost and extremely lightweight wireless neural stimulation device which is made from off-the-shelf components. The device has low power consumption and does not require a high-power RF preamplifier. Neural stimulation can be carried out in either a voltage source mode or a current source mode. Using the device, we carry out wireless stimulation in the premotor brain area HVC of a songbird and demonstrate that such stimulation causes rapid perturbations of the acoustic structure of the song. Published by Elsevier B.V.

Multispot single-molecule FRET: High-throughput analysis of freely diffusing molecules.

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Antonino Ingargiola

Full Text Available We describe an 8-spot confocal setup for high-throughput smFRET assays and illustrate its performance with two characteristic experiments. First, measurements on a series of freely diffusing doubly-labeled dsDNA samples allow us to demonstrate that data acquired in multiple spots in parallel can be properly corrected and result in measured sample characteristics consistent with those obtained with a standard single-spot setup. We then take advantage of the higher throughput provided by parallel acquisition to address an outstanding question about the kinetics of the initial steps of bacterial RNA transcription. Our real-time kinetic analysis of promoter escape by bacterial RNA polymerase confirms results obtained by a more indirect route, shedding additional light on the initial steps of transcription. Finally, we discuss the advantages of our multispot setup, while pointing potential limitations of the current single laser excitation design, as well as analysis challenges and their solutions.

The gravitational wave spectrum of non-axisymmetric, freely precessing neutron stars

International Nuclear Information System (INIS)

Broeck, Chris van den

2005-01-01

Evidence for free precession has been observed in the radio signature of several pulsars. Freely precessing pulsars radiate gravitationally at frequencies near the rotation rate and twice the rotation rate, which for rotation frequencies greater than ∼10 Hz is in the LIGO band. In older work, the gravitational wave spectrum of a precessing neutron star has been evaluated to first order in a small precession angle. Here, we calculate the contributions to second order in the wobble angle, and we find that a new spectral line emerges. We show that for reasonable wobble angles, the second-order line may well be observable with the proposed advanced LIGO detectors for precessing neutron stars as far away as the galactic centre. Observation of the full second-order spectrum permits a direct measurement of the star's wobble angle, oblateness and deviation from axisymmetry, with the potential to significantly increase our understanding of neutron star structure

Comparative study between CardiaMed valves (freely floating valve leaflets versus St. Jude Medical (fixed valve leaflets in mitral valve replacement surgery

Directory of Open Access Journals (Sweden)

Mostafa Ahmed

2017-09-01

Conclusions: CardiaMed freely floating leaflet prostheses showed good hemodynamic characteristics. The prosthesis adequately corrects hemodynamics and is safe and no worse than the St. Jude Medical valve in the mitral valve position.

Cortisol and prolactin concentrations during repeated blood sample collection from freely moving, mouse-sized mammals (Phodopus spp.).

Science.gov (United States)

Reburn, C J; Wynne-Edwards, K E

2000-04-01

Validation of a method for obtaining blood samples that does not change cortisol or prolactin concentrations yet allows serial blood samples to be collected from animals under anesthesia, without prior handling, from freely interacting social groups of small mammals. Results from five experiments are reported. Male dwarf hamsters (Phodopus spp.) were housed in modified home cages under continuous flow of compressed air that could be switched to isoflurane in O2 vehicle without approaching the cages. Dwarf hamsters respond to manual restraint with behavioral distress and increase in the concentration of the dominant glucocorticoid, cortisol, and decrease in prolactin concentration. Both effects are evident within one minute. In contrast, when this new method was used, neither cortisol nor prolactin changed in response to repeated sample collection (up to 8 successive samples at 2 hour intervals), prolonged isoflurane exposure, or substantial blood volume reduction (30%). Prolactin concentration was suppressed and cortisol concentration was increased in response to stimuli from other hamsters tested without anesthesia. Suppression of prolactin concentration was graded in response to the degree of stress and equaled the pharmacologic reduction caused by bromocryptine mesylate (50 microg of CB154 x 3 days). The technique is superior to alternatives for studies of behavioral endocrinology of freely interacting small mammals.

Stereotypic Laryngeal and Respiratory Motor Patterns Generate Different Call Types in Rat Ultrasound Vocalization

Science.gov (United States)

RIEDE, TOBIAS

2014-01-01

Rodents produce highly variable ultrasound whistles as communication signals unlike many other mammals, who employ flow-induced vocal fold oscillations to produce sound. The role of larynx muscles in controlling sound features across different call types in ultrasound vocalization (USV) was investigated using laryngeal muscle electromyographic (EMG) activity, subglottal pressure measurements and vocal sound output in awake and spontaneously behaving Sprague–Dawley rats. Results support the hypothesis that glottal shape determines fundamental frequency. EMG activities of thyroarytenoid and cricothyroid muscles were aligned with call duration. EMG intensity increased with fundamental frequency. Phasic activities of both muscles were aligned with fast changing fundamental frequency contours, for example in trills. Activities of the sternothyroid and sternohyoid muscles, two muscles involved in vocal production in other mammals, are not critical for the production of rat USV. To test how stereotypic laryngeal and respiratory activity are across call types and individuals, sets of ten EMG and subglottal pressure parameters were measured in six different call types from six rats. Using discriminant function analysis, on average 80% of parameter sets were correctly assigned to their respective call type. This was significantly higher than the chance level. Since fundamental frequency features of USV are tightly associated with stereotypic activity of intrinsic laryngeal muscles and muscles contributing to build-up of subglottal pressure, USV provide insight into the neurophysiological control of peripheral vocal motor patterns. PMID:23423862

Acute phenylalanine/tyrosine depletion of phasic dopamine in the rat brain.

Science.gov (United States)

Shnitko, Tatiana A; Taylor, Sarah C; Stringfield, Sierra J; Zandy, Shannon L; Cofresí, Roberto U; Doherty, James M; Lynch, William B; Boettiger, Charlotte A; Gonzales, Rueben A; Robinson, Donita L

2016-06-01

Dopamine plays a critical role in striatal and cortical function, and depletion of the dopamine precursors phenylalanine and tyrosine is used in humans to temporarily reduce dopamine and probe the role of dopamine in behavior. This method has been shown to alter addiction-related behaviors and cognitive functioning presumably by reducing dopamine transmission, but it is unclear what specific aspects of dopamine transmission are altered. We performed this study to confirm that administration of an amino acid mixture omitting phenylalanine and tyrosine (Phe/Tyr[-]) reduces tyrosine tissue content in the prefrontal cortex (PFC) and nucleus accumbens (NAc), and to test the hypothesis that Phe/Tyr[-] administration reduces phasic dopamine release in the NAc. Rats were injected with a Phe/Tyr[-] amino acid mixture, a control amino acid mixture, or saline. High-performance liquid chromatography was used to determine the concentration of tyrosine, dopamine, or norepinephrine in tissue punches from the PFC and ventral striatum. In a separate group of rats, phasic dopamine release was measured with fast-scan cyclic voltammetry in the NAc core after injection with either the Phe/Tyr[-] mixture or the control amino acid solution. Phe/Tyr[-] reduced tyrosine content in the PFC and NAc, but dopamine and norepinephrine tissue content were not reduced. Moreover, Phe/Tyr[-] decreased the frequency of dopamine transients, but not their amplitude, in freely moving rats. These results indicate that depletion of tyrosine via Phe/Tyr[-] decreases phasic dopamine transmission, providing insight into the mechanism by which this method modifies dopamine-dependent behaviors in human imaging studies.

Comparison of the effects of sibutramine and other monoamine reuptake inhibitors on food intake in the rat

Science.gov (United States)

Jackson, Helen C; Needham, Andrew M; Hutchins, Lisa J; Mazurkiewicz, Sarah E; Heal, David J

1997-01-01

The effects of the potent 5-hydroxytryptamine (5-HT) and noradrenaline reuptake inhibitor (serotonin-noradrenaline reuptake inhibitor, SNRI), sibutramine, on the cumulative food intake of freely-feeding male Sprague-Dawley rats during an 8 h dark period were investigated and compared to those of the selective 5-HT reuptake inhibitor (selective serotonin reuptake inhibitor, SSRI), fluoxetine; the selective noradrenaline reuptake inhibitor, nisoxetine; the 5-HT and noradrenaline reuptake inhibitors, venlafaxine and duloxetine; and the 5-HT releaser and 5-HT reuptake inhibitor, (+)-fenfluramine. Sibutramine (3 and 10 mg kg−1, p.o.) and (+)-fenfluramine (1 and 3 mg kg−1, p.o.) produced a significant, dose-dependent decrease in food intake over the 8 h dark period. These responses became apparent within the first 2 h following drug administration. Fluoxetine (3, 10 and 30 mg kg−1, p.o.), and nisoxetine (3, 10 and 30 mg kg−1, p.o.) had no significant effect on food intake during the 8 h dark period. However, a combination of fluoxetine and nisoxetine (30 mg kg−1, p.o., of each) significantly decreased food intake 2 and 8 h after drug administration. Venlafaxine (100 and 300 mg kg−1, p.o.) and duloxetine (30 mg kg−1, p.o.) also significantly decreased food intake in the 2 and 8 h following drug administration. The results of this study demonstrate that inhibition of 5-HT and noradrenaline reuptake by sibutramine, venlafaxine, duloxetine, or by a combination of fluoxetine and nisoxetine, markedly reduces food intake in freely-feeding rats and suggest that this may be a novel approach for the treatment of obesity. PMID:9283714

The Role of the Rat Medial Prefrontal Cortex in Adapting to Changes in Instrumental Contingency

Science.gov (United States)

Coutureau, Etienne; Esclassan, Frederic; Di Scala, Georges; Marchand, Alain R.

2012-01-01

In order to select actions appropriate to current needs, a subject must identify relationships between actions and events. Control over the environment is determined by the degree to which action consequences can be predicted, as described by action-outcome contingencies – i.e. performing an action should affect the probability of the outcome. We evaluated in a first experiment adaptation to contingency changes in rats with neurotoxic lesions of the medial prefrontal cortex. Results indicate that this brain region is not critical to adjust instrumental responding to a negative contingency where the rats must refrain from pressing a lever, as this action prevents reward delivery. By contrast, this brain region is required to reduce responding in a non-contingent situation where the same number of rewards is freely delivered and actions do not affect the outcome any more. In a second experiment, we determined that this effect does not result from a different perception of temporal relationships between actions and outcomes since lesioned rats adapted normally to gradually increasing delays in reward delivery. These data indicate that the medial prefrontal cortex is not directly involved in evaluating the correlation between action-and reward-rates or in the perception of reward delays. The deficit in lesioned rats appears to consist of an abnormal response to the balance between contingent and non-contingent rewards. By highlighting the role of prefrontal regions in adapting to the causal status of actions, these data contribute to our understanding of the neural basis of choice tasks. PMID:22496747

Parameters estimation online for Lorenz system by a novel quantum-behaved particle swarm optimization

International Nuclear Information System (INIS)

Gao Fei; Tong Hengqing; Li Zhuoqiu

2008-01-01

This paper proposes a novel quantum-behaved particle swarm optimization (NQPSO) for the estimation of chaos' unknown parameters by transforming them into nonlinear functions' optimization. By means of the techniques in the following three aspects: contracting the searching space self-adaptively; boundaries restriction strategy; substituting the particles' convex combination for their centre of mass, this paper achieves a quite effective search mechanism with fine equilibrium between exploitation and exploration. Details of applying the proposed method and other methods into Lorenz systems are given, and experiments done show that NQPSO has better adaptability, dependability and robustness. It is a successful approach in unknown parameter estimation online especially in the cases with white noises

Brain maps 4.0-Structure of the rat brain: An open access atlas with global nervous system nomenclature ontology and flatmaps.

Science.gov (United States)

Swanson, Larry W

2018-04-15

The fourth edition (following editions in 1992, 1998, 2004) of Brain maps: structure of the rat brain is presented here as an open access internet resource for the neuroscience community. One new feature is a set of 10 hierarchical nomenclature tables that define and describe all parts of the rat nervous system within the framework of a strictly topographic system devised previously for the human nervous system. These tables constitute a global ontology for knowledge management systems dealing with neural circuitry. A second new feature is an aligned atlas of bilateral flatmaps illustrating rat nervous system development from the neural plate stage to the adult stage, where most gray matter regions, white matter tracts, ganglia, and nerves listed in the nomenclature tables are illustrated schematically. These flatmaps are convenient for future development of online applications analogous to "Google Maps" for systems neuroscience. The third new feature is a completely revised Atlas of the rat brain in spatially aligned transverse sections that can serve as a framework for 3-D modeling. Atlas parcellation is little changed from the preceding edition, but the nomenclature for rat is now aligned with an emerging panmammalian neuroanatomical nomenclature. All figures are presented in Adobe Illustrator vector graphics format that can be manipulated, modified, and resized as desired, and freely used with a Creative Commons license. © 2018 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc.

In vivo retention of poloxamer-based in situ hydrogels for vaginal application in mouse and rat models

Directory of Open Access Journals (Sweden)

Yu Liu

2017-07-01

Full Text Available The purpose of this study is to evaluate the in vivo retention capabilities of poloxamer-based in situ hydrogels for vaginal application with nonoxinol-9 as the model drug. Two in situ hydrogel formulations, which contained 18% poloxamer 407 plus 1% poloxamer 188 (GEL1, relative hydrophobic or 6% poloxamer 188 (GEL2, relative hydrophilic, were compared with respect to the rheological properties, in vitro hydrogel erosion and drug release. The vaginal retention capabilities of these hydrogel formulations were further determined in two small animal models, including drug quantitation of vaginal rinsing fluid in mice and isotope tracing with 99mTc in rats. The two formulations exhibited similar phase transition temperatures ranging from 27 to 32 °C. Increasing the content of poloxamer 188 resulted in higher rheological moduli under body temperature, but slightly accelerated hydrogel erosion and drug release. When compared in vivo, GEL1 was eliminated significantly slower in rat vagina than GEL2, while the vaginal retention of these two hydrogel formulations behaved similarly in mice. In conclusion, increases in the hydrophilic content of formulations led to faster hydrogel erosion, drug release and intravaginal elimination. Rats appear to be a better animal model than mice to evaluate the in situ hydrogel for vaginal application.

Characterization of noradrenaline release in the locus coeruleus of freely moving awake rats by in vivo microdialysis.

Science.gov (United States)

Fernández-Pastor, Begoña; Mateo, Yolanda; Gómez-Urquijo, Sonia; Javier Meana, J

2005-07-01

The origin and regulation of noradrenaline (NA) in the locus coeruleus (LC) is unknown. The neurochemical features of NA overflow (nerve impulse dependence, neurotransmitter synthesis, vesicle storage, reuptake, alpha2-adrenoceptor-mediated regulation) were characterized in the LC. Brain microdialysis was performed in awake rats. Dialysates were analyzed for NA. NA in the LC decreased via local infusion of Ca2+-free medium (-42+/-5%) or the sodium channel blocker tetrodotoxine (TTX) (-47+/-8%) but increased (333+/-40%) via KCl-induced depolarization. The tyrosine hydroxylase (TH) inhibitor alpha-methyl-p-tyrosine (250 mg kg(-1), i.p.) and the vesicle depletory drug reserpine (5 mg kg(-1), i.p.) decreased NA. Therefore, extracellular NA in the LC satisfies the criteria for an impulse flow-dependent vesicular exocytosis of neuronal origin. Local perfusion of the alpha2-adrenoceptor agonist clonidine (0.1-100 microM) decreased NA (E(max)=-79+/-5%) in the LC, whereas the opposite effect (E(max)=268+/-53%) was observed with the alpha2A-adrenoceptor antagonist BRL44408 (0.1-100 microM). This suggests a tonic modulation of NA release through local alpha2A-adrenoceptors. The selective NA reuptake inhibitor desipramine (DMI) (0.1-100 microM) administered into the LC increased NA in the LC (E(max)=223+/-40%) and simultaneously decreased NA in the cingulate cortex, confirming the modulation exerted by NA in the LC on firing activity of noradrenergic cells and on the subsequent NA release in noradrenergic terminals. Synaptic processes underlying NA release in the LC are similar to those in noradrenergic terminal areas. NA in the LC could represent local somatodendritic release, but also the presence of neurotransmitter release from collateral axon terminals.

Ongoing behavioral state information signaled in the lateral habenula guides choice flexibility in freely moving rats

Directory of Open Access Journals (Sweden)

Phillip Michael Baker

2015-11-01

behaviors as rats were unimpaired on initial discrimination acquisition or retention of probabilistic learning. Taken together, these novel findings compliment other work discussed supporting a role for the LHb in action selection when cognitive or emotional demands are increased. Finally, we discuss future mechanisms by which a superior understanding of the LHb can be obtained through additional examination of behavioral flexibility tasks.

Oxytocin and vasopressin modulation of the neural correlates of motivation and emotion: results from functional MRI studies in awake rats.

Science.gov (United States)

Febo, Marcelo; Ferris, Craig F

2014-09-11

Oxytocin and vasopressin modulate a range of species typical behavioral functions that include social recognition, maternal-infant attachment, and modulation of memory, offensive aggression, defensive fear reactions, and reward seeking. We have employed novel functional magnetic resonance mapping techniques in awake rats to explore the roles of these neuropeptides in the maternal and non-maternal brain. Results from the functional neuroimaging studies that are summarized here have directly and indirectly confirmed and supported previous findings. Oxytocin is released within the lactating rat brain during suckling stimulation and activates specific subcortical networks in the maternal brain. Both vasopressin and oxytocin modulate brain regions involved unconditioned fear, processing of social stimuli and the expression of agonistic behaviors. Across studies there are relatively consistent brain networks associated with internal motivational drives and emotional states that are modulated by oxytocin and vasopressin. This article is part of a Special Issue entitled Oxytocin and Social Behav. Copyright © 2014 Elsevier B.V. All rights reserved.

Voluntary running enhances glymphatic influx in awake behaving, young mice.

Science.gov (United States)

von Holstein-Rathlou, Stephanie; Petersen, Nicolas Caesar; Nedergaard, Maiken

2018-01-01

Vascular pathology and protein accumulation contribute to cognitive decline, whereas exercise can slow vascular degeneration and improve cognitive function. Recent investigations suggest that glymphatic clearance measured in aged mice while anesthetized is enhanced following exercise. We predicted that exercise would also stimulate glymphatic activity in awake, young mice with higher baseline glymphatic function. Therefore, we assessed glymphatic function in young female C57BL/6J mice following five weeks voluntary wheel running and in sedentary mice. The active mice ran a mean distance of 6km daily. We injected fluorescent tracers in cisterna magna of awake behaving mice and in ketamine/xylazine anesthetized mice, and later assessed tracer distribution in coronal brain sections. Voluntary exercise consistently increased CSF influx during wakefulness, primarily in the hypothalamus and ventral parts of the cortex, but also in the middle cerebral artery territory. While glymphatic activity was higher under ketamine/xylazine anesthesia, we saw a decrease in glymphatic function during running in awake mice after five weeks of wheel running. In summary, daily running increases CSF flux in widespread areas of the mouse brain, which may contribute to the pro-cognitive effects of exercise. Copyright © 2017 Elsevier B.V. All rights reserved.

A Swarm Optimization Genetic Algorithm Based on Quantum-Behaved Particle Swarm Optimization.

Science.gov (United States)

Sun, Tao; Xu, Ming-Hai

2017-01-01

Quantum-behaved particle swarm optimization (QPSO) algorithm is a variant of the traditional particle swarm optimization (PSO). The QPSO that was originally developed for continuous search spaces outperforms the traditional PSO in search ability. This paper analyzes the main factors that impact the search ability of QPSO and converts the particle movement formula to the mutation condition by introducing the rejection region, thus proposing a new binary algorithm, named swarm optimization genetic algorithm (SOGA), because it is more like genetic algorithm (GA) than PSO in form. SOGA has crossover and mutation operator as GA but does not need to set the crossover and mutation probability, so it has fewer parameters to control. The proposed algorithm was tested with several nonlinear high-dimension functions in the binary search space, and the results were compared with those from BPSO, BQPSO, and GA. The experimental results show that SOGA is distinctly superior to the other three algorithms in terms of solution accuracy and convergence.

Effects of chronic administration of caffeine and stress on feeding behavior of rats.

Science.gov (United States)

Pettenuzzo, Leticia Ferreira; Noschang, Cristie; von Pozzer Toigo, Eduardo; Fachin, Andrelisa; Vendite, Deusa; Dalmaz, Carla

2008-10-20

Anorectic effects of caffeine are controversial in the literature, while stress and obesity are growing problems in our society. Since many stressed people are coffee drinkers, the objective of the present study was to evaluate the effect of stress and chronic administration of caffeine on feeding behavior and body weight in male and female rats. Wistar rats (both males and females) were divided into 3 groups: control (receiving water), caffeine 0.3 g/L and caffeine 1.0 g/L (in the drinking water). These groups were subdivided into non-stressed and stressed (repeated-restraint stress for 40 days). During the entire treatment, chow consumption was monitored and rats were weighed monthly. Afterwards, feeding behavior was evaluated during 3-min trials in food-deprived and ad libitum fed animals and also in repeated exposures, using palatable food (Froot Loops and Cheetos). Chronic administration of caffeine did not affect rat chow consumption or body weight gain, but diminished the consumption of both salty (Cheetos) and sweet (Froot Loops) palatable food. In the repeated trial tests, stress diminished savory snack consumption in the later exposures [I.S. Racotta, J. Leblanc, D. Richard The effect of caffeine on food intake in rats: involvement of corticotropin-releasing factor and the sympatho-adrenal system. Pharmacol Biochem Behav. 1994, 48:887-892; S.D. Comer, M. Haney, R.W. Foltin, M.W. Fischman Effects of caffeine withdrawal on humans living in a residential laboratory. Exp Clin Psychopharmacol. 1997, 5:399-403; A. Jessen, B. Buemann, S. Toubro, I.M. Skovgaard, A. Astrup The appetite-suppressant effect of nicotine is enhanced by caffeine. Diab Ob Metab. 2005, 7:327-333; J.M. Carney Effects of caffeine, theophylline and theobromine on scheduled controlled responding in rats. Br J Pharmacol. 1982, 75:451-454] and caffeine diminished consumption of both palatable foods (savory and sweet) during the early and later exposures. Most responses to caffeine were stronger

Deuterium isotope effect on metabolism of N-nitrosodimethylamine in vivo in rat

International Nuclear Information System (INIS)

Swann, P.F.; Mace, R.; Angeles, R.M.; Keefer, L.K.

1983-01-01

The maximal rates of metabolic oxidation of N-nitrosodimethylamine (NDMA) and N-nitrosodimethylamine-d6 (NDMA-d6) in vivo (VH and VD, respectively) have been measured by following 14CO2 exhalation in rats after intraperitoneal injection of the two 14C-labelled carcinogens at high doses (20 or 40 mg/kg). Complete deuteration of NDMA reduced only slightly the maximal rate of metabolism when the two substrates were administered separately (VH/VD approximately 1.2). However, much larger (approximately 4-fold) deuterium isotope effects were observed when mixtures of NDMA with NDMA-d6 were injected. These results are tentatively interpreted as evidence that C-H bond cleavage is not a rate limiting feature of overall metabolism, but that the complex between NDMA and the principal enzyme(s) metabolizing it in vivo freely equilibrates with unbound substrate. Single, large, intraperitoneal doses of NDMA and NDMA-d6 produced a similar alkylation of rat liver DNA and also of kidney DNA. However, a small oral dose (54 micrograms/kg) of NDMA-d6 produced 1/3 less alkylation of liver DNA and 3 times as much alkylation of kidney DNA as did an equimolar dose of NDMA. The reduction in alkylation of liver DNA correlates well with, and possibly explains, the decreased ability of NDMA-d6 to induce liver tumors in rats. The associated increase in the alkylation of kidney DNA suggests that this change is due to a decrease in the amount of nitrosamine removed from the portal blood on the first pass through the liver

The effects of cellulase on capsaicin production in freely suspended cells and immobilized cell cultures of capsicum annuum

International Nuclear Information System (INIS)

Islek, C.

2014-01-01

The effect of different concentrations of cellulase on the production of capsaicin in freely suspended cell and immobilized cell cultures of Kahramanmara pepper seeds (Capsicum annuum L.) were studied. Calluses were obtained from in vitro germinated hypocotyl explants of pepper seedlings and cell suspensions were prepared from these calluses. Immobilized cell suspension cultures with calcium alginate and free cell suspension cultures were obtained by using cell suspensions. Elicitor such as cellulase (5-30 micro g/ml), was applied both for the free and immobilized cell suspensions and control group without elicitor was prepared. The concentration of capsaicin in freely suspended cells, immobilized cells and their filtrates were identified by HPLC after extraction with ethyl acetate. It was found that the immobilization process had an increasing effect on the capsaicin accumulation. The concentration of capsaicin in the immobilized cells for both control groups and elicitor added samples was higher than the free cells. In general, capsaicin concentration in the filtrate for free cells was higher than the immobilized cells. When all the cellulase and the sampling hours were compared, the highest capsaicin concentration for the immobilized cells was determined as 362,91 micro g/ml f.w. at the 24th hour for 30 micro g/ml cellulase applied samples. (author)

The glycine reuptake inhibitor org 25935 interacts with basal and ethanol-induced dopamine release in rat nucleus accumbens.

Science.gov (United States)

Lidö, Helga Höifödt; Stomberg, Rosita; Fagerberg, Anne; Ericson, Mia; Söderpalm, Bo

2009-07-01

The mesolimbic dopamine (DA) projection from the ventral tegmental area to nucleus accumbens (nAc), a central part of the reward system, is activated by ethanol (EtOH) and other drugs of abuse. We have previously demonstrated that the glycine receptor in the nAc and its amino acid agonists may be implicated in the DA activation and reinforcing properties of EtOH. We have also reported that the glycine transporter 1 inhibitor, Org 25935, produces a robust and dose-dependent decrease in EtOH consumption in Wistar rats. The present study explores the interaction between EtOH and Org 25935 with respect to DA levels in the rat nAc. The effects of Org 25935 (6 mg/kg, i.p.) and/or EtOH (2.5 g/kg, i.p.) on accumbal DA levels were examined by means of in vivo microdialysis (coupled to HPLC-ED) in freely moving male Wistar rats. The effect of Org 25935 on accumbal glycine output was also investigated. Systemic Org 25935 increased DA output in a subpopulation of rats (52% in Experiment 1 and 38% in Experiment 2). In Experiment 2, EtOH produced a significant increase in DA levels in vehicles (35%) and in Org 25935 nonresponders (19%), whereas EtOH did not further increase the DA level in rats responding to Org 25935 (2%). The same dose of Org 25935 increased glycine levels by 87% in nAc. This study demonstrates that Org 25935, probably via increased glycine levels, (i) counteracts EtOH-induced increases of accumbal DA levels and (ii) increases basal DA levels in a subpopulation of rats. The results are in line with previous findings and it is suggested that the effects observed involve interference with accumbal GlyRs and are related to the alcohol consumption modulating effect of Org 25935.

Existence of ''free will'' as a problem in physics

International Nuclear Information System (INIS)

Peres, A.

1986-01-01

The proof of Bell's inequality is based on the assumption that distant observers can freely and independently choose their experiments. As Bell's inequality is experimentally violated, it appears that distant physical systems may behave as a single, nonlocal, indivisible entity. This apparent contradiction is resolved. It is shown that the ''free will'' assumption is, under usual circumstances, an excellent approximation

RatMap--rat genome tools and data.

Science.gov (United States)

Petersen, Greta; Johnson, Per; Andersson, Lars; Klinga-Levan, Karin; Gómez-Fabre, Pedro M; Ståhl, Fredrik

2005-01-01

The rat genome database RatMap (http://ratmap.org or http://ratmap.gen.gu.se) has been one of the main resources for rat genome information since 1994. The database is maintained by CMB-Genetics at Goteborg University in Sweden and provides information on rat genes, polymorphic rat DNA-markers and rat quantitative trait loci (QTLs), all curated at RatMap. The database is under the supervision of the Rat Gene and Nomenclature Committee (RGNC); thus much attention is paid to rat gene nomenclature. RatMap presents information on rat idiograms, karyotypes and provides a unified presentation of the rat genome sequence and integrated rat linkage maps. A set of tools is also available to facilitate the identification and characterization of rat QTLs, as well as the estimation of exon/intron number and sizes in individual rat genes. Furthermore, comparative gene maps of rat in regard to mouse and human are provided.

RatMap—rat genome tools and data

Science.gov (United States)

Petersen, Greta; Johnson, Per; Andersson, Lars; Klinga-Levan, Karin; Gómez-Fabre, Pedro M.; Ståhl, Fredrik

2005-01-01

The rat genome database RatMap (http://ratmap.org or http://ratmap.gen.gu.se) has been one of the main resources for rat genome information since 1994. The database is maintained by CMB–Genetics at Göteborg University in Sweden and provides information on rat genes, polymorphic rat DNA-markers and rat quantitative trait loci (QTLs), all curated at RatMap. The database is under the supervision of the Rat Gene and Nomenclature Committee (RGNC); thus much attention is paid to rat gene nomenclature. RatMap presents information on rat idiograms, karyotypes and provides a unified presentation of the rat genome sequence and integrated rat linkage maps. A set of tools is also available to facilitate the identification and characterization of rat QTLs, as well as the estimation of exon/intron number and sizes in individual rat genes. Furthermore, comparative gene maps of rat in regard to mouse and human are provided. PMID:15608244

A wireless power transmission system for implantable devices in freely moving rodents.

Science.gov (United States)

Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Kim, Jinhyung; Kim, Junghoon; Lee, Sung Eun; Kim, Sung June

2014-08-01

Reliable wireless power delivery for implantable devices in animals is highly desired for safe and effective experimental use. Batteries require frequent replacement; wired connections are inconvenient and unsafe, and short-distance inductive coupling requires the attachment of an exterior transmitter to the animal's body. In this article, we propose a solution by which animals with implantable devices can move freely without attachments. Power is transmitted using coils attached to the animal's cage and is received by a receiver coil implanted in the animal. For a three-dimensionally uniform delivery of power, we designed a columnar dual-transmitter coil configuration. A resonator-based inductive link was adopted for efficient long-range power delivery, and we used a novel biocompatible liquid crystal polymer substrate as the implantable receiver device. Using this wireless power delivery system, we obtain an average power transfer efficiency of 15.2% (minimum efficiency of 10% and a standard deviation of 2.6) within a cage of 15×20×15 cm3.

FlyMAD: rapid thermogenetic control of neuronal activity in freely walking Drosophila.

Science.gov (United States)

Bath, Daniel E; Stowers, John R; Hörmann, Dorothea; Poehlmann, Andreas; Dickson, Barry J; Straw, Andrew D

2014-07-01

Rapidly and selectively modulating the activity of defined neurons in unrestrained animals is a powerful approach in investigating the circuit mechanisms that shape behavior. In Drosophila melanogaster, temperature-sensitive silencers and activators are widely used to control the activities of genetically defined neuronal cell types. A limitation of these thermogenetic approaches, however, has been their poor temporal resolution. Here we introduce FlyMAD (the fly mind-altering device), which allows thermogenetic silencing or activation within seconds or even fractions of a second. Using computer vision, FlyMAD targets an infrared laser to freely walking flies. As a proof of principle, we demonstrated the rapid silencing and activation of neurons involved in locomotion, vision and courtship. The spatial resolution of the focused beam enabled preferential targeting of neurons in the brain or ventral nerve cord. Moreover, the high temporal resolution of FlyMAD allowed us to discover distinct timing relationships for two neuronal cell types previously linked to courtship song.

Robust optical fiber patch-cords for in vivo optogenetic experiments in rats.

Science.gov (United States)

Trujillo-Pisanty, Ivan; Sanio, Christian; Chaudhri, Nadia; Shizgal, Peter

2015-01-01

In vivo optogenetic experiments commonly employ long lengths of optical fiber to connect the light source (commonly a laser) to the optical fiber implants in the brain. Commercially available patch cords are expensive and break easily. Researchers have developed methods to build these cables in house for in vivo experiments with rodents [1-4]. However, the half-life of those patch cords is greatly reduced when they are used with behaving rats, which are strong enough to break the delicate cable tip and to bite through the optical fiber and furcation tubing. Based on [3] we have strengthened the patch-cord tip that connects to the optical implant, and we have incorporated multiple layers of shielding to produce more robust and resistant cladding. Here, we illustrate how to build these patch cords with FC or M3 connectors. However, the design can be adapted for use with other common optical-fiber connectors. We have saved time and money by using this design in our optical self-stimulation experiments with rats, which are commonly several months long and last four to eleven hours per session. The main advantages are: •Long half-life.•Resistant to moderate rodent bites.•Suitable for long in vivo optogenetic experiments with large rodents.

Dopamine D1-like receptor in lateral habenula nucleus affects contextual fear memory and long-term potentiation in hippocampal CA1 in rats.

Science.gov (United States)

Chan, Jiangping; Guan, Xin; Ni, Yiling; Luo, Lilu; Yang, Liqiang; Zhang, Pengyue; Zhang, Jichuan; Chen, Yanmei

2017-03-15

The Lateral Habenula (LHb) plays an important role in emotion and cognition. Recent experiments suggest that LHb has functional interaction with the hippocampus and plays an important role in spatial learning. LHb is reciprocally connected with midbrain monoaminergic brain areas such as the ventral tegmental area (VTA). However, the role of dopamine type 1 receptor (D1R) in LHb in learning and memory is not clear yet. In the present study, D1R agonist or antagonist were administered bilaterally into the LHb in rats. We found that both D1R agonist and antagonist impaired the acquisition of contextual fear memory in rats. D1R agonist or antagonist also impaired long term potentiation (LTP) in hippocampal CA3-CA1 synapses in freely moving rats and attenuated learning induced phosphorylation of α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor (AMPAR) subunit 1 (GluA1) at Ser831 and Ser845 in hippocampus. Taken together, our results suggested that dysfunction of D1R in LHb affected the function of hippocampus. Copyright © 2016 Elsevier B.V. All rights reserved.

Persistent palatable food preference in rats with a history of limited and extended access to methamphetamine self-administration

Science.gov (United States)

Caprioli, Daniele; Zeric, Tamara; Thorndike, Eric B; Venniro, Marco

2015-01-01

Recent studies have shown that when given a mutually exclusive choice between cocaine and palatable foods most rats prefer the non-drug rewards over cocaine. Here, we used a discrete choice procedure to assess whether palatable food preference generalizes to rats with a history of limited (3 hr/day) or extended (6 or 9 hr/day) access to methamphetamine self-administration. On different daily sessions, we trained rats to lever-press for either methamphetamine (0.1–0.2 mg/kg/infusion) or palatable food (5 pellets per reward delivery) for several weeks; regular food was freely available. We then assessed food-methamphetamine preference either during training, after priming methamphetamine injections (0.5–1.0 mg/kg), following a satiety manipulation (palatable food exposure in the home cage), or after 21 days of withdrawal from methamphetamine. We also assessed progressive ratio responding for palatable food and methamphetamine. We found that independent of the daily drug access conditions and the withdrawal period, the rats strongly preferred the palatable food over methamphetamine, even when they were given free access to the palatable food in the home cage. Intake of methamphetamine and progressive ratio responding for the drug, both of which increased or escalated over time, did not predict preference in the discrete choice test. Results demonstrate that most rats strongly prefer palatable food pellets over intravenous methamphetamine, confirming previous studies using discrete choice procedures with intravenous cocaine. Results also demonstrate that escalation of drug self-administration, a popular model of compulsive drug use, is not associated with a cardinal feature of human addiction of reduced behavioral responding for non-drug rewards. PMID:25582886

Persistent palatable food preference in rats with a history of limited and extended access to methamphetamine self-administration.

Science.gov (United States)

Caprioli, Daniele; Zeric, Tamara; Thorndike, Eric B; Venniro, Marco

2015-09-01

Recent studies have shown that when given a mutually exclusive choice between cocaine and palatable foods, most rats prefer the non-drug rewards over cocaine. Here, we used a discrete choice procedure to assess whether palatable food preference generalizes to rats with a history of limited (3 hours/day) or extended (6 or 9 hours/day) access to methamphetamine self-administration. On different daily sessions, we trained rats to lever-press for either methamphetamine (0.1-0.2 mg/kg/infusion) or palatable food (five pellets per reward delivery) for several weeks; regular food was freely available. We then assessed food-methamphetamine preference either during training, after priming methamphetamine injections (0.5-1.0 mg/kg), following a satiety manipulation (palatable food exposure in the home cage) or after 21 days of withdrawal from methamphetamine. We also assessed progressive ratio responding for palatable food and methamphetamine. We found that independent of the daily drug access conditions and the withdrawal period, the rats strongly preferred the palatable food over methamphetamine, even when they were given free access to the palatable food in the home cage. Intake of methamphetamine and progressive ratio responding for the drug, both of which increased or escalated over time, did not predict preference in the discrete choice test. Results demonstrate that most rats strongly prefer palatable food pellets over intravenous methamphetamine, confirming previous studies using discrete choice procedures with intravenous cocaine. Results also demonstrate that escalation of drug self-administration, a popular model of compulsive drug use, is not associated with a cardinal feature of human addiction of reduced behavioral responding for non-drug rewards. © 2015 Society for the Study of Addiction.

Chronic cuffing of cervical vagus nerve inhibits efferent fiber integrity in rat model

Science.gov (United States)

Somann, Jesse P.; Albors, Gabriel O.; Neihouser, Kaitlyn V.; Lu, Kun-Han; Liu, Zhongming; Ward, Matthew P.; Durkes, Abigail; Robinson, J. Paul; Powley, Terry L.; Irazoqui, Pedro P.

2018-06-01

Objective. Numerous studies of vagal nerve stimulation (VNS) have been published showing it to be a potential treatment for chronic inflammation and other related diseases and disorders. Studies in recent years have shown that electrical stimulation of the vagal efferent fibers can artificially modulate cytokine levels and reduce systematic inflammation. Most VNS research in the treatment of inflammation have been acute studies on rodent subjects. Our study tested VNS on freely moving animals by stimulating and recording from the cervical vagus with nerve cuff electrodes over an extended period of time. Approach. We used methods of electrical stimulation, retrograde tracing (using Fluorogold) and post necropsy histological analysis of nerve tissue, flow cytometry to measure plasma cytokine levels, and MRI scanning of gastric emptying. This novel combination of methods allowed examination of physiological aspects of VNS previously unexplored. Main results. Through our study of 53 rat subjects, we found that chronically cuffing the left cervical vagus nerve suppressed efferent Fluorogold transport in 43 of 44 animals (36 showed complete suppression). Measured cytokine levels and gastric emptying rates concurrently showed nominal differences between chronically cuffed rats and those tested with similar acute methods. Meanwhile, results of electrophysiological and histological tests of the cuffed nerves revealed them to be otherwise healthy, consistent with previous literature. Significance. We hypothesize that due to these unforeseen and unexplored physiological consequences of the chronically cuffed vagus nerve in a rat, that inflammatory modulation and other vagal effects by VNS may become unreliable in chronic studies. Given our findings, we submit that it would benefit the VNS community to re-examine methods used in previous literature to verify the efficacy of the rat model for chronic VNS studies.

Analysis of clinical outcomes of linear vs. deep stop decompression from 3.5 to 6 atmospheres absolute (350 - 600 kpa) in awake rats

DEFF Research Database (Denmark)

Cronjé, Frans J; Meintjes, W A Jack; Bennett, Peter B

2011-01-01

Recreational divers are introducing "deep stops" at half the depth (HD-DS) to reduce the risk of spinal DCS with only Doppler evidence to support it. Therefore this research was designed to show the effect of an HD-DS on spinal DCS manifestations by evaluating whether: (1) air diving-induced spinal...... DCS could be produced in awake, freely moving rats at 3.5-6.0 atm abs (350-600 kPa); and (2) whether the introduction of an HD-DS reduced spinal DCS in such a model. Fifty-one female, Wistar rats (221 to 450 g) underwent one-hour compression at 350 to 600 kPa with seven minutes of decompression with....../without a five-minute DS (HD-DS / No-DS). Animals were observed for three hours. Outcomes were classified as: (1) asymptomatic; (2) breathing difficulties; (3) paralysis/weakness; (4) immobility; or (5) death. Eight animals, exposed to 385 kPa air breathing for 60 minutes followed by a three-staged decompression...

Cyclosporin safety in a simplified rat brain tumor implantation model

Directory of Open Access Journals (Sweden)

Francisco H. C. Felix

2012-01-01

Full Text Available Brain cancer is the second neurological cause of death. A simplified animal brain tumor model using W256 (carcinoma 256, Walker cell line was developed to permit the testing of novel treatment modalities. Wistar rats had a cell tumor solution inoculated stereotactically in the basal ganglia (right subfrontal caudate. This model yielded tumor growth in 95% of the animals, and showed absence of extracranial metastasis and systemic infection. Survival median was 10 days. Estimated tumor volume was 17.08±6.7 mm³ on the 7th day and 67.25±19.8 mm³ on 9th day post-inoculation. Doubling time was 24.25 h. Tumor growth induced cachexia, but no hematological or biochemical alterations. This model behaved as an undifferentiated tumor and can be promising for studying tumor cell migration in the central nervous system. Dexamethasone 3.0 mg/kg/day diminished significantly survival in this model. Cyclosporine 10 mg/kg/day administration was safely tolerated.

Two-dimensional model of a freely expanding plasma

International Nuclear Information System (INIS)

Khalid, Q.

1975-01-01

The free expansion of an initially confined plasma is studied by the computer experiment technique. The research is an extension to two dimensions of earlier work on the free expansion of a collisionless plasma in one dimension. In the two-dimensional rod model, developed in this research, the plasma particles, electrons and ions are modeled as infinitely long line charges or rods. The line charges move freely in two dimensions normal to their parallel axes, subject only to a self-consistent electric field. Two approximations, the grid approximation and the periodic boundary condition are made in order to reduce the computation time. In the grid approximation, the space occupied by the plasma at a given time is divided into boxes. The particles are subject to an average electric field calculated for that box assuming that the total charge within each box is located at the center of the box. However, the motion of each particle is exactly followed. The periodic boundary condition allows us to consider only one-fourth of the total number of particles of the plasma, representing the remaining three-fourths of the particles as symmetrically placed images of those whose positions are calculated. This approximation follows from the expected azimuthal symmetry of the plasma. The dynamics of the expansion are analyzed in terms of average ion and electron positions, average velocities, oscillation frequencies and relative distribution of energy between thermal, flow and electric field energies. Comparison is made with previous calculations of one-dimensional models which employed plane, spherical or cylindrical sheets as charged particles. In order to analyze the effect of the grid approximation, the model is solved for two different grid sizes and for each grid size the plasma dynamics is determined. For the initial phase of expansion, the agreement for the two grid sizes is found to be good

Deterioration in brain and heart functions following a single sub-lethal (0.8 LCt50) inhalation exposure of rats to sarin vapor:

International Nuclear Information System (INIS)

Allon, N.; Chapman, S.; Egoz, I.; Rabinovitz, I.; Kapon, J.; Weissman, B.A.; Yacov, G.; Bloch-Shilderman, E.; Grauer, E.

2011-01-01

The main injuries among victims of the terrorist act in the Tokyo subway resulted from sub-lethal inhalation and whole body exposure to sarin vapor. In order to study the long term effects of such exposure and to simulate these conditions, freely moving rats were exposed to sarin vapor (27.2 ± 1.7 μg/l) for 10 min. About 50% of the rats showed no overt symptoms and the rest had mild to moderate clinical symptoms that subsided within 4 h following exposure. A reduction of weight was noted during the first 3 days with full recovery on the 4th day. Rat's heart was challenged with epinephrine 1 and 6 months post exposure. A significant reduction in the threshold for epinephrine-induced arrhythmia (EPIA) was noted in rats exposed to sarin. A time dependent increase in the kD and Bmax values of muscarinic auto receptors (M2) was recorded in the rat's cortex and striatum. No changes were recorded in the rats' brain trans locator protein (TSPO) levels, concomitant with no observed changes in the animals' performance in A Morris water maze test. A significant increase in open field activity was noted 6 months following exposure to sarin vapor as well as a significant decrease in prostaglandin E 2 (PGE 2 ) production in the brain. It is speculated that down regulation of the M2 auto receptor function, caused hyper reactivity of the cholinergic system which leads to the changes described above. The continuous reduction in M2 auto-receptor system through an unknown mechanism may be the cause for long lasting decline in sarin-exposed casualties' health.

Polyoxymethylene passive samplers to assess the effectiveness of biochar by reducing the content of freely dissolved fipronil and ethiprole.

Science.gov (United States)

Li, Shasha; Wang, Pingping; Liu, Xingang; Wu, Xiaohu; Dong, Fengshou; Xu, Jun; Zheng, Yongquan

2018-07-15

An equilibrium passive sampler based on polyoxymethylene (POM) was used to determine the freely dissolved concentrations (C free ) of fipronil and ethiprole. The sorption equilibrium times of fipronil and ethiprole in POM were 14.2d and 24.0d, respectively. The POM-water partitioning coefficients (logK POM-water ) were 2.6 for fipronil and 1.4 for ethiprole. The method was further used to evaluate the sorption behavior of biochars which produced by pyrolysis of Magnolia wood (Magnolia denudata) at 300°C, 500°C and 700°C. The amounts of target compounds adsorbed increased with increasing pyrolysis temperature of the biochars. Biochars characterized by a low polarity index had better sorption capacity for the target compounds. The additions of biochars to sediment were effective in reducing C free , and the enhancement was found to be more pronounced with high biochar content. C free in sediment with more organic matter was significantly higher after biochar addition. Increasing the sediment-biochar contact time from 7 to 30d resulted in an increase in sorption of the compounds. We conclude that Magnolia wood biochar effectively reduces the content of freely dissolved fipronil and ethiprole content in sediment. Copyright © 2018. Published by Elsevier B.V.

Real-time supervisor system based on trinary logic to control experiments with behaving animals and humans.

Science.gov (United States)

Kutz, D F; Marzocchi, N; Fattori, P; Cavalcanti, S; Galletti, C

2005-06-01

A new method is presented based on trinary logic able to check the state of different control variables and synchronously record the physiological and behavioral data of behaving animals and humans. The basic information structure of the method is a time interval of defined maximum duration, called time slice, during which the supervisor system periodically checks the status of a specific subset of input channels. An experimental condition is a sequence of time slices subsequently executed according to the final status of the previous time slice. The proposed method implements in its data structure the possibility to branch like an if-else cascade and the possibility to repeat parts of it recursively like the while-loop. Therefore its data structure contains the most basic control structures of programming languages. The method was implemented using a real-time version of LabVIEW programming environment to program and control our experimental setup. Using this supervision system, we synchronously record four analog data channels at 500 Hz (including eye movements) and the time stamps of up to six neurons at 100 kHz. The system reacts with a resolution within 1 ms to changes of state of digital input channels. The system is set to react to changes in eye position with a resolution within 4 ms. The time slices, experimental conditions, and data are handled by relational databases. This facilitates the construction of new experimental conditions and data analysis. The proposed implementation allows continuous recording without an inter-trial gap for data storage or task management. The implementation can be used to drive electrophysiological experiments of behaving animals and psychophysical studies with human subjects.

Therapeutic deep brain stimulation in Parkinsonian rats directly influences motor cortex.

Science.gov (United States)

Li, Qian; Ke, Ya; Chan, Danny C W; Qian, Zhong-Ming; Yung, Ken K L; Ko, Ho; Arbuthnott, Gordon W; Yung, Wing-Ho

2012-12-06

Much recent discussion about the origin of Parkinsonian symptoms has centered around the idea that they arise with the increase of beta frequency waves in the EEG. This activity may be closely related to an oscillation between subthalamic nucleus (STN) and globus pallidus. Since STN is the target of deep brain stimulation, it had been assumed that its action is on the nucleus itself. By means of simultaneous recordings of the firing activities from populations of neurons and the local field potentials in the motor cortex of freely moving Parkinsonian rats, this study casts doubt on this assumption. Instead, we found evidence that the corrective action is upon the cortex, where stochastic antidromic spikes originating from the STN directly modify the firing probability of the corticofugal projection neurons, destroy the dominance of beta rhythm, and thus restore motor control to the subjects, be they patients or rodents. Copyright © 2012 Elsevier Inc. All rights reserved.

An in vivo MRI Template Set for Morphometry, Tissue Segmentation, and fMRI Localization in Rats

Science.gov (United States)

Valdés-Hernández, Pedro Antonio; Sumiyoshi, Akira; Nonaka, Hiroi; Haga, Risa; Aubert-Vásquez, Eduardo; Ogawa, Takeshi; Iturria-Medina, Yasser; Riera, Jorge J.; Kawashima, Ryuta

2011-01-01

Over the last decade, several papers have focused on the construction of highly detailed mouse high field magnetic resonance image (MRI) templates via non-linear registration to unbiased reference spaces, allowing for a variety of neuroimaging applications such as robust morphometric analyses. However, work in rats has only provided medium field MRI averages based on linear registration to biased spaces with the sole purpose of approximate functional MRI (fMRI) localization. This precludes any morphometric analysis in spite of the need of exploring in detail the neuroanatomical substrates of diseases in a recent advent of rat models. In this paper we present a new in vivo rat T2 MRI template set, comprising average images of both intensity and shape, obtained via non-linear registration. Also, unlike previous rat template sets, we include white and gray matter probabilistic segmentations, expanding its use to those applications demanding prior-based tissue segmentation, e.g., statistical parametric mapping (SPM) voxel-based morphometry. We also provide a preliminary digitalization of latest Paxinos and Watson atlas for anatomical and functional interpretations within the cerebral cortex. We confirmed that, like with previous templates, forepaw and hindpaw fMRI activations can be correctly localized in the expected atlas structure. To exemplify the use of our new MRI template set, were reported the volumes of brain tissues and cortical structures and probed their relationships with ontogenetic development. Other in vivo applications in the near future can be tensor-, deformation-, or voxel-based morphometry, morphological connectivity, and diffusion tensor-based anatomical connectivity. Our template set, freely available through the SPM extension website, could be an important tool for future longitudinal and/or functional extensive preclinical studies. PMID:22275894

An in vivo MRI template set for morphometry, tissue segmentation and fMRI localization in rats

Directory of Open Access Journals (Sweden)

Pedro Antonio Valdes Hernandez

2011-11-01

Full Text Available Over the last decade, several papers have focused on the construction of highly detailed mouse high field MRI templates via nonlinear registration to unbiased reference spaces, allowing for a variety of neuroimaging applications such as robust morphometric analyses. However, work in rats has only provided medium field MRI averages based on linear registration to biased spaces with the sole purpose of approximate fMRI localization. This precludes any morphometric analysis in spite of the need of exploring in detail the neuroanatomical substrates of diseases in a recent advent of rat models. In this paper we present a new in vivo rat T2 MRI template set, comprising average images of both intensity and shape, obtained via nonlinear registration. Also, unlike previous rat template sets, we include white and gray matter probabilistic segmentations, expanding its use to those applications demanding prior-based tissue segmentation, e.g. SPM voxel-based morphometry. We also provide a preliminary digitalization of latest Paxinos & Watson atlas for anatomical and functional interpretations within the cerebral cortex. We confirmed that, like with previous templates, forepaw and hindpaw fMRI activations can be correctly localized in the expected atlas structure. To exemplify the use of our new MRI template set, we reported the volumes of brain tissues and cortical structures and probed their relationships with ontogenetic development. Other in vivo applications in the near future can be tensor-, deformation- or voxel-based morphometry, morphological connectivity and diffusion tensor-based anatomical connectivity. Our template set, freely available through the SPM extension website, could be an important tool for future longitudinal and/or functional extensive preclinical studies.

An in vivo MRI Template Set for Morphometry, Tissue Segmentation, and fMRI Localization in Rats.

Science.gov (United States)

Valdés-Hernández, Pedro Antonio; Sumiyoshi, Akira; Nonaka, Hiroi; Haga, Risa; Aubert-Vásquez, Eduardo; Ogawa, Takeshi; Iturria-Medina, Yasser; Riera, Jorge J; Kawashima, Ryuta

2011-01-01

Over the last decade, several papers have focused on the construction of highly detailed mouse high field magnetic resonance image (MRI) templates via non-linear registration to unbiased reference spaces, allowing for a variety of neuroimaging applications such as robust morphometric analyses. However, work in rats has only provided medium field MRI averages based on linear registration to biased spaces with the sole purpose of approximate functional MRI (fMRI) localization. This precludes any morphometric analysis in spite of the need of exploring in detail the neuroanatomical substrates of diseases in a recent advent of rat models. In this paper we present a new in vivo rat T2 MRI template set, comprising average images of both intensity and shape, obtained via non-linear registration. Also, unlike previous rat template sets, we include white and gray matter probabilistic segmentations, expanding its use to those applications demanding prior-based tissue segmentation, e.g., statistical parametric mapping (SPM) voxel-based morphometry. We also provide a preliminary digitalization of latest Paxinos and Watson atlas for anatomical and functional interpretations within the cerebral cortex. We confirmed that, like with previous templates, forepaw and hindpaw fMRI activations can be correctly localized in the expected atlas structure. To exemplify the use of our new MRI template set, were reported the volumes of brain tissues and cortical structures and probed their relationships with ontogenetic development. Other in vivo applications in the near future can be tensor-, deformation-, or voxel-based morphometry, morphological connectivity, and diffusion tensor-based anatomical connectivity. Our template set, freely available through the SPM extension website, could be an important tool for future longitudinal and/or functional extensive preclinical studies.

Different patterns of neuronal activities in the infralimbic and prelimbic cortices and behavioral expression in response to two affective odors, 2,5-dihydro-2,4,5-trimethylthiazoline and a mixture of cis-3-hexenol and trans-2-hexenal, in the freely moving rat.

Science.gov (United States)

Nikaido, Y; Nakashima, T

2011-03-17

The medial prefrontal cortex (mPFC) is involved in stimulus perception, attentional control, emotional behavior, and the stress response. These functions are thought to be mediated by the infralimbic (IL) and prelimbic (PL) subregions of mPFC; however, few studies have examined the roles of IL and PL cortices in olfactory cognition. In the present study, we investigated the acute effects of two odors, 2,5-dihydro-2,4,5-trimethylthiazoline (TMT) and a mixture of cis-3-hexenol and trans-2-hexenal (green odor: GO), on behavioral responses and IL and PL neuronal activities using extracellular single-unit recordings in a freely moving rat. We found that the total number of spike firings in IL and PL neurons did not change with 10s presentation of odors. TMT presentation induced significant changes in burst firing activity in IL and PL neurons, while GO presentation induced changes in burst firing only in IL neurons. In the temporal profile of the firing activity of IL neurons, TMT exposure induced transient activation and GO exposure induced sustained activation. Those of PL neurons showed sustained activation during TMT exposure and transient activations during GO exposure. GO exposure induced a stretch-attend posture, whereas TMT exposure induced immobility. Furthermore, multiple regression analysis indicated that the property of the odor and neuronal activities of IL and PL regions were correlated with behavioral responses. These findings reveal that olfaction-related neurons exist in IL and PL regions, and that the neurons in these regions might temporarily encode odor information in order to modulate motor outputs by tuning firing properties in the early stage of cognition according to the odor property. Copyright © 2010 Elsevier B.V. All rights reserved.

Betanin reduces the accumulation and cross-links of collagen in high-fructose-fed rat heart through inhibiting non-enzymatic glycation.

Science.gov (United States)

Han, Junyan; Tan, Chang; Wang, Yiheng; Yang, Shaobin; Tan, Dehong

2015-02-05

We attempted to determine whether betanin (from natural pigments) that has antioxidant properties would be protective against fructose-induced diabetic cardiac fibrosis in Sprague-Dawley rats. Fructose water solution (30%) was accessed freely, and betanin (25 and 100 mg/kg/d) was administered by intra-gastric gavage continuously for 60 d. Rats were sacrificed after overnight fast. The rat blood and left ventricle were collected. In vitro antiglycation assay in bovine serum albumin/fructose system was also performed. In rats treated only with fructose, levels of plasma markers: glucose, insulin, HOMA and glycated hemoglobin rised, left ventricle collagen accumulated and cross-linked, profibrotic factor-transforming growth factor (TGF)-β1 and connective tissue growth factor (CTGF) protein expression increased, and soluble collagen decreased, compared with those in normal rats, showing fructose induces diabetic cardiac fibrosis. Treatment with betanin antagonized the changes of these parameters, demonstrating the antifibrotic role of betanin in the selected diabetic models. In further mechanistic study, betanin decreased protein glycation indicated by the decreased levels of protein glycation reactive intermediate (methylglyoxal), advanced glycation end product (N(ε)-(carboxymethyl) lysine) and receptors for advanced glycation end products (AGEs), antagonized oxidative stress and nuclear factor-κB activation elicited by fructose feeding, suggesting inhibition of glycation, oxidative stress and nuclear factor-κB activation may be involved in the antifibrotic mechanisms. Betanin also showed anitglycative effect in BSA/fructose system, which supported that anitglycation was involved in betanin's protective roles in vivo. Taken together, the potential for using betanin as an auxillary therapy for diabetic cardiomyopathy deserves to be explored further. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Single molecular image of cytosolic free Ca2+ of skeletal muscle cells in rats pre- and post-exercise-induced fatigue

Science.gov (United States)

Liu, Yi; Zhang, Heming; Zhao, Yanping; Liu, Zhiming

2009-08-01

A growing body of literature indicated the cytosolic free Ca2+ concentration of skeletal muscle cells changes significantly during exercise-induced fatigue. But it is confusing whether cytosolic free Ca2+ concentration increase or decrease. Furthermore, current researches mainly adopt muscle tissue homogenate as experiment material, but the studies based on cellular and subcellular level is seldom. This study is aimed to establish rat skeletal muscle cell model of exercise-induced fatigue, and confirm the change of cytosolic free Ca2+ concentration of skeletal muscle cells in rats preand post- exercise-induced fatigue. In this research, six male Wistar rats were randomly divided into two groups: control group (n=3) and exercise-induced fatigue group (n=3). The former group were allowed to freely move and the latter were forced to loaded swimming to exhaustive. Three days later, all the rats were sacrificed, the muscle tissue from the same site of skeletal muscle were taken out and digested to cells. After primary culture of the two kinds of skeletal muscle cells from tissue, a fluorescent dye-Fluo-3 AM was used to label the cytosolic free Ca2+. The fluorescent of Ca2+ was recorded by confocal laser scanning microscopy. The results indicated that, the Ca2+ fluorescence intensity of cells from the rat of exercise-induced fatigue group was significantly higher than those in control group. In conclusion, cytosolic free Ca2+ concentration of skeletal muscle cells has a close relation with exercise-induced fatigue, and the increase of cytosolic free Ca2+ concentration may be one of the important factors of exercise-induced fatigue.

[Effects of excess pyridoxine-HCl on growth and urinary excretion of water-soluble vitamins in weaning rats].

Science.gov (United States)

Fukuwatari, Tsutomu; Itoh, Keiko; Shibata, Katsumi

2009-04-01

To determine the tolerable upper intake level of pyridoxine-HCl in humans, we investigated the effects of excess pyridoxine-HCl administration on body weight gain, food intake, tissue weight, and urinary excretion of water-soluble vitamins in weaning rats. The weaning rats were freely fed ordinary diet containing 0.0007% pyridoxine-HCl (control diet) or the same diet with 0.1%, 0.5%, 0.8% or 1.0% pyridoxine-HCl for 30 days. The body weight gain in the 0.8% and 1.0% groups, and the total food intake in the 1.0% group were significantly lower than those in the control group. The urinary excretion of pantothenic acid in the pyridoxine-HCl added groups were higher than that in the control group, while excessive pyridoxine-HCl intake did not affect the urinary excretion of other water-soluble vitamins. These results showed that the no-observed-adverse-effect-level (NOAEL) for pyridoxine-HCl was 0.1% in diet, corresponding to 90 mg/kg body weight/day, and lowest-observed-adverse-effect-level (LOAEL) was 0.5% in diet, corresponding to 450 mg/kg body weight/day.

'Fingerprints' of central stimulatory drug effects by means of quantitative radioelectroencephalography in the rat (tele-stereo-EEG).

Science.gov (United States)

Dimpfel, W; Spüler, M; Nickel, B; Tibes, U

1986-01-01

The new electrophysiological model earlier described as stereo-EEG is extended now to allow recording from the freely moving rat by means of a telemetric device. Chronic implantation of 4 electrodes into the brain allows simultaneous transmission of field potentials from frontal cortex, hippocampus, striatum and reticular formation. Frequency analysis of these potentials results in a drug-specific 'fingerprint' which cannot only be used to compare different chemicals with each other but also to detect onset and time dependence of drug actions. Application of the model to the question if fenetylline has its own intrinsic mode of action or merely develops its stimulatory effect after metabolic separation into its molecular moieties amphetamine and theophylline (prodrug hypothesis) revealed that fenetylline indeed displays its own stimulatory effect to the same extent and at a similar time course as amphetamine and theophylline. The 'fingerprint' as obtained by the analysis of the action of fenetylline in the rat resembles closely that obtained after the application of theophylline with respect to decreased alpha activity, but resembles amphetamine with respect to beta 1 activity. Thus the applied method allows studying structure function relationships as the action of fenetylline seems to reflect both its molecular moieties.

The influence of autonomic interventions on the sleep-wake-related changes in gastric myoelectrical activity in rats.

Science.gov (United States)

Huang, Y M; Yang, C C H; Lai, C J; Kuo, T B J

2011-06-01

Significant changes in autonomic activity occur at sleep-wake transitions and constitute an ideal setting for investigating the modulatory role of the autonomic nervous system on gastric myoelectrical activity (GMA). Using continuous power spectral analysis of electroencephalogram, electromyogram, and electrogastromyogram (EGMG) data from freely moving rats that had undergone chemical sympathetomy and/or truncal vagotomy, sleep-wake-related fluctuations in GMA were compared among the intervention groups. The pattern and extent of fluctuations in EGMG power across the sleep-wake states was blunted most significantly in rats undergoing both chemical sympathectomy and truncal vagotomy. The effect of these interventions also varied with respect to the transition between different sleep-wake states. The most prominent influences were observed between active waking and quiet sleep and between paradoxical sleep and quiet sleep. The sleep-wake-related fluctuations in EGMG power are a result of joint contributions from both sympathetic and vagal innervation. Vagotomy mainly resulted in a reduction in EGMG power, while the role of sympathetic innervation was unveiled by vagotomy and this was reflected most obviously in the extent of the fluctuations in EGMG power. © 2011 Blackwell Publishing Ltd.

Asymmetric multisensory interactions of visual and somatosensory responses in a region of the rat parietal cortex.

Directory of Open Access Journals (Sweden)

Michael T Lippert

Full Text Available Perception greatly benefits from integrating multiple sensory cues into a unified percept. To study the neural mechanisms of sensory integration, model systems are required that allow the simultaneous assessment of activity and the use of techniques to affect individual neural processes in behaving animals. While rodents qualify for these requirements, little is known about multisensory integration and areas involved for this purpose in the rodent. Using optical imaging combined with laminar electrophysiological recordings, the rat parietal cortex was identified as an area where visual and somatosensory inputs converge and interact. Our results reveal similar response patterns to visual and somatosensory stimuli at the level of current source density (CSD responses and multi-unit responses within a strip in parietal cortex. Surprisingly, a selective asymmetry was observed in multisensory interactions: when the somatosensory response preceded the visual response, supra-linear summation of CSD was observed, but the reverse stimulus order resulted in sub-linear effects in the CSD. This asymmetry was not present in multi-unit activity however, which showed consistently sub-linear interactions. These interactions were restricted to a specific temporal window, and pharmacological tests revealed significant local intra-cortical contributions to this phenomenon. Our results highlight the rodent parietal cortex as a system to model the neural underpinnings of multisensory processing in behaving animals and at the cellular level.

Freely dissolved concentrations of anionic surfactants in seawater solutions: optimization of the non-depletive solid-phase microextraction method and application to linear alkylbenzene sulfonates.

NARCIS (Netherlands)

Rico Rico, A.; Droge, S.T.J.; Widmer, D.; Hermens, J.L.M.

2009-01-01

A solid-phase microextraction method (SPME) has been optimized for the analysis of freely dissolved anionic surfactants, namely linear alkylbenzene sulfonates (LAS), in seawater. An effect of the thermal conditioning treatment on the polyacrylate fiber coating was demonstrated for both uptake

Why consumers behave as they do with respect to food safety and risk information

DEFF Research Database (Denmark)

Verbeke, Wim; Frewer, Lynn J.; Scholderer, Joachim

2007-01-01

rankings. The aim of this contribution is to provide a better understanding to food risk analysts of why consumers behave as they do with respect to food safety and risk information. This paper presents some cases of seemingly irrational and inconsistent consumer behaviour with respect to food safety...... and risk information and provides explanations for these behaviours based on the nature of the risk and individual psychological processes. Potential solutions for rebuilding consumer confidence in food safety and bridging between lay and expert opinions towards food risks are reviewed. These include......In recent years, it seems that consumers are generally uncertain about the safety and quality of their food and their risk perception differs substantially from that of experts. Hormone and veterinary drug residues in meat persist to occupy a high position in European consumers' food concern...

Exploration of freely available web-interfaces for comparative homology modelling of microbial proteins.

Science.gov (United States)

Nema, Vijay; Pal, Sudhir Kumar

2013-01-01

This study was conducted to find the best suited freely available software for modelling of proteins by taking a few sample proteins. The proteins used were small to big in size with available crystal structures for the purpose of benchmarking. Key players like Phyre2, Swiss-Model, CPHmodels-3.0, Homer, (PS)2, (PS)(2)-V(2), Modweb were used for the comparison and model generation. Benchmarking process was done for four proteins, Icl, InhA, and KatG of Mycobacterium tuberculosis and RpoB of Thermus Thermophilus to get the most suited software. Parameters compared during analysis gave relatively better values for Phyre2 and Swiss-Model. This comparative study gave the information that Phyre2 and Swiss-Model make good models of small and large proteins as compared to other screened software. Other software was also good but is often not very efficient in providing full-length and properly folded structure.

Effect of cascade remnants on freely migrating defects in Cu-1% Au alloys

Energy Technology Data Exchange (ETDEWEB)

Iwase, A; Rehn, L E; Baldo, P M; Funk, L [Argonne National Lab., IL (United States). Materials Science Div.

1997-03-01

The effects of cascade remnants on Freely Migrating Defects (FMD) were studied by measuring Radiation-Induced Segregation (RIS) in Cu-1%Au at 400degC during simultaneous irradiation with 1.5-MeV He and (400-800)-keV heavy ions (Ne, Ar or Cu). The large RIS observed during 1.5-MeV He-only irradiation was dramatically suppressed under simultaneous heavy ion irradiation. For Cu simultaneous irradiation, the suppression disappeared immediately after the Cu irradiation ceased, while for simultaneous inert gas (Ne or Ar) irradiation, the suppression persisted after the ion beam was turned off. These results demonstrate that the displacement cascades created by heavy ions introduce additional annihilation sites, which reduce the steady-state FMD concentrations. As the cascade remnants produced by Cu ions are thermally unstable at 400degC, the RIS suppression occurs only during simultaneous irradiation. On the other hand, the inert gas atoms which accumulate in the specimen apparently stabilize the cascade remnants, allowing the suppression to persist. (author)

Mechanically, the shoot apical meristem of Arabidopsis behaves like a shell inflated by a pressure of about 1 MPa

Directory of Open Access Journals (Sweden)

Léna eBeauzamy

2015-11-01

Full Text Available In plants, the shoot apical meristem contains the stem cells and is responsible for the generation of all aerial organs. Mechanistically, organogenesis is associated with an auxin-dependent local softening of the epidermis. This has been proposed to be sufficient to trigger outgrowth, because the epidermis is thought to be under tension and stiffer than internal tissues in all the aerial part of the plant. However, this has not been directly demonstrated in the shoot apical meristem. Here we tested this hypothesis in Arabidopsis using indentation methods and modeling. We considered two possible scenarios: either the epidermis does not have unique properties and the meristem behaves as a homogeneous linearly-elastic tissue, or the epidermis is under tension and the meristem exhibits the response of a shell under pressure. Large indentation depths measurements with a large tip (~size of the meristem were consistent with a shell-like behavior. This also allowed us to deduce a value of turgor pressure, estimated at 0.82 ± 0.16 MPa. Indentation with atomic force microscopy provided local measurements of pressure in the epidermis, further confirming the values obtained from large deformations. Altogether, our data demonstrate that the Arabidopsis shoot apical meristem behaves like a shell under a MPa range pressure and support a key role for the epidermis in shaping the shoot apex.

Using disposable solid-phase microextraction (SPME) to determine the freely dissolved concentration of polybrominated diphenyl ethers (PBDEs) in sediments

International Nuclear Information System (INIS)

Jia Fang; Cui Xinyi; Wang Wei; Delgado-Moreno, Laura; Gan, Jay

2012-01-01

Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants (BFRs). The ubiquity and persistence of PBDEs in sediment have raised concerns over their environmental fate and ecological risks. Due to strong affinity for sediment organic matter, environmental fate and bioavailability of PBDEs closely depend on their phase distribution. In this study, disposable polydimethylsiloxane (PDMS) fiber was used to derive the freely dissolved concentration (C free ) of PBDEs in sediment porewater as a measurement of bioavailability. The PDMS-to-water partition coefficient (log K PDMS ) was 5.46–5.83 for BDE 47, 99, and 153. In sediments, PBDEs were predominantly sorbed to the sediment phase, with C free accounting for free of PBDEs decreased as their bromination or sediment organic carbon content increased. The strong association with dissolved organic matter (DOM) implies a potential for facilitated offsite transport and dispersion in the environment that depends closely on the stability of sediment aggregates. - Highlights: ► A disposable SPME method was developed for measuring C free of PBDEs in sediment. ► C free decreased with increasing congener bromination or sediment OC content. ► C free of PBDEs accounted for DOC values suggest a high probability for DOM-facilitated offsite transport. - A SPME method based on disposable PDMS fibers was developed for measuring the freely dissolved concentration of PBDEs (C free ) in sediment porewater.

Freely-available, true-color volume rendering software and cryohistology data sets for virtual exploration of the temporal bone anatomy.

Science.gov (United States)

Kahrs, Lüder Alexander; Labadie, Robert Frederick

2013-01-01

Cadaveric dissection of temporal bone anatomy is not always possible or feasible in certain educational environments. Volume rendering using CT and/or MRI helps understanding spatial relationships, but they suffer in nonrealistic depictions especially regarding color of anatomical structures. Freely available, nonstained histological data sets and software which are able to render such data sets in realistic color could overcome this limitation and be a very effective teaching tool. With recent availability of specialized public-domain software, volume rendering of true-color, histological data sets is now possible. We present both feasibility as well as step-by-step instructions to allow processing of publicly available data sets (Visible Female Human and Visible Ear) into easily navigable 3-dimensional models using free software. Example renderings are shown to demonstrate the utility of these free methods in virtual exploration of the complex anatomy of the temporal bone. After exploring the data sets, the Visible Ear appears more natural than the Visible Human. We provide directions for an easy-to-use, open-source software in conjunction with freely available histological data sets. This work facilitates self-education of spatial relationships of anatomical structures inside the human temporal bone as well as it allows exploration of surgical approaches prior to cadaveric testing and/or clinical implementation. Copyright © 2013 S. Karger AG, Basel.

Adaptive quantization of local field potentials for wireless implants in freely moving animals: an open-source neural recording device

Science.gov (United States)

Martinez, Dominique; Clément, Maxime; Messaoudi, Belkacem; Gervasoni, Damien; Litaudon, Philippe; Buonviso, Nathalie

2018-04-01

Objective. Modern neuroscience research requires electrophysiological recording of local field potentials (LFPs) in moving animals. Wireless transmission has the advantage of removing the wires between the animal and the recording equipment but is hampered by the large number of data to be sent at a relatively high rate. Approach. To reduce transmission bandwidth, we propose an encoder/decoder scheme based on adaptive non-uniform quantization. Our algorithm uses the current transmitted codeword to adapt the quantization intervals to changing statistics in LFP signals. It is thus backward adaptive and does not require the sending of side information. The computational complexity is low and similar at the encoder and decoder sides. These features allow for real-time signal recovery and facilitate hardware implementation with low-cost commercial microcontrollers. Main results. As proof-of-concept, we developed an open-source neural recording device called NeRD. The NeRD prototype digitally transmits eight channels encoded at 10 kHz with 2 bits per sample. It occupies a volume of 2  ×  2  ×  2 cm3 and weighs 8 g with a small battery allowing for 2 h 40 min of autonomy. The power dissipation is 59.4 mW for a communication range of 8 m and transmission losses below 0.1%. The small weight and low power consumption offer the possibility of mounting the entire device on the head of a rodent without resorting to a separate head-stage and battery backpack. The NeRD prototype is validated in recording LFPs in freely moving rats at 2 bits per sample while maintaining an acceptable signal-to-noise ratio (>30 dB) over a range of noisy channels. Significance. Adaptive quantization in neural implants allows for lower transmission bandwidths while retaining high signal fidelity and preserving fundamental frequencies in LFPs.

In vivo measurement of aerodynamic weight support in freely flying birds

Science.gov (United States)

Lentink, David; Haselsteiner, Andreas; Ingersoll, Rivers

2014-11-01

Birds dynamically change the shape of their wing during the stroke to support their body weight aerodynamically. The wing is partially folded during the upstroke, which suggests that the upstroke of birds might not actively contribute to aerodynamic force production. This hypothesis is supported by the significant mass difference between the large pectoralis muscle that powers the down-stroke and the much smaller supracoracoideus that drives the upstroke. Previous works used indirect or incomplete techniques to measure the total force generated by bird wings ranging from muscle force, airflow, wing surface pressure, to detailed kinematics measurements coupled with bird mass-distribution models to derive net force through second derivatives. We have validated a new method that measures aerodynamic force in vivo time-resolved directly in freely flying birds which can resolve this question. The validation of the method, using independent force measurements on a quadcopter with pulsating thrust, show the aerodynamic force and impulse are measured within 2% accuracy and time-resolved. We demonstrate results for quad-copters and birds of similar weight and size. The method is scalable and can be applied to both engineered and natural flyers across taxa. The first author invented the method, the second and third authors validated the method and present results for quadcopters and birds.

Robust, highly customizable, and economical multi-channel electrode for chronic multi-unit recording in behaving animals.

Science.gov (United States)

Tateyama, Yukina; Oyama, Kei; Shiraishi, Masaru; Iijima, Toshio; Tsutsui, Ken-Ichiro

2017-12-01

Multi-unit recording has been one of the most widely used techniques to investigate the correlation between multiple neuronal activities and behavior. However, a common problem of currently used multi-channel electrodes is their physical weakness. In this study, we developed a novel multi-channel electrode with sufficient physical strength to penetrate a thickened dura mater. This electrode consists of low-cost materials and is easily fabricated, and it enables recording without removing dura mater, thereby reducing the risk of inflammation, infection, or brain herniation. The low-cost multi-channel electrode developed in this study would be a useful tool for chronic recording in behaving animals. Copyright © 2017. Published by Elsevier B.V.

Attenuation correction for freely moving small animal brain PET studies based on a virtual scanner geometry

International Nuclear Information System (INIS)

Angelis, G I; Kyme, A Z; Ryder, W J; Fulton, R R; Meikle, S R

2014-01-01

Attenuation correction in positron emission tomography brain imaging of freely moving animals is a very challenging problem since the torso of the animal is often within the field of view and introduces a non negligible attenuating factor that can degrade the quantitative accuracy of the reconstructed images. In the context of unrestrained small animal imaging, estimation of the attenuation correction factors without the need for a transmission scan is highly desirable. An attractive approach that avoids the need for a transmission scan involves the generation of the hull of the animal’s head based on the reconstructed motion corrected emission images. However, this approach ignores the attenuation introduced by the animal’s torso. In this work, we propose a virtual scanner geometry which moves in synchrony with the animal’s head and discriminates between those events that traversed only the animal’s head (and therefore can be accurately compensated for attenuation) and those that might have also traversed the animal’s torso. For each recorded pose of the animal’s head a new virtual scanner geometry is defined and therefore a new system matrix must be calculated leading to a time-varying system matrix. This new approach was evaluated on phantom data acquired on the microPET Focus 220 scanner using a custom-made phantom and step-wise motion. Results showed that when the animal’s torso is within the FOV and not appropriately accounted for during attenuation correction it can lead to bias of up to 10% . Attenuation correction was more accurate when the virtual scanner was employed leading to improved quantitative estimates (bias < 2%), without the need to account for the attenuation introduced by the extraneous compartment. Although the proposed method requires increased computational resources, it can provide a reliable approach towards quantitatively accurate attenuation correction for freely moving animal studies. (paper)

Noninvasive quantification of cerebral metabolic rate for glucose in rats using 18F-FDG PET and standard input function

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Hori, Yuki; Ihara, Naoki; Teramoto, Noboru; Kunimi, Masako; Honda, Manabu; Kato, Koichi; Hanakawa, Takashi

2015-01-01

Measurement of arterial input function (AIF) for quantitative positron emission tomography (PET) studies is technically challenging. The present study aimed to develop a method based on a standard arterial input function (SIF) to estimate input function without blood sampling. We performed 18F-fluolodeoxyglucose studies accompanied by continuous blood sampling for measurement of AIF in 11 rats. Standard arterial input function was calculated by averaging AIFs from eight anesthetized rats, after normalization with body mass (BM) and injected dose (ID). Then, the individual input function was estimated using two types of SIF: (1) SIF calibrated by the individual's BM and ID (estimated individual input function, EIFNS) and (2) SIF calibrated by a single blood sampling as proposed previously (EIF1S). No significant differences in area under the curve (AUC) or cerebral metabolic rate for glucose (CMRGlc) were found across the AIF-, EIFNS-, and EIF1S-based methods using repeated measures analysis of variance. In the correlation analysis, AUC or CMRGlc derived from EIFNS was highly correlated with those derived from AIF and EIF1S. Preliminary comparison between AIF and EIFNS in three awake rats supported an idea that the method might be applicable to behaving animals. The present study suggests that EIFNS method might serve as a noninvasive substitute for individual AIF measurement. PMID:25966947

Fast optical signal not detected in awake behaving monkeys.

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Radhakrishnan, Harsha; Vanduffel, Wim; Deng, Hong Ping; Ekstrom, Leeland; Boas, David A; Franceschini, Maria Angela

2009-04-01

While the ability of near-infrared spectroscopy (NIRS) to measure cerebral hemodynamic evoked responses (slow optical signal) is well established, its ability to measure non-invasively the 'fast optical signal' is still controversial. Here, we aim to determine the feasibility of performing NIRS measurements of the 'fast optical signal' or Event-Related Optical Signals (EROS) under optimal experimental conditions in awake behaving macaque monkeys. These monkeys were implanted with a 'recording well' to expose the dura above the primary visual cortex (V1). A custom-made optical probe was inserted and fixed into the well. The close proximity of the probe to the brain maximized the sensitivity to changes in optical properties in the cortex. Motion artifacts were minimized by physical restraint of the head. Full-field contrast-reversing checkerboard stimuli were presented to monkeys trained to perform a visual fixation task. In separate sessions, two NIRS systems (CW4 and ISS FD oximeter), which previously showed the ability to measure the fast signal in human, were used. In some sessions EEG was acquired simultaneously with the optical signal. The increased sensitivity to cortical optical changes with our experimental setup was quantified with 3D Monte Carlo simulations on a segmented MRI monkey head. Averages of thousands of stimuli in the same animal, or grand averages across the two animals and across repeated sessions, did not lead to detection of the fast optical signal using either amplitude or phase of the optical signal. Hemodynamic responses and visual evoked potentials were instead always detected with single trials or averages of a few stimuli. Based on these negative results, despite the optimal experimental conditions, we doubt the usefulness of non-invasive fast optical signal measurements with NIRS.

Differential cardiorespiratory effects of endomorphin 1, endomorphin 2, DAMGO, and morphine.

Science.gov (United States)

Czapla, M A; Gozal, D; Alea, O A; Beckerman, R C; Zadina, J E

2000-09-01

The novel endogenous mu-opioid receptor (MOR) agonists endomorphin 1 (EM1) and 2 (EM2) were tested for their cardiorespiratory effects in conscious, freely behaving rats. After systemic (intravenous) administration of EM1, EM2, or the selective MOR agonist DAMGO, analgesia, minute ventilation (V E), heart rate (HR) and mean arterial blood pressure (BP) were measured. The threshold dose for analgesia was similar for all 3 peptides ( approximately 900 nmol/kg). All 3 compounds elicited biphasic V E responses, with marked, short-lived V E depressions (4-6 s) followed by more sustained V E increases (10-12 min). However, compared with responses elicited by EM2 or DAMGO, EM1 decreased V E only at higher doses, and produced greater V E stimulation. Morphine produced a V E decrease, but no subsequent V E increase. EM2 and DAMGO decreased HR and BP, while EM1 decreased HR, but did not decrease BP in conscious rats at doses up to 9,600 nmol/kg. In anesthetized rats, all 3 peptides decreased HR and BP. The decreases in V E, HR, and BP were blocked by the MOR antagonist, naloxone HCI (NIx). Only the HR and BP responses, however, were blocked by naloxone-methiodide (MeNIx), indicating central mediation of V E responses and peripheral mediation of cardiovascular responses. We conclude that MOR-selective compounds vary in their cardiorespiratory response characteristics which could be linked to differential cellular actions. The results support the concept that the analgesic, respiratory, and cardiovascular effects of MOR agonists can be dissociated and that EM1-like compounds could provide the basis for novel, safer analgesics.

[Teratologic cranio-encephalic effects of chronic thinner inhalation in progenitors, in rats and humans].

Science.gov (United States)

Barroso-Moguel, R; Villeda-Hernández, J; Méndez-Armenta, M

1991-01-01

Inhalation of thinner by youngsters and adolescents is an increasing drug abuse problem in Mexico. It presents serious repercussions upon socio-economic, cultural, legal and health (neurologic and psychiatric) problems. We report a comparative study in humans and rats which demonstrate the embryotoxic and craneo encephalic teratologic effects in the children and brood of progenitors who have chronically inhaled thinner (in the case of pregnant women, before, at the beginning and throughout pregnancy). Inhaled thinner passes directly to the blood stream and crosses the placentary barrier freely reaching the embryo. It may cause craneal bone and partial or total encephalon agenesia, added to macro and microscopic lesions secondary to direct aggression to the neuroepithelial germ cells. Abortions and premature labor with weight and size underdeveloped products and placentary hemorrhages occur. Usually these die, but if they survive they show trascendental mental retardation, as well as neurologic and psychiatric sequels.

Hydrodynamic study of freely swimming shark fish propulsion for marine vehicles using 2D particle image velocimetry.

Science.gov (United States)

Babu, Mannam Naga Praveen; Mallikarjuna, J M; Krishnankutty, P

Two-dimensional velocity fields around a freely swimming freshwater black shark fish in longitudinal (XZ) plane and transverse (YZ) plane are measured using digital particle image velocimetry (DPIV). By transferring momentum to the fluid, fishes generate thrust. Thrust is generated not only by its caudal fin, but also using pectoral and anal fins, the contribution of which depends on the fish's morphology and swimming movements. These fins also act as roll and pitch stabilizers for the swimming fish. In this paper, studies are performed on the flow induced by fins of freely swimming undulatory carangiform swimming fish (freshwater black shark, L  = 26 cm) by an experimental hydrodynamic approach based on quantitative flow visualization technique. We used 2D PIV to visualize water flow pattern in the wake of the caudal, pectoral and anal fins of swimming fish at a speed of 0.5-1.5 times of body length per second. The kinematic analysis and pressure distribution of carangiform fish are presented here. The fish body and fin undulations create circular flow patterns (vortices) that travel along with the body waves and change the flow around its tail to increase the swimming efficiency. The wake of different fins of the swimming fish consists of two counter-rotating vortices about the mean path of fish motion. These wakes resemble like reverse von Karman vortex street which is nothing but a thrust-producing wake. The velocity vectors around a C-start (a straight swimming fish bends into C-shape) maneuvering fish are also discussed in this paper. Studying flows around flapping fins will contribute to design of bioinspired propulsors for marine vehicles.

Navigating actions through the rodent parietal cortex

Directory of Open Access Journals (Sweden)

Jonathan R. Whitlock

2014-05-01

Full Text Available The posterior parietal cortex (PPC participates in a manifold of cognitive functions, including visual attention, working memory, spatial processing and movement planning. Given the vast interconnectivity of PPC with sensory and motor areas, it is not surprising that neuronal recordings show that PPC often encodes mixtures of spatial information as well as the movements required to reach a goal. Recent work sought to discern the relative strength of spatial versus motor signaling in PPC by recording single unit activity in PPC of freely behaving rats during selective changes in either the spatial layout of the local environment or in the pattern of locomotor behaviors executed during navigational tasks. The results revealed unequivocally a predominant sensitivity of PPC neurons to locomotor action structure, with subsets of cells even encoding upcoming movements more than 1 second in advance. In light of these and other recent findings in the field, I propose that one of the key contributions of PPC to navigation is the synthesis of goal-directed behavioral sequences, and that the rodent PPC may serve as an apt system to investigate cellular mechanisms for spatial motor planning as traditionally studied in humans and monkeys.

Subglottal pressure, tracheal airflow, and intrinsic laryngeal muscle activity during rat ultrasound vocalization

Science.gov (United States)

2011-01-01

Vocal production requires complex planning and coordination of respiratory, laryngeal, and vocal tract movements, which are incompletely understood in most mammals. Rats produce a variety of whistles in the ultrasonic range that are of communicative relevance and of importance as a model system, but the sources of acoustic variability were mostly unknown. The goal was to identify sources of fundamental frequency variability. Subglottal pressure, tracheal airflow, and electromyographic (EMG) data from two intrinsic laryngeal muscles were measured during 22-kHz and 50-kHz call production in awake, spontaneously behaving adult male rats. During ultrasound vocalization, subglottal pressure ranged between 0.8 and 1.9 kPa. Pressure differences between call types were not significant. The relation between fundamental frequency and subglottal pressure within call types was inconsistent. Experimental manipulations of subglottal pressure had only small effects on fundamental frequency. Tracheal airflow patterns were also inconsistently associated with frequency. Pressure and flow seem to play a small role in regulation of fundamental frequency. Muscle activity, however, is precisely regulated and very sensitive to alterations, presumably because of effects on resonance properties in the vocal tract. EMG activity of cricothyroid and thyroarytenoid muscle was tonic in calls with slow or no fundamental frequency modulations, like 22-kHz and flat 50-kHz calls. Both muscles showed brief high-amplitude, alternating bursts at rates up to 150 Hz during production of frequency-modulated 50-kHz calls. A differentiated and fine regulation of intrinsic laryngeal muscles is critical for normal ultrasound vocalization. Many features of the laryngeal muscle activation pattern during ultrasound vocalization in rats are shared with other mammals. PMID:21832032

How Do Children Behave Regarding Their Birth Order in Dental Setting?

Science.gov (United States)

Ghaderi, Faezeh; Fijan, Soleiman; Hamedani, Shahram

2015-12-01

Prediction of child cooperation level in dental setting is an important issue for a dentist to select the proper behavior management method. Many psychological studies have emphasized the effect of birth order on patient behavior and personality; however, only a few researches evaluated the effect of birth order on child's behavior in dental setting. This study was designed to evaluate the influence of children ordinal position on their behavior in dental setting. A total of 158 children with at least one primary mandibular molar needing class I restoration were selected. Children were classified based on the ordinal position; first, middle, or last child as well as single child. A blinded examiner recorded the pain perception of children during injection based on Visual Analogue Scale (VAS) and Sound, Eye and Movement (SEM) scale. To assess the child's anxiety, the questionnaire known as "Dental Subscale of the Children's Fear Survey Schedule" (CFSS-DS) was employed. The results showed that single children were significantly less cooperative and more anxious than the other children (p<0.001). The middle children were significantly more cooperative in comparison with the other child's position (p< 0.001). Single child may behave less cooperatively in dental setting. The order of child birth must also be considered in prediction of child's behavior for behavioral management.

The 5-HT6 receptor antagonist idalopirdine potentiates the effects of donepezil on gamma oscillations in the frontal cortex of anesthetized and awake rats without affecting sleep-wake architecture.

Science.gov (United States)

Amat-Foraster, Maria; Leiser, Steven C; Herrik, Kjartan F; Richard, Nelly; Agerskov, Claus; Bundgaard, Christoffer; Bastlund, Jesper F; de Jong, Inge E M

2017-02-01

The 5-HT 6 receptor is a promising target for cognitive disorders, in particular for Alzheimer's disease (AD). The high affinity and selective 5-HT 6 receptor antagonist idalopirdine (Lu AE58054) is currently in development for mild-moderate AD as adjunct therapy to acetylcholinesterase inhibitors (AChEIs). We studied the effects of idalopirdine alone and in combination with the AChEI donepezil on cortical function using two in vivo electrophysiological methods. Neuronal network oscillations in the frontal cortex were measured during electrical stimulation of the brainstem nucleus pontis oralis (nPO) in the anesthetized rat and by an electroencephalogram (EEG) in the awake, freely moving rat. In conjunction with the EEG study, we investigated the effects of idalopirdine and donepezil on sleep-wake architecture using telemetric polysomnography. Idalopirdine (2 mg/kg i.v.) increased gamma power in the medial prefrontal cortex (mPFC) during nPO stimulation. Donepezil (0.3 and 1 mg/kg i.v.) also increased cortical gamma power and pretreatment with idalopirdine (2 mg/kg i.v.) potentiated and prolonged the effects of donepezil. Similarly, donepezil (1 and 3 mg/kg s.c.) dose-dependently increased frontal cortical gamma power in the freely moving rat and pretreatment with idalopirdine (10 mg/kg p.o.) augmented the effect of donepezil 1 mg/kg. Analysis of the sleep-wake architecture showed that donepezil (1 and 3 mg/kg s.c.) dose-dependently delayed sleep onset and decreased the time spent in both REM and non REM sleep stages. In contrast, idalopirdine (10 mg/kg p.o.) did not affect sleep-wake architecture nor the effects of donepezil. In summary, we show that idalopirdine potentiates the effects of donepezil on frontal cortical gamma oscillations, a pharmacodynamic biomarker associated with cognition, without modifying the effects of donepezil on sleep. The increased cortical excitability may contribute to the procognitive effects of idalopirdine in donepezil

Effects of acute chlorpyrifos exposure on in vivo acetylcholine accumulation in rat striatum

International Nuclear Information System (INIS)

Karanth, Subramanya; Liu, Jing; Mirajkar, Nikita; Pope, Carey

2006-01-01

This study examined the acute effects of chlorpyrifos (CPF) on cholinesterase inhibition and acetylcholine levels in the striatum of freely moving rats using in vivo microdialysis. Adult, male Sprague-Dawley rats were treated with vehicle (peanut oil, 2 ml/kg) or CPF (84, 156 or 279 mg/kg, sc) and functional signs of toxicity, body weight and motor activity recorded. Microdialysis was conducted at 1, 4 and 7 days after CPF exposure for measurement of acetylcholine levels in striatum. Rats were then sacrificed and the contralateral striatum and diaphragm were collected for biochemical measurements. Few overt signs of cholinergic toxicity were noted in any rats. Body weight gain was significantly affected in the high-dose (279 mg/kg) group only, while motor activity (nocturnal rearing) was significantly reduced in all CPF-treated groups at one day (84 mg/kg) or from 1-4 days (156 and 279 mg/kg) after dosing. Cholinesterase activities in both diaphragm and striatum were markedly inhibited (50-92%) in a time-dependent manner, but there were relatively minimal dose-related changes. In contrast, time- and dose-dependent changes in striatal acetylcholine levels were noted, with significantly higher levels noted in the high-dose group compared to other groups. Maximal increases in striatal acetylcholine levels were observed at 4-7 days after dosing (84 mg/kg, 7-9-fold; 156 mg/kg, 10-13-fold; 279 mg/kg, 35-57-fold). Substantially higher acetylcholine levels were noted when an exogenous cholinesterase inhibitor was included in the perfusion buffer, but CPF treatment-related differences were substantially lower in magnitude under those conditions. The results suggest that marked differences in acetylcholine accumulation can occur with dosages of CPF eliciting relatively similar degrees of cholinesterase inhibition. Furthermore, the minimal expression of classic signs of cholinergic toxicity in the presence of extensive brain acetylcholine accumulation suggests that some

A Calibrated Method of Massage Therapy Decreases Systolic Blood Pressure Concomitant With Changes in Heart Rate Variability in Male Rats.

Science.gov (United States)

Spurgin, Kurt A; Kaprelian, Anthony; Gutierrez, Roberto; Jha, Vidyasagar; Wilson, Christopher G; Dobyns, Abigail; Xu, Karen H; Curras-Collazo, Margarita C

2017-02-01

The purpose of this study was to develop a method for applying calibrated manual massage pressures by using commonly available, inexpensive sphygmomanometer parts and validate the use of this approach as a quantitative method of applying massage therapy to rodents. Massage pressures were monitored by using a modified neonatal blood pressure (BP) cuff attached to an aneroid gauge. Lightly anesthetized rats were stroked on the ventral abdomen for 5 minutes at pressures of 20 mm Hg and 40 mm Hg. Blood pressure was monitored noninvasively for 20 minutes following massage therapy at 5-minute intervals. Interexaminer reliability was assessed by applying 20 mm Hg and 40 mm Hg pressures to a digital scale in the presence or absence of the pressure gauge. With the use of this method, we observed good interexaminer reliability, with intraclass coefficients of 0.989 versus 0.624 in blinded controls. In Long-Evans rats, systolic BP dropped by an average of 9.86% ± 0.27% following application of 40 mm Hg massage pressure. Similar effects were seen following 20 mm Hg pressure (6.52% ± 1.7%), although latency to effect was greater than at 40 mm Hg. Sprague-Dawley rats behaved similarly to Long-Evans rats. Low-frequency/high-frequency ratio, a widely-used index of autonomic tone in cardiovascular regulation, showed a significant increase within 5 minutes after 40 mm Hg massage pressure was applied. The calibrated massage method was shown to be a reproducible method for applying massage pressures in rodents and lowering BP. Copyright © 2016. Published by Elsevier Inc.

A Comparison of Urge Intensity and the Probability of Tic Completion During Tic Freely and Tic Suppression Conditions.

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Specht, Matt W; Nicotra, Cassandra M; Kelly, Laura M; Woods, Douglas W; Ricketts, Emily J; Perry-Parrish, Carisa; Reynolds, Elizabeth; Hankinson, Jessica; Grados, Marco A; Ostrander, Rick S; Walkup, John T

2014-03-01

Tic-suppression-based treatments (TSBTs) represent a safe and effective treatment option for Chronic Tic Disorders (CTDs). Prior research has demonstrated that treatment naive youths with CTDs have the capacity to safely and effectively suppress tics for prolonged periods. It remains unclear how tic suppression is achieved. The current study principally examines how effective suppression is achieved and preliminary correlates of the ability to suppress tics. Twelve youths, ages 10 to 17 years, with moderate-to-marked CTDs participated in an alternating sequence of tic freely and reinforced tic suppression conditions during which urge intensity and tic frequency were frequently assessed. Probability of tics occurring was half as likely following high-intensity urges during tic suppression (31%) in contrast to low-intensity urges during tic freely conditions (60%). Age was not associated with ability to suppress. Intelligence indices were associated with or trended toward greater ability to suppress tics. Attention difficulties were not associated with ability to suppress but were associated with tic severity. In contrast to our "selective suppression" hypothesis, we found participants equally capable of suppressing their tics regardless of urge intensity during reinforced tic suppression. Tic suppression was achieved with an "across-the-board" effort to resist urges. Preliminary data suggest that ability to suppress may be associated with general cognitive variables rather than age, tic severity, urge severity, and attention. Treatment naive youths appear to possess a capacity for robust tic suppression. TSBTs may bolster these capacities and/or enable their broader implementation, resulting in symptom improvement. © The Author(s) 2014.

Temporal analysis of the spontaneous baroreceptor reflex during mild emotional stress in the rat.

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Bajić, Dragana; Loncar-Turukalo, Tatjana; Stojicić, Sonja; Sarenac, Olivera; Bojić, Tijana; Murphy, David; Paton, Julian F R; Japundzić-Zigon, Nina

2010-03-01

The effect of emotional stress on the spontaneous baroreceptor reflex (sBRR) in freely moving rats was investigated. Six male Wistar rats equipped with an intra-arterial polyethylene catheter were exposed to a 2-min air-jet stress. For time course analysis of the sBRR response to stress, the records of systolic blood pressure (SBP) and pulse interval (PI) were divided into five regions: baseline (BASELINE), acute exposure to air-jet stress (STRESS), immediate recovery (IMMED. RECOVERY), remaining recovery (RECOVERY), and delayed response (DELAYED RESPONSE). In addition to sBRR sensitivity and effectiveness, we introduce the sequence coverage area and its median for evaluation of the sBRR operating range and set point. During exposure to STRESS and IMMED. RECOVERY, sBRR sensitivity was preserved, its effectiveness was decreased, its operating range was enlarged, and the set point was shifted towards higher SBP and lower PI values. According to the joint symbolic dynamics analysis, the SBP and PI relationship became less predictable hence more prone to respond to stress. In RECOVERY the parameters regained baseline values and DELAYED RESPONSE occurred during which re-setting of sBRR was noted. It follows that emotional stress modulates sBRR differentially during the time course of stress and recovery, affecting both linearity and unpredictability of the BP and PI relationship.

Non-freely generated W-algebras and construction of N=2 super W-algebras

International Nuclear Information System (INIS)

Blumenhagen, R.

1994-07-01

Firstly, we investigate the origin of the bosonic W-algebras W(2, 3, 4, 5), W(2, 4, 6) and W(2, 4, 6) found earlier by direct construction. We present a coset construction for all three examples leading to a new type of finitely, non-freely generated quantum W-algebras, which we call unifying W-algebras. Secondly, we develop a manifest covariant formalism to construct N = 2 super W-algebras explicitly on a computer. Applying this algorithm enables us to construct the first four examples of N = 2 super W-algebras with two generators and the N = 2 super W 4 algebra involving three generators. The representation theory of the former ones shows that all examples could be divided into four classes, the largest one containing the N = 2 special type of spectral flow algebras. Besides the W-algebra of the CP(3) Kazama-Suzuki coset model, the latter example with three generators discloses a second solution which could also be explained as a unifying W-algebra for the CP(n) models. (orig.)

Oxytocin differentially affects sucrose taking and seeking in male and female rats.

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Zhou, Luyi; Ghee, Shannon M; See, Ronald E; Reichel, Carmela M

2015-04-15

Oxytocin has a modulatory role in natural and drug reward processes. While the role of oxytocin in pair bonding and reproduction has been extensively studied, sex differences in conditioned and unconditioned behavioral responses to oxytocin treatment have not been fully characterized. Here, we determined whether male and female rats would show similar dose response curves in response to acute oxytocin on measures of locomotor activity, sucrose seeking, and sucrose intake. Male and freely cycling female rats received vehicle or oxytocin (0.1, 0.3, 1, 3mg/kg, IP) injections before behavioral tests designed to assess general motor activity, as well as sucrose self-administration and seeking. Lower doses of oxytocin decreased motor activity in a novel environment in females relative to males. Likewise, lower doses of oxytocin in females decreased responding for sucrose during maintenance of sucrose self-administration and reinstatement to sucrose-conditioned cues. However, sucrose seeking in response to a sucrose prime was only decreased by the highest oxytocin dose in both sexes. In general, oxytocin had similar effects in both sexes. However, females were more sensitive to lower doses of oxytocin than males. These findings are consistent with the notion that oxytocin regulates many of the same behaviors in males and females, but that the effects are typically more profound in females. Therapeutic use of oxytocin should include sex as a factor in determining dose regimens. Copyright © 2015 Elsevier B.V. All rights reserved.

Sleep and the gut microbiome: antibiotic-induced depletion of the gut microbiota reduces nocturnal sleep in mice

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Seebach, Bradley; Lendrum, Jonathan; Liu, Sumei; Klein, Barrett

2017-01-01

Several bacterial cell wall components such as peptidoglycan and muramyl peptide are potent inducers of mammalian slow-wave sleep when exogenously administered to freely behaving animals. It has been proposed that the native gut microflora may serve as a quasi-endogenous pool of somnogenic bacterial cell wall products given their quantity and close proximity to the intestinal portal. This proposal suggests that deliberate manipulation of the host's intestinal flora may elicit changes in host ...

The organization of prospective thinking: evidence of event clusters in freely generated future thoughts.

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Demblon, Julie; D'Argembeau, Arnaud

2014-02-01

Recent research suggests that many imagined future events are not represented in isolation, but instead are embedded in broader event sequences-referred to as event clusters. It remains unclear, however, whether the production of event clusters reflects the underlying organizational structure of prospective thinking or whether it is an artifact of the event-cuing task in which participants are explicitly required to provide chains of associated future events. To address this issue, the present study examined whether the occurrence of event clusters in prospective thought is apparent when people are left to think freely about events that might happen in their personal future. The results showed that the succession of events participants spontaneously produced when envisioning their future frequently included event clusters. This finding provides more compelling evidence that prospective thinking involves higher-order autobiographical knowledge structures that organize imagined events in coherent themes and sequences. Copyright © 2014 Elsevier Inc. All rights reserved.

In vitro solubility of uranium tetrafluoride with oxidizing medium compared with in vivo solubility in rats

International Nuclear Information System (INIS)

Ansoborlo, E.; Chalabreysse, J.; Escallon, S.; Henge-Napoli, M.H.

1990-01-01

A simple in vitro solubility test for UF 4 was developed to investigate effects of addition of enzymes, proteins or gases (eg O 2 ) to synthetic biological fluid or Gamble solvent. Tests were made concomitantly with an in vivo inhalation study using male rats. With Gamble solvent alone, UF 4 showed class Y behaviour with dissolution half-time 300-500 days. When O 2 or carbonates were added to Gamble solvent, UF 4 showed class W behaviour (half-time 25-50 days). In the presence of oxygen and pyrogallol, the superoxide ion was formed and UF 4 behaved as class D (half-time 2-3 days). Results correlated with those of the inhalation experiment in which dissolution half-time was 2.5 and 5.2 days. Data also agree with urine monitoring data for workers exposed to UF 4 over 20 years. (author)

Observations on the interactions of Schwann cells and astrocytes following x irradiation of neonatal rat spinal cord

Energy Technology Data Exchange (ETDEWEB)

Blakemore, W F; Patterson, R C

1975-10-01

Myelination was inhibited in the spinal cord of three day-old rats with 2000 rads of x irradiation. Myelination subsequently occurred as a result of caudal migration of oligodendrocytes and extensive invasion of the cord by Schwann cells. Although oligodendrocytes were present in areas containing Schwann cells, astrocytes were absent. The presence of Schwann cells in the neuropil of the spinal cord did not stimulate production of basement membrane by astrocytes, so no new glial limiting membrane was formed. Evidence is presented which suggests that if astrocytes do not form a glial limiting membrane when opposed by large numbers of Schwann cells they are destroyed by the invading cells. It is suggested that the glial limiting membrane normally inhibits entry of Schwann cells into the central nervous system; if this is destroyed and not reconstituted, Schwann cells can migrate freely into the neuropil.

A mathematical model for pressure-based organs behaving as biological pressure vessels.

Science.gov (United States)

Casha, Aaron R; Camilleri, Liberato; Gauci, Marilyn; Gatt, Ruben; Sladden, David; Chetcuti, Stanley; Grima, Joseph N

2018-04-26

We introduce a mathematical model that describes the allometry of physical characteristics of hollow organs behaving as pressure vessels based on the physics of ideal pressure vessels. The model was validated by studying parameters such as body and organ mass, systolic and diastolic pressures, internal and external dimensions, pressurization energy and organ energy output measurements of pressure-based organs in a wide range of mammals and birds. Seven rules were derived that govern amongst others, lack of size efficiency on scaling to larger organ sizes, matching organ size in the same species, equal relative efficiency in pressurization energy across species and direct size matching between organ mass and mass of contents. The lung, heart and bladder follow these predicted theoretical relationships with a similar relative efficiency across various mammalian and avian species; an exception is cardiac output in mammals with a mass exceeding 10kg. This may limit massive body size in mammals, breaking Cope's rule that populations evolve to increase in body size over time. Such a limit was not found in large flightless birds exceeding 100kg, leading to speculation about unlimited dinosaur size should dinosaurs carry avian-like cardiac characteristics. Copyright © 2018. Published by Elsevier Ltd.

5-7 Year Old Children's Conceptions of Behaving Artifacts and the Influence of Constructing Their Behavior on the Development of Theory of Mind (ToM and Theory of Artificial Mind (ToAM

Directory of Open Access Journals (Sweden)

Karen Spektor-Precel

2015-12-01

Full Text Available Nowadays, we are surrounded by artifacts that are capable of adaptive behavior, such as electric pots, boiler timers, automatic doors, and robots. The literature concerning human beings’ conceptions of “traditional” artifacts is vast, however, little is known about our conceptions of behaving artifacts, nor of the influence of the interaction with such artifacts on cognitive development, especially among children. Since these artifacts are provided with an artificial “mind,” it is of interest to assess whether and how children develop a Theory of Artificial Mind (ToAM which is distinct from their Theory of Mind (ToM. The study examined a new theoretical scheme named ToAM (Theory of Artificial Mind by means of qualitative and quantitative methodology among twenty four 5-7 year old children from central Israel. It also examined the effects of interacting with behaving artifacts (constructing versus observing the robot’s behavior using the “RoboGan” interface on children’s development of ToAM and their ToM and looked for conceptions that evolve among children while interacting with behaving artifacts which are indicative of the acquisition of ToAM. In the quantitative analysis it was found that the interaction with behaving artifacts, whether as observers or constructors and for both age groups, brought into awareness children’s ToM as well as influenced their ability to understand that robots can behave independently and based on external and environmental conditions. In the qualitative analysis it was found that participating in the intervention influenced the children’s ToAM for both constructors and for the younger observer. Engaging in building the robot’s behavior influenced the children’s ability to explain several of the robots’ behaviors, their understanding of the robot’s script-based behavior and rule-based behavior and the children’s metacognitive development. The theoretical and practical importance of

Opioidergic and dopaminergic modulation of cost/benefit decision-making in Long Evans Rats.

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Morales, Ileana; Currie, Paul J; Hackenberg, Timothy D; Pastor, Raúl

2017-10-01

Eating disorders are associated with impaired decision-making and dysfunctional reward-related neurochemistry. The present study examined the potential contributions of dopamine and opioid signaling to these processes using two different decision-making tasks. In one task, Long Evans Rats chose between working for a preferred food (high-carbohydrate banana-flavored sucrose pellets) by lever pressing on a progressive-ratio schedule of reinforcement vs. obtaining less preferred laboratory chow that was concurrently available. In a second (effort-free) task, rats chose between the same two reinforcers when they were both available freely. Rats were trained in these tasks before receiving haloperidol (0.00, 0.05, 0.10mg/kg, intraperitoneally (i.p.)) or naloxone (0.0, 1.5, 3.0mg/kg, i.p.). In the first task, haloperidol decreased breakpoint, lever presses, number of reinforcers earned, and increased chow intake, whereas naloxone decreased breakpoint and number of reinforcers earned but had no effect on chow consumption. In the effort-free task, haloperidol reduced intakes of both foods without affecting preference, whereas naloxone selectively reduced the consumption of banana-pellets. The present findings support converging evidence suggesting that DA signaling affects processes more closely related to appetitive motivation, leaving other components of motivation unchanged. By contrast, opioid signaling appears to mediate aspects of hedonic feeding by selectively altering intakes of highly palatable foods. For preferred foods, both appetitive and consummatory aspects of food intake were altered by opioid receptor antagonism. Our findings argue against a general suppression of appetite by either compound, as appetite manipulations have been shown to unselectively alter intakes of both types of food regardless of the task employed. Copyright © 2017 Elsevier Inc. All rights reserved.

Evidence for Long-Timescale Patterns of Synaptic Inputs in CA1 of Awake Behaving Mice.

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Kolb, Ilya; Talei Franzesi, Giovanni; Wang, Michael; Kodandaramaiah, Suhasa B; Forest, Craig R; Boyden, Edward S; Singer, Annabelle C

2018-02-14

Repeated sequences of neural activity are a pervasive feature of neural networks in vivo and in vitro In the hippocampus, sequential firing of many neurons over periods of 100-300 ms reoccurs during behavior and during periods of quiescence. However, it is not known whether the hippocampus produces longer sequences of activity or whether such sequences are restricted to specific network states. Furthermore, whether long repeated patterns of activity are transmitted to single cells downstream is unclear. To answer these questions, we recorded intracellularly from hippocampal CA1 of awake, behaving male mice to examine both subthreshold activity and spiking output in single neurons. In eight of nine recordings, we discovered long (900 ms) reoccurring subthreshold fluctuations or "repeats." Repeats generally were high-amplitude, nonoscillatory events reoccurring with 10 ms precision. Using statistical controls, we determined that repeats occurred more often than would be expected from unstructured network activity (e.g., by chance). Most spikes occurred during a repeat, and when a repeat contained a spike, the spike reoccurred with precision on the order of ≤20 ms, showing that long repeated patterns of subthreshold activity are strongly connected to spike output. Unexpectedly, we found that repeats occurred independently of classic hippocampal network states like theta oscillations or sharp-wave ripples. Together, these results reveal surprisingly long patterns of repeated activity in the hippocampal network that occur nonstochastically, are transmitted to single downstream neurons, and strongly shape their output. This suggests that the timescale of information transmission in the hippocampal network is much longer than previously thought. SIGNIFICANCE STATEMENT We found long (≥900 ms), repeated, subthreshold patterns of activity in CA1 of awake, behaving mice. These repeated patterns ("repeats") occurred more often than expected by chance and with 10 ms

The embodiment of tourism among bisexually-behaving Dominican male sex workers.

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Padilla, Mark B

2008-10-01

While theories of "structure" and social inequality have increasingly informed global health efforts for HIV prevention--with growing recognition of the linkages between large-scale political and economic factors in the distribution and impact of the HIV/AIDS epidemic--there is still little theorization of precisely how structural factors shape the very bodies and sexualities of specific populations and groups. In order to extend the theoretical understanding of these macro-micro linkages, this article examines how the growth of the tourism industry in the Dominican Republic has produced sexual practices and identities that reflect both the influence of large-scale structural processes and the resistant responses of local individuals. Drawing on social science theories of political economy, embodiment, and authenticity, I argue that an understanding of patterns of sexuality and HIV risk in the region requires analysis of how political-economic transformations related to tourism intersect with the individual experiences and practices of sexuality on the ground. The analysis draws on long-term ethnographic research with bisexually behaving male sex workers in two cities in the Dominican Republic, including participant observation, in-depth interviews, focus groups, and surveys. By examining the global and local values placed on these men's bodies and the ways sex workers use their bodies to broker tourists' pleasure, we may better understand how the large-scale structures of the tourism industry are linked to the specific meanings and practices of sexuality.

An Image Enhancement Method Using the Quantum-Behaved Particle Swarm Optimization with an Adaptive Strategy

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Xiaoping Su

2013-01-01

Full Text Available Image enhancement techniques are very important to image processing, which are used to improve image quality or extract the fine details in degraded images. In this paper, two novel objective functions based on the normalized incomplete Beta transform function are proposed to evaluate the effectiveness of grayscale image enhancement and color image enhancement, respectively. Using these objective functions, the parameters of transform functions are estimated by the quantum-behaved particle swarm optimization (QPSO. We also propose an improved QPSO with an adaptive parameter control strategy. The QPSO and the AQPSO algorithms, along with genetic algorithm (GA and particle swarm optimization (PSO, are tested on several benchmark grayscale and color images. The results show that the QPSO and AQPSO perform better than GA and PSO for the enhancement of these images, and the AQPSO has some advantages over QPSO due to its adaptive parameter control strategy.

Impact of extraneous mispositioned events on motion-corrected brain SPECT images of freely moving animals

International Nuclear Information System (INIS)

Angelis, Georgios I.; Ryder, William J.; Bashar, Rezaul; Meikle, Steven R.; Fulton, Roger R.

2014-01-01

Purpose: Single photon emission computed tomography (SPECT) brain imaging of freely moving small animals would allow a wide range of important neurological processes and behaviors to be studied, which are normally inhibited by anesthetic drugs or precluded due to the animal being restrained. While rigid body motion of the head can be tracked and accounted for in the reconstruction, activity in the torso may confound brain measurements, especially since motion of the torso is more complex (i.e., nonrigid) and not well correlated with that of the head. The authors investigated the impact of mispositioned events and attenuation due to the torso on the accuracy of motion corrected brain images of freely moving mice. Methods: Monte Carlo simulations of a realistic voxelized mouse phantom and a dual compartment phantom were performed. Each phantom comprised a target and an extraneous compartment which were able to move independently of each other. Motion correction was performed based on the known motion of the target compartment only. Two SPECT camera geometries were investigated: a rotating single head detector and a stationary full ring detector. The effects of motion, detector geometry, and energy of the emitted photons (hence, attenuation) on bias and noise in reconstructed brain regions were evaluated. Results: The authors observed two main sources of bias: (a) motion-related inconsistencies in the projection data and (b) the mismatch between attenuation and emission. Both effects are caused by the assumption that the orientation of the torso is difficult to track and model, and therefore cannot be conveniently corrected for. The motion induced bias in some regions was up to 12% when no attenuation effects were considered, while it reached 40% when also combined with attenuation related inconsistencies. The detector geometry (i.e., rotating vs full ring) has a big impact on the accuracy of the reconstructed images, with the full ring detector being more

Aconitine-induced Ca2+ overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

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Sun, Gui-bo; Sun, Hong; Meng, Xiang-bao; Hu, Jin; Zhang, Qiang; Liu, Bo; Wang, Min; Xu, Hui-bo; Sun, Xiao-bo

2014-01-01

Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na + channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca 2+ in aconitine poisoning. In this study, we explored the importance of pathological Ca 2+ signaling in aconitine poisoning in vitro and in vivo. We found that Ca 2+ overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca 2+ handling proteins demonstrated that aconitine promoted Ca 2+ overload through the expression regulation of Ca 2+ handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca 2+ overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca 2+ overload causes arrhythmia in rats

Trait aggressiveness does not predict social dominance of rats in the Visible Burrow System.

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Buwalda, Bauke; Koolhaas, Jaap M; de Boer, Sietse F

2017-09-01

Hierarchical social status greatly influences health and well-being in mammals, including humans. The social rank of an individual is established during competitive encounters with conspecifics. Intuitively, therefore, social dominance and aggressiveness may seem intimately linked. Yet, whether an aggressive personality trait may predispose individuals to a particular rank in a social colony setting remains largely unclear. Here we tested the hypothesis that high trait aggressiveness in Wildtype Groningen (WTG) rats, as assessed in a classic resident-intruder offensive aggression paradigm predicts social dominance in a mixed-sex colony housing using the Visible Burrow System (VBS). We also hypothesized that hierarchical steepness, as reflected in the number and intensity of the social conflicts, positively correlates with the average level of trait aggressiveness of the male subjects in the VBS. Clear and stable hierarchical ranking was formed within a few days in VBS colonies as indicated and reflected by a rapid loss of body weight in subordinates which stabilized after 2-3days. Social conflicts, that occurred mainly during these first few days, also resulted in bite wounds in predominantly subordinate males. Data clearly showed that trait aggressiveness does not predict dominance status. The most aggressive male in a mixed sex group of conspecifics living in a closed VBS environment does not always become the dominant male. In addition, data did not convincingly indicate that in colonies with only highly aggressive males, agonistic interactions were more intense. Number of bite wounds and body weight loss did not positively correlate with trait-aggressiveness of subordinates. In this study, rats from this wild-derived rat strain behave differently from Long-Evans laboratory rats that have been studied up till now in many experiments using the VBS. Strain dependent differences in the capacity to display appropriate social behavior fitting an adaptive strategy to

Modification of medullary respiratory-related discharge patterns by behaviors and states of arousal.

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Chang, F C

1992-02-07

The modulatory influences of behaviors and states of arousal on bulbar respiratory-related unit (RRU) discharge patterns were studied in an unanesthetized, freely behaving guinea pig respiratory model system. When fully instrumented, this model system permits concurrent monitoring and recording of (i) single units from either Bötzinger complex or nucleus para-ambiguus; (ii) electrocorticogram; and, (iii) diaphragmatic EMG. In addition to being used in surveys of RRU discharge patterns in freely behaving states, the model system also offered a unique opportunity in investigating the effects of pentobarbital on RRU discharge patterns before, throughout the course of, and during recovery from anesthesia. In anesthetized preparations, a particular RRU discharge pattern (such as tonic, incrementing or decrementing) typically displayed little, if any notable variation. The most striking development following pentobarbital was a state of progressive bradypnea attributable to a significantly augmented RRU cycle duration, burst duration and an increase in the RRU spike frequencies during anesthesia. In freely behaving states, medullary RRU activities rarely adhered to a fixed, immutable discharge pattern. More specifically, the temporal organization (such as burst duration, cycle duration, and the extent of modulation of within-burst spike frequencies) of RRU discharge patterns regularly showed complex and striking variations, not only with states of arousal (sleep/wakefulness, anesthesia) but also with discrete alterations in electrocorticogram (ECoG) activities and a multitude of on-going behavioral repertoires such as volitional movement, postural modification, phonation, mastication, deglutition, sniffing/exploratory behavior, alerting/startle reflexes. Only during sleep, and on occasions when the animal assumed a motionless, resting posture, could burst patterns of relatively invariable periodicity and uniform temporal attributes be observed. RRU activities during

Hospital doctors behave differently, and only by respecting the fundamentals of professional organizations will managers be able to create common goals with professionals.

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Van Dijck, H

2014-08-01

Hospital doctors behave differently from other hospital workers. The general and specific characteristics of the doctors' behavior are described. As professionals, doctors want to make autonomous decisions and more specifically, they negotiate differently. The best description of their negotiation style is one that features multi-actor, multi-issue characteristics. They behave as actors in a network in never-ending rounds of negotiations with variable issues up for discussion: one time you lose, the next you win. A doctor's career starts with a long residency period in which he or she absorbs professional habits. His or her knowledge and way of organizing are implicit. It is hard for him or her to explicitly describe what he or she is doing. This makes it difficult for managers to discuss quality issues with doctors. Dealing with disruptive behavior is not easy either. The difficult tasks of the chief medical officer, who acts as a go-between, are highlighted. Only when managers respect the fundamentals of the professional organization will they be able to create common goals with the professionals. Common goals bring about better care in hospitals.

Adrenaline release by the 5-HT1A receptor agonist 8-OH-DPAT is partly responsible for pituitary activation

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Korte, S.M; Buwalda, B; Bohus, B.G J; de Kloet, E.R

1996-01-01

In male Wistar rats the effect of adrenalectomy on pituitary activation by the 5-HT1A receptor agonist. 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), was studied. Rats were injected intravenously with 8-OH-DPAT (0.10 mg/kg) in their home cages. Blood samples were withdrawn from freely moving

Functional cardiovascular action of L-cysteine microinjected into pressor sites of the rostral ventrolateral medulla of the rat.

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Takemoto, Yumi

2014-04-01

The endogenous sulfur-containing amino acid L-cysteine injected into the cerebrospinal fluid space of the cisterna magna increases arterial blood pressure (ABP) and heart rate (HR) in the freely moving rat. The present study examined (1) cardiovascular responses to L-cysteine microinjected into the rostral ventrolateral medulla (RVLM), where a group of neurons regulate activities of cardiovascular sympathetic neurons and (2) involvement of ionotropic excitatory amino acid (iEAA) receptors in response. In the RVLM of urethane-anesthetized rats accessed ventrally and identified with pressor responses to L-glutamate (10 mM, 34 nl), microinjections of L-cysteine increased ABP and HR dose dependently (3-100 mM, 34 nl). The cardiovascular responses to L-cysteine (30 mM) were not attenuated by a prior injection of either antagonist alone, MK801 (20 mM, 68 nl) for the NMDA type of iEAA receptors, or CNQX (2 mM) for the non-NMDA type. However, inhibition of both NMDA and non-NMDA receptors with additional prior injection of either antagonist completely blocked those responses to L-cysteine. The results indicate that L-cysteine has functional cardiovascular action in the RVLM of the anesthetized rat, and the responses to L-cysteine involve both NMDA and non-NMDA receptors albeit in a mutually exclusive parallel fashion. The findings may suggest endogenous roles of L-cysteine indirectly via iEAA receptors in the neuronal network of the RVLM for cardiovascular regulation in physiological and pathological situations.

Comparison of voiding function and nociceptive behavior in two rat models of cystitis induced by cyclophosphamide or acetone

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Saitoh, Chikashi; Yokoyama, Hitoshi; Chancellor, Michael B.; de Groat, William C.; Yoshimura, Naoki

2009-01-01

Aims Nociceptive behavior and its relationship with bladder dysfunction were investigated in two cystitis models, which were induced by intraperitoneal (ip) injection of cyclophosphamide (CYP) or intravesical instillation of acetone, using freely moving, non-catheterized conscious rats. Methods Female Sprague-Dawley rats were used. Cystitis was induced by ip injection of CYP (100 and 200mg/kg) or intravesical instillation of acetone (10, 30 and 50%) via a polyethylene catheter temporarily inserted into the bladder through the urethra. Then the incidence of nociceptive behavior (immobility with decreased breathing rates) was scored. Voided urine was collected simultaneously and continuously to measure bladder capacity. The plasma extravasation in the bladder was quantified by an evans blue (EB) dye leakage technique. Results CYP (100mg/kg, ip) induced nociceptive behavior without affecting bladder capacity or EB concentration in the bladder. A higher dose of CYP (200mg/kg, ip) decreased bladder capacity and increased EB levels as well as nociceptive behavior. In contrast, intravesical instillation of acetone (30%) decreased bladder capacity and increased EB levels, but evoked nociceptive behavior less frequently compared with CYP-treated animals. In capsaicin pretreated rats, nociceptive behavior induced by CYP or acetone was reduced; however, the overall effects of CYP or acetone on bladder capacity and bladder EB levels were unaffected. Conclusions These results suggest that there is a difference in the induction process of nociceptive behavior and small bladder capacity after two different types of bladder irritation and that C-fiber sensitization is more directly involved in pain sensation than reduced bladder capacity. PMID:19618450

Solving the economic dispatch problem with a modified quantum-behaved particle swarm optimization method

Energy Technology Data Exchange (ETDEWEB)

Jun Sun; Wei Fang; Daojun Wang; Wenbo Xu [School of Information Technology, Jiangnan Univ., Wuxi, Jiangsu 214122 (China)

2009-12-15

In this paper, a modified quantum-behaved particle swarm optimization (QPSO) method is proposed to solve the economic dispatch (ED) problem in power systems, whose objective is to simultaneously minimize the generation cost rate while satisfying various equality and inequality constraints. The proposed method, denoted as QPSO-DM, combines the QPSO algorithm with differential mutation operation to enhance the global search ability of the algorithm. Many nonlinear characteristics of the generator, such as ramp rate limits, prohibited operating zones, and nonsmooth cost functions are considered when the proposed method is used in practical generator operation. The feasibility of the QPSO-DM method is demonstrated by three different power systems. It is compared with the QPSO, the differential evolution (DE), the particle swarm optimization (PSO), and the genetic algorithm (GA) in terms of the solution quality, robustness and convergence property. The simulation results show that the proposed QPSO-DM method is able to obtain higher quality solutions stably and efficiently in the ED problem than any other tested optimization algorithm. (author)

Solving the economic dispatch problem with a modified quantum-behaved particle swarm optimization method

International Nuclear Information System (INIS)

Sun Jun; Fang Wei; Wang Daojun; Xu Wenbo

2009-01-01

In this paper, a modified quantum-behaved particle swarm optimization (QPSO) method is proposed to solve the economic dispatch (ED) problem in power systems, whose objective is to simultaneously minimize the generation cost rate while satisfying various equality and inequality constraints. The proposed method, denoted as QPSO-DM, combines the QPSO algorithm with differential mutation operation to enhance the global search ability of the algorithm. Many nonlinear characteristics of the generator, such as ramp rate limits, prohibited operating zones, and nonsmooth cost functions are considered when the proposed method is used in practical generator operation. The feasibility of the QPSO-DM method is demonstrated by three different power systems. It is compared with the QPSO, the differential evolution (DE), the particle swarm optimization (PSO), and the genetic algorithm (GA) in terms of the solution quality, robustness and convergence property. The simulation results show that the proposed QPSO-DM method is able to obtain higher quality solutions stably and efficiently in the ED problem than any other tested optimization algorithm.

Fenofibrate--a lipid-lowering drug--reduces voluntary alcohol drinking in rats.

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Karahanian, Eduardo; Quintanilla, Maria Elena; Fernandez, Katia; Israel, Yedy

2014-11-01

The administration of disulfiram raises blood acetaldehyde levels when ethanol is ingested, leading to an aversion to alcohol. This study was aimed at assessing the effect of fenofibrate on voluntary ethanol ingestion in rats. Fenofibrate reduces blood triglyceride levels by increasing fatty acid oxidation by liver peroxisomes, along with an increase in the activity of catalase, which can oxidize ethanol to acetaldehyde. UChB drinker rats were allowed to consume alcohol 10% v/v freely for 60 days, until consumption stabilized at around 7 g ethanol/kg/24 h. About 1-1.2 g ethanol/kg of this intake is consumed in the first 2 h of darkness of the circadian cycle. Fenofibrate subsequently administered (50 mg/kg/day by mouth [p.o.]) for 14 days led to a 60-70% (p intake was determined within the first 2 h of darkness, the reduction was 85-90% (p chronically allowed access to ethanol and subsequently treated with fenofibrate, would a) increase liver catalase activity, and b) increase blood acetaldehyde levels after a 24-h ethanol deprivation and the subsequent administration of 1 g ethanol/kg. The oral administration of 1 g ethanol/kg produced a rapid increase in blood (arterial) acetaldehyde in fenofibrate-treated animals versus controls also administered 1 g/kg ethanol (70 μM vs. 7 μM; p alcohol dehydrogenase and aldehyde dehydrogenase) remained unchanged. No liver damage was induced, as measured by serum glutamic-pyruvic transaminase (GPT) activity. The effect of fenofibrate in reducing alcohol intake was fully reversible. Overall, in rats allowed chronic ethanol intake, by mouth (p.o.), fenofibrate administration increased liver catalase activity and reduced voluntary ethanol intake. The administration of 1 g ethanol/kg (p.o.) to these animals increased blood acetaldehyde levels in fenofibrate-treated animals, suggesting the possible basis for the reduction in ethanol intake. Copyright © 2014 Elsevier Inc. All rights reserved.

Specific and differential activation of mitogen-activated protein kinase cascades by unfamiliar taste in the insular cortex of the behaving rat.

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Berman, D E; Hazvi, S; Rosenblum, K; Seger, R; Dudai, Y

1998-12-01

Rats were given to drink an unfamiliar taste solution under conditions that result in long-term memory of that taste. The insular cortex, which contains the taste cortex, was then removed and assayed for activation of mitogen-activated protein kinase (MAPK) cascades by using antibodies to the activated forms of various MAPKs. Extracellular responsive kinase 1-2 (ERK1-2) in the cortical homogenate was significantly activated within taste solution, without alteration in the total level of the ERK1-2 proteins. The activity subsided to basal levels within ERK1-2 was not activated when the taste was made familiar. The effect of the unfamiliar taste was specific to the insular cortex. Jun N-terminal kinase 1-2 (JNK1-2) was activated by drinking the taste but with a delayed time course, whereas the activity of Akt kinase and p38MAPK remained unchanged. Elk-1, a member of the ternary complex factor and an ERK/JNK downstream substrate, was activated with a time course similar to that of ERK1-2. Microinjection of a reversible inhibitor of MAPK/ERK kinase into the insular cortex shortly before exposure to the novel taste in a conditioned taste aversion training paradigm attenuated long-term taste aversion memory without significantly affecting short-term memory or the sensory, motor, and motivational faculties required to express long-term taste aversion memory. It was concluded that ERK and JNK are specifically and differentially activated in the insular cortex after exposure to a novel taste, and that this activation is required for consolidation of long-term taste memory.

Charging and switching of ferroelectrets: how much can ferroelectrets behave like ferroelectrics?

International Nuclear Information System (INIS)

Schwoediauer, R.; Graz, I.; Bauer, S.

2004-01-01

Dielectrics with good charge storage capability, so called charge electrets, are non or weakly-polar materials. Despite their non-polar nature porous charge electrets with internally charged surfaces can exhibit very pronounced piezoelectricity. Such systems have been termed 'ferroelectrets' and they have been receiving growing attention over the last few years. Their puzzling and unexpected features resemble very much those normally known from traditional ferroelectrics: ferroelectrets are piezo- and pyroelectric, their polarization can be reversed by means of an external field and electrical as well as mechanical hysteresis loops were observed. As conventional ferroelectrics are different and more complicated than ferromagnets, so are ferroelectrets different and more complex than most ferroelectrics. Here we report about the very different charging and switching mechanism in ferroelectrets, both in simple model-systems and in less simple foam structures. These mechanisms are crucial and form the basis for the striking phenomenological similarities to ferroelectrics. We also want to address some of the specific peculiarities and pitfalls related to present ferroelectrets and their characterization. Interfacial charge injection at high electric fields and anelastic non-linearities, for instance, can be the cause for false ferroelectric-like hysteresis effects which do not reflect any polarization reversal. Our contribution is an attempt towards a more comprehensive picture of how much ferroelectrets behave like ferroelectrics. (author)

Inhibition of rat microsomal lipid peroxidation by the oral administration of D002

Directory of Open Access Journals (Sweden)

Menéndez R.

2000-01-01

Full Text Available The effect of D002, a defined mixture of higher primary alcohols purified from bee wax, on in vivo and in vitro lipid peroxidation was studied. The extent of lipid peroxidation was measured on the basis of the levels of thiobarbituric acid reactive substances (TBARS. When D002 (5-100 mg/kg body weight was administered orally to rats for two weeks, a partial inhibition of the in vitro enzymatic and non-enzymatic lipid peroxidation was observed in liver and brain microsomes. Maximal protection (46% occurred at a dose of 25 mg/kg. D002 behaved differently depending on both the presence of NADPH and the integrity of liver microsomes, which suggests that under conditions where microsomal metabolism was favored the protective effect of D002 was increased. D002 (25 mg/kg also completely inhibited carbon tetrachloride- and toluene-induced in vivo lipid peroxidation in liver and brain. Also, D002 significantly lowered in a dose-dependent manner the basal level of TBARS in liver (19-40% and brain (28-44% microsomes. We conclude that the oral administration of D002 (5, 25 and 100 mg/kg for two weeks protected rat liver and brain microsomes against microsomal lipid peroxidation in vitro and in vivo. Thus, D002 could be useful as a dietary natural antioxidant supplement. More studies are required before these data can be extrapolated to the recommendation for the use of D002 as a dietary antioxidant supplement for humans.

Effects of lesions of the nucleus accumbens core on choice between small certain rewards and large uncertain rewards in rats

Directory of Open Access Journals (Sweden)

Howes Nathan J

2005-05-01

Full Text Available Abstract Background Animals must frequently make choices between alternative courses of action, seeking to maximize the benefit obtained. They must therefore evaluate the magnitude and the likelihood of the available outcomes. Little is known of the neural basis of this process, or what might predispose individuals to be overly conservative or to take risks excessively (avoiding or preferring uncertainty, respectively. The nucleus accumbens core (AcbC is known to contribute to rats' ability to choose large, delayed rewards over small, immediate rewards; AcbC lesions cause impulsive choice and an impairment in learning with delayed reinforcement. However, it is not known how the AcbC contributes to choice involving probabilistic reinforcement, such as between a large, uncertain reward and a small, certain reward. We examined the effects of excitotoxic lesions of the AcbC on probabilistic choice in rats. Results Rats chose between a single food pellet delivered with certainty (p = 1 and four food pellets delivered with varying degrees of uncertainty (p = 1, 0.5, 0.25, 0.125, and 0.0625 in a discrete-trial task, with the large-reinforcer probability decreasing or increasing across the session. Subjects were trained on this task and then received excitotoxic or sham lesions of the AcbC before being retested. After a transient period during which AcbC-lesioned rats exhibited relative indifference between the two alternatives compared to controls, AcbC-lesioned rats came to exhibit risk-averse choice, choosing the large reinforcer less often than controls when it was uncertain, to the extent that they obtained less food as a result. Rats behaved as if indifferent between a single certain pellet and four pellets at p = 0.32 (sham-operated or at p = 0.70 (AcbC-lesioned by the end of testing. When the probabilities did not vary across the session, AcbC-lesioned rats and controls strongly preferred the large reinforcer when it was certain, and strongly

Aconitine-induced Ca{sup 2+} overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

Energy Technology Data Exchange (ETDEWEB)

Sun, Gui-bo; Sun, Hong; Meng, Xiang-bao [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Hu, Jin; Zhang, Qiang; Liu, Bo [Academy of Chinese Medical Sciences of Jilin Province, Changchun, Jilin 130021 (China); Wang, Min [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Xu, Hui-bo, E-mail: xhb_6505@163.com [Academy of Chinese Medical Sciences of Jilin Province, Changchun, Jilin 130021 (China); Sun, Xiao-bo, E-mail: sun_xiaobo163@163.com [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China)

2014-08-15

Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na{sup +} channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca{sup 2+} in aconitine poisoning. In this study, we explored the importance of pathological Ca{sup 2+} signaling in aconitine poisoning in vitro and in vivo. We found that Ca{sup 2+} overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca{sup 2+} handling proteins demonstrated that aconitine promoted Ca{sup 2+} overload through the expression regulation of Ca{sup 2+} handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca{sup 2+} overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca

Deep Brain Stimulation of Hemiparkinsonian Rats with Unipolar and Bipolar Electrodes for up to 6 Weeks: Behavioral Testing of Freely Moving Animals

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Kathrin Badstuebner

2017-01-01

Full Text Available Although the clinical use of deep brain stimulation (DBS is increasing, its basic mechanisms of action are still poorly understood. Platinum/iridium electrodes were inserted into the subthalamic nucleus of rats with unilateral 6-OHDA-induced lesions of the medial forebrain bundle. Six behavioral parameters were compared with respect to their potential to detect DBS effects. Locomotor function was quantified by (i apomorphine-induced rotation, (ii initiation time, (iii the number of adjusting steps in the stepping test, and (iv the total migration distance in the open field test. Sensorimotor neglect and anxiety were quantified by (v the retrieval bias in the corridor test and (vi the ratio of migration distance in the center versus in the periphery in the open field test, respectively. In our setup, unipolar stimulation was found to be more efficient than bipolar stimulation for achieving beneficial long-term DBS effects. Performance in the apomorphine-induced rotation test showed no improvement after 6 weeks. DBS reduced the initiation time of the contralateral paw in the stepping test after 3 weeks of DBS followed by 3 weeks without DBS. Similarly, sensorimotor neglect was improved. The latter two parameters were found to be most appropriate for judging therapeutic DBS effects.

Modulation of rat behaviour by using a rat-like robot

International Nuclear Information System (INIS)

Shi, Qing; Ishii, Hiroyuki; Kinoshita, Shinichi; Takanishi, Atsuo; Okabayashi, Satoshi; Iida, Naritoshi; Kimura, Hiroshi; Shibata, Shigenobu

2013-01-01

In this paper, we study the response of a rat to a rat-like robot capable of generating different types of behaviour (stressful, friendly, neutral). Experiments are conducted in an open-field where a rat-like robot called WR-4 is put together with live rats. The activity level of each rat subject is evaluated by scoring its locomotor activity and frequencies of performing rearing (rising up on its hind limbs) and body grooming (body cuddling and head curling) actions, whereas the degree of preference of that is indicated by the robot–rat distance and the frequency of contacting WR-4. The moving speed and behaviour of WR-4 are controlled in real-time based on the feedback from rat motion. The activity level and degree of preference of rats for each experimental condition are analysed and compared to understand the influence of robot behaviour. The results of this study show that the activity level and degree of preference of the rat decrease when exposed to a stressful robot, and increase when the robot exhibit friendly behaviour, suggesting that a rat-like robot can modulate rat behaviour in a controllable, predictable way. (paper)

Effects of immobilization and remobilization on the ankle joint in Wistar rats

International Nuclear Information System (INIS)

Kunz, R.I.; Coradini, J.G.; Silva, L.I.; Bertolini, G.R.F.; Brancalhão, R.M.C.; Ribeiro, L.F.C.

2014-01-01

A sprained ankle is a common musculoskeletal sports injury and it is often treated by immobilization of the joint. Despite the beneficial effects of this therapeutic measure, the high prevalence of residual symptoms affects the quality of life, and remobilization of the joint can reverse this situation. The aim of this study was to analyze the effects of immobilization and remobilization on the ankle joint of Wistar rats. Eighteen male rats had their right hindlimb immobilized for 15 days, and were divided into the following groups: G1, immobilized; G2, remobilized freely for 14 days; and G3, remobilized by swimming and jumping in water for 14 days, performed on alternate days, with progression of time and a series of exercises. The contralateral limb was the control. After the experimental period, the ankle joints were processed for microscopic analysis. Histomorphometry did not show any significant differences between the control and immobilized/remobilized groups and members, in terms of number of chondrocytes and thickness of the articular cartilage of the tibia and talus. Morphological analysis of animals from G1 showed significant degenerative lesions in the talus, such as exposure of the subchondral bone, flocculation, and cracks between the anterior and mid-regions of the articular cartilage and the synovial membrane. Remobilization by therapeutic exercise in water led to recovery in the articular cartilage and synovial membrane of the ankle joint when compared with free remobilization, and it was shown to be an effective therapeutic measure in the recovery of the ankle joint

Effects of immobilization and remobilization on the ankle joint in Wistar rats

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Kunz, R.I. [Laboratório de Biologia Estrutural e Funcional, Universidade Estadual do Oeste do Paraná, Cascavel, PR (Brazil); Coradini, J.G.; Silva, L.I.; Bertolini, G.R.F. [Laboratório do Estudo das Lesões e Recursos Fisioterapêuticos, Universidade Estadual do Oeste do Paraná, Cascavel, PR (Brazil); Brancalhão, R.M.C.; Ribeiro, L.F.C. [Laboratório de Biologia Estrutural e Funcional, Universidade Estadual do Oeste do Paraná, Cascavel, PR (Brazil)

2014-08-15

A sprained ankle is a common musculoskeletal sports injury and it is often treated by immobilization of the joint. Despite the beneficial effects of this therapeutic measure, the high prevalence of residual symptoms affects the quality of life, and remobilization of the joint can reverse this situation. The aim of this study was to analyze the effects of immobilization and remobilization on the ankle joint of Wistar rats. Eighteen male rats had their right hindlimb immobilized for 15 days, and were divided into the following groups: G1, immobilized; G2, remobilized freely for 14 days; and G3, remobilized by swimming and jumping in water for 14 days, performed on alternate days, with progression of time and a series of exercises. The contralateral limb was the control. After the experimental period, the ankle joints were processed for microscopic analysis. Histomorphometry did not show any significant differences between the control and immobilized/remobilized groups and members, in terms of number of chondrocytes and thickness of the articular cartilage of the tibia and talus. Morphological analysis of animals from G1 showed significant degenerative lesions in the talus, such as exposure of the subchondral bone, flocculation, and cracks between the anterior and mid-regions of the articular cartilage and the synovial membrane. Remobilization by therapeutic exercise in water led to recovery in the articular cartilage and synovial membrane of the ankle joint when compared with free remobilization, and it was shown to be an effective therapeutic measure in the recovery of the ankle joint.

[Peculiar history to formation of 'Freely recuperate zone' in the National Sanatorium Kuryu Rakusen-en, Gunma, Japan (relation between the 'Old Yunosawa-ward' and 'Freely recuperate zone' in the National Sanatorium Kuryu Rakusen-en)].

Science.gov (United States)

Kitahara, Makoto

2011-09-01

Hansen's disease sufferers had been visiting the hot spring, Kusatsu-Spa, in Gunma, Japan, for Toji (which means 'hot springs treatment' in Japanese) since the middle ages, as it was known reportedly for a long time to be effective in curing the disease. In 1869, Kusatsu-Spa was hit by a massive fire. The innkeepers, who suffered devastating damages, were trying to reconstruct the economy quickly by promoting the medical benefits of the hot spring. This made many Hansen's disease patients to visit and of which many stayed on a long term bases. They would use the hot spring with ordinary visitors. And, they had received the treatment of the spotted moxa cautery with the hot-spring treatment. Later on, Kusatsu- Spa became well known throughout Japan and as the numbers of ordinary visitors increased, they voiced their concerns in sharing the hot spring with the Hansen's disease patients. Therefore, the innkeepers decided to move the patients to another district called Yunosawa and suggested to make a special village of just the patients. In 1887, the representative of the patients came to an agreement with the mayor of Yunosawa to establish a treatment centre there. Yunosawa became part of an administrative area of Kusatsu Town. The area seemed to become a local-governing area mainly shaped by Hansen's disease sufferers and the first legal residential area where Hansen's disease sufferers were given citizenships and may convalesce freely. However, in 1931, leprosy prevention law was passed, and the Japanese government built a new medical treatment centre of Hansen's disease, 4km away from Kusatsu- Spa, which is called National Sanatorium Kuryu Rakusen-en. After deliberations with the representative of the Hansen's disease patients living in the Yunosawa area and the governor of Gunma Prefecture, who received the order from the Japanese government to move them, had agreed to the mass relocation in 1941. This is how Yunosawa had closed its 55 years history and many

Noradrenaline from Locus Coeruleus Neurons Acts on Pedunculo-Pontine Neurons to Prevent REM Sleep and Induces Its Loss-Associated Effects in Rats.

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Khanday, Mudasir Ahmad; Somarajan, Bindu I; Mehta, Rachna; Mallick, Birendra Nath

2016-01-01

Normally, rapid eye movement sleep (REMS) does not appear during waking or non-REMS. Isolated, independent studies showed that elevated noradrenaline (NA) levels inhibit REMS and induce REMS loss-associated cytomolecular, cytomorphological, psychosomatic changes and associated symptoms. However, the source of NA and its target in the brain for REMS regulation and function in health and diseases remained to be confirmed in vivo . Using tyrosine hydroxylase (TH)-siRNA and virus-coated TH-shRNA in normal freely moving rats, we downregulated NA synthesis in locus coeruleus (LC) REM-OFF neurons in vivo . These TH-downregulated rats showed increased REMS, which was prevented by infusing NA into the pedunculo-pontine tegmentum (PPT), the site of REM-ON neurons, normal REMS returned after recovery. Moreover, unlike normal or control-siRNA- or shRNA-injected rats, upon REMS deprivation (REMSD) TH-downregulated rat brains did not show elevated Na-K ATPase (molecular changes) expression and activity. To the best of our knowledge, these are the first in vivo findings in an animal model confirming that NA from the LC REM-OFF neurons (1) acts on the PPT REM-ON neurons to prevent appearance of REMS, and (2) are responsible for inducing REMSD-associated molecular changes and symptoms. These observations clearly show neuro-physio-chemical mechanism of why normally REMS does not appear during waking. Also, that LC neurons are the primary source of NA, which in turn causes some, if not many, REMSD-associated symptoms and behavioral changes. The findings are proof-of-principle for the first time and hold potential to be exploited for confirmation toward treating REMS disorder and amelioration of REMS loss-associated symptoms in patients.

Pharmacokinetics of [14C]teicoplanin in male rats after single intravenous dose

International Nuclear Information System (INIS)

Bernareggi, A.; Cavenaghi, L.; Assandri, A.

1986-01-01

The pharmacokinetic profile of [ 14 C]teicoplanin was studied in male Sprague-Dawley rats given a single 10,000-U/kg intravenous dose. The disposition of the antimicrobial activity in the body was estimated by a three-compartment open model. Plasma concentration data were fitted to a three-exponent equation. The profile of total 14 C in plasma was similar to that of the microbiological activity. The cumulative recovery of total 14 C 5 days after drug administration averaged 76.3% of the administered dose in the urine and 8.7% in the feces. The residual dose remaining in the animal carcasses was 11.1%. Teicoplanin was widely distributed in the body. In almost all organs, the maximum concentration of [ 14 C]teicoplanin was already reached at the first time of killing, which was 0.25 h after the administration of drug. The liver, kidneys, skin, and fat contained most of the residual dose found in the animal carcasses 120 h after administration and behaved as a deep compartment with the adrenal glands and spleen

Reshaping of bulbar odor response by nasal flow rate in the rat.

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Emmanuelle Courtiol

2011-01-01

Full Text Available The impact of respiratory dynamics on odor response has been poorly studied at the olfactory bulb level. However, it has been shown that sniffing in the behaving rodent is highly dynamic and varies both in frequency and flow rate. Bulbar odor response could vary with these sniffing parameter variations. Consequently, it is necessary to understand how nasal airflow can modify and shape odor response at the olfactory bulb level.To assess this question, we used a double cannulation and simulated nasal airflow protocol on anesthetized rats to uncouple nasal airflow from animal respiration. Both mitral/tufted cell extracellular unit activity and local field potentials (LFPs were recorded. We found that airflow changes in the normal range were sufficient to substantially reorganize the response of the olfactory bulb. In particular, cellular odor-evoked activities, LFP oscillations and spike phase-locking to LFPs were strongly modified by nasal flow rate.Our results indicate the importance of reconsidering the notion of odor coding as odor response at the bulbar level is ceaselessly modified by respiratory dynamics.

Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

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Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K. [Department of Radiological Sciences, Guy' s, King' s and St. Thomas' School of Medicine, London (United Kingdom)

1999-10-01

Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

Differential uptake of FDG and DG during post-ischaemic reperfusion in the isolated, perfused rat heart

International Nuclear Information System (INIS)

Garlick, P.B.; Medina, R.A.; Southworth, R.; Marsden, P.K.

1999-01-01

Fluorine-18 2-fluoro-2-deoxyglucose (FDG) and 2-deoxyglucose (DG) are widely used as tracers of glucose uptake in the myocardium. Although there is agreement that the two analogues behave similarly to glucose under control conditions, there is growing evidence that some interventions (e.g. insulin stimulation or ischaemia/reperfusion) cause differential changes in their behaviour. The addition of a two-surface coil nuclear magnetic resonance (NMR) probe and a dual-perfusion cannula to our recently developed PET and NMR dual-acquisition (PANDA) system allows us to collect PET (FDG) images and phosphorus-31 NMR (2-deoxyglucose-6-phosphate) spectra simultaneously from each independently perfused coronary bed of the heart. We have used this technique to study the effect of regional ischaemia/reperfusion on FDG and DG uptake in the isolated, perfused rat heart. During control perfusion, FDG uptake was almost identical in both coronary beds. When one coronary bed was made ischaemic, FDG uptake ceased on that side but continued on the control side. Reperfusion failed to restore FDG uptake. In contrast, NMR spectra showed that, during reperfusion, the uptake and phosphorylation of DG did not differ between the two coronary beds. The results thus demonstrate that regional myocardial ischaemia/reperfusion has different effects on the uptake of FDG and DG in the isolated, perfused rat heart. (orig.)

Critical Evaluation of Acetylcholine Determination in Rat Brain Microdialysates using Ion-Pair Liquid Chromatography with Amperometric Detection

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Yvette Michotte

2008-08-01

Full Text Available Liquid chromatography with amperometric detection remains the most widely used method for acetylcholine quantification in microdialysis samples. Separation of acetylcholine from choline and other matrix components on a microbore chromatographic column (1 mm internal diameter, conversion of acetylcholine in an immobilized enzyme reactor and detection of the produced hydrogen peroxide on a horseradish peroxidase redox polymer coated glassy carbon electrode, achieves sufficient sensitivity for acetylcholine quantification in rat brain microdialysates. However, a thourough validation within the concentration range required for this application has not been carried out before. Furthermore, a rapid degradation of the chromatographic columns and enzyme systems have been reported. In the present study an ion-pair liquid chromatography assay with amperometric detection was validated and its long-term stability evaluated. Working at pH 6.5 dramatically increased chromatographic stability without a loss in sensitivity compared to higher pH values. The lower limit of quantification of the method was 0.3 nM. At this concentration the repeatability was 15.7%, the inter-day precision 8.7% and the accuracy 103.6%. The chromatographic column was stable over 4 months, the immobilized enzyme reactor up to 2-3 months and the enzyme coating of the amperometric detector up to 1-2 months. The concentration of acetylcholine in 30 μl microdialysates obtained under basal conditions from the hippocampus of freely moving rats was 0.40 ± 0.12 nM (mean ± SD, n = 30. The present method is therefore suitable for acetylcholine determination in rat brain microdialysates.

Biologic effects of fenbendazole in rats and mice: a review.

Science.gov (United States)

Villar, David; Cray, Carolyn; Zaias, Julia; Altman, Norman H

2007-11-01

This review summarizes findings from toxicologic, carcinogenic, immunologic, and metabolic studies on fenbendazole (FBZ). Currently, FBZ is used to treat or prevent pinworm outbreaks in laboratory rodents. Because antiparasitic treatments usually are not part of experimental designs, interactions from the medication on the outcomes of ongoing experiments are a concern. At therapeutic levels, FBZ does not alter the total content of cytochromes P450 but does induce certain hepatic cytochrome P450 isoforms, namely 1A1, 1A2, and 2B1. Although expressed constitutively at low or undetectable levels, these isoforms particularly are known for bioactivating a number of procarcinogens. Lifetime studies in rats have shown that FBZ is not a carcinogen but that it may behave as a tumor promoter when given after certain initiators. Unlike in other animal species, FBZ treatment-associated myelosuppression has not been reported to occur in rodents. The few currently available immunologic studies in mice, including an autoimmune model, have not shown effects on selected immune responses. However, data from other animal species suggest that the ability of B and T lymphocytes to proliferate in the secondary immune response may be suppressed during treatment with FBZ.

Identifying non-toxic doses of manganese for manganese-enhanced magnetic resonance imaging to map brain areas activated by operant behavior in trained rats.

Science.gov (United States)

Gálosi, Rita; Szalay, Csaba; Aradi, Mihály; Perlaki, Gábor; Pál, József; Steier, Roy; Lénárd, László; Karádi, Zoltán

2017-04-01

Manganese-enhanced magnetic resonance imaging (MEMRI) offers unique advantages such as studying brain activation in freely moving rats, but its usefulness has not been previously evaluated during operant behavior training. Manganese in a form of MnCl 2 , at a dose of 20mg/kg, was intraperitoneally infused. The administration was repeated and separated by 24h to reach the dose of 40mg/kg or 60mg/kg, respectively. Hepatotoxicity of the MnCl 2 was evaluated by determining serum aspartate aminotransferase, alanine aminotransferase, total bilirubin, albumin and protein levels. Neurological examination was also carried out. The animals were tested in visual cue discriminated operant task. Imaging was performed using a 3T clinical MR scanner. T1 values were determined before and after MnCl 2 administrations. Manganese-enhanced images of each animal were subtracted from their baseline images to calculate decrease in the T1 value (ΔT1) voxel by voxel. The subtracted T1 maps of trained animals performing visual cue discriminated operant task, and those of naive rats were compared. The dose of 60mg/kg MnCl 2 showed hepatotoxic effect, but even these animals did not exhibit neurological symptoms. The dose of 20 and 40mg/kg MnCl 2 increased the number of omissions and did not affect the accuracy of performing the visual cue discriminated operant task. Using the accumulated dose of 40mg/kg, voxels with a significant enhanced ΔT1 value were detected in the following brain areas of the visual cue discriminated operant behavior performed animals compared to those in the controls: the visual, somatosensory, motor and premotor cortices, the insula, cingulate, ectorhinal, entorhinal, perirhinal and piriform cortices, hippocampus, amygdala with amygdalohippocampal areas, dorsal striatum, nucleus accumbens core, substantia nigra, and retrorubral field. In conclusion, the MEMRI proved to be a reliable method to accomplish brain activity mapping in correlation with the operant behavior

Glomerular barrier behaves as an atomically precise bandpass filter in a sub-nanometre regime

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Du, Bujie; Jiang, Xingya; Das, Anindita; Zhou, Qinhan; Yu, Mengxiao; Jin, Rongchao; Zheng, Jie

2017-11-01

The glomerular filtration barrier is known as a 'size cutoff' slit, which retains nanoparticles or proteins larger than 6-8 nm in the body and rapidly excretes smaller ones through the kidneys. However, in the sub-nanometre size regime, we have found that this barrier behaves as an atomically precise 'bandpass' filter to significantly slow down renal clearance of few-atom gold nanoclusters (AuNCs) with the same surface ligands but different sizes (Au18, Au15 and Au10-11). Compared to Au25 (∼1.0 nm), just few-atom decreases in size result in four- to ninefold reductions in renal clearance efficiency in the early elimination stage, because the smaller AuNCs are more readily trapped by the glomerular glycocalyx than larger ones. This unique in vivo nano-bio interaction in the sub-nanometre regime also slows down the extravasation of sub-nanometre AuNCs from normal blood vessels and enhances their passive targeting to cancerous tissues through an enhanced permeability and retention effect. This discovery highlights the size precision in the body's response to nanoparticles and opens a new pathway to develop nanomedicines for many diseases associated with glycocalyx dysfunction.

PA21, a novel phosphate binder, improves renal osteodystrophy in rats with chronic renal failure.

Science.gov (United States)

Yaguchi, Atsushi; Tatemichi, Satoshi; Takeda, Hiroo; Kobayashi, Mamoru

2017-01-01

The effects of PA21, a novel iron-based and non-calcium-based phosphate binder, on hyperphosphatemia and its accompanying bone abnormality in chronic kidney disease-mineral and bone disorder (CKD-MBD) were evaluated. Rats with adenine-induced chronic renal failure (CRF) were prepared by feeding them an adenine-containing diet for four weeks. They were also freely fed a diet that contained PA21 (0.5, 1.5, and 5%), sevelamer hydrochloride (0.6 and 2%) or lanthanum carbonate hydrate (0.6 and 2%) for four weeks. Blood biochemical parameters were measured and bone histomorphometry was performed for femurs, which were isolated after drug treatment. Serum phosphorus and parathyroid hormone (PTH) levels were higher in the CRF rats. Administration of phosphate binders for four weeks decreased serum phosphorus and PTH levels in a dose-dependent manner and there were significant decreases in the AUC0-28 day of these parameters in 5% PA21, 2% sevelamer hydrochloride, and 2% lanthanum carbonate hydrate groups compared with that in the CRF control group. Moreover, osteoid volume improved significantly in 5% of the PA21 group, and fibrosis volume and cortical porosity were ameliorated in 5% PA21, 2% sevelamer hydrochloride, and 2% lanthanum carbonate hydrate groups. These results suggest that PA21 is effective against hyperphosphatemia, secondary hyperparathyroidism, and bone abnormalities in CKD-MBD as sevelamer hydrochloride and lanthanum carbonate hydrate are, and that PA21 is a new potential alternative to phosphate binders.

Early Life Stress and Sleep Restriction as Risk Factors in PTSD: An Integrative Pre-Clinical Approach

Science.gov (United States)

2015-04-01

results in less robust conditioned fear and post- extinction fear cue responses in adult rats. Pharmacol Biochem Behav. 120:17-24.  The Pre-pubertal...LT, Berthelsen H. (2000) The effect of environmental enrichment on the behaviour of caged rabbits (Oryctolagus cuniculus). Appl Anim Behav Sci. 68(2...the Beta 2 adrenergic receptor, Beta Arrestin-1 and p53 with Mdm2 in the ventral hippocampus one month after underwater trauma. Behavioural Brain

How cheap is soaring flight in raptors? A preliminary investigation in freely-flying vultures.

Science.gov (United States)

Duriez, Olivier; Kato, Akiko; Tromp, Clara; Dell'Omo, Giacomo; Vyssotski, Alexei L; Sarrazin, François; Ropert-Coudert, Yan

2014-01-01

Measuring the costs of soaring, gliding and flapping flight in raptors is challenging, but essential for understanding their ecology. Among raptors, vultures are scavengers that have evolved highly efficient soaring-gliding flight techniques to minimize energy costs to find unpredictable food resources. Using electrocardiogram, GPS and accelerometer bio-loggers, we report the heart rate (HR) of captive griffon vultures (Gyps fulvus and G. himalayensis) trained for freely-flying. HR increased three-fold at take-off (characterized by prolonged flapping flight) and landing (>300 beats-per-minute, (bpm)) compared to baseline levels (80-100 bpm). However, within 10 minutes after the initial flapping phase, HR in soaring/gliding flight dropped to values similar to baseline levels, i.e. slightly lower than theoretically expected. However, the extremely rapid decrease in HR was unexpected, when compared with other marine gliders, such as albatrosses. Weather conditions influenced flight performance and HR was noticeably higher during cloudy compared to sunny conditions when prolonged soaring flight is made easier by thermal ascending air currents. Soaring as a cheap locomotory mode is a crucial adaptation for vultures who spend so long on the wing for wide-ranging movements to find food.

Draft Tube Baffle (DTB) crystallizers: A study of stationary and dynamically behaving Crystal Size Distributions (CSD)

Science.gov (United States)

Deleer, B. G. M.

1981-11-01

Based on population balance, CSD behavior as a function of geometrical and operating variables was studied, using a crystallizer. A potash alum-water system, involving a separation technique which uses surface active agents and an apolar, organic liquid to separate potash alum crystals from mother liquid under the influence of gravity was used to check experimental findings against literature data. Results show action of annular settling spaces is strongly influenced by fluid velocities perpendicular to those directed upwards. The well-mixed volume decreases with increasing crystallizer size until a minimum effective volume is reached. As supersaturation is constant throughout the crystallizer volume under stationary operating conditions, the annular settling space behaves like a growth chamber for crystals in its volume. Swirl in the lower part of the annular volume introduces significant back mixing. Crystals within this space either grow and return to the well-mixed part, or withdraw from the annular volume permanently.

Identification and Characterization of Mesenchymal-Epithelial Progenitor-Like Cells in Normal and Injured Rat Liver

Science.gov (United States)

Liu, Daqing; Yovchev, Mladen I.; Zhang, Jinghang; Alfieri, Alan A.; Tchaikovskaya, Tatyana; Laconi, Ezio; Dabeva, Mariana D.

2016-01-01

In normal rat liver, thymocyte antigen 1 (Thy1) is expressed in fibroblasts/myofibroblasts and in some blood progenitor cells. Thy1-expressing cells also accumulate in the liver during impaired liver regeneration. The origin and nature of these cells are not well understood. By using RT-PCR analysis and immunofluorescence microscopy, we describe the presence of rare Thy1+ cells in the liver lobule of normal animals, occasionally forming small collections of up to 20 cells. These cells constitute a small portion (1.7% to 1.8%) of nonparenchymal cells and reveal a mixed mesenchymal-epithelial phenotype, expressing E-cadherin, cytokeratin 18, and desmin. The most potent mitogens for mesenchymal-epithelial Thy1+ cells in vitro are the inflammatory cytokines interferon γ, IL-1, and platelet-derived growth factor-BB, which are not produced by Thy1+ cells. Thy1+ cells express all typical mesenchymal stem cell and hepatic progenitor cell markers and produce growth factor and cytokine mRNA (Hgf, Il6, Tgfa, and Tweak) for proteins that maintain oval cell growth and differentiation. Under appropriate conditions, mesenchymal-epithelial cells differentiate in vitro into hepatocyte-like cells. In this study, we show that the adult rat liver harbors a small pool of endogenous mesenchymal-epithelial cells not recognized previously. In the quiescent state, these cells express both mesenchymal and epithelial cell markers. They behave like hepatic stem cells/progenitors with dual phenotype, exhibiting high plasticity and long-lasting proliferative activity. PMID:25447047

Differential stimulation of luminol-enhanced chemiluminescence (CL) and arachidonic acid metabolism in rat peritoneal neutrophils

Energy Technology Data Exchange (ETDEWEB)

Sturm, R.J.; Adams, L.M.; Cullinan, C.A.; Berkenkopf, J.W.; Weichman, B.M.

1986-03-05

Phorbol 12-myristate, 13-acetate (PMA) induced the production of radical oxygen species (ROS) from rat peritoneal neutrophils as assessed by CL. ROS generation occurred in a time- (maximum at 13.5 min) and dose- (concentration range of 1.7-498 nM) related fashion. However, 166 nM PMA did not induce either cyclooxygenase (CO) or lipoxygenase (LPO) product formation by 20 min post-stimulation. Conversely, A23187, at concentrations between 0.1 and 10 ..mu..M, stimulated both pathways of arachidonic acid metabolism, but had little or no effect upon ROS production. When suboptimal concentrations of PMA (5.5 nM) and A23187 (0.1-1 ..mu..M) were coincubated with the neutrophils, a synergistic ROS response was elicited. However, arachidonic acid metabolism in the presence of PMA was unchanged relative to A12187 alone. Nordihydroguaiaretic acid (NDGA) inhibited both PMA-induced CL (IC/sub 50/ = 0.9 ..mu..M) and A23187-induced arachidonic acid metabolism (IC/sub 50/ = 1.7 ..mu..M and 6.0 ..mu..M for LPO and CO, respectively). The mixed LPO-CO inhibitor, BW755C, behaved in a qualitatively similar manner to NDGA, whereas the CO inhibitors, indomethacin, piroxicam and naproxen had no inhibitory effect on ROS generation at concentrations as high as 100 ..mu..M. These results suggest that NDGA and BW755C may inhibit CL and arachidonic acid metabolism by distinct mechanisms in rat neutrophils.

Spike avalanches exhibit universal dynamics across the sleep-wake cycle.

Directory of Open Access Journals (Sweden)

Tiago L Ribeiro

2010-11-01

Full Text Available Scale-invariant neuronal avalanches have been observed in cell cultures and slices as well as anesthetized and awake brains, suggesting that the brain operates near criticality, i.e. within a narrow margin between avalanche propagation and extinction. In theory, criticality provides many desirable features for the behaving brain, optimizing computational capabilities, information transmission, sensitivity to sensory stimuli and size of memory repertoires. However, a thorough characterization of neuronal avalanches in freely-behaving (FB animals is still missing, thus raising doubts about their relevance for brain function.To address this issue, we employed chronically implanted multielectrode arrays (MEA to record avalanches of action potentials (spikes from the cerebral cortex and hippocampus of 14 rats, as they spontaneously traversed the wake-sleep cycle, explored novel objects or were subjected to anesthesia (AN. We then modeled spike avalanches to evaluate the impact of sparse MEA sampling on their statistics. We found that the size distribution of spike avalanches are well fit by lognormal distributions in FB animals, and by truncated power laws in the AN group. FB data surrogation markedly decreases the tail of the distribution, i.e. spike shuffling destroys the largest avalanches. The FB data are also characterized by multiple key features compatible with criticality in the temporal domain, such as 1/f spectra and long-term correlations as measured by detrended fluctuation analysis. These signatures are very stable across waking, slow-wave sleep and rapid-eye-movement sleep, but collapse during anesthesia. Likewise, waiting time distributions obey a single scaling function during all natural behavioral states, but not during anesthesia. Results are equivalent for neuronal ensembles recorded from visual and tactile areas of the cerebral cortex, as well as the hippocampus.Altogether, the data provide a comprehensive link between behavior

3D-e-Chem-VM: Structural Cheminformatics Research Infrastructure in a Freely Available Virtual Machine.

Science.gov (United States)

McGuire, Ross; Verhoeven, Stefan; Vass, Márton; Vriend, Gerrit; de Esch, Iwan J P; Lusher, Scott J; Leurs, Rob; Ridder, Lars; Kooistra, Albert J; Ritschel, Tina; de Graaf, Chris

2017-02-27

3D-e-Chem-VM is an open source, freely available Virtual Machine ( http://3d-e-chem.github.io/3D-e-Chem-VM/ ) that integrates cheminformatics and bioinformatics tools for the analysis of protein-ligand interaction data. 3D-e-Chem-VM consists of software libraries, and database and workflow tools that can analyze and combine small molecule and protein structural information in a graphical programming environment. New chemical and biological data analytics tools and workflows have been developed for the efficient exploitation of structural and pharmacological protein-ligand interaction data from proteomewide databases (e.g., ChEMBLdb and PDB), as well as customized information systems focused on, e.g., G protein-coupled receptors (GPCRdb) and protein kinases (KLIFS). The integrated structural cheminformatics research infrastructure compiled in the 3D-e-Chem-VM enables the design of new approaches in virtual ligand screening (Chemdb4VS), ligand-based metabolism prediction (SyGMa), and structure-based protein binding site comparison and bioisosteric replacement for ligand design (KRIPOdb).

SAGES: a suite of freely-available software tools for electronic disease surveillance in resource-limited settings.

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Sheri L Lewis

Full Text Available Public health surveillance is undergoing a revolution driven by advances in the field of information technology. Many countries have experienced vast improvements in the collection, ingestion, analysis, visualization, and dissemination of public health data. Resource-limited countries have lagged behind due to challenges in information technology infrastructure, public health resources, and the costs of proprietary software. The Suite for Automated Global Electronic bioSurveillance (SAGES is a collection of modular, flexible, freely-available software tools for electronic disease surveillance in resource-limited settings. One or more SAGES tools may be used in concert with existing surveillance applications or the SAGES tools may be used en masse for an end-to-end biosurveillance capability. This flexibility allows for the development of an inexpensive, customized, and sustainable disease surveillance system. The ability to rapidly assess anomalous disease activity may lead to more efficient use of limited resources and better compliance with World Health Organization International Health Regulations.

[Effects of seawater immersion on the inflammatory response and oxygen free radical injury of rats with superficial partial-thickness scald at early stage].

Science.gov (United States)

Yang, Y X; Wang, J H; Liu, L; Zou, Q; Zhang, Y; Bai, Z

2017-06-20

Objective: To study the effects of seawater immersion on the inflammatory response and oxygen free radical injury of rats with superficial-thickness scald at early stage. Methods: Seventy Wistar rats were divided into healthy control group (HC, n =7), pure scald group (PS, n =21), scald+ fresh water immersion group (SF, n =21), and scald+ seawater immersion group (SS, n =21) according to the random number table. Rats in group HC did not receive any treatment, while 5% total body surface area superficial partial-thickness scald was made on the back of rats in the latter three groups. Rats in group PS lived freely immediately post burn, while wounds on the back of rats in groups SF and SS were immersed into fresh water and seawater, respectively. Serum and full-thickness skin tissue in the center of wounds on the back of 7 rats in groups PS, SF, and SS at post immersion (injury) hour (PIH) 2, 4, and 6 were collected, respectively, while serum and full-thickness skin tissue at the same position of the 7 rats in group HC were collected at PIH 6 of rats in other groups. Morphology of skin tissue was observed with HE staining; tumor necrosis factor-alpha (TNF-α) content in serum and skin tissue was determined by enzyme-linked immunosorbent assay; superoxide dismutase (SOD) content in serum and skin tissue was determined by hydroxylamine method; malondialdehyde content in serum and skin tissue was determined by thiobarbituric acid method. Data were processed with analysis of variance of factorial design, one-way analysis of variance, Welch test, LSD test, and Tamhane test. Results: (1) Epidermal cells of skin tissue of rats in group HC arranged in order and continuously, and the dermis tissue and accessory structures were clear and complete. The skin layer and epidermis of wounds of rats in group PS had no significant change, but the edema of epidermis and dermis and infiltration of inflammatory cells enhanced over time at PIH 2, 4, and 6. The horny layer of epidermis of

You are fair, but I expect you to also behave unfairly: Positive asymmetry in trait-behavior relations for moderate morality information.

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Patrice Rusconi

Full Text Available Trait inference in person perception is based on observers' implicit assumptions about the relations between trait adjectives (e.g., fair and the either consistent or inconsistent behaviors (e.g., having double standards that an actor can manifest. This article presents new empirical data and theoretical interpretations on people' behavioral expectations, that is, people's perceived trait-behavior relations along the morality (versus competence dimension. We specifically address the issue of the moderate levels of both traits and behaviors almost neglected by prior research by using a measure of the perceived general frequency of behaviors. A preliminary study identifies a set of competence- and morality-related traits and a subset of traits balanced for valence. Studies 1-2 show that moral target persons are associated with greater behavioral flexibility than immoral ones where abstract categories of behaviors are concerned. For example, participants judge it more likely that a fair person would behave unfairly than an unfair person would behave fairly. Study 3 replicates the results of the first 2 studies using concrete categories of behaviors (e.g., telling the truth/omitting some information. Study 4 shows that the positive asymmetry in morality-related trait-behavior relations holds for both North-American and European (i.e., Italian individuals. A small-scale meta-analysis confirms the existence of a positive asymmetry in trait-behavior relations along both morality and competence dimensions for moderate levels of both traits and behaviors. We discuss these findings in relation to prior models and results on trait-behavior relations and we advance a motivational explanation based on self-protection.

You are fair, but I expect you to also behave unfairly: Positive asymmetry in trait-behavior relations for moderate morality information.

Science.gov (United States)

Rusconi, Patrice; Sacchi, Simona; Capellini, Roberta; Brambilla, Marco; Cherubini, Paolo

2017-01-01

Trait inference in person perception is based on observers' implicit assumptions about the relations between trait adjectives (e.g., fair) and the either consistent or inconsistent behaviors (e.g., having double standards) that an actor can manifest. This article presents new empirical data and theoretical interpretations on people' behavioral expectations, that is, people's perceived trait-behavior relations along the morality (versus competence) dimension. We specifically address the issue of the moderate levels of both traits and behaviors almost neglected by prior research by using a measure of the perceived general frequency of behaviors. A preliminary study identifies a set of competence- and morality-related traits and a subset of traits balanced for valence. Studies 1-2 show that moral target persons are associated with greater behavioral flexibility than immoral ones where abstract categories of behaviors are concerned. For example, participants judge it more likely that a fair person would behave unfairly than an unfair person would behave fairly. Study 3 replicates the results of the first 2 studies using concrete categories of behaviors (e.g., telling the truth/omitting some information). Study 4 shows that the positive asymmetry in morality-related trait-behavior relations holds for both North-American and European (i.e., Italian) individuals. A small-scale meta-analysis confirms the existence of a positive asymmetry in trait-behavior relations along both morality and competence dimensions for moderate levels of both traits and behaviors. We discuss these findings in relation to prior models and results on trait-behavior relations and we advance a motivational explanation based on self-protection.

Quantitative cognitive-test characterization of reconnectable implantable fiber-optic neurointerfaces for optogenetic neurostimulation.

Science.gov (United States)

Fedotov, I V; Ivashkina, O I; Pochechuev, M S; Roshchina, M A; Toropova, K A; Fedotov, A B; Anokhin, K V; Zheltikov, A M

2017-11-01

Cognitive tests on representative groups of freely behaving transgenic mice are shown to enable a quantitative characterization of reconnectable implantable fiber-optic neurointerfaces for optogenetic neurostimulation. A systematic analysis of such tests provides a robust quantitative measure for the cognitive effects induced by fiber-optic neurostimulation, validating the performance of fiber-optic neurointerfaces for long-term optogenetic brain stimulations and showing no statistically significant artifacts in the behavior of transgenic mice due to interface implantation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Validation of transit-time flowmetry for chronic measurements of regional blood flow in resting and exercising rats

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S.L. Amaral

1997-07-01

Full Text Available The objective of the present study was to validate the transit-time technique for long-term measurements of iliac and renal blood flow in rats. Flow measured with ultrasonic probes was confirmed ex vivo using excised arteries perfused at varying flow rates. An implanted 1-mm probe reproduced with accuracy different patterns of flow relative to pressure in freely moving rats and accurately quantitated the resting iliac flow value (on average 10.43 ± 0.99 ml/min or 2.78 ± 0.3 ml min-1 100 g body weight-1. The measurements were stable over an experimental period of one week but were affected by probe size (resting flows were underestimated by 57% with a 2-mm probe when compared with a 1-mm probe and by anesthesia (in the same rats, iliac flow was reduced by 50-60% when compared to the conscious state. Instantaneous changes of iliac and renal flow during exercise and recovery were accurately measured by the transit-time technique. Iliac flow increased instantaneously at the beginning of mild exercise (from 12.03 ± 1.06 to 25.55 ± 3.89 ml/min at 15 s and showed a smaller increase when exercise intensity increased further, reaching a plateau of 38.43 ± 1.92 ml/min at the 4th min of moderate exercise intensity. In contrast, exercise-induced reduction of renal flow was smaller and slower, with 18% and 25% decreases at mild and moderate exercise intensities. Our data indicate that transit-time flowmetry is a reliable method for long-term and continuous measurements of regional blood flow at rest and can be used to quantitate the dynamic flow changes that characterize exercise and recovery

Kinetics of cardiac and vascular remodeling by spontaneously hypertensive rats after discontinuation of long-term captopril treatment

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W.A. Rocha

2010-04-01

Full Text Available Angiotensin-converting enzyme inhibitors reduce blood pressure and attenuate cardiac and vascular remodeling in hypertension. However, the kinetics of remodeling after discontinuation of the long-term use of these drugs are unknown. Our objective was to investigate the temporal changes occurring in blood pressure and vascular structure of spontaneously hypertensive rats (SHR. Captopril treatment was started in the pre-hypertensive state. Rats (4 weeks were assigned to three groups: SHR-Cap (N = 51 treated with captopril (1 g/L in drinking water from the 4th to the 14th week; SHR-C (N = 48 untreated SHR; Wistar (N = 47 control rats. Subgroups of animals were studied at 2, 4, and 8 weeks after discontinuation of captopril. Direct blood pressure was recorded in freely moving animals after femoral artery catheterism. The animals were then killed to determine left ventricular hypertrophy (LVH and the aorta fixed at the same pressure measured in vivo. Captopril prevented hypertension (105 ± 3 vs 136 ± 5 mmHg, LVH (2.17 ± 0.05 vs 2.97 ± 0.14 mg/g body weight and the increase in cross-sectional area to luminal area ratio of the aorta (0.21 ± 0.01 vs 0.26 ± 0.02 μm² (SHR-Cap vs SHR-C. However, these parameters increased progressively after discontinuation of captopril (22nd week: 141 ± 2 mmHg, 2.50 ± 0.06 mg/g, 0.27 ± 0.02 μm². Prevention of the development of hypertension in SHR by using captopril during the prehypertensive period prevents the development of cardiac and vascular remodeling. Recovery of these processes follows the kinetic of hypertension development after discontinuation of captopril.

Structure of the vitreoretinal border region in spontaneously hypertensive rats (SHR rats)

DEFF Research Database (Denmark)

Heegaard, Steffen

1993-01-01

Øjenpatologi, vitreoretinal border region, inner limiting membrane of the retina, spontaneously hypertensive rats, SHR rats, ultrastructure......Øjenpatologi, vitreoretinal border region, inner limiting membrane of the retina, spontaneously hypertensive rats, SHR rats, ultrastructure...

Cross-fostering does not alter the neurochemistry or behavior of spontaneously hypertensive rats

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Russell Vivienne A

2009-06-01

Full Text Available Abstract Background Attention-deficit/hyperactivity disorder (ADHD is a highly heritable developmental disorder resulting from complex gene-gene and gene-environment interactions. The most widely used animal model, the spontaneously hypertensive rat (SHR, displays the major symptoms of ADHD (deficits in attention, impulsivity and hyperactivity and has a disturbance in the noradrenergic system when compared to control Wistar-Kyoto rats (WKY. The aim of the present study was to determine whether the ADHD-like characteristics of SHR were purely genetically determined or dependent on the gene-environment interaction provided by the SHR dam. Methods SHR/NCrl (Charles River, USA, WKY/NCrl (Charles River, USA and Sprague Dawley rats (SD/Hsd, Harlan, UK were bred at the University of Cape Town. Rat pups were cross-fostered on postnatal day 2 (PND 2. Control rats remained with their birth mothers to serve as a reference for their particular strain phenotype. Behavior in the open-field and the elevated-plus maze was assessed between PND 29 and 33. Two days later, rats were decapitated and glutamate-stimulated release of [3H]norepinephrine was determined in prefrontal cortex and hippocampal slices. Results There was no significant effect of "strain of dam" but there was a significant effect of "pup strain" on all parameters investigated. SHR pups travelled a greater distance in the open field, spent a longer period of time in the inner zone and entered the inner zone of the open-field more frequently than SD or WKY. SD were more active than WKY in the open-field. WKY took longer to enter the inner zone than SHR or SD. In the elevated-plus maze, SHR spent less time in the closed arms, more time in the open arms and entered the open arms more frequently than SD or WKY. There was no difference between WKY and SD behavior in the elevated-plus maze. SHR released significantly more [3H]norepinephrine in response to glutamate than SD or WKY in both hippocampus

Effects of music composed by Mozart and Ligeti on blood pressure and heart rate circadian rhythms in normotensive and hypertensive rats.

Science.gov (United States)

Lemmer, Björn

2008-11-01

There is continuing discussion on the effect of music ("Mozart effect") on numerous functions in man and experimental animals. Radiotelemetry now allows one to monitor cardiovascular functions in freely-moving unrestrained experimental animals. Radiotelemetry was used to monitor systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), and motor activity (MA) in male normotensive WKY and hypertensive SHR animals. Rats were synchronized to a 12 h light (L): 12 h dark (D) regimen in an isolated, ventilated, light-controlled, sound-isolated animal container. Music (Mozart, Symphony # 40; Ligeti, String Quartet # 2) were played for 2 h at 75 dB in the animal cabin starting at the onset of L or D in a cross-over design. Data were collected every 5 min for 24 h under control conditions and during and after music. In addition, plasma concentrations of norepinephrine (NE) were determined in unrestrained animals at 3 h intervals over 24 h. In both WKY and SHR, highly significant circadian rhythms were obtained in SBP, DBP, HR, and MA under control conditions; HR was lower and BP higher in SHR than in WKY. NE was circadian rhythmic in both strains with higher values in D; the increase in NE with immobilization was much more pronounced in SHR than in WKY. The music of Mozart had no effect on either parameter in WKY, neither in L nor in D. In contrast, in SHR, the music of Mozart presented in L significantly decreased HR and left BP unaffected, leading to a small decrease in cardiac output. The music of Ligeti significantly increased BP both in L and in D and reflexively reduced HR in L, the effects being long-lasting over 24 h. Interestingly, white noise at 75 dB had no effect at all on either function in both strains. The effects of both Mozart and Ligeti cannot be attributed to a stress reaction, as stress due to cage switch increased HR and BP both in WKY and SHR. The study clearly demonstrates that music of different character (tempo, rhythm, pitch, tonality) can

Tolerance to disulfiram induced by chronic alcohol intake in the rat.

Science.gov (United States)

Tampier, Lutske; Quintanilla, María Elena; Israel, Yedy

2008-06-01

Disulfiram, an inhibitor of aldehyde dehydrogenase used in the treatment of alcoholism, is an effective medication when its intake is supervised by a third person. However, its therapeutic efficacy varies widely, in part due to the fact that disulfiram is a pro-drug that requires its transformation into an active form and because it shows a wide range of secondary effects which often prevent the use of doses that ensure full therapeutic effectiveness. In this preclinical study in rats we report the development of tolerance to disulfiram induced by the chronic ingestion of ethanol, an additional source of variation for the actions of disulfiram with possible therapeutic significance, We also addresses the likely mechanism of this effect. Wistar-derived rats bred for generations as high ethanol drinkers (UChB) were trained for either 3 days (Group A) or 30 days (Group B) to choose between ethanol (10% v/v) or water, which were freely available from 2 bottles on a 24-hour basis. Subsequently, animals in both groups were administered disulfiram or cyanamide (another inhibitor of aldehyde dehydrogenase) and ethanol intake in this free choice paradigm was determined. Animals were also administered a standard dose of 1 g ethanol/kg (i.p) and arterial blood acetaldehyde was measured. Disulfiram (12.5 and 25 mg/kg) and cyanamide (10 mg/kg) markedly inhibited ethanol intake (up to 60 to 70%) in animals that had ethanol access for only 3 days (Group A). However both drugs were inactive in inhibiting ethanol intake in animals that had consumed ethanol for 30 days (Group B). Following the injection of 1 g ethanol/kg, arterial blood acetaldehyde levels reached levels of 150 and 300 microM for disulfiram and cyanamide respectively, values which were virtually identical regardless of the length of prior ethanol intake of the animals. Chronic ethanol intake in high-drinker rats leads to marked tolerance to the aversive effects of disulfiram and cyanamide on ethanol intake despite

Effects of long-term heat stress and dietary restriction on the expression of genes of steroidogenic pathway and small heat-shock proteins in rat testicular tissue.

Science.gov (United States)

Bozkaya, F; Atli, M O; Guzeloglu, A; Kayis, S A; Yildirim, M E; Kurar, E; Yilmaz, R; Aydilek, N

2017-08-01

The aim was to investigate the effects of long-term heat stress and dietary restriction on the expression of certain genes involving in steroidogenic pathway and small heat-shock proteins (sHSPs) in rat testis. Sprague Dawley rats (n = 24) were equally divided into four groups. Group I and II were kept at an ambient temperature of 22°C, while Groups III and IV were reared at 38°C for 9 weeks. Feed was freely available for Group I and Group III, while Group II and Group IV were fed 60% of the diet consumed by their ad libitum counterparts. At the end of 9 weeks, testicles were collected under euthanasia. Total RNA was isolated from testis tissue samples. Expression profiles of the genes encoding androgen-binding protein, follicle-stimulating hormone receptor, androgen receptor, luteinising hormone receptor, steroidogenic acute regulatory protein (StAR), cyclooxygenase-2 and sHSP genes were assessed at mRNA levels using qPCR. Long-term heat stress decreased the expression of StAR and HspB10 genes while dietary restriction upregulated StAR gene expression. The results suggested that long-term heat stress negatively affected the expression of StAR and HspB10 genes and the dietary restriction was able to reverse negative effect of heat stress on the expression of StAR gene in rat testis. © 2016 Blackwell Verlag GmbH.

EFFECT OF ETHANOL ON HEPATOBILIARY TRANSPORT OF CATIONIC DRUGS - A STUDY IN THE ISOLATED-PERFUSED RAT-LIVER, RAT HEPATOCYTES AND RAT MITOCHONDRIA

NARCIS (Netherlands)

STEEN, H; MEIJER, DKF; Merema, M.T.

The effect of ethanol on the hepatic uptake of various cationic drugs was studied in isolated perfused rat livers, isolated rat hepatocytes and isolated rat liver mitochondria. In isolated rat hepatocytes and in isolated perfused rat livers, the uptake of the model organic cation

You are fair, but I expect you to also behave unfairly: Positive asymmetry in trait-behavior relations for moderate morality information

Science.gov (United States)

Rusconi, Patrice; Sacchi, Simona; Capellini, Roberta; Brambilla, Marco; Cherubini, Paolo

2017-01-01

Trait inference in person perception is based on observers’ implicit assumptions about the relations between trait adjectives (e.g., fair) and the either consistent or inconsistent behaviors (e.g., having double standards) that an actor can manifest. This article presents new empirical data and theoretical interpretations on people’ behavioral expectations, that is, people’s perceived trait-behavior relations along the morality (versus competence) dimension. We specifically address the issue of the moderate levels of both traits and behaviors almost neglected by prior research by using a measure of the perceived general frequency of behaviors. A preliminary study identifies a set of competence- and morality-related traits and a subset of traits balanced for valence. Studies 1–2 show that moral target persons are associated with greater behavioral flexibility than immoral ones where abstract categories of behaviors are concerned. For example, participants judge it more likely that a fair person would behave unfairly than an unfair person would behave fairly. Study 3 replicates the results of the first 2 studies using concrete categories of behaviors (e.g., telling the truth/omitting some information). Study 4 shows that the positive asymmetry in morality-related trait-behavior relations holds for both North-American and European (i.e., Italian) individuals. A small-scale meta-analysis confirms the existence of a positive asymmetry in trait-behavior relations along both morality and competence dimensions for moderate levels of both traits and behaviors. We discuss these findings in relation to prior models and results on trait-behavior relations and we advance a motivational explanation based on self-protection. PMID:28700702

The central GABAergic system and control of food intake under different experimental conditions.

Science.gov (United States)

Olgiati, V R; Netti, C; Guidobono, F; Pecile, A

1980-01-01

Intracerebroventricular injections of gamma-aminobutyric acid (GABA) and of the GABA-transaminase inhibitor, ethanolamine-O-sulphate (EOS), decreased the food intake of freely-fed (GABA and EOS) and food-deprived rats (EOS). The effect, still evident 24 h after treatment, was not decreased by the GABA receptor-blocker bicuculline. In contrast, intracerebroventricular injections of the GABA receptor-agonist, muscimol, caused an increase in food intake of freely-fed rats that was antagonized by bicuculline. The eating of animals receiving only bicuculline was stimulated in free-feeding and depressed in food-deprived conditions. These opposite results suggest that muscimol binds preferentially to some GABA receptors, probably those within the satiety-controlling areas (i.e. ventromedial hypothalamus), and that bicuculline influences mainly those postsynaptic neurons where GABAergic inputs prevail. These observations and the data from EOS- and GABA-treated rats provide evidence for involvement of GABA neurons in the regulation of feeding behaviour. The balance of the different effects produced in each of these areas by this modulation appears to be a decrease in feeding behaviour.

On the importance of telemetric temperature sensor location during intraperitoneal implantation in rats.

Science.gov (United States)

Chapon, P A; Bulla, J; Gauthier, A; Moussay, S

2014-04-01

This study aims to assess the thermal homogeneity of the intraperitoneal (IP) cavity and the relevance of using a fixed telemetric temperature sensor at a given location in studying rodents. Ten rats were intraperitoneally implanted with three Jonah® capsules each; after assessing the accuracy and reliability of the sensors. Two capsules were attached, one to the right iliac fossa (RIF) and the other to the left hypochondrium (LH), and another was placed between the intestines but not attached (Free). In the ex vivo condition, the differences between sensors and reference values remained in the range of ±0.1. In the in vivo condition, each sensor enabled the observation of temperature patterns. However, sensor location affected mean and median temperature values while the rats were moving freely. Indeed, temperature data collected in the LH were 0.1 significantly higher than those collected in the RIF and temperature data collected in the LH were 0.11 significantly higher than those collected with the Free capsules. In in vivo conditions, intra-sensor variability of temperature data was not affected by sensor location. Taking into account sensor accuracy, similar intra-sensor variability, and mean differences observed between the three locations, the impact of sensor location within the IP cavity could be considered negligible. In in vivo conditions, temperature differences between locations regularly exceeded ±0.2 and reached up to 2.5. These extreme values could be explained by behavioral factors such as food or water intake. Finally, considering the good thermal homogeneity of the IP cavity and possible adverse consequences of sensor attachment, it seems better to let sensors range free within the cavity.

Modulation of Hippocampal Activity by Vagus Nerve Stimulation in Freely Moving Rats

NARCIS (Netherlands)

Larsen, L.E.; Wadman, W.J.; van Mierlo, P.; Delbeke, J.; Grimonprez, A.; Van Nieuwenhuyse, B.; Portelli, J.; Boon, P; Vonck, K.; Raedt, R.

2015-01-01

BACKGROUND: Vagus Nerve Stimulation (VNS) has seizure-suppressing effects but the underlying mechanism is not fully understood. To further elucidate the mechanisms underlying VNS-induced seizure suppression at a neurophysiological level, the present study examined effects of VNS on hippocampal

Cancer Feature Selection and Classification Using a Binary Quantum-Behaved Particle Swarm Optimization and Support Vector Machine

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Maolong Xi

2016-01-01

Full Text Available This paper focuses on the feature gene selection for cancer classification, which employs an optimization algorithm to select a subset of the genes. We propose a binary quantum-behaved particle swarm optimization (BQPSO for cancer feature gene selection, coupling support vector machine (SVM for cancer classification. First, the proposed BQPSO algorithm is described, which is a discretized version of original QPSO for binary 0-1 optimization problems. Then, we present the principle and procedure for cancer feature gene selection and cancer classification based on BQPSO and SVM with leave-one-out cross validation (LOOCV. Finally, the BQPSO coupling SVM (BQPSO/SVM, binary PSO coupling SVM (BPSO/SVM, and genetic algorithm coupling SVM (GA/SVM are tested for feature gene selection and cancer classification on five microarray data sets, namely, Leukemia, Prostate, Colon, Lung, and Lymphoma. The experimental results show that BQPSO/SVM has significant advantages in accuracy, robustness, and the number of feature genes selected compared with the other two algorithms.

Cancer Feature Selection and Classification Using a Binary Quantum-Behaved Particle Swarm Optimization and Support Vector Machine

Science.gov (United States)

Sun, Jun; Liu, Li; Fan, Fangyun; Wu, Xiaojun

2016-01-01

This paper focuses on the feature gene selection for cancer classification, which employs an optimization algorithm to select a subset of the genes. We propose a binary quantum-behaved particle swarm optimization (BQPSO) for cancer feature gene selection, coupling support vector machine (SVM) for cancer classification. First, the proposed BQPSO algorithm is described, which is a discretized version of original QPSO for binary 0-1 optimization problems. Then, we present the principle and procedure for cancer feature gene selection and cancer classification based on BQPSO and SVM with leave-one-out cross validation (LOOCV). Finally, the BQPSO coupling SVM (BQPSO/SVM), binary PSO coupling SVM (BPSO/SVM), and genetic algorithm coupling SVM (GA/SVM) are tested for feature gene selection and cancer classification on five microarray data sets, namely, Leukemia, Prostate, Colon, Lung, and Lymphoma. The experimental results show that BQPSO/SVM has significant advantages in accuracy, robustness, and the number of feature genes selected compared with the other two algorithms. PMID:27642363

Changes in the binding of copper in the plasma of molybdenum supplemented rats

International Nuclear Information System (INIS)

Nederbragt, H.; van den Hamer, C.J.

1981-01-01

After incubating plasma of Mo-supplemented rats (Mo-plasma) with /sup 64/Cu only part of it could be removed by dialysis against EDTA or histidine or by treatment with dithiocarbamate; this nondialyzable Cu was shown to be bound to albumin. The maximal amount of /sup 64/Cu bound this way equaled the Mo-induced increase in total plasma Cu. After addition of stable Cu, dialysis of Mo-plasma against a histidine solution showed that no extra Cu became tightly bound, suggesting that the /sup 64/Cu binding was due to an exchange between added /sup 64/Cu and stable Cu already present. Incubating Mo-plasma with Hg compounds prevented /sup 64/Cu binding and released stable Cu, indicating that Cu in Mo-plasma was sulfhydryl bound. Part of the Mo in Mo-plasma was freely dialyzable. The remaining part was shown to be SH bound as well. The estimated atomic ratio of SH-bound Cu and Mo was unity. Molybdenum increased the number of SH groups in plasma, and for each Cu atom at least one SH group was calculated to be present

2H Kinetic Isotope Effects and pH Dependence of Catalysis as Mechanistic Probes of Rat Monoamine Oxidase A: Comparisons with the Human Enzyme‡

Science.gov (United States)

Wang, Jin; Edmondson, Dale E.

2011-01-01

Monoamine oxidase A (MAO A) is a mitochondrial outer membrane-bound flavoenzyme important in the regulation of serotonin and dopamine levels. Since the rat is extensively used as an animal model in drug studies, it is important to understand how rat MAO A behaves in comparison with the more extensively studied human enzyme. For many reversible inhibitors, rat MAO A exhibits Ki values similar to those of human MAO A. The pH profile of kcat for rat MAO A shows a pKa of 8.2±0.1 for the benzylamine ES complex and pKa values of 7.5±0.1 and 7.6±0.1 for the respective ES complexes with p-CF3-1H and p-CF3-2H-benzylamine. In contrast to the human enzyme, the rat enzyme exhibits a single pKa value (8.3±0.1) with kcat/Km benzylamine vs. pH and pKa values of 7.8±0.1 and 8.1±0.2 are found for the ascending limbs, respectively, of kcat/Km vs. pH profiles for p-CF3-1H and p-CF3-2H-benzylamine and 9.3±0.1 and 9.1±0.2 for their respective descending limbs. The oxidation of para-substituted benzylamine substrate analogues by rat MAO A exhibit large deuterium kinetic isotope effects on kcat and on kcat/Km. These effects are pH-independent, and range from 7 to 14, demonstrating a rate-limiting α-C-H bond cleavage step in catalysis. Quantitative structure-activity correlations of log kcat with the electronic substituent parameter (σ) at pH 7.5 and at 9.0 show a dominant contribution with positive ρ values (+1.2 – 1.3) and a pH-independent negative contribution from the steric term. Quantitative structure-activity relationship analysis of the binding affinities of the para-substituted benzylamine analogues to rat MAO A show an increased van der Waals volumes (Vw) increases the affinity of the deprotonated amine for the enzyme. These results demonstrate that rat MAO A exhibits similar but not identical functional properties with the human enzyme and provide additional support for C-H bond cleavage via a polar nucleophilic mechanism. PMID:21819071

²H kinetic isotope effects and pH dependence of catalysis as mechanistic probes of rat monoamine oxidase A: comparisons with the human enzyme.

Science.gov (United States)

Wang, Jin; Edmondson, Dale E

2011-09-06

Monoamine oxidase A (MAO A) is a mitochondrial outer membrane-bound flavoenzyme important in the regulation of serotonin and dopamine levels. Because the rat is extensively used as an animal model in drug studies, it is important to understand how rat MAO A behaves in comparison with the more extensively studied human enzyme. For many reversible inhibitors, rat MAO A exhibits K(i) values similar to those of human MAO A. The pH profile of k(cat) for rat MAO A shows a pK(a) of 8.2 ± 0.1 for the benzylamine ES complex and pK(a) values of 7.5 ± 0.1 and 7.6 ± 0.1 for the ES complexes with p-CF(3)-(1)H- and p-CF(3)-(2)H-benzylamine, respectively. In contrast to the human enzyme, the rat enzyme exhibits a single pK(a) value (8.3 ± 0.1) with k(cat)/K(m) for benzylamine versus pH and pK(a) values of 7.8 ± 0.1 and 8.1 ± 0.2 for the ascending limbs, respectively, of k(cat)/K(m) versus pH profiles for p-CF(3)-(1)H- and p-CF(3)-(2)H-benzylamine and 9.3 ± 0.1 and 9.1 ± 0.2 for the descending limbs, respectively. The oxidation of para-substituted benzylamine substrate analogues by rat MAO A has large deuterium kinetic isotope effects on k(cat) and on k(cat)/K(m). These effects are pH-independent and range from 7 to 14, demonstrating a rate-limiting α-C-H bond cleavage step in catalysis. Quantitative structure-activity correlations of log k(cat) with the electronic substituent parameter (σ) at pH 7.5 and 9.0 show a dominant contribution with positive ρ values (1.2-1.3) and a pH-independent negative contribution from the steric term. Quantitative structure-activity relationship analysis of the binding affinities of the para-substituted benzylamine analogues for rat MAO A shows an increased van der Waals volume (V(w)) increases the affinity of the deprotonated amine for the enzyme. These results demonstrate that rat MAO A exhibits functional properties similar but not identical with those of the human enzyme and provide additional support for C-H bond cleavage via a polar

Two-Dimensional Self-Propelled Fish Motion in Medium: An Integrated Method for Deforming Body Dynamics and Unsteady Fluid Dynamics

International Nuclear Information System (INIS)

Yan, Yang; Yong-Liang, Yu; Bing-Gang, Tong; Guan-Hao, Wu

2008-01-01

We present (1) the dynamical equations of deforming body and (2) an integrated method for deforming body dynamics and unsteady fluid dynamics, to investigate a modelled freely self-propelled fish. The theoretical model and practical method is applicable for studies on the general mechanics of animal locomotion such as flying in air and swimming in water, particularly of free self-propulsion. The present results behave more credibly than the previous numerical studies and are close to the experimental results, and the aligned vortices pattern is discovered in cruising swimming

Dimension dependence of clustering dynamics in models of ballistic aggregation and freely cooling granular gas

Science.gov (United States)

Paul, Subhajit; Das, Subir K.

2018-03-01

Via event-driven molecular dynamics simulations we study kinetics of clustering in assemblies of inelastic particles in various space dimensions. We consider two models, viz., the ballistic aggregation model (BAM) and the freely cooling granular gas model (GGM), for each of which we quantify the time dependence of kinetic energy and average mass of clusters (that form due to inelastic collisions). These quantities, for both the models, exhibit power-law behavior, at least in the long time limit. For the BAM, corresponding exponents exhibit strong dimension dependence and follow a hyperscaling relation. In addition, in the high packing fraction limit the behavior of these quantities become consistent with a scaling theory that predicts an inverse relation between energy and mass. On the other hand, in the case of the GGM we do not find any evidence for such a picture. In this case, even though the energy decay, irrespective of packing fraction, matches quantitatively with that for the high packing fraction picture of the BAM, it is inversely proportional to the growth of mass only in one dimension, and the growth appears to be rather insensitive to the choice of the dimension, unlike the BAM.

Effect of pyrolysis temperatures on freely dissolved polycyclic aromatic hydrocarbon (PAH) concentrations in sewage sludge-derived biochars.

Science.gov (United States)

Zielińska, Anna; Oleszczuk, Patryk

2016-06-01

The aim of this study was to evaluate the effect of sewage sludge pyrolysis on freely dissolved (Cfree) polycyclic aromatic hydrocarbon (PAH) contents in biochars. Four sewage sludges with varying properties and PAH contents were pyrolysed at temperatures of 500 °C, 600 °C or 700 °C. Cfree PAH contents were determined using polyoxymethylene (POM). The contents of Cfree PAHs in the sludges ranged from 262 to 294 ng L(-1). Sewage sludge-derived biochars have from 2.3- to 3.4-times lower Cfree PAH contents comparing to corresponding sewage sludges. The Cfree PAH contents in the biochars ranged between 81 ng L(-1) and 126 ng L(-1). As regards agricultural use of biochar, the lower contents of Cfree PAHs in the biochars compared to the sewage sludges makes biochar a safer material than sewage sludge in terms of PAH contents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Direct measurement of the ballistic motion of a freely floating colloid in Newtonian and viscoelastic fluids.

Science.gov (United States)

Hammond, Andrew P; Corwin, Eric I

2017-10-01

A thermal colloid suspended in a liquid will transition from a short-time ballistic motion to a long-time diffusive motion. However, the transition between ballistic and diffusive motion is highly dependent on the properties and structure of the particular liquid. We directly observe a free floating tracer particle's ballistic motion and its transition to the long-time regime in both a Newtonian fluid and a viscoelastic Maxwell fluid. We examine the motion of the free particle in a Newtonian fluid and demonstrate a high degree of agreement with the accepted Clercx-Schram model for motion in a dense fluid. Measurements of the functional form of the ballistic-to-diffusive transition provide direct measurements of the temperature, viscosity, and tracer radius. We likewise measure the motion in a viscoelastic Maxwell fluid and find a significant disagreement between the theoretical asymptotic behavior and our measured values of the microscopic properties of the fluid. We observe a greatly increased effective mass for a freely moving particle and a decreased plateau modulus.

Evaluation of the effects and mechanisms of action of glufosinate, an organophosphate insecticide, on striatal dopamine release by using in vivo microdialysis in freely moving rats.

Science.gov (United States)

Ferreira Nunes, Brenda V; Durán, Rafael; Alfonso, Miguel; de Oliveira, Iris Machado; Ferreira Faro, Lilian R

2010-10-01

The purpose of the present work was to assess the effects of glufosinate ammonium (GLA), an aminoacid structurally related to glutamate, on in vivo dopamine (DA) release from rat striatum, using brain microdialysis coupled to HPLC-EC. Intrastriatal administration of GLA produced significant concentration-dependent increases in DA levels. At least two mechanisms can be proposed to explain these increases: GLA could be inducing DA release from synaptic vesicles or producing an inhibition of DA transporter (DAT). Thus, we investigated the effects of GLA under Ca(++)-free condition, and after pretreatment with reserpine and TTX. It was observed that the pretreatment with Ca(++)-free Ringer, reserpine or TTX significantly reduced the DA release induced by GLA. Coinfusion of GLA and nomifensine shows that the GLA-induced DA release did not involve the DAT. These results show that GLA-induced striatal DA release is probably mediated by an exocytotic-, Ca(++)-, action potential-dependent mechanism, being independent of DAT.

Beta oscillations in freely moving Parkinson's subjects are attenuated during deep brain stimulation.

Science.gov (United States)

Quinn, Emma J; Blumenfeld, Zack; Velisar, Anca; Koop, Mandy Miller; Shreve, Lauren A; Trager, Megan H; Hill, Bruce C; Kilbane, Camilla; Henderson, Jaimie M; Brontë-Stewart, Helen

2015-11-01

Investigations into the effect of deep brain stimulation (DBS) on subthalamic (STN) beta (13-30 Hz) oscillations have been performed in the perioperative period with the subject tethered to equipment. Using an embedded sensing neurostimulator, this study investigated whether beta power was similar in different resting postures and during forward walking in freely moving subjects with Parkinson's disease (PD) and whether STN DBS attenuated beta power in a voltage-dependent manner. Subthalamic local field potentials were recorded from the DBS lead, using a sensing neurostimulator (Activa(®) PC+S, Medtronic, Inc., Food and Drug Administration- Investigational Device Exemption (IDE)-, institutional review board-approved) from 15 PD subjects (30 STNs) off medication during lying, sitting, and standing, during forward walking, and during randomized periods of 140 Hz DBS at 0 V, 1 V, and 2.5/3 V. Continuous video, limb angular velocity, and forearm electromyography recordings were synchronized with neural recordings. Data were parsed to avoid any movement or electrical artifact during resting states. Beta power was similar during lying, sitting, and standing (P = 0.077, n = 28) and during forward walking compared with the averaged resting state (P = 0.466, n = 24), although akinetic rigid PD subjects tended to exhibit decreased beta power when walking. Deep brain stimulation at 3 V and at 1 V attenuated beta power compared with 0 V (P closed-loop DBS. © 2015 International Parkinson and Movement Disorder Society.

Angiotensin II and CRF receptors in the central nucleus of the amygdala mediate hemodynamic response variability to cocaine in conscious rats.

Science.gov (United States)

Watanabe, Mari A; Kucenas, Sarah; Bowman, Tamara A; Ruhlman, Melissa; Knuepfer, Mark M

2010-01-14

Stress or cocaine evokes either a large increase in systemic vascular resistance (SVR) or a smaller increase in SVR accompanied by an increase in cardiac output (designated vascular and mixed responders, respectively) in Sprague-Dawley rats. We hypothesized that the central nucleus of the amygdala (CeA) mediates this variability. Conscious, freely-moving rats, instrumented for measurement of arterial pressure and cardiac output and for drug delivery into the CeA, were given cocaine (5 mg/kg, iv, 4-6 times) and characterized as vascular (n=15) or mixed responders (n=10). Subsequently, we administered cocaine after bilateral microinjections (100 nl) of saline or selective agents in the CeA. Muscimol (80 pmol), a GABA(A) agonist, or losartan (43.4 pmol), an AT(1) receptor antagonist, attenuated the cocaine-induced increase in SVR in vascular responders, selectively, such that vascular responders were no longer different from mixed responders. The corticotropin releasing factor (CRF) antagonist, alpha-helical CRF(9-41) (15.7 pmol), abolished the difference between cardiac output and SVR in mixed and vascular responders. We conclude that greater increases in SVR observed in vascular responders are dependent on AT(1) receptor activation and, to a lesser extent on CRF receptors. Therefore, AT(1) and CRF receptors in the CeA contribute to hemodynamic response variability to intravenous cocaine.

Laying hens behave differently in artificially and naturally sourced ammoniated environments.

Science.gov (United States)

Pokharel, B B; Dos Santos, V M; Wood, D; Van Heyst, B; Harlander-Matauschek, A

2017-12-01

Laying hens are chronically exposed to high levels of ammonia (NH3), one of the most abundant aerial pollutants in poultry houses. Tests for aversion to NH3 in laying hens have used artificially sourced NH3/air mixtures (i.e., from a gas cylinder) showing that birds prefer fresh air to NH3. However, artificially sourced NH3/air mixtures may not accurately reflect barn air conditions, where manure emits a variety of gases. Herein, we investigated whether laying hens differentiate between artificially and naturally sourced NH3/air mixtures and how exposure to NH3 affects foraging and aversive behavior. A total of 20 laying hens was exposed to artificially sourced [A] (from an anhydrous NH3 cylinder) and naturally sourced [N] (from conspecific laying hen excreta) gas mixtures. Hens were exposed to A and N mixtures with NH3 concentrations of 25 and 45 ppm, as well as fresh air [FA]. During the experiment, all birds were exposed to each treatment 3 times using a custom-built polycarbonate chamber, containing a foraging area (containing raisins, mealworms, and feed mix) and a gas delivery system. All testing sessions were video recorded, analyzed with INTERACT® software, and subjected to a GLIMMIX procedure in SAS. Our results showed that the laying hens spent less time foraging overall (P hens were more likely to forage for a longer time (with fewer interruptions) in N than in A treatments (P hens also reacted with greater aversion towards treatment A compared to treatment N (P hens of our study preferred fresh to ammoniated air and that they behaved differently in artificially and naturally sourced NH3/air mixtures, possibly due to the presence of familiar stimuli from the excreta. These findings have implications for new developments in methodological approaches for behavioral testing and for recommendations regarding NH3 levels inside poultry barns. © 2017 Poultry Science Association Inc.

Beta-endorphin in genetically hypoprolactinemic rat: IPL nude rat

International Nuclear Information System (INIS)

Cohen, H.; Sabbagh, I.; Abou-Samra, A.B.; Bertrand, J.

1986-01-01

Beta-endorphin has been reported to regulate not only stress- and suckling-induced but also basal prolactin secretion. In the aim to better evaluate the endogenous beta-endorphin-prolactin interrelation, the authors measured beta-endorphin levels in a new rat strain, genetically hypoprolactinemic and characterized by a total lack of lactation: IPL nude rat. Beta-endorphin was measured using a specific anti-h-β endorphin in plasma and extracts of anterior and neurointermediate lobes of the pituitary, hypothalamus and brain. Pituitary extracts were also chromatographed on Sephadex G50 column. Results obtained showed that in IPL nude females on diestrus and males, the beta-endorphin contents of the neurointermediate lobe was significantly lower than in normal rats, while the values found in the other organs and plasma were similar. However, elution pattern of the anterior pituitary extracts from male rats showed greater immunoactivity eluting as I 125 h-beta-endorphin than in normal rat; this was not the case for the female rat. These results are consistent with a differential regulation of beta-endorphin levels of anterior and neurointermediate lobe by catecholamines. Moreover they suggest that PRL secretion was more related to neurointermediate beta-endorphin. 40 references, 2 figures, 4 tables

Beta-endorphin in genetically hypoprolactinemic rat: IPL nude rat

Energy Technology Data Exchange (ETDEWEB)

Cohen, H.; Sabbagh, I.; Abou-Samra, A.B.; Bertrand, J.

1986-01-20

Beta-endorphin has been reported to regulate not only stress- and suckling-induced but also basal prolactin secretion. In the aim to better evaluate the endogenous beta-endorphin-prolactin interrelation, the authors measured beta-endorphin levels in a new rat strain, genetically hypoprolactinemic and characterized by a total lack of lactation: IPL nude rat. Beta-endorphin was measured using a specific anti-h-..beta.. endorphin in plasma and extracts of anterior and neurointermediate lobes of the pituitary, hypothalamus and brain. Pituitary extracts were also chromatographed on Sephadex G50 column. Results obtained showed that in IPL nude females on diestrus and males, the beta-endorphin contents of the neurointermediate lobe was significantly lower than in normal rats, while the values found in the other organs and plasma were similar. However, elution pattern of the anterior pituitary extracts from male rats showed greater immunoactivity eluting as I/sup 125/ h-beta-endorphin than in normal rat; this was not the case for the female rat. These results are consistent with a differential regulation of beta-endorphin levels of anterior and neurointermediate lobe by catecholamines. Moreover they suggest that PRL secretion was more related to neurointermediate beta-endorphin. 40 references, 2 figures, 4 tables.

Muscarinic Long-Term Enhancement of Tonic and Phasic GABAA Inhibition in Rat CA1 Pyramidal Neurons

Science.gov (United States)

Domínguez, Soledad; Fernández de Sevilla, David; Buño, Washington

2016-01-01

Acetylcholine (ACh) regulates network operation in the hippocampus by controlling excitation and inhibition in rat CA1 pyramidal neurons (PCs), the latter through gamma-aminobutyric acid type-A receptors (GABAARs). Although, the enhancing effects of ACh on GABAARs have been reported (Dominguez et al., 2014, 2015), its role in regulating tonic GABAA inhibition has not been explored in depth. Therefore, we aimed at determining the effects of the activation of ACh receptors on responses mediated by synaptic and extrasynaptic GABAARs. Here, we show that under blockade of ionotropic glutamate receptors ACh, acting through muscarinic type 1 receptors, paired with post-synaptic depolarization induced a long-term enhancement of tonic GABAA currents (tGABAA) and puff-evoked GABAA currents (pGABAA). ACh combined with depolarization also potentiated IPSCs (i.e., phasic inhibition) in the same PCs, without signs of interactions of synaptic responses with pGABAA and tGABAA, suggesting the contribution of two different GABAA receptor pools. The long-term enhancement of GABAA currents and IPSCs reduced the excitability of PCs, possibly regulating plasticity and learning in behaving animals. PMID:27833531

Population Structure of Rat-Derived Pneumocystis carinii in Danish Wild Rats

DEFF Research Database (Denmark)

Palmer, Robert J.; Settnes, Osvald P.; Lodal, Jens

2000-01-01

The rat model of Pneumocystis carinii pneumonia is frequently used to study human P. carinii infection, but there are many differences between the rat and human infections. We studied naturally acquired P. carinii in wild rats to examine the relevance of the rat model for human infection. P. cari...

Circulating CO3-610, a degradation product of collagen III, closely reflects liver collagen and portal pressure in rats with fibrosis

Science.gov (United States)

2011-01-01

Background Hepatic fibrosis is characterized by intense tissue remodeling, mainly driven by matrix metalloproteinases. We previously identified CO3-610, a type III collagen neoepitope generated by matrix metalloproteinase (MMP)-9, and tested its performance as a fibrosis marker in rats with bile-duct ligation. In this study, we assessed whether CO3-610 could be used as a surrogate biomarker of liver fibrosis and portal hypertension in carbon tetrachloride-induced experimental fibrosis. Results For this study, 68 Wistar rats were used. Serum CO3-610 was measured by ELISA. Liver fibrosis was quantified by Sirius red staining. Serum hyaluronic acid (HA) was measured with a binding-protein assay. Gene expression of collagens I and III, Mmp2 and Mmp9, and tissue inhibitors of matrix metalloproteinase 1 (Timp1) and 2(Timp2) was quantified by PCR. Hemodynamic measurements were taken in a subgroup of animals. A close direct relationship was found between serum CO3-610 and hepatic collagen content (r = 0.78; P fibrosis (43.5 ± 3.3 ng/mL, P Liver Mmp9 expression increased significantly in fibrotic animals but decreased to control levels in cirrhotic ones. Conclusions Circulating CO3-610 behaves as a reliable indicator of hepatic remodeling and portal hypertension in experimental fibrosis. This peptide could ultimately be a useful marker for the management of liver disease in patients. PMID:21813019

ONLINE MONITORING OF EXTRACELLULAR BRAIN GLUCOSE USING MICRODIALYSIS AND A NADPH-LINKED ENZYMATIC ASSAY

NARCIS (Netherlands)

VANDERKUIL, JHF; KORF, J

A method to monitor extracellular glucose in freely moving rats, based on intracerebral microdialysis coupled to an enzyme reactor is described. The dialysate is continuously mixed with a solution containing the enzymes hexokinase and glucose-6-phosphate dehydrogenase, and the fluorescence of NADPH

An improved quantum-behaved particle swarm optimization method for short-term combined economic emission hydrothermal scheduling

Energy Technology Data Exchange (ETDEWEB)

Lu, Songfeng; Sun, Chengfu; Lu, Zhengding [School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

2010-03-15

This paper presents a modified quantum-behaved particle swarm optimization (QPSO) for short-term combined economic emission scheduling (CEES) of hydrothermal power systems with several equality and inequality constraints. The hydrothermal scheduling is formulated as a bi-objective problem: (i) minimizing fuel cost and (ii) minimizing pollutant emission. The bi-objective problem is converted into a single objective one by price penalty factor. The proposed method, denoted as QPSO-DM, combines the QPSO algorithm with differential mutation operation to enhance the global search ability. In this study, heuristic strategies are proposed to handle the equality constraints especially water dynamic balance constraints and active power balance constraints. A feasibility-based selection technique is also employed to meet the reservoir storage volumes constraints. To show the efficiency of the proposed method, different case studies are carried out and QPSO-DM is compared with the differential evolution (DE), the particle swarm optimization (PSO) with same heuristic strategies in terms of the solution quality, robustness and convergence property. The simulation results show that the proposed method is capable of yielding higher-quality solutions stably and efficiently in the short-term hydrothermal scheduling than any other tested optimization algorithms. (author)

An improved quantum-behaved particle swarm optimization method for short-term combined economic emission hydrothermal scheduling

Energy Technology Data Exchange (ETDEWEB)

Lu Songfeng [School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Sun Chengfu, E-mail: ajason_369@sina.co [School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Lu Zhengding [School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

2010-03-15

This paper presents a modified quantum-behaved particle swarm optimization (QPSO) for short-term combined economic emission scheduling (CEES) of hydrothermal power systems with several equality and inequality constraints. The hydrothermal scheduling is formulated as a bi-objective problem: (i) minimizing fuel cost and (ii) minimizing pollutant emission. The bi-objective problem is converted into a single objective one by price penalty factor. The proposed method, denoted as QPSO-DM, combines the QPSO algorithm with differential mutation operation to enhance the global search ability. In this study, heuristic strategies are proposed to handle the equality constraints especially water dynamic balance constraints and active power balance constraints. A feasibility-based selection technique is also employed to meet the reservoir storage volumes constraints. To show the efficiency of the proposed method, different case studies are carried out and QPSO-DM is compared with the differential evolution (DE), the particle swarm optimization (PSO) with same heuristic strategies in terms of the solution quality, robustness and convergence property. The simulation results show that the proposed method is capable of yielding higher-quality solutions stably and efficiently in the short-term hydrothermal scheduling than any other tested optimization algorithms.

An improved quantum-behaved particle swarm optimization method for short-term combined economic emission hydrothermal scheduling

International Nuclear Information System (INIS)

Lu Songfeng; Sun Chengfu; Lu Zhengding

2010-01-01

This paper presents a modified quantum-behaved particle swarm optimization (QPSO) for short-term combined economic emission scheduling (CEES) of hydrothermal power systems with several equality and inequality constraints. The hydrothermal scheduling is formulated as a bi-objective problem: (i) minimizing fuel cost and (ii) minimizing pollutant emission. The bi-objective problem is converted into a single objective one by price penalty factor. The proposed method, denoted as QPSO-DM, combines the QPSO algorithm with differential mutation operation to enhance the global search ability. In this study, heuristic strategies are proposed to handle the equality constraints especially water dynamic balance constraints and active power balance constraints. A feasibility-based selection technique is also employed to meet the reservoir storage volumes constraints. To show the efficiency of the proposed method, different case studies are carried out and QPSO-DM is compared with the differential evolution (DE), the particle swarm optimization (PSO) with same heuristic strategies in terms of the solution quality, robustness and convergence property. The simulation results show that the proposed method is capable of yielding higher-quality solutions stably and efficiently in the short-term hydrothermal scheduling than any other tested optimization algorithms.

Establishment of a novel dwarf rat strain: cartilage calcification insufficient (CCI) rats.

Science.gov (United States)

Tanaka, Masami; Watanabe, Minoru; Yokomi, Izuru; Matsumoto, Naoki; Sudo, Katsuko; Satoh, Hitoshi; Igarashi, Tsuneo; Seki, Azusa; Amano, Hitoshi; Ohura, Kiyoshi; Ryu, Kakei; Shibata, Shunichi; Nagayama, Motohiko; Tanuma, Jun-ichi

2015-01-01

Rats with dwarfism accompanied by skeletal abnormalities, such as shortness of the limbs, tail, and body (dwarf rats), emerged in a Jcl-derived Sprague-Dawley rat colony maintained at the Institute for Animal Experimentation, St. Marianna University Graduate School of Medicine. Since the dwarfism was assumed to be due to a genetic mutation based on its frequency, we bred the dwarf rats and investigated their characteristics in order to identify the causative factors of their phenotypes and whether they could be used as a human disease model. One male and female that produced dwarf progeny were selected, and reproduction was initiated by mating the pair. The incidence of dwarfism was 25.8% among the resultant litter, and dwarfism occurred in both genders, suggesting that it was inherited in an autosomal recessive manner. At 12 weeks of age, the body weights of the male and female dwarf rats were 40% and 57% of those of the normal rats, respectively. In soft X-ray radiographic and histological examinations, shortening and hypoplasia of the long bones, such as the tibia and femur, were observed, which were suggestive of endochondral ossification abnormalities. An immunohistochemical examination detected an aggrecan synthesis disorder, which might have led to delayed calcification and increased growth plate thickening in the dwarf rats. We hypothesized that the principal characteristics of the dwarf rats were systemically induced by insufficient cartilage calcification in their long bones; thus, we named them cartilage calcification insufficient (CCI) rats.

Establishment of a novel dwarf rat strain: cartilage calcification insufficient (CCI) rats

Science.gov (United States)

TANAKA, Masami; WATANABE, Minoru; YOKOMI, Izuru; MATSUMOTO, Naoki; SUDO, Katsuko; SATOH, Hitoshi; IGARASHI, Tsuneo; SEKI, Azusa; AMANO, Hitoshi; OHURA, Kiyoshi; RYU, Kakei; SHIBATA, Shunichi; NAGAYAMA, Motohiko; TANUMA, Jun-ichi

2014-01-01

Rats with dwarfism accompanied by skeletal abnormalities, such as shortness of the limbs, tail, and body (dwarf rats), emerged in a Jcl-derived Sprague-Dawley rat colony maintained at the Institute for Animal Experimentation, St. Marianna University Graduate School of Medicine. Since the dwarfism was assumed to be due to a genetic mutation based on its frequency, we bred the dwarf rats and investigated their characteristics in order to identify the causative factors of their phenotypes and whether they could be used as a human disease model. One male and female that produced dwarf progeny were selected, and reproduction was initiated by mating the pair. The incidence of dwarfism was 25.8% among the resultant litter, and dwarfism occurred in both genders, suggesting that it was inherited in an autosomal recessive manner. At 12 weeks of age, the body weights of the male and female dwarf rats were 40% and 57% of those of the normal rats, respectively. In soft X-ray radiographic and histological examinations, shortening and hypoplasia of the long bones, such as the tibia and femur, were observed, which were suggestive of endochondral ossification abnormalities. An immunohistochemical examination detected an aggrecan synthesis disorder, which might have led to delayed calcification and increased growth plate thickening in the dwarf rats. We hypothesized that the principal characteristics of the dwarf rats were systemically induced by insufficient cartilage calcification in their long bones; thus, we named them cartilage calcification insufficient (CCI) rats. PMID:25736479

Estimation of unsteady aerodynamics in the wake of a freely flying European starling (Sturnus vulgaris.

Directory of Open Access Journals (Sweden)

Hadar Ben-Gida

Full Text Available Wing flapping is one of the most widespread propulsion methods found in nature; however, the current understanding of the aerodynamics in bird wakes is incomplete. The role of the unsteady motion in the flow and its contribution to the aerodynamics is still an open question. In the current study, the wake of a freely flying European starling has been investigated using long-duration high-speed Particle Image Velocimetry (PIV in the near wake. Kinematic analysis of the wings and body of the bird has been performed using additional high-speed cameras that recorded the bird movement simultaneously with the PIV measurements. The wake evolution of four complete wingbeats has been characterized through reconstruction of the time-resolved data, and the aerodynamics in the wake have been analyzed in terms of the streamwise forces acting on the bird. The profile drag from classical aerodynamics was found to be positive during most of the wingbeat cycle, yet kinematic images show that the bird does not decelerate. It is shown that unsteady aerodynamics are necessary to satisfy the drag/thrust balance by approximating the unsteady drag term. These findings may shed light on the flight efficiency of birds by providing a partial answer to how they minimize drag during flapping flight.

Precision measurement of electric organ discharge timing from freely moving weakly electric fish.

Science.gov (United States)

Jun, James J; Longtin, André; Maler, Leonard

2012-04-01

Physiological measurements from an unrestrained, untethered, and freely moving animal permit analyses of neural states correlated to naturalistic behaviors of interest. Precise and reliable remote measurements remain technically challenging due to animal movement, which perturbs the relative geometries between the animal and sensors. Pulse-type electric fish generate a train of discrete and stereotyped electric organ discharges (EOD) to sense their surroundings actively, and rapid modulation of the discharge rate occurs while free swimming in Gymnotus sp. The modulation of EOD rates is a useful indicator of the fish's central state such as resting, alertness, and learning associated with exploration. However, the EOD pulse waveforms remotely observed at a pair of dipole electrodes continuously vary as the fish swims relative to the electrodes, which biases the judgment of the actual pulse timing. To measure the EOD pulse timing more accurately, reliably, and noninvasively from a free-swimming fish, we propose a novel method based on the principles of waveform reshaping and spatial averaging. Our method is implemented using envelope extraction and multichannel summation, which is more precise and reliable compared with other widely used threshold- or peak-based methods according to the tests performed under various source-detector geometries. Using the same method, we constructed a real-time electronic pulse detector performing an additional online pulse discrimination routine to enhance further the detection reliability. Our stand-alone pulse detector performed with high temporal precision (<10 μs) and reliability (error <1 per 10(6) pulses) and permits longer recording duration by storing only event time stamps (4 bytes/pulse).

Effects of some dopamine antagonists on spatial memory performance in rats--experimental research.

Science.gov (United States)

Rusu, Gabriela; Popa, Gratiela; Ochiuz, Lacramioara; Nechifor, M; Tartau, Liliana

2014-01-01

Dopamine is a neurotransmitter with an important role in forming long-lasting memories for some time, especially in episodic memory. Literature data show that dopamine receptor stimulation may be detrimental to spatial working memory functions in lab animals. (R)-(+)-7-Chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride derivative--SCH-23390 is a synthetic compound that acts as a selective, high-affinity antagonist of D1 receptors. Experimental studies suggest that SCH 23390 may prevent the spatial working memory disturbances induced by the active substances of marijuana. Melperone is an atypic antipsychotic drug presenting also dopaminergic D2 and 5-HT2A receptor antagonistic activity. This neuroleptic agent is used in the treatment of some types of schizophrenia. Experimental research on the effects of two dopamine receptor antagonists on spatial memory performance in rats. The experiment was carried out in white Wistar rats (200-250g), divided into 3 groups of 7 animals each, treated intraperitoneally with the same volume of solution for 14 days, as follows: Group I (Control): saline solution 0.1 ml/10g kbw; Group II (coded SCH): SCH-23390 0.3 mg/kbw; Group III (coded MLP): melperone 2 mg/kbw. The dopaminergic agent spatial memory performance was assessed by recording spontaneous alternation behavior in a single session in Y-maze. Each animal was placed at the end of one arm and allowed to move freely through the maze during an 8 min session. Alternation was defined as a consecutive entry in three different arms. The alternation percentage was computed with the following formula: number of alternations divided by total number of arm visits minus 2. Data were presented as +/- standard deviation and significance was tested by SPSS Statistics for Windows version 13.0 and ANOVA method. P-values less than 0.05 were considered statistically significant compared to those in the control group. Experimental researches were carried out in

The temporoammonic input to the hippocampal CA1 region displays distinctly different synaptic plasticity compared to the Schaffer collateral input in vivo: significance for synaptic information processing

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Ayla eAksoy Aksel

2013-08-01

Full Text Available In terms of its sub-regional differentiation, the hippocampal CA1 region receives cortical information directly via the perforant (temporoammonic path (pp-CA1 synapse and indirectly via the tri-synaptic pathway where the last relay station is the Schaffer collateral-CA1 synapse (Sc-CA1 synapse. Research to date on pp-CA1 synapses has been conducted predominantly in vitro and never in awake animals, but these studies hint that information processing at this synapse might be distinct to processing at the Sc-CA1 synapse. Here, we characterized synaptic properties and synaptic plasticity at the pp-CA1 synapse of freely behaving adult rats. We established that field excitatory postsynaptic potentials at the pp-CA1 have longer onset latencies and a shorter time-to-peak compared to the Sc-CA1 synapse. LTP (> 24h was successfully evoked by tetanic afferent stimulation of pp-CA1 synapses. Low frequency stimulation evoked synaptic depression at Sc-CA1 synapses, but did not elicit LTD at pp-CA1 synapses unless the Schaffer collateral afferents to the CA1 region had been severed. Paired-pulse responses also showed significant differences. Our data suggest that synaptic plasticity at the pp-CA1 synapse is distinct from the Sc-CA1 synapse and that this may reflect its specific role in hippocampal information processing.

Spatial olfactory learning facilitates long-term depression in the hippocampus.

Science.gov (United States)

André, Marion Agnès Emma; Manahan-Vaughan, Denise

2013-10-01

Recently, it has emerged that visual spatial exploration facilitates synaptic plasticity at different synapses within the trisynaptic network. Particularly striking is the finding that visuospatial contexts facilitate hippocampal long-term depression (LTD), raising the possibility that this form of plasticity may be important for memory formation. It is not known whether other sensory modalities elicit similar permissive effects on LTD. Here, we explored if spatial olfactory learning facilitates LTD in the hippocampus region of freely behaving rats. Patterned afferent stimulation of the Schaffer collaterals elicited short-term depression (STD) (<1 h) of evoked responses in the Stratum radiatum of the CA1 region. Coupling of this protocol with novel exploration of a spatial constellation of olfactory cues facilitated short-term depression into LTD that lasted for over 24 h. Facilitation of LTD did not occur when animals were re-exposed 1 week later to the same odors in the same spatial constellation. Evaluation of learning behavior revealed that 1 week after the 1st odor exposure, the animals remembered the odors and their relative positions. These data support that the hippocampus can use nonvisuospatial resources, and specifically can use spatial olfactory information, to facilitate LTD and to generate spatial representations. The data also support that a tight relationship exists between the processing of spatial contextual information and the expression of LTD in the hippocampus. Copyright © 2013 Wiley Periodicals, Inc.

Persistent deficits in hippocampal synaptic plasticity accompany losses of hippocampus-dependent memory in a rodent model of psychosis

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Valentina eWiescholleck

2013-03-01

Full Text Available Irreversible N-methyl-D-aspartate receptor (NMDAR antagonism is known to provoke symptoms of psychosis and schizophrenia in healthy humans. NMDAR hypofunction is believed to play a central role in the pathophysiology of both disorders and in an animal model of psychosis, that is based on irreversible antagonism of NMDARs, pronounced deficits in hippocampal synaptic plasticity have been reported shortly after antagonist treatment. Here, we examined the long-term consequences for long-term potentiation (LTP of a single acute treatment with an irreversible antagonist and investigated whether deficits are associated with memory impairments.The ability to express long-term potentiation (LTP at the perforant pathway – dentate gyrus synapse, as well as object recognition memory was assessed 1, 2, 3 and 4 weeks after a single -treatment of the antagonist, MK801. Here, LTP in freely behaving rats was significantly impaired at all time-points compared to control LTP before treatment. Object recognition memory was also significantly poorer in MK801-treated compared to vehicle-treated animals for several weeks after treatment. Histological analysis revealed no changes in brain tissue.Taken together, these data support that acute treatment with an irreversible NMDAR antagonist persistently impairs hippocampal functioning on behavioral, as well as synaptic levels. The long-term deficits in synaptic plasticity may underlie the cognitive impairments that are associated with schizophrenia-spectrum disorders.

Untangling cortico-striatal connectivity and cross-frequency coupling in L-DOPA-induced dyskinesia

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Jovana eBelic

2016-03-01

Full Text Available We simultaneously recorded local field potentials in the primary motor cortex and sensorimotor striatum in awake, freely behaving, 6-OHDA lesioned hemi-parkinsonian rats in order to study the features directly related to pathological states such as parkinsonian state and levodopa-induced dyskinesia. We analysed the spectral characteristics of the obtained signals and observed that during dyskinesia the most prominent feature was a relative power increase in the high gamma frequency range at around 80 Hz, while for the parkinsonian state it was in the beta frequency range. Here we show that during both pathological states effective connectivity in terms of Granger causality is bidirectional with an accent on the striatal influence on the cortex. In the case of dyskinesia, we also found a high increase in effective connectivity at 80 Hz. In order to further understand the 80- Hz phenomenon, we performed cross-frequency analysis and observed characteristic patterns in the case of dyskinesia but not in the case of the parkinsonian state or the healthy state. We noted a large decrease in the modulation of the amplitude at 80 Hz by the phase of low frequency oscillations (up to ~10 Hz across both structures in the case of dyskinesia. This may suggest a lack of coupling between the low frequency activity of the recorded network and the group of neurons active at ~80 Hz.

A low-cost multichannel wireless neural stimulation system for freely roaming animals

Science.gov (United States)

Alam, Monzurul; Chen, Xi; Fernandez, Eduardo

2013-12-01

Objectives. Electrical stimulation of nerve tissue and recording of neural activity are the basis of many therapies and neural prostheses. Conventional stimulation systems have a number of practical limitations, especially in experiments involving freely roaming subjects. Our main objective was to develop a modular, versatile and inexpensive multichannel wireless system able to overcome some of these constraints. Approach. We have designed and implemented a new multichannel wireless neural stimulator based on commercial components. The system is small (2 cm × 4 cm × 0.5 cm) and light in weight (9 g) which allows it to be easily carried in a small backpack. To test and validate the performance and reliability of the whole system we conducted several bench tests and in vivo experiments. Main results. The performance and accuracy of the stimulator were comparable to commercial threaded systems. Stimulation sequences can be constructed on-the-fly with 251 selectable current levels (from 0 to 250 µA) with 1 µA step resolution. The pulse widths and intervals can be as long as 65 ms in 2 µs time resolution. The system covers approximately 10 m of transmission range in a regular laboratory environment and 100 m in free space (line of sight). Furthermore it provides great flexibility for experiments since it allows full control of the stimulator and the stimulation parameters in real time. When there is no stimulation, the device automatically goes into low-power sleep mode to preserve battery power. Significance. We introduce the design of a powerful multichannel wireless stimulator assembled from commercial components. Key features of the system are their reliability, robustness and small size. The system has a flexible design that can be modified straightforwardly to tailor it to any specific experimental need. Furthermore it can be effortlessly adapted for use with any kind of multielectrode arrays.

Identification of behaviour in freely moving dogs (Canis familiaris using inertial sensors.

Directory of Open Access Journals (Sweden)

Linda Gerencsér

Full Text Available Monitoring and describing the physical movements and body postures of animals is one of the most fundamental tasks of ethology. The more precise the observations are the more sophisticated the interpretations can be about the biology of a certain individual or species. Animal-borne data loggers have recently contributed much to the collection of motion-data from individuals, however, the problem of translating these measurements to distinct behavioural categories to create an ethogram is not overcome yet. The objective of the present study was to develop a "behaviour tracker": a system composed of a multiple sensor data-logger device (with a tri-axial accelerometer and a tri-axial gyroscope and a supervised learning algorithm as means of automated identification of the behaviour of freely moving dogs. We collected parallel sensor measurements and video recordings of each of our subjects (Belgian Malinois, N=12; Labrador Retrievers, N=12 that were guided through a predetermined series of standard activities. Seven behavioural categories (lay, sit, stand, walk, trot, gallop, canter were pre-defined and each video recording was tagged accordingly. Evaluation of the measurements was performed by support vector machine (SVM classification. During the analysis we used different combinations of independent measurements for training and validation (belonging to the same or different individuals or using different training data size to determine the robustness of the application. We reached an overall accuracy of above 90% perfect identification of all the defined seven categories of behaviour when both training and validation data belonged to the same individual, and over 80% perfect recognition rate using a generalized training data set of multiple subjects. Our results indicate that the present method provides a good model for an easily applicable, fast, automatic behaviour classification system that can be trained with arbitrary motion patterns and

The three-kidney rat

International Nuclear Information System (INIS)

Provoost, A.P.; Van Aken, M.

1984-01-01

In contrast to the numerous research into the adaption of renal function when nephons are lost, much less attention has been paid to the effects of an extra kidney. Through the availability of inbred rat strains, techniques to transplant rat kidneys, and methods to measure total and individual kidney function repeatedly in the same animal, it became possible to study the renal function in rats with three kidneys. Adult male rats of a highly inbred Wistar strain were used. Nine recipients of a third kidney (3-K) were compared with 5 sham operated control (2-K) rats. The total GFR, as measured by the plasma clearance of Cr-5l EDTA, was taken 1,3,6,9, and 15 weeks after operation. The contribution of each kidney to the total renal function was determined by a Tc-99m DTPA scan performed at weeks 10 and 16. After transplantation the total GFR of 3-K rats was, in general, not different from the value before transplantation or from that of 2-K rats. The lack of increase of the GFR of 3-K rats was not the result of a non-functioning graft

Quantitation and renewal of alveolar and bronchiolar cell populations of rat lungs. Changes during some pathological processes

International Nuclear Information System (INIS)

Fritsch, Paul.

1979-02-01

The various cells of alveolar and bronchiolar tissues of rat lungs were studied qualitatively and quantitatively. In physiological conditions, the renewal rate of the cell populations is low and the frequency of the various cell types is constant. This stability, especially at the level of the alveolar tissue, was also found during the latency period and the development of radiation-induced lung cancers. A particular cellular population was demonstrated: marginated leukocyte pool at the level of the pulmonary circulation. This pool was different both qualitatively and quantitatively from the leukocytes of the systemic circulation and, in physiological conditions, behaved as a cellular reservoir of monocytes chiefly re-distributed according to the body needs. In pathological conditions, its fast migration contributed to the defence of the alveolar medium. A quantitative study of the renewal of alveolar macrophages showed that under 1 p. cent of the marginated leukocyte pool is used daily to keep up this population. This fraction undergoes a maturation stage by cellular division within the endoalveolar medium. In some pathological conditions, this division can be completely inhibited [fr

Synchrotron x-ray study of the orientational ordering D2-D1 structural phase transition of freely suspended discotic strands in triphenylene hexa-n-dodecanoate

International Nuclear Information System (INIS)

Safinya, C.R.; Liang, K.S.; Varady, W.A.; Clark, N.A.; Andersson, G.

1984-01-01

We demonstrate the feasibility of x-ray scattering studies of freely suspended strands of discotic liquid crystals (of triphenylene hexa-n-dodecanoate). We are able to grow strands, which are stable for days, of diameter >50 μm with a few single crystal domains. Unexpectedly, we find that the quasi two-dimensional structural phase transition from columnar D2 to columnar D1 corresponds to the orientational ordering of columns of molecules with the molecules tilted at finite angles to the column axis in both phases

The evolution of prestige: freely conferred deference as a mechanism for enhancing the benefits of cultural transmission.

Science.gov (United States)

Henrich, J; Gil-White, F J.

2001-05-01

This paper advances an "information goods" theory that explains prestige processes as an emergent product of psychological adaptations that evolved to improve the quality of information acquired via cultural transmission. Natural selection favored social learners who could evaluate potential models and copy the most successful among them. In order to improve the fidelity and comprehensiveness of such ranked-biased copying, social learners further evolved dispositions to sycophantically ingratiate themselves with their chosen models, so as to gain close proximity to, and prolonged interaction with, these models. Once common, these dispositions created, at the group level, distributions of deference that new entrants may adaptively exploit to decide who to begin copying. This generated a preference for models who seem generally "popular." Building on social exchange theories, we argue that a wider range of phenomena associated with prestige processes can more plausibly be explained by this simple theory than by others, and we test its predictions with data from throughout the social sciences. In addition, we distinguish carefully between dominance (force or force threat) and prestige (freely conferred deference).

Respiratory gas exchange as a new aid to monitor acidosis in endotoxemic rats: relationship to metabolic fuel substrates and thermometabolic responses.

Science.gov (United States)

Steiner, Alexandre A; Flatow, Elizabeth A; Brito, Camila F; Fonseca, Monique T; Komegae, Evilin N

2017-01-01

This study introduces the respiratory exchange ratio (RER; the ratio of whole-body CO 2 production to O 2 consumption) as an aid to monitor metabolic acidosis during the early phase of endotoxic shock in unanesthetized, freely moving rats. Two serotypes of lipopolysaccharide (lipopolysaccharide [LPS] O55:B5 and O127:B8) were tested at shock-inducing doses (0.5-2 mg/kg). Phasic rises in RER were observed consistently across LPS serotypes and doses. The RER rise often exceeded the ceiling of the quotient for oxidative metabolism, and was mirrored by depletion of arterial bicarbonate and decreases in pH It occurred independently of ventilatory adjustments. These data indicate that the rise in RER results from a nonmetabolic CO 2 load produced via an acid-induced equilibrium shift in the bicarbonate buffer. Having validated this new experimental aid, we asked whether acidosis was interconnected with the metabolic and thermal responses that accompany endotoxic shock in unanesthetized rats. Contrary to this hypothesis, however, acidosis persisted regardless of whether the ambient temperature favored or prevented downregulation of mitochondrial oxidation and regulated hypothermia. We then asked whether the substrate that fuels aerobic metabolism could be a relevant factor in LPS-induced acidosis. Food deprivation was employed to divert metabolism away from glucose oxidation and toward fatty acid oxidation. Interestingly, this intervention attenuated the RER response to LPS by 58%, without suppressing other key aspects of systemic inflammation. We conclude that acid production in unanesthetized rats with endotoxic shock results from a phasic activation of glycolysis, which occurs independently of physiological changes in mitochondrial oxidation and body temperature. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Depression and poor sleep

DEFF Research Database (Denmark)

Sánchez, Connie; Brennum, Lise T; Stórustovu, Signe í

2007-01-01

The effects of five antidepressants (escitalopram, paroxetine, duloxetine, venlafaxine, and reboxetine) on the sleep architecture were investigated in freely moving rats in the light phase of a 12:12 h light:dark cycle following a single i.p. dose of antidepressant. Overall, paroxetine and escita...

Gonadal hormones and heart rate as an emotional response

NARCIS (Netherlands)

de Loos, Wolter Statius

1988-01-01

Animai experiments may give information on the physiology of hormones under stress conditions. The model for the investigation of acute emotional stress in animals that has been chosen permits the study of heart rate in freely moving laboratory rats as a sensitive psychophysiological parameter, This

Nitric oxide synthase, calcitonin gene-related peptide and NK-1 receptor mechanisms are involved in GTN-induced neuronal activation

DEFF Research Database (Denmark)

Ramachandran, Roshni; Bhatt, Deepak Kumar; Ploug, Kenneth Beri

2014-01-01

BACKGROUND AND AIM: Infusion of glyceryltrinitrate (GTN), a nitric oxide (NO) donor, in awake, freely moving rats closely mimics a universally accepted human model of migraine and responds to sumatriptan treatment. Here we analyse the effect of nitric oxide synthase (NOS) and calcitonin gene-rela...

Increased Protein Kinase A Activity in the Prkar1a-defective Mouse is Associated with Hyperarousal and Increased Anxiety

Science.gov (United States)

2011-03-09

Armario A, and Castellanos JM. A comparison of corticoadrenal and gonadal responses to acute immobilization stress in rats and mice. Physiol Behav 32: 517...519, 1984. 9. Armario A, and Castellanos JM. Effect of acute and chronic stress on testosterone secretion in male rats. J Endocrinol Invest 7: 659...661, 1984. 10. Armario A, Castellanos JM, and Balasch J. Effects of chronic noise or daily water restriction on the pituitary-adrenal axis in male

Role of glutamate receptors and nitric oxide on the effects of glufosinate ammonium, an organophosphate pesticide, on in vivo dopamine release in rat striatum.

Science.gov (United States)

Faro, Lilian R F; Ferreira Nunes, Brenda V; Alfonso, Miguel; Ferreira, Vania M; Durán, Rafael

2013-09-15

The purpose of the present work was to assess the possible role of glutamatergic receptors and nitric oxide (NO) production on effects of glufosinate ammonium (GLA), an organophosphate pesticide structurally related to glutamate, on in vivo striatal dopamine release in awake and freely moving rats. For this, we used antagonists of NMDA (MK-801 and AP5) or AMPA/kainate (CNQX) receptors, or nitric oxide synthase (NOS) inhibitors (l-NAME and 7-NI), to study the effects of GLA on release of dopamine from rat striatum. So, intrastriatal infusion of 10mM GLA significantly increased dopamine levels (1035±140%, compared with basal levels) and administration of GLA to MK-801 (250μM) or AP5 (650μM) pretreated animals, produced increases in dopamine overflow that were ∼40% and ∼90% smaller than those observed in animals not pretreated with MK-801 or AP5. Administration of GLA to CNQX (500μM) pretreated animals produced an effect that was not significantly different from the one produced in animals not pretreated with CNQX. On the other hand, administration of GLA to l-NAME (100μM) or 7-NI (100μM) pretreated animals, produced increases in dopamine overflow that were ∼80% and ∼75% smaller than those observed in animals not pretreated with these inhibitors. In summary, GLA appears to act, at least in part, through an overstimulation of NMDA (and not AMPA/kainate) receptors with possible NO production to induce in vivo dopamine release. Administration of NMDA receptor antagonists and NOS inhibitors partially blocks the release of dopamine from rat striatum. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The equation x^py^q = z^r and groups that act freely on Λ-trees

OpenAIRE

Brady, N.; Ciobanu, Laura; Martino, A.; Rourke, S. O

2009-01-01

Let G be a group that acts freely on a Λ-tree, where Λ is an ordered abelian group, and let x,y,z be elements in G. We show that if xpyq = zr with integers p, q, r ≥ 4, then x, y and z commute. As a result, the one-relator groups with xpyq = zr as relator, are examples of hyperbolic and CAT( − 1) groups which do not act freely on any Λ-tree.

Adjunctive Treatment with Asenapine Augments the Escitalopram-Induced Effects on Monoaminergic Outflow and Glutamatergic Neurotransmission in the Medial Prefrontal Cortex of the Rat

Science.gov (United States)

Björkholm, Carl; Frånberg, Olivia; Malmerfelt, Anna; Marcus, Monica M.; Konradsson-Geuken, Åsa; Schilström, Björn; Jardemark, Kent

2015-01-01

Background: Substantial clinical data support the addition of low doses of atypical antipsychotic drugs to selective serotonin reuptake inhibitors (SSRIs) to rapidly enhance the antidepressant effect in treatment-resistant depression. Preclinical studies suggest that this effect is at least partly explained by an increased catecholamine outflow in the medial prefrontal cortex (mPFC). Methods: In the present study we used in vivo microdialysis in freely moving rats and in vitro intracellular recordings of pyramidal cells of the rat mPFC to investigate the effects of adding the novel atypical antipsychotic drug asenapine to the SSRI escitalopram with regards to monoamine outflow in the mPFC and dopamine outflow in nucleus accumbens as well as glutamatergic transmission in the mPFC. Results: The present study shows that addition of low doses (0.05 and 0.1 mg/kg) of asenapine to escitalopram (5 mg/kg) markedly enhances dopamine, noradrenaline, and serotonin release in the rat mPFC as well as dopamine release in the nucleus accumbens. Moreover, this drug combination facilitated both N-methyl-d-Aspartate (NMDA)– and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)–induced currents as well as electrically evoked excitatory postsynaptic potentials in pyramidal cells of the rat mPFC. Conclusions: Our results support the notion that the augmentation of SSRIs by atypical antipsychotic drugs in treatment-resistant depression may, at least in part, be related to enhanced catecholamine output in the prefrontal cortex and that asenapine may be clinically used to achieve this end. In particular, the subsequent activation of the D1 receptor may be of importance for the augmented antidepressant effect, as this mechanism facilitated both NMDA and AMPA receptor-mediated transmission in the mPFC. Our novel observation that the drug combination, like ketamine, facilitates glutamatergic transmission in the mPFC may contribute to explain the rapid and potent antidepressant

Micro sized implantable ball lens-based fiber optic probe design

Science.gov (United States)

Cha, Jaepyeong; Kang, Jin U.

2014-02-01

A micro sized implantable ball lens-based fiber optic probe design is described for continuous monitoring of brain activity in freely behaving mice. A prototype uses a 500-micron ball lens and a highly flexible 350-micron-diameter fiber bundle, which are enclosed by a 21G stainless steel sheath. Several types and thickness of brain tissue, consisting of fluorescent probes such as GFP, GCaMP3 calcium indicator, are used to evaluate the performance of the imaging probe. Measured working distance is approximately 400-μm, but is long enough to detect neural activities from cortical and cerebellar tissues of mice brain.

5-7 Year Old Children's Conceptions of Behaving Artifacts and the Influence of Constructing Their Behavior on the Development of Theory of Mind (ToM) and Theory of Artificial Mind (ToAM)

Science.gov (United States)

Spektor-Precel, Karen; Mioduser, David

2015-01-01

Nowadays, we are surrounded by artifacts that are capable of adaptive behavior, such as electric pots, boiler timers, automatic doors, and robots. The literature concerning human beings' conceptions of "traditional" artifacts is vast, however, little is known about our conceptions of behaving artifacts, nor of the influence of the…

Examining the use of evidence-based and social media supported tools in freely accessible physical activity intervention websites.

Science.gov (United States)

Vandelanotte, Corneel; Kirwan, Morwenna; Rebar, Amanda; Alley, Stephanie; Short, Camille; Fallon, Luke; Buzza, Gavin; Schoeppe, Stephanie; Maher, Carol; Duncan, Mitch J

2014-08-17

It has been shown that physical activity is more likely to increase if web-based interventions apply evidence-based components (e.g. self-monitoring) and incorporate interactive social media applications (e.g. social networking), but it is unclear to what extent these are being utilized in the publicly available web-based physical activity interventions. The purpose of this study was to evaluate whether freely accessible websites delivering physical activity interventions use evidence-based behavior change techniques and provide social media applications. In 2013, a systematic search strategy examined 750 websites. Data was extracted on a wide range of variables (e.g. self-monitoring, goal setting, and social media applications). To evaluate website quality a new tool, comprising three sub-scores (Behavioral Components, Interactivity and User Generated Content), was developed to assess implementation of behavior change techniques and social media applications. An overall website quality scored was obtained by summing the three sub-scores. Forty-six publicly available websites were included in the study. The use of self-monitoring (54.3%), goal setting (41.3%) and provision of feedback (46%) was relatively low given the amount of evidence supporting these features. Whereas the presence of features allowing users to generate content (73.9%), and social media components (Facebook (65.2%), Twitter (47.8%), YouTube (48.7%), smartphone applications (34.8%)) was relatively high considering their innovative and untested nature. Nearly all websites applied some behavioral and social media applications. The average Behavioral Components score was 3.45 (±2.53) out of 10. The average Interactivity score was 3.57 (±2.16) out of 10. The average User Generated Content Score was 4.02 (±2.77) out of 10. The average overall website quality score was 11.04 (±6.92) out of 30. Four websites (8.7%) were classified as high quality, 12 websites (26.1%) were classified as moderate

The petit rat (pet/pet), a new semilethal mutant dwarf rat with thymic and testicular anomalies.

Science.gov (United States)

Chiba, Junko; Suzuki, Katsushi; Suzuki, Hiroetsu

2008-12-01

The petit rat (pet/pet) is a recently discovered semilethal mutant dwarf. The neonatal pet/pet rats had a low body weight and small thymus and testis. During the first 3 d after birth, 50% of the male and 80% of the female pet/pet pups were lost or found dead. Surviving pet/pet rats showed marked retardation of postnatal growth, and their body weights were 41% (female rats) and 32% (male rats) of those of normal rats at the adult stage. The pet/pet rats exhibited proportional dwarfism, and their longitudinal bones were shorter than those of controls without skeletal malformations. Most organs of male pet/pet rats, especially the thymus, testis, adipose tissue surrounding the kidney, and accessory sex organs, weighed markedly less at 140 d of age than did those of their normal counterparts. The thymus of pet/pet rats was small with abnormal thymic follicles. Testes from pet/pet rats exhibited 2 patterns of abnormal histology. Spermatogenesis was present in testes that were only slightly anomalous, but the seminiferous tubules were reduced in diameter. In severely affected testes, most of the seminiferous tubules showed degeneration, and interstitial tissue was increased. Plasma growth hormone concentrations did not differ between pet/pet and normal male rats. The dwarf phenotype of pet/pet rats was inherited as an autosomal recessive trait. These results indicate that the pet/pet rat has a semilethal growth-hormone-independent dwarf phenotype that is accompanied by thymic and testicular anomalies and low birth weight.

Role for the Ventral Posterior Medial/Posterior Lateral Thalamus and Anterior Cingulate Cortex in Affective/Motivation Pain Induced by Varicella Zoster Virus

Directory of Open Access Journals (Sweden)

Phillip R. Kramer

2017-10-01

Full Text Available Varicella zoster virus (VZV infects the face and can result in chronic, debilitating pain. The mechanism for this pain is unknown and current treatment is often not effective, thus investigations into the pain pathway become vital. Pain itself is multidimensional, consisting of sensory and affective experiences. One of the primary brain substrates for transmitting sensory signals in the face is the ventral posterior medial/posterior lateral thalamus (VPM/VPL. In addition, the anterior cingulate cortex (ACC has been shown to be vital in the affective experience of pain, so investigating both of these areas in freely behaving animals was completed to address the role of the brain in VZV-induced pain. Our lab has developed a place escape avoidance paradigm (PEAP to measure VZV-induced affective pain in the orofacial region of the rat. Using this assay as a measure of the affective pain experience a significant response was observed after VZV injection into the whisker pad and after VZV infusion into the trigeminal ganglion. Local field potentials (LFPs are the summed electrical current from a group of neurons. LFP in both the VPM/VPL and ACC was attenuated in VZV injected rats after inhibition of neuronal activity. This inhibition of VPM/VPL neurons was accomplished using a designer receptor exclusively activated by a designer drug (DREADD. Immunostaining showed that cells within the VPM/VPL expressed thalamic glutamatergic vesicle transporter-2, NeuN and DREADD suggesting inhibition occurred primarily in excitable neurons. From these results we conclude: (1 that VZV associated pain does not involve a mechanism exclusive to the peripheral nerve terminals, and (2 can be controlled, in part, by excitatory neurons within the VPM/VPL that potentially modulate the affective experience by altering activity in the ACC.

Immunology taught by rats

OpenAIRE

Klenerman, P; Barnes, EJ

2017-01-01

Immunology may be best taught by viruses, and possibly by humans, but the rats of New York City surprisingly also have plenty to offer. A survey published in 2014 of the pathogens carried by rats trapped in houses and parks in Manhattan identified a huge burden of infectious agents in these animals, including several novel viruses. Among these are Norway rat hepaciviruses (NrHVs), which belong to the same family as hepatitis C virus (HCV). NrHVs were found in rat livers, raising the possibili...

August rats are more resistant to arrhythmogenic effect of myocardial ischemia and reperfusion than Wistar rats.

Science.gov (United States)

Belkina, L M; Kirillina, T N; Pshennikova, M G; Arkhipenko, Yu V

2002-06-01

As differentiated from Wistar rats, myocardial ischemia and reperfusion produce no ventricular fibrillation in August rats. Pretreatment with nitric oxide synthase inhibitor Nw-nitro-L-arginine increased mortality rate in August rats with acute myocardial infarction from 20 to 40%. Under these conditions mortality rate in Wistar rats increased from 50 to 71%. Interstrain differences in the resistance of these animals to the arrhythmogenic effect of ischemia are probably associated with higher activity of the nitric oxide system in August rats compared to Wistar rats.

Kinetics of different 123-I and 14-C fatty acids in normal and diabetic rat myocardium in vivo

International Nuclear Information System (INIS)

Beckurts, T.E.; Shreeve, W.W.; Machulla, H.-J.; Feinendegen, L.E.

1984-01-01

For measuring myocardial metabolism by single photon scintigraphy various iodinated substrate analogues have been proposed. The present study compares in normal and diabetic rats the metabolic pathways of 14-C-palmitic acid (PA), 123-I-para-phenylpentadecanoic acid (I-pPPDA), 123-I-ortho-phenylpentadecanoic acid (I-oPPDA), 14-C-stearic acid (SA) and 123-I-w-heptadecanoic acid (I-ωHDA). In normal and diabetic rats free fatty acids showed a rapid tracer accumulation and an initial rapid, then a slow rate component of release. PA and I-pPPDA were preferentially esterified into triglycerides, whereas SA and I-ωHDA equally distributed between triglycerides and phospholipids. I-oPPDA nearly exclusively labelled the free fatty acid pool. - Turnover of SA and I-ωHDA was similar in triglycerides and phospholipids; yet PA and I-pPPDA continued to increase in triglycerides for 3-5 minutes after injection but decreased in phospholipids. - Following induction of diabetes by Streptocotocin, the primary effect was an inhibition of incorporation of all substrates tested into triglycerides and phospholipids with an initial rapid turnover in the total lipid fraction. - Of the total myocardial activities a considerable fraction was water soluble and another bound to solid tissue residue, with an early maximum and subsequent decline; the values for 14-C-labelled substrates remained below those of radioiodine. Thus different labelled fatty acids behave metabolically differently and promise to be useful for differentiating various intracellular metabolic pathways. External analysis of myocardial fatty acids metabolism requires correction for labelled catabolites. (Author)

Excitation of lateral habenula neurons as a neural mechanism underlying ethanol-induced conditioned taste aversion.

Science.gov (United States)

Tandon, Shashank; Keefe, Kristen A; Taha, Sharif A

2017-02-15

The lateral habenula (LHb) has been implicated in regulation of drug-seeking behaviours through aversion-mediated learning. In this study, we recorded neuronal activity in the LHb of rats during an operant task before and after ethanol-induced conditioned taste aversion (CTA) to saccharin. Ethanol-induced CTA caused significantly higher baseline firing rates in LHb neurons, as well as elevated firing rates in response to cue presentation, lever press and saccharin taste. In a separate cohort of rats, we found that bilateral LHb lesions blocked ethanol-induced CTA. Our results strongly suggest that excitation of LHb neurons is required for ethanol-induced CTA, and point towards a mechanism through which LHb firing may regulate voluntary ethanol consumption. Ethanol, like other drugs of abuse, has both rewarding and aversive properties. Previous work suggests that sensitivity to ethanol's aversive effects negatively modulates voluntary alcohol intake and thus may be important in vulnerability to developing alcohol use disorders. We previously found that rats with lesions of the lateral habenula (LHb), which is implicated in aversion-mediated learning, show accelerated escalation of voluntary ethanol consumption. To understand neural encoding in the LHb contributing to ethanol-induced aversion, we recorded neural firing in the LHb of freely behaving, water-deprived rats before and after an ethanol-induced (1.5 g kg -1 20% ethanol, i.p.) conditioned taste aversion (CTA) to saccharin taste. Ethanol-induced CTA strongly decreased motivation for saccharin in an operant task to obtain the tastant. Comparison of LHb neural firing before and after CTA induction revealed four main differences in firing properties. First, baseline firing after CTA induction was significantly higher. Second, firing evoked by cues signalling saccharin availability shifted from a pattern of primarily inhibition before CTA to primarily excitation after CTA induction. Third, CTA induction reduced

Excitation of lateral habenula neurons as a neural mechanism underlying ethanol‐induced conditioned taste aversion

Science.gov (United States)

Keefe, Kristen A.; Taha, Sharif A.

2016-01-01

Key points The lateral habenula (LHb) has been implicated in regulation of drug‐seeking behaviours through aversion‐mediated learning.In this study, we recorded neuronal activity in the LHb of rats during an operant task before and after ethanol‐induced conditioned taste aversion (CTA) to saccharin.Ethanol‐induced CTA caused significantly higher baseline firing rates in LHb neurons, as well as elevated firing rates in response to cue presentation, lever press and saccharin taste.In a separate cohort of rats, we found that bilateral LHb lesions blocked ethanol‐induced CTA.Our results strongly suggest that excitation of LHb neurons is required for ethanol‐induced CTA, and point towards a mechanism through which LHb firing may regulate voluntary ethanol consumption. Abstract Ethanol, like other drugs of abuse, has both rewarding and aversive properties. Previous work suggests that sensitivity to ethanol's aversive effects negatively modulates voluntary alcohol intake and thus may be important in vulnerability to developing alcohol use disorders. We previously found that rats with lesions of the lateral habenula (LHb), which is implicated in aversion‐mediated learning, show accelerated escalation of voluntary ethanol consumption. To understand neural encoding in the LHb contributing to ethanol‐induced aversion, we recorded neural firing in the LHb of freely behaving, water‐deprived rats before and after an ethanol‐induced (1.5 g kg−1 20% ethanol, i.p.) conditioned taste aversion (CTA) to saccharin taste. Ethanol‐induced CTA strongly decreased motivation for saccharin in an operant task to obtain the tastant. Comparison of LHb neural firing before and after CTA induction revealed four main differences in firing properties. First, baseline firing after CTA induction was significantly higher. Second, firing evoked by cues signalling saccharin availability shifted from a pattern of primarily inhibition before CTA to primarily excitation after CTA

Environmental tobacco smoke is just as damaging to DNA as mainstream smoke.

OpenAIRE

Bermúdez, E; Stone, K; Carter, K M; Pryor, W A

1994-01-01

This study demonstrates the ability of tar isolated from environmental tobacco smoke (ETS) to nick DNA in mammalian cells. Solutions of ETS tar behave similarly to aqueous solutions of cigarette tar from mainstream smoke. Both solutions contain the tar semiquinone radical, and this radical associates with the DNA in viable rat alveolar macrophages. Solutions of tar from ETS cause single-strand DNA breaks in rat thymocytes in proportion to the amount of tar present, until a plateau is reached....

Dopamine and noradrenaline efflux in the prefrontal cortex in the light and dark period: Effects of novelty and handling and comparison to the nucleus accumbens

NARCIS (Netherlands)

Feenstra, M. G.; Botterblom, M. H.; Mastenbroek, S.

2000-01-01

We used on-line microdialysis measurements of dopamine and noradrenaline extracellular concentrations in the medial prefrontal cortex of awake, freely moving rats during the dark and the light period of the day to study whether (i) basal efflux would be higher in the active, dark period than in the

The effect of a discrete signal on context conditioning: Assessment by preference and freezing tests

NARCIS (Netherlands)

Maes, J.H.R.; LoLordo, V.M.

1996-01-01

Four experiments with rats assessed conditioning to contextual cues after the delivery of footshocks that were either signaled by a discrete stimulus or unsignaled. Two different tests were used. The first was a context preference test in which subjects were allowed to move freely in a brightly lit,

Individually reared rats

International Nuclear Information System (INIS)

Kraeuchi, K.; Gentsch, C.; Feer, H.

1981-01-01

The influence of social isolation in rats on postsynaptic alpha 1 - and beta-adrenergic receptors, on the cAMP generating system and on the presynaptic uptake mechanism in the central noradrenergic system was examined in different brain regions. Rearing rats in isolation from the 19th day of life for 12 weeks leads in all regions to a general tendency for a reduction in 3 H-DHA binding, to an enhanced 3 H-WB4101 binding and to a decreased responsiveness of the noradrenaline sensitive cAMP generating system. These changes reach significance only in the pons-medulla-thallamusregion. Isolated rats showed an increased synaptosomal uptake of noradrenaline, most pronounced and significant in the hypothalamus. Our data provide further support for a disturbance in central noradrenergic function in isolated rats. (author)

Renal function in streptozotocin-diabetic rats

DEFF Research Database (Denmark)

Jensen, P K; Christiansen, J S; Steven, K

1981-01-01

to the rise in kidney glomerular filtration rate (diabetic rats: 37.0 nl/min; control rats: 27.9 nl/min). Likewise renal plasma flow was significantly higher in the diabetic rats (4.1 ml/min) than in the control group (3.0 ml/min). Glomerular capillary pressure was identical in both groups (56.0 and 56.0 mm......-1mmHg-1). Kidney weight was significantly higher in the diabetic rats (1.15 g; control rats: 0.96 g) while body weight was similar in both groups (diabetic rats: 232 g; control rats: 238 g). Calculations indicate that the increases in transglomerular hydraulic pressure, renal plasma flow......Renal function was examined with micropuncture methods in the insulin-treated streptozotocin-diabetic rat. Kidney glomerular filtration rate was significantly higher in the diabetic rats (1.21 ml/min) than in the control group (0.84 ml/min) Nephron glomerular filtration rate increased in proportion...

Social class, power, and selfishness: when and why upper and lower class individuals behave unethically.

Science.gov (United States)

Dubois, David; Rucker, Derek D; Galinsky, Adam D

2015-03-01

Are the rich more unethical than the poor? To answer this question, the current research introduces a key conceptual distinction between selfish and unethical behavior. Based on this distinction, the current article offers 2 novel findings that illuminate the relationship between social class and unethical behavior. First, the effects of social class on unethical behavior are not invariant; rather, the effects of social class are moderated by whether unethical behavior benefits the self or others. Replicating past work, social class positively predicted unethical behavior; however, this relationship was only observed when that behavior was self-beneficial. When unethical behavior was performed to benefit others, social class negatively predicted unethical behavior; lower class individuals were more likely than upper class individuals to engage in unethical behavior. Overall, social class predicts people's tendency to behave selfishly, rather than predicting unethical behavior per se. Second, individuals' sense of power drove the effects of social class on unethical behavior. Evidence for this relationship was provided in three forms. First, income, but not education level, predicted unethical behavior. Second, feelings of power mediated the effect of social class on unethical behavior, but feelings of status did not. Third, two distinct manipulations of power produced the same moderation by self-versus-other beneficiary as was found with social class. The current theoretical framework and data both synthesize and help to explain a range of findings in the social class and power literatures. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Rats do not eat alone in public: Food-deprived rats socialize rather than competing for baits.

Directory of Open Access Journals (Sweden)

Omri Weiss

Full Text Available Limited resources result in competition among social animals. Nevertheless, social animals also have innate preferences for cooperative behavior. In the present study, 12 dyads of food-deprived rats were tested in four successive trials, and then re-tested as eight triads of food-deprived rats that were unfamiliar to each other. We found that the food-deprived dyads or triads of rats did not compete for the food available to them at regular spatially-marked locations that they had previously learnt. Rather, these rats traveled together to collect the baits. One rat, or two rats in some triads, lead (ran ahead to collect most of the baits, but "leaders" differed across trials so that, on average, each rat ultimately collected similar amounts of baits. Regardless of which rat collected the baits, the rats traveled together with no substantial difference among them in terms of their total activity. We suggest that rats, which are a social species that has been found to display reciprocity, have evolved to travel and forage together and to share limited resources. Consequently, they displayed a sort of 'peace economy' that on average resulted in equal access to the baits across trials. For social animals, this type of dynamics is more relaxed, tolerant, and effective in the management of conflicts. Rather than competing for the limited available food, the food-deprived rats socialized and coexisted peacefully.

Determination of rat vertebral bone compressive fatigue properties in untreated intact rats and zoledronic-acid-treated, ovariectomized rats

NARCIS (Netherlands)

Brouwers, J.E.M.; Ruchselman, M.; Rietbergen, van B.; Bouxsein, M.L.

2009-01-01

Summary Compressive fatigue properties of whole vertebrae, which may be clinically relevant for osteoporotic vertebral fractures, were determined in untreated, intact rats and zoledronic-acid-treated, ovariectomized rats. Typical fatigue behavior was found and was similar to that seen in other

When and Where Learning is Taking Place: Multisynaptic Changes in Strength During Different Behaviors Related to the Acquisition of an Operant Conditioning Task by Behaving Rats.

Science.gov (United States)

Fernández-Lamo, Iván; Delgado-García, José M; Gruart, Agnès

2018-03-01

Although it is generally assumed that brain circuits are modified by new experiences, the question of which changes in synaptic efficacy take place in cortical and subcortical circuits across the learning process remains unanswered. Rats were trained in the acquisition of an operant conditioning in a Skinner box provided with light beams to detect animals' approaches to lever and feeder. Behaviors such as pressing the lever, eating, exploring, and grooming were also recorded. Animals were chronically implanted with stimulating and recording electrodes in hippocampal, prefrontal, and subcortical sites relevant to the task. Field synaptic potentials were evoked during the performance of the above-mentioned behaviors and before, during, and after the acquisition process. Afferent pathways to the hippocampus and the intrinsic hippocampal circuit were slightly modified in synaptic strength during the performance of those behaviors. In contrast, afferent and efferent circuits of the medial prefrontal cortex were significantly modified in synaptic strength across training sessions, mostly at the moment of the largest change in the learning curve. Performance of behaviors nondirectly related to the acquisition process (exploring, grooming) also evoked changes in synaptic strength across training. This study helps to understand when and where learning is being engraved in the brain. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Back to front: cerebellar connections and interactions with the prefrontal cortex

Directory of Open Access Journals (Sweden)

Thomas C Watson

2014-02-01

Full Text Available Although recent neuroanatomical evidence has demonstrated closed-loop connectivity between prefrontal cortex and the cerebellum, the physiology of cerebello-cerebral circuits and the extent to which cerebellar output modulates neuronal activity in neocortex during behavior remain relatively unexplored. We show that electrical stimulation of the contralateral cerebellar fastigial nucleus (FN in awake, behaving rats evokes distinct local field potential (LFP responses (onset latency ~13 ms in the prelimbic (PrL subdivision of the medial prefrontal cortex. Trains of FN stimulation evoke heterogeneous patterns of response in putative pyramidal cells in frontal and prefrontal regions in both urethane-anaesthetized and awake, behaving rats. However, the majority of cells showed decreased firing rates during stimulation and subsequent rebound increases; more than 90% of cells showed significant changes in response. Simultaneous recording of on-going LFP activity from FN and PrL while rats were at rest or actively exploring an open field arena revealed significant network coherence restricted to the theta frequency range (5-10 Hz. Granger causality analysis indicated that this coherence was significantly directed from cerebellum to PrL during active locomotion. Our results demonstrate the presence of a cerebello-prefrontal pathway in rat and reveal behaviorally dependent coordinated network activity between the two structures, which could facilitate transfer of sensorimotor information into ongoing neocortical processing during goal directed behaviors.

N-methyl-D-aspartate receptor independent changes in expression of polysialic acid-neural cell adhesion molecule despite blockade of homosynaptic long-term potentiation and heterosynaptic long-term depression in the awake freely behaving rat dentate gyrus

Czech Academy of Sciences Publication Activity Database

Rodríguez Arellano, Jose Julio; Dallerac, G. M.; Tabuchi, M.; Davies, H.A.; Colyer, F. M.; Stewart, M.G.; Doyere, V.

2008-01-01

Roč. 4, 03 (2008), s. 169-178 ISSN 1740-925X Institutional research plan: CEZ:AV0Z50390703 Keywords : Adhesion molecules * hippocampus * synaptic plasticity Subject RIV: FH - Neurology Impact factor: 0.937, year: 2008

Effects of Constant Flow vs. Constant Pressure Perfusion on Fluid Filtration in Severe Hypothermic Isolated Blood-Perfused Rat Lungs.

Science.gov (United States)

Halsøy, Kathrine; Kondratiev, Timofey; Tveita, Torkjel; Bjertnaes, Lars J

2016-01-01

Victims of severe accidental hypothermia are prone to fluid extravasation but rarely develop lung edema. We hypothesize that combined hypothermia-induced increase in pulmonary vascular resistance (PVR) and a concomitant fall in cardiac output protect the lungs against edema development. Our aim was to explore in hypothermic-isolated blood-perfused rat lungs whether perfusion at constant pressure influences fluid filtration differently from perfusion at constant flow. Isolated blood-perfused rat lungs were hanging freely in a weight transducer for measuring weight changes (ΔW). Fluid filtration coefficient (Kfc), was determined by transiently elevating left atrial pressure (Pla) by 5.8 mmHg two times each during normothermia (37°C) and during hypothermia (15°C). The lung preparations were randomized to two groups. One group was perfused with constant flow (Constant flow group) and the other group with constant pulmonary artery pressure (Constant PPA group). Microvascular pressure (Pmv) was determined before and during elevation of Pla (ΔPmv) by means of the double occlusion technique. Kfc was calculated with the formula Kfc = ΔW/ΔPmv/min. All Kfc values were normalized to predicted lung weight (P LW ), which was based on body weight (BW) according to the formula: P LW  = 0.0053 BW - 0.48 and presented as Kfc PLW in mg/min/mmHg/g. At cessation, bronchoalveolar lavage (BAL) fluid/perfusate protein concentration (B/P) ratio was determined photometrically. Data were analyzed with parametric or non-parametric tests as appropriate. p  Kfc PLW and B/P ratio increased significantly by more than 10-fold during hypothermia concerted by visible signs of edema in the trachea. Hemoglobin and hematocrit increased within the Constant flow group and between the groups at cessation of the experiments. In hypothermic rat lungs perfused at constant flow, fluid filtration coefficient per gram P LW and B/P ratio increased more than 10-fold concerted by increased

Development of a population pharmacokinetic model to predict brain distribution and dopamine D2 receptor occupancy of raclopride in non-anesthetized rat.

Science.gov (United States)

Wong, Yin Cheong; Ilkova, Trayana; van Wijk, Rob C; Hartman, Robin; de Lange, Elizabeth C M

2018-01-01

Raclopride is a selective antagonist of the dopamine D2 receptor. It is one of the most frequently used in vivo D2 tracers (at low doses) for assessing drug-induced receptor occupancy (RO) in animals and humans. It is also commonly used as a pharmacological blocker (at high doses) to occupy the available D2 receptors and antagonize the action of dopamine or drugs on D2 in preclinical studies. The aims of this study were to comprehensively evaluate its pharmacokinetic (PK) profiles in different brain compartments and to establish a PK-RO model that could predict the brain distribution and RO of raclopride in the freely moving rat using a LC-MS based approach. Rats (n=24) received a 10-min IV infusion of non-radiolabeled raclopride (1.61μmol/kg, i.e. 0.56mg/kg). Plasma and the brain tissues of striatum (with high density of D2 receptors) and cerebellum (with negligible amount of D2 receptors) were collected. Additional microdialysis experiments were performed in some rats (n=7) to measure the free drug concentration in the extracellular fluid of the striatum and cerebellum. Raclopride concentrations in all samples were analyzed by LC-MS. A population PK-RO model was constructed in NONMEM to describe the concentration-time profiles in the unbound plasma, brain extracellular fluid and brain tissue compartments and to estimate the RO based on raclopride-D2 receptor binding kinetics. In plasma raclopride showed a rapid distribution phase followed by a slower elimination phase. The striatum tissue concentrations were consistently higher than that of cerebellum tissue throughout the whole experimental period (10-h) due to higher non-specific tissue binding and D2 receptor binding in the striatum. Model-based simulations accurately predicted the literature data on rat plasma PK, brain tissue PK and D2 RO at different time points after intravenous or subcutaneous administration of raclopride at tracer dose (RO 30%). For the first time a predictive model that could describe

In vivo recording of aerodynamic force with an aerodynamic force platform: from drones to birds.

Science.gov (United States)

Lentink, David; Haselsteiner, Andreas F; Ingersoll, Rivers

2015-03-06

Flapping wings enable flying animals and biomimetic robots to generate elevated aerodynamic forces. Measurements that demonstrate this capability are based on experiments with tethered robots and animals, and indirect force calculations based on measured kinematics or airflow during free flight. Remarkably, there exists no method to measure these forces directly during free flight. Such in vivo recordings in freely behaving animals are essential to better understand the precise aerodynamic function of their flapping wings, in particular during the downstroke versus upstroke. Here, we demonstrate a new aerodynamic force platform (AFP) for non-intrusive aerodynamic force measurement in freely flying animals and robots. The platform encloses the animal or object that generates fluid force with a physical control surface, which mechanically integrates the net aerodynamic force that is transferred to the earth. Using a straightforward analytical solution of the Navier-Stokes equation, we verified that the method is accurate. We subsequently validated the method with a quadcopter that is suspended in the AFP and generates unsteady thrust profiles. These independent measurements confirm that the AFP is indeed accurate. We demonstrate the effectiveness of the AFP by studying aerodynamic weight support of a freely flying bird in vivo. These measurements confirm earlier findings based on kinematics and flow measurements, which suggest that the avian downstroke, not the upstroke, is primarily responsible for body weight support during take-off and landing.

Bioluminescent system for dynamic imaging of cell and animal behavior

Energy Technology Data Exchange (ETDEWEB)

Hara-Miyauchi, Chikako [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Tsuji, Osahiko [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Hanyu, Aki [Division of Biochemistry, The Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo 135-8550 (Japan); Okada, Seiji [Department of Advanced Medical Initiatives, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582 (Japan); Yasuda, Akimasa [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Fukano, Takashi [Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Akazawa, Chihiro [Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Nakamura, Masaya [Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Imamura, Takeshi [Department of Molecular Medicine for Pathogenesis, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295 (Japan); Core Research for Evolutional Science and Technology, The Japan Science and Technology Corporation, Tokyo 135-8550 (Japan); Matsuzaki, Yumi [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Okano, Hirotaka James, E-mail: hjokano@jikei.ac.jp [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Division of Regenerative Medicine Jikei University School of Medicine, Tokyo 150-8461 (Japan); and others

2012-03-09

Highlights: Black-Right-Pointing-Pointer We combined a yellow variant of GFP and firefly luciferase to make ffLuc-cp156. Black-Right-Pointing-Pointer ffLuc-cp156 showed improved photon yield in cultured cells and transgenic mice. Black-Right-Pointing-Pointer ffLuc-cp156 enabled video-rate bioluminescence imaging of freely-moving animals. Black-Right-Pointing-Pointer ffLuc-cp156 mice enabled tracking real-time drug delivery in conscious animals. -- Abstract: The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies.

Bioluminescent system for dynamic imaging of cell and animal behavior

International Nuclear Information System (INIS)

Hara-Miyauchi, Chikako; Tsuji, Osahiko; Hanyu, Aki; Okada, Seiji; Yasuda, Akimasa; Fukano, Takashi; Akazawa, Chihiro; Nakamura, Masaya; Imamura, Takeshi; Matsuzaki, Yumi; Okano, Hirotaka James

2012-01-01

Highlights: ► We combined a yellow variant of GFP and firefly luciferase to make ffLuc-cp156. ► ffLuc-cp156 showed improved photon yield in cultured cells and transgenic mice. ► ffLuc-cp156 enabled video-rate bioluminescence imaging of freely-moving animals. ► ffLuc-cp156 mice enabled tracking real-time drug delivery in conscious animals. -- Abstract: The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies.

Effect of a Hypocretin/Orexin Antagonist on Neurocognitive Performance

Science.gov (United States)

2015-11-01

release in freely-moving rat. Location: Hall A-C Presentation time: Tuesday , Nov 15, 2011, 1:00 PM - 2:00 PM Authors: *J. VAZQUEZ, A. NGUYEN, T. KILDUFF...induces sleep in rats but does not impair spatial reference memory performance during wake Location: Hall A-C Presentation time: Tuesday , Nov 15, 2011, 2...of a platform in a spatial reference memory task ( Morris Water Maze). Next day, they were dosed with either ALM (100 mg/kg i.p.), ZOL (30 mg/kg i.p

Daily Reservoir Runoff Forecasting Method Using Artificial Neural Network Based on Quantum-behaved Particle Swarm Optimization

Directory of Open Access Journals (Sweden)

Chun-tian Cheng

2015-07-01

Full Text Available Accurate daily runoff forecasting is of great significance for the operation control of hydropower station and power grid. Conventional methods including rainfall-runoff models and statistical techniques usually rely on a number of assumptions, leading to some deviation from the exact results. Artificial neural network (ANN has the advantages of high fault-tolerance, strong nonlinear mapping and learning ability, which provides an effective method for the daily runoff forecasting. However, its training has certain drawbacks such as time-consuming, slow learning speed and easily falling into local optimum, which cannot be ignored in the real world application. In order to overcome the disadvantages of ANN model, the artificial neural network model based on quantum-behaved particle swarm optimization (QPSO, ANN-QPSO for short, is presented for the daily runoff forecasting in this paper, where QPSO was employed to select the synaptic weights and thresholds of ANN, while ANN was used for the prediction. The proposed model can combine the advantages of both QPSO and ANN to enhance the generalization performance of the forecasting model. The methodology is assessed by using the daily runoff data of Hongjiadu reservoir in southeast Guizhou province of China from 2006 to 2014. The results demonstrate that the proposed approach achieves much better forecast accuracy than the basic ANN model, and the QPSO algorithm is an alternative training technique for the ANN parameters selection.

Neonatal finasteride administration decreases dopamine release in nucleus accumbens after alcohol and food presentation in adult male rats.

Science.gov (United States)

Llidó, Anna; Bartolomé, Iris; Darbra, Sònia; Pallarès, Marc

2016-08-01

Endogenous levels of the neurosteroid (NS) allopregnanolone (AlloP) during neonatal stages are crucial for the correct development of the central nervous system (CNS). In a recent work we reported that the neonatal administration of AlloP or finasteride (Finas), an inhibitor of the enzyme 5α-reductase needed for AlloP synthesis, altered the voluntary consumption of ethanol and the ventrostriatal dopamine (DA) levels in adulthood, suggesting that neonatal NS manipulations can increase alcohol abuse vulnerability in adulthood. Moreover, other authors have associated neonatal NS alterations with diverse dopaminergic (DAergic) alterations. Thus, the aim of the present work is to analyse if manipulations of neonatal AlloP alter the DAergic response in the nucleus accumbens (NAcc) during alcohol intake in rats. We administered AlloP or Finas from postnatal day (PND) 5 to PND9. At PND98, we measured alcohol consumption using a two-bottle free-choice model (ethanol 10% (v/v)+glucose 3% (w/v), and glucose 3% (w/v)) for 12 days. On the last day of consumption, we measured the DA and 3,4-dihydroxyphenylacetic acid (DOPAC) release in NAcc in response to ethanol intake. The samples were obtained by means of in vivo microdialysis in freely moving rats, and DA and DOPAC levels were determined by means of high-performance liquid chromatography analysis (HPLC). The results revealed that neonatal Finas increased ethanol consumption in some days of the consumption phase, and decreased the DA release in the NAcc in response to solutions (ethanol+glucose) and food presentation. Taken together, these results suggest that neonatal NS alterations can affect alcohol rewarding properties. Copyright © 2016 Elsevier B.V. All rights reserved.