Rhythm generation through period concatenation in rat somatosensory cortex.

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Mark A Kramer

2008-09-01

Full Text Available Rhythmic voltage oscillations resulting from the summed activity of neuronal populations occur in many nervous systems. Contemporary observations suggest that coexistent oscillations interact and, in time, may switch in dominance. We recently reported an example of these interactions recorded from in vitro preparations of rat somatosensory cortex. We found that following an initial interval of coexistent gamma ( approximately 25 ms period and beta2 ( approximately 40 ms period rhythms in the superficial and deep cortical layers, respectively, a transition to a synchronous beta1 ( approximately 65 ms period rhythm in all cortical layers occurred. We proposed that the switch to beta1 activity resulted from the novel mechanism of period concatenation of the faster rhythms: gamma period (25 ms+beta2 period (40 ms = beta1 period (65 ms. In this article, we investigate in greater detail the fundamental mechanisms of the beta1 rhythm. To do so we describe additional in vitro experiments that constrain a biologically realistic, yet simplified, computational model of the activity. We use the model to suggest that the dynamic building blocks (or motifs of the gamma and beta2 rhythms combine to produce a beta1 oscillation that exhibits cross-frequency interactions. Through the combined approach of in vitro experiments and mathematical modeling we isolate the specific components that promote or destroy each rhythm. We propose that mechanisms vital to establishing the beta1 oscillation include strengthened connections between a population of deep layer intrinsically bursting cells and a transition from antidromic to orthodromic spike generation in these cells. We conclude that neural activity in the superficial and deep cortical layers may temporally combine to generate a slower oscillation.

Neuromagnetic beta and gamma oscillations in the somatosensory cortex after music training in healthy older adults and a chronic stroke patient.

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Jamali, Shahab; Fujioka, Takako; Ross, Bernhard

2014-06-01

Extensive rehabilitation training can lead to functional improvement even years after a stroke. Although neuronal plasticity is considered as a main origin of such ameliorations, specific subtending mechanisms need further investigation. Our aim was to obtain objective neuromagnetic measures sensitive to brain reorganizations induced by a music-supported training. We applied 20-Hz vibrotactile stimuli to the index finger and the ring finger, recorded somatosensory steady-state responses with magnetoencephalography, and analyzed the cortical sources displaying oscillations synchronized with the external stimuli in two groups of healthy older adults before and after musical training or without training. In addition, we applied the same analysis for an anecdotic report of a single chronic stroke patient with hemiparetic arm and hand problems, who received music-supported therapy (MST). Healthy older adults showed significant finger separation within the primary somatotopic map. Beta dipole sources were more anterior located compared to gamma sources. An anterior shift of sources and increases in synchrony between the stimuli and beta and gamma oscillations were observed selectively after music training. In the stroke patient a normalization of somatotopic organization was observed after MST, with digit separation recovered after training and stimulus induced gamma synchrony increased. The proposed stimulation paradigm captures the integrity of primary somatosensory hand representation. Source position and synchronization between the stimuli and gamma activity are indices, sensitive to music-supported training. Responsiveness was also observed in a chronic stroke patient, encouraging for the music-supported therapy. Notably, changes in somatosensory responses were observed, even though the therapy did not involve specific sensory discrimination training. The proposed protocol can be used for monitoring changes in neuronal organization during training and will improve

Assessing Somatosensory Utilization during Unipedal Postural Control.

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Goel, Rahul; De Dios, Yiri E; Gadd, Nichole E; Caldwell, Erin E; Peters, Brian T; Reschke, Millard F; Bloomberg, Jacob J; Oddsson, Lars I E; Mulavara, Ajitkumar P

2017-01-01

Multisensory-visual, vestibular and somatosensory information is integrated for appropriate postural control. The primary goal of this study was to assess somatosensory utilization during a functional motor task of unipedal postural control, in normal healthy adults. Assessing individual bias in the utilization of individual sensory contributions during postural control may help customization of rehabilitation protocols. In this study, a test paradigm of unipedal stance control in supine orientation with and without vision was assessed. Postural control in this test paradigm was hypothesized to utilize predominantly contributions of somatosensory information from the feet and ankle joint, with minimal vestibular input. Fourteen healthy subjects "stood" supine on their dominant leg while strapped to a backpack frame that was freely moving on air-bearings, to remove available otolith tilt cues with respect to gravity that influences postural control when standing upright. The backpack was attached through a cable to a pneumatic cylinder that provided a gravity-like load. Subjects performed three trials each with Eyes-open (EO) and Eyes-closed (EC) while loaded with 60% body weight. There was no difference in unipedal stance time (UST) across the two conditions with EC condition challenging the postural control system greater than the EO condition. Stabilogram-diffusion analysis (SDA) indicated that the critical mean square displacement was significantly different between the two conditions. Vestibular cues, both in terms of magnitude and the duration for which relevant information was available for postural control in this test paradigm, were minimized. These results support our hypothesis that maintaining unipedal stance in supine orientation without vision, minimizes vestibular contribution and thus predominantly utilizes somatosensory information for postural control.

Chronic stress and peripheral pain: Evidence for distinct, region-specific changes in visceral and somatosensory pain regulatory pathways.

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Zheng, Gen; Hong, Shuangsong; Hayes, John M; Wiley, John W

2015-11-01

Chronic stress alters the hypothalamic-pituitary-adrenal (HPA) axis and enhances visceral and somatosensory pain perception. It is unresolved whether chronic stress has distinct effects on visceral and somatosensory pain regulatory pathways. Previous studies reported that stress-induced visceral hyperalgesia is associated with reciprocal alterations of endovanilloid and endocannabinoid pain pathways in DRG neurons innervating the pelvic viscera. In this study, we compared somatosensory and visceral hyperalgesia with respect to differential responses of peripheral pain regulatory pathways in a rat model of chronic, intermittent stress. We found that chronic stress induced reciprocal changes in the endocannabinoid 2-AG (increased) and endocannabinoid degradation enzymes COX-2 and FAAH (decreased), associated with down-regulation of CB1 and up-regulation of TRPV1 receptors in L6-S2 DRG but not L4-L5 DRG neurons. In contrast, sodium channels Nav1.7 and Nav1.8 were up-regulated in L4-L5 but not L6-S2 DRGs in stressed rats, which was reproduced in control DRGs treated with corticosterone in vitro. The reciprocal changes of CB1, TRPV1 and sodium channels were cell-specific and observed in the sub-population of nociceptive neurons. Behavioral assessment showed that visceral hyperalgesia persisted, whereas somatosensory hyperalgesia and enhanced expression of Nav1.7 and Nav1.8 sodium channels in L4-L5 DRGs normalized 3 days after completion of the stress phase. These data indicate that chronic stress induces visceral and somatosensory hyperalgesia that involves differential changes in endovanilloid and endocannabinoid pathways, and sodium channels in DRGs innervating the pelvic viscera and lower extremities. These results suggest that chronic stress-induced visceral and lower extremity somatosensory hyperalgesia can be treated selectively at different levels of the spinal cord. Copyright © 2015 Elsevier Inc. All rights reserved.

Morphometric analysis of feedforward pathways from the primary somatosensory area (S1 of rats

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A.L. de Sá

2016-01-01

Full Text Available We used biotinylated dextran amine (BDA to anterogradely label individual axons projecting from primary somatosensory cortex (S1 to four different cortical areas in rats. A major goal was to determine whether axon terminals in these target areas shared morphometric similarities based on the shape of individual terminal arbors and the density of two bouton types: en passant (Bp and terminaux (Bt. Evidence from tridimensional reconstructions of isolated axon terminal fragments (n=111 did support a degree of morphological heterogeneity establishing two broad groups of axon terminals. Morphological parameters associated with the complexity of terminal arbors and the proportion of beaded Bp vs stalked Bt were found to differ significantly in these two groups following a discriminant function statistical analysis across axon fragments. Interestingly, both groups occurred in all four target areas, possibly consistent with a commonality of presynaptic processing of tactile information. These findings lay the ground for additional work aiming to investigate synaptic function at the single bouton level and see how this might be associated with emerging properties in postsynaptic targets.

Hypergravity exposure decreases gamma-aminobutyric acid immunoreactivity in axon terminals contacting pyramidal cells in the rat somatosensory cortex: a quantitative immunocytochemical image analysis

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D'Amelio, F.; Wu, L. C.; Fox, R. A.; Daunton, N. G.; Corcoran, M. L.; Polyakov, I.

1998-01-01

Quantitative evaluation of gamma-aminobutyric acid immunoreactivity (GABA-IR) in the hindlimb representation of the rat somatosensory cortex after 14 days of exposure to hypergravity (hyper-G) was conducted by using computer-assisted image processing. The area of GABA-IR axosomatic terminals apposed to pyramidal cells of cortical layer V was reduced in rats exposed to hyper-G compared with control rats, which were exposed either to rotation alone or to vivarium conditions. Based on previous immunocytochemical and behavioral studies, we suggest that this reduction is due to changes in sensory feedback information from muscle receptors. Consequently, priorities for muscle recruitment are altered at the cortical level, and a new pattern of muscle activity is thus generated. It is proposed that the reduction observed in GABA-IR of the terminal area around pyramidal neurons is the immunocytochemical expression of changes in the activity of GABAergic cells that participate in reprogramming motor outputs to achieve effective movement control in response to alterations in the afferent information.

Predictability of painful stimulation modulates the somatosensory-evoked potential in the rat

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Schaap, M.W.H.; van Oostrom, H.; Doornenbal, A.; Baars, A.M.; Arndt, S.S.; Hellebrekers, L.J.

2013-01-01

Abstract Somatosensory-evoked potentials (SEPs) are used in humans and animals to increase knowledge about nociception and pain. Since the SEP in humans increases when noxious stimuli are administered unpredictably, predictability potentially influences the SEP in animals as well. To assess the

[Maturation of cerebral somatosensory evoked potentials].

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Cadilhac, J; Zhu, Y; Georgesco, M; Echenne, B; Rodiere, M

1985-07-01

Cerebral somatosensory evoked potentials (SEPs) were elicited by stimulation of the median nerve and/or posterior tibial nerve in 117 children of 1 day to 16 years old. A major negative wave (N) was consistently recorded from the parietal region of the scalp when the arm was stimulated. The peak latency, the onset latency, the rising time and the duration of H wave are closely correlated with age and body length. The latencies are shortest in the subjects of 1-3 years old. SEPs to lower extremity stimulation were inconstant in the infants before the age of one. The major positive wave (P) has a variable topographic distribution along the middle line, over the scalp. The latencies are also very variable in the different subjects of the same age as well as in the same subject with different locations of active electrode. Among the parameters studied as for N wave, only the rising time of P wave is significantly correlated with age. The latencies of P wave have the shortest value in the subjects of 1-3 years old. The comparison of SEPs to upper and to lower limb stimulations shows that there is no relationship between them in respect to their morphology and amplitude. The minimum value of the latencies of N and P waves was observed at the same age but the difference between the peak latencies of P and N waves in the same subject increases considerably after 2 years of age and reaches the adult value after 5 years of age. These resultats indicate that the maturation of the peripheral somatosensory pathways proceeds at a higher rate than that of the central somatosensory pathways, that the maturation of the somatosensory pathways of the upper limb precedes that of the lower limb, and that the rising time of N or P waves is a good index of cortical maturation. The clinical utility of these SEPs in pediatrics is discussed.

Whisker Deprivation Drives Two Phases of Inhibitory Synapse Weakening in Layer 4 of Rat Somatosensory Cortex.

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Melanie A Gainey

Full Text Available Inhibitory synapse development in sensory neocortex is experience-dependent, with sustained sensory deprivation yielding fewer and weaker inhibitory synapses. Whether this represents arrest of synapse maturation, or a more complex set of processes, is unclear. To test this, we measured the dynamics of inhibitory synapse development in layer 4 of rat somatosensory cortex (S1 during continuous whisker deprivation from postnatal day 7, and in age-matched controls. In deprived columns, spontaneous miniature inhibitory postsynaptic currents (mIPSCs and evoked IPSCs developed normally until P15, when IPSC amplitude transiently decreased, recovering by P16 despite ongoing deprivation. IPSCs remained normal until P22, when a second, sustained phase of weakening began. Delaying deprivation onset by 5 days prevented the P15 weakening. Both early and late phase weakening involved measurable reduction in IPSC amplitude relative to prior time points. Thus, deprivation appears to drive two distinct phases of active IPSC weakening, rather than simple arrest of synapse maturation.

Ovariectomy results in variable changes in nociception, mood and depression in adult female rats.

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Li-Hong Li

Full Text Available Decline in the ovarian hormones with menopause may influence somatosensory, cognitive, and affective processing. The present study investigated whether hormonal depletion alters the nociceptive, depressive-like and learning behaviors in experimental rats after ovariectomy (OVX, a common method to deplete animals of their gonadal hormones. OVX rats developed thermal hyperalgesia in proximal and distal tail that was established 2 weeks after OVX and lasted the 7 weeks of the experiment. A robust mechanical allodynia was also occurred at 5 weeks after OVX. In the 5th week after OVX, dilute formalin (5%-induced nociceptive responses (such as elevating and licking or biting during the second phase were significantly increased as compared to intact and sham-OVX females. However, chronic constriction injury (CCI of the sciatic nerve-induced mechanical allodynia did not differ as hormonal status (e.g. OVX and ovarian intact. Using formalin-induced conditioned place avoidance (F-CPA, which is believed to reflect the pain-related negative emotion, we further found that OVX significantly attenuated F-CPA scores but did not alter electric foot-shock-induced CPA (S-CPA. In the open field and forced swimming test, there was an increase in depressive-like behaviors in OVX rats. There was no detectable impairment of spatial performance by Morris water maze task in OVX rats up to 5 weeks after surgery. Estrogen replacement retrieved OVX-induced nociceptive hypersensitivity and depressive-like behaviors. This is the first study to investigate the impacts of ovarian removal on nociceptive perception, negative emotion, depressive-like behaviors and spatial learning in adult female rats in a uniform and standard way.

Somatosensory abnormalities in knee OA.

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Wylde, Vikki; Palmer, Shea; Learmonth, Ian D; Dieppe, Paul

2012-03-01

The aim of this study was to use quantitative sensory testing (QST) to explore the range and prevalence of somatosensory abnormalities demonstrated by patients with advanced knee OA. One hundred and seven knee OA patients and 50 age- and sex-matched healthy participants attended a 1-h QST session. Testing was performed on the medial side of the knee and the pain-free forearm. Light-touch thresholds were assessed using von Frey filaments, pressure pain thresholds using a digital pressure algometer, and thermal sensation and pain thresholds using a Thermotest MSA. Significant differences in median threshold values from knee OA patients and healthy participants were identified using Mann-Whitney U-tests. The z-score transformations were used to determine the prevalence of the different somatosensory abnormalities in knee OA patients. Testing identified 70% of knee OA patients as having at least one somatosensory abnormality. Comparison of median threshold values between knee OA patients and healthy participants revealed that patients had localized thermal and tactile hypoaesthesia and pressure hyperalgesia at the osteoarthritic knee. Tactile hypoaesthesia and pressure hyperalgesia were also present at the pain-free forearm. The most prevalent somatosensory abnormalities were tactile hypoaesthesia and pressure hyperalgesia, evident in between 20 and 34% of patients. This study found that OA patients demonstrate an array of somatosensory abnormalities, of which the most prevalent were tactile hypoaesthesia and pressure hyperalgesia. Further research is now needed to establish the clinical implications of these somatosensory abnormalities.

ASYMMETRY OF SOMATOSENSORY CORTICAL PLASTICITY IN PATIENT WITH BILATERAL CARPAL TUNNEL SYNDROME

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Hikmat Hadoush

2017-09-01

Full Text Available Background: Following peripheral nerve lesion, the adult somatosensory system showedcortical reorganizational abilities.Previous studies identified the digits' somatotopy map changes and somatosensory cortical plasticity in response to the Carpal Tunnel Syndrome (CTS that affected the dominant hand only. Objective: Answering the remained question is that what the extent of the cortical plasticity would be in left and right somatosensory cortices in response to CTS affecting the right and left hands simultaneously. Methods: Cortical representations activated by tactile stimulation of median nerve (index and ulnar nerve (little of both dominant and non-dominant hands were evaluated by Magnetoencephalography (MEG systemfor healthy participants and patient with bilateral moderate CTS. index – little fingers'somatotopy map and inter-digit cortical distance was then mapped and calculated for each participant on the real MRI data and the 3D brain surface image. Results: in healthy participants, index – little inter-digit somatosensory cortical distance of right hand (dominant was significantly larger than the index – little inter-digitsomatosensory cortical distance of left hand (11.2±2.1mm vs.7.0±2.9mm, P = 0.006. However, in patient with bilateral CTS, the index – little inter-digit somatosensory cortical distance of righthand (dominant was significantly smaller than the index – little inter-digit somatosensory cortical distance of left hand (5.8mm vs. 7.4mm. Conclusion: our data could be interpreted as the hand use – dependency served more median nerve – cortical territory from the ulnar nerve invasion in the right somatotopy map (left hand than the left somatotopy map of the right hand.

Molecular Correlates of Cortical Network Modulation by Long-Term Sensory Experience in the Adult Rat Barrel Cortex

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Vallès, Astrid; Granic, Ivica; De Weerd, Peter; Martens, Gerard J. M.

2014-01-01

Modulation of cortical network connectivity is crucial for an adaptive response to experience. In the rat barrel cortex, long-term sensory stimulation induces cortical network modifications and neuronal response changes of which the molecular basis is unknown. Here, we show that long-term somatosensory stimulation by enriched environment…

Effect of Somatosensory Impairments on Balance Control

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Alireza Hassanpour

2012-10-01

Full Text Available Background and Aim: The somatosensory system is one of the most effective systems in balance control. It consists of peripheral and central components. Knowing the role of these components in balance control assists the developing of effective rehabilitation protocols. In some diseases peripheral components and in others central components are impaired. This paper reviews the effect of impairment of peripheral and central components of the somatosensory system on balance control.Methods: In this study publication about somatosensory impairments from 1983 through 2011 in PubMed, Scopus, ProQuest, Google Scholar, Iran Medex, Iran Doc and Magiran were reviewed. Medical subject headings terms and keywords related to balance, somatosensory, somatosensory loss, and sensory integration/processing were used to perform the searches.Conclusion: Somatosensory impairments either with peripheral or central origin, can cause problems in balance control. However, these problems are not considered in some patients. In these impairments, balance training is recommended to be used alongside other routine treatments in the patients' rehabilitation programs.

Uptake of trace elements in adult and suckling rat lenses

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Nabekura, Tomohiro; Ito, Yoshimasa; Minami, Takeshi; Hirunuma, Rieko; Enomoto, Shuichi

2001-01-01

The uptake of trace elements in the lens was compared in adult and suckling rat lenses. Multitracers, including 15 trace elements, As, Be, Co, Fe, Mn, Rb, Rh, Ru, Sc, Se, Sr, Y, V, Zn, and Zr, were incubated with the lenses for 4 hr and their concentrations in the lens were measured. A high uptake rate of Zn was observed in the lenses of both adult and suckling rats in comparison with those of the other elements, and the Zn concentration in the lens of suckling rats was higher than that of adult rats. The uptake rate of Sr was higher in adult rats than in suckling rats. On the other contrary, Rb and Se concentrations in the lens were higher in suckling rats than in adult rats. The present study suggests that the different mechanisms depending on development serve to transport trace elements into the lens. (author)

Development of rat female genital cortex and control of female puberty by sexual touch.

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Constanze Lenschow

2017-09-01

Full Text Available Rat somatosensory cortex contains a large sexually monomorphic genital representation. Genital cortex undergoes an unusual 2-fold expansion during puberty. Here, we investigate genital cortex development and female rat sexual maturation. Ovariectomies and estradiol injections suggested sex hormones cause the pubertal genital cortex expansion but not its maintenance at adult size. Genital cortex expanded by thalamic afferents invading surrounding dysgranular cortex. Genital touch was a dominant factor driving female sexual maturation. Raising female rats in contact with adult males promoted genital cortex expansion, whereas contact to adult females or nontactile (audio-visual-olfactory male cues did not. Genital touch imposed by human experimenters powerfully advanced female genital cortex development and sexual maturation. Long-term blocking of genital cortex by tetrodotoxin in pubescent females housed with males prevented genital cortex expansion and decelerated vaginal opening. Sex hormones, sexual experience, and neural activity shape genital cortex, which contributes to the puberty promoting effects of sexual touch.

Development of rat female genital cortex and control of female puberty by sexual touch.

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Lenschow, Constanze; Sigl-Glöckner, Johanna; Brecht, Michael

2017-09-01

Rat somatosensory cortex contains a large sexually monomorphic genital representation. Genital cortex undergoes an unusual 2-fold expansion during puberty. Here, we investigate genital cortex development and female rat sexual maturation. Ovariectomies and estradiol injections suggested sex hormones cause the pubertal genital cortex expansion but not its maintenance at adult size. Genital cortex expanded by thalamic afferents invading surrounding dysgranular cortex. Genital touch was a dominant factor driving female sexual maturation. Raising female rats in contact with adult males promoted genital cortex expansion, whereas contact to adult females or nontactile (audio-visual-olfactory) male cues did not. Genital touch imposed by human experimenters powerfully advanced female genital cortex development and sexual maturation. Long-term blocking of genital cortex by tetrodotoxin in pubescent females housed with males prevented genital cortex expansion and decelerated vaginal opening. Sex hormones, sexual experience, and neural activity shape genital cortex, which contributes to the puberty promoting effects of sexual touch.

Temporal factors affecting somatosensory-auditory interactions in speech processing

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Takayuki eIto

2014-11-01

Full Text Available Speech perception is known to rely on both auditory and visual information. However, sound specific somatosensory input has been shown also to influence speech perceptual processing (Ito et al., 2009. In the present study we addressed further the relationship between somatosensory information and speech perceptual processing by addressing the hypothesis that the temporal relationship between orofacial movement and sound processing contributes to somatosensory-auditory interaction in speech perception. We examined the changes in event-related potentials in response to multisensory synchronous (simultaneous and asynchronous (90 ms lag and lead somatosensory and auditory stimulation compared to individual unisensory auditory and somatosensory stimulation alone. We used a robotic device to apply facial skin somatosensory deformations that were similar in timing and duration to those experienced in speech production. Following synchronous multisensory stimulation the amplitude of the event-related potential was reliably different from the two unisensory potentials. More importantly, the magnitude of the event-related potential difference varied as a function of the relative timing of the somatosensory-auditory stimulation. Event-related activity change due to stimulus timing was seen between 160-220 ms following somatosensory onset, mostly around the parietal area. The results demonstrate a dynamic modulation of somatosensory-auditory convergence and suggest the contribution of somatosensory information for speech processing process is dependent on the specific temporal order of sensory inputs in speech production.

Human umbilical cord blood cells restore brain damage induced changes in rat somatosensory cortex.

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Maren Geissler

Full Text Available Intraperitoneal transplantation of human umbilical cord blood (hUCB cells has been shown to reduce sensorimotor deficits after hypoxic ischemic brain injury in neonatal rats. However, the neuronal correlate of the functional recovery and how such a treatment enforces plastic remodelling at the level of neural processing remains elusive. Here we show by in-vivo recordings that hUCB cells have the capability of ameliorating the injury-related impairment of neural processing in primary somatosensory cortex. Intact cortical processing depends on a delicate balance of inhibitory and excitatory transmission, which is disturbed after injury. We found that the dimensions of cortical maps and receptive fields, which are significantly altered after injury, were largely restored. Additionally, the lesion induced hyperexcitability was no longer observed in hUCB treated animals as indicated by a paired-pulse behaviour resembling that observed in control animals. The beneficial effects on cortical processing were reflected in an almost complete recovery of sensorimotor behaviour. Our results demonstrate that hUCB cells reinstall the way central neurons process information by normalizing inhibitory and excitatory processes. We propose that the intermediate level of cortical processing will become relevant as a new stage to investigate efficacy and mechanisms of cell therapy in the treatment of brain injury.

Radiation nephropathy in young and adult rats

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Jongejan, H.T.; van der Kogel, A.J.; Provoost, A.P.; Molenaar, J.C.

1987-01-01

The effects of bilateral kidney irradiation were compared in young and adult rats. During a 1 year period after a single dose of 0, 7.5, 10, 12.5, or 15 Gy on both kidneys, renal function (glomerular filtration rate and effective renal plasma flow), urine composition, and systolic blood pressure were measured periodically. The first changes after irradiation were observed in the glomerular filtration rate and urine osmolality. One month after 10, 12.5, and 15 Gy, glomerular filtration rate (GFR) and urine osmolality had declined below control values in the young rats. After this initial decline, renal function increased at control rate or even more during the third and fourth month after irradiation but decreased progressively thereafter. In the adult rats, GFR and urine osmolality started to decrease 3 months after 10, 12.5, and 15 Gy. A rise in systolic blood pressure and proteinuria started 2-3 months after 12.5 and 15 Gy in both age groups. Early changes in the glomerular filtration rate with a drop in urine osmolality in young rats, occurring during a period of rapid renal development indicated an irradiation-induced inhibition of glomerular and tubular development. Although renal function deteriorated at a later time in adult rats, dose-response relationships obtained in young and adult rats did not show significant differences

Long-term neuroplasticity of the face primary motor cortex and adjacent somatosensory cortex induced by tooth loss can be reversed following dental implant replacement in rats.

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Avivi-Arber, Limor; Lee, Jye-Chang; Sood, Mandeep; Lakschevitz, Flavia; Fung, Michelle; Barashi-Gozal, Maayan; Glogauer, Michael; Sessle, Barry J

2015-11-01

Tooth loss is common, and exploring the neuroplastic capacity of the face primary motor cortex (face-M1) and adjacent primary somatosensory cortex (face-S1) is crucial for understanding how subjects adapt to tooth loss and their prosthetic replacement. The aim was to test if functional reorganization of jaw and tongue motor representations in the rat face-M1 and face-S1 occurs following tooth extraction, and if subsequent dental implant placement can reverse this neuroplasticity. Rats (n = 22) had the right maxillary molar teeth extracted under local and general anesthesia. One month later, seven rats had dental implant placement into healed extraction sites. Naive rats (n = 8) received no surgical treatment. Intracortical microstimulation (ICMS) and recording of evoked jaw and tongue electromyographic responses were used to define jaw and tongue motor representations at 1 month (n = 8) or 2 months (n = 7) postextraction, 1 month postimplant placement, and at 1-2 months in naive rats. There were no significant differences across study groups in the onset latencies of the ICMS-evoked responses (P > 0.05), but in comparison with naive rats, tooth extraction caused a significant (P rats. These novel findings suggest that face-M1 and adjacent face-S1 may play a role in adaptive mechanisms related to tooth loss and their replacement with dental implants. © 2015 Wiley Periodicals, Inc.

Subliminal stimulation and somatosensory signal detection.

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Ferrè, Elisa Raffaella; Sahani, Maneesh; Haggard, Patrick

2016-10-01

Only a small fraction of sensory signals is consciously perceived. The brain's perceptual systems may include mechanisms of feedforward inhibition that protect the cortex from subliminal noise, thus reserving cortical capacity and conscious awareness for significant stimuli. Here we provide a new view of these mechanisms based on signal detection theory, and gain control. We demonstrated that subliminal somatosensory stimulation decreased sensitivity for the detection of a subsequent somatosensory input, largely due to increased false alarm rates. By delivering the subliminal somatosensory stimulus and the to-be-detected somatosensory stimulus to different digits of the same hand, we show that this effect spreads across the sensory surface. In addition, subliminal somatosensory stimulation tended to produce an increased probability of responding "yes", whether the somatosensory stimulus was present or not. Our results suggest that subliminal stimuli temporarily reduce input gain, avoiding excessive responses to further small inputs. This gain control may be automatic, and may precede discriminative classification of inputs into signals or noise. Crucially, we found that subliminal inputs influenced false alarm rates only on blocks where the to-be-detected stimuli were present, and not on pre-test control blocks where they were absent. Participants appeared to adjust their perceptual criterion according to a statistical distribution of stimuli in the current context, with the presence of supraliminal stimuli having an important role in the criterion-setting process. These findings clarify the cognitive mechanisms that reserve conscious perception for salient and important signals. Copyright © 2016 Elsevier B.V. All rights reserved.

Clinical application of somatosensory amplification in psychosomatic medicine

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Nakao Mutsuhiro

2007-10-01

Full Text Available Abstract Many patients with somatoform disorders are frequently encountered in psychosomatic clinics as well as in primary care clinics. To assess such patients objectively, the concept of somatosensory amplification may be useful. Somatosensory amplification refers to the tendency to experience a somatic sensation as intense, noxious, and disturbing. It may have a role in a variety of medical conditions characterized by somatic symptoms that are disproportionate to demonstrable organ pathology. It may also explain some of the variability in somatic symptomatology found among different patients with the same serious medical disorder. It has been assessed with a self-report questionnaire, the Somatosensory Amplification Scale. This instrument was developed in a clinical setting in the U.S., and the reliability and validity of the Japanese and Turkish versions have been confirmed as well. Many studies have attempted to clarify the specific role of somatosensory amplification as a pathogenic mechanism in somatization. It has been reported that somatosensory amplification does not correlate with heightened sensitivity to bodily sensations and that emotional reactivity exerts its influence on somatization via a negatively biased reporting style. According to our recent electroencephalographic study, somatosensory amplification appears to reflect some aspects of long-latency cognitive processing rather than short-latency interoceptive sensitivity. The concept of somatosensory amplification can be useful as an indicator of somatization in the therapy of a broad range of disorders, from impaired self-awareness to various psychiatric disorders. It also provides useful information for choosing appropriate pharmacological or psychological therapy. While somatosensory amplification has a role in the presentation of somatic symptoms, it is closely associated with other factors, namely, anxiety, depression, and alexithymia that may also influence the same

Effects of Ketamine on Neuronal Spontaneous Excitatory Postsynaptic Currents and Miniature Excitatory Postsynaptic Currents in the Somatosensory Cortex of Rats

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Chengdong Yuan

2016-07-01

Full Text Available Background: Ketamine is a commonly used intravenous anesthetic which produces dissociation anesthesia, analgesia, and amnesia. The mechanism of ketamine-induced synaptic inhibition in high-level cortical areas is still unknown. We aimed to elucidate the effects of different concentrations of ketamine on the glutamatergic synaptic transmission of the neurons in the primary somatosensory cortex by using the whole-cell patch-clamp method. Methods: Sprague-Dawley rats (11–19 postnatal days, n=36 were used to obtain brain slices (300 μM. Spontaneous excitatory postsynaptic currents (data from 40 neurons were recorded at a command potential of -70 mV in the presence of bicuculline (a competitive antagonist of GABAA receptors, 30 μM and strychnine (glycine receptor antagonist, 30 μM. Miniature excitatory postsynaptic currents (data from 40 neurons were also recorded when 1 μM of tetrodotoxin was added into the artificial cerebrospinal fluid. We used GraphPad Prism5for statistical analysis. Significant differences in the mean amplitude and frequency were tested using the Student paired 2-tailed t test. Values of P<0.05 were considered significant. Results: Different concentrations of ketamine inhibited the frequency and amplitude of the spontaneous excitatory postsynaptic currents as well as the amplitude of the miniature excitatory postsynaptic currents in a concentration-dependent manner, but they exerted no significant effect on the frequency of the miniature excitatory postsynaptic currents. Conclusion: Ketamine inhibited the excitatory synaptic transmission of the neurons in the primary somatosensory cortex. The inhibition may have been mediated by a reduction in the sensitivity of the postsynaptic glutamatergic receptors.

Feedforward somatosensory inhibition is normal in cervical dystonia.

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Ferrè, Elisa R; Ganos, Christos; Bhatia, Kailash P; Haggard, Patrick

2015-03-01

Insufficient cortical inhibition is a key pathophysiological finding in dystonia. Subliminal sensory stimuli were reported to transiently inhibit somatosensory processing. Here we investigated whether such subliminal feedforward inhibition is reduced in patients with cervical dystonia. Sixteen cervical dystonia patients and 16 matched healthy controls performed a somatosensory detection task. We measured the drop in sensitivity to detect a threshold-level digital nerve shock when it was preceded by a subliminal conditioning shock, compared to when it was not. Subliminal conditioning shocks reduced sensitivity to threshold stimuli to a similar extent in both patients and controls, suggesting that somatosensory subliminal feedforward inhibition is normal in cervical dystonia. Somatosensory feedforward inhibition was normal in this group of cervical dystonia patients. Our results qualify previous concepts of a general dystonic deficit in sensorimotor inhibitory processing. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of mastication on human somatosensory processing: A study using somatosensory-evoked potentials.

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Nakata, Hiroki; Aoki, Mai; Sakamoto, Kiwako

2017-04-01

The aim of the present study was to investigate the effects of mastication on somatosensory processing using somatosensory-evoked potentials (SEPs). Fourteen healthy subjects received a median nerve stimulation at the right wrist under two conditions: Mastication and Control. SEPs were recorded in five sessions for approximately seven minutes: Pre, Post 1, 2, 3, and 4. Subjects were asked to chew gum for five minutes after one session in Mastication. Control included the same five sessions. The amplitudes and latencies of P14, N20, P25, N35, P45, and N60 components at C3', frontal N30 component at Fz, and P100 and N140 components at Pz were analyzed. The amplitude of P45-N60 was significantly smaller at Post 1, 2, 3, and 4 than at Pre in Control, but not in Mastication. The latency of P25 was significantly longer at Post 2, 3, and 4 than at Pre in Control, but not in Mastication. The latency of P100 was significantly longer at Post 2 than at Pre in Control, but not in Mastication. These results suggest the significant effects of mastication on the neural activity of human somatosensory processing. Copyright © 2016 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

Making sense out of spinal cord somatosensory development

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Seal, Rebecca P.

2016-01-01

The spinal cord integrates and relays somatosensory input, leading to complex motor responses. Research over the past couple of decades has identified transcription factor networks that function during development to define and instruct the generation of diverse neuronal populations within the spinal cord. A number of studies have now started to connect these developmentally defined populations with their roles in somatosensory circuits. Here, we review our current understanding of how neuronal diversity in the dorsal spinal cord is generated and we discuss the logic underlying how these neurons form the basis of somatosensory circuits. PMID:27702783

Development of acute hydrocephalus does not change brain tissue mechanical properties in adult rats, but in juvenile rats.

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Pong, Alice C; Jugé, Lauriane; Bilston, Lynne E; Cheng, Shaokoon

2017-01-01

Regional changes in brain stiffness were previously demonstrated in an experimental obstructive hydrocephalus juvenile rat model. The open cranial sutures in the juvenile rats have influenced brain compression and mechanical properties during hydrocephalus development and the extent by which closed cranial sutures in adult hydrocephalic rat models affect brain stiffness in-vivo remains unclear. The aims of this study were to determine changes in brain tissue mechanical properties and brain structure size during hydrocephalus development in adult rat with fixed cranial volume and how these changes were related to brain tissue deformation. Hydrocephalus was induced in 9 female ten weeks old Sprague-Dawley rats by injecting 60 μL of a kaolin suspension (25%) into the cisterna magna under anaesthesia. 6 sham-injected age-matched female SD rats were used as controls. MR imaging (9.4T, Bruker) was performed 1 day before and then at 3 days post injection. T2-weighted anatomical MR images were collected to quantify ventricle and brain tissue cross-sectional areas. MR elastography (800 Hz) was used to measure the brain stiffness (G*, shear modulus). Brain tissue in the adult hydrocephalic rats was more compressed than the juvenile hydrocephalic rats because the skulls of the adult hydrocephalic rats were unable to expand like the juvenile rats. In the adult hydrocephalic rats, the cortical gray matter thickness and the caudate-putamen cross-sectional area decreased (Spearman, P hydrocephalus is complex and is not solely dependent on brain tissue deformation. Further studies on the interactions between brain tissue stiffness, deformation, tissue oedema and neural damage are necessary before MRE can be used as a tool to track changes in brain biomechanics in hydrocephalus.

Voxel-based lesion-symptom mapping of stroke lesions underlying somatosensory deficits

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Sarah Meyer

2016-01-01

Full Text Available The aim of this study was to investigate the relationship between stroke lesion location and the resulting somatosensory deficit. We studied exteroceptive and proprioceptive somatosensory symptoms and stroke lesions in 38 patients with first-ever acute stroke. The Erasmus modified Nottingham Sensory Assessment was used to clinically evaluate somatosensory functioning in the arm and hand within the first week after stroke onset. Additionally, more objective measures such as the perceptual threshold of touch and somatosensory evoked potentials were recorded. Non-parametric voxel-based lesion-symptom mapping was performed to investigate lesion contribution to different somatosensory deficits in the upper limb. Additionally, structural connectivity of brain areas that demonstrated the strongest association with somatosensory symptoms was determined, using probabilistic fiber tracking based on diffusion tensor imaging data from a healthy age-matched sample. Voxels with a significant association to somatosensory deficits were clustered in two core brain regions: the central parietal white matter, also referred to as the sensory component of the superior thalamic radiation, and the parietal operculum close to the insular cortex, representing the secondary somatosensory cortex. Our objective recordings confirmed findings from clinical assessments. Probabilistic tracking connected the first region to thalamus, internal capsule, brain stem, postcentral gyrus, cerebellum, and frontal pathways, while the second region demonstrated structural connections to thalamus, insular and primary somatosensory cortex. This study reveals that stroke lesions in the sensory fibers of the superior thalamocortical radiation and the parietal operculum are significantly associated with multiple exteroceptive and proprioceptive deficits in the arm and hand.

Voxel-based lesion-symptom mapping of stroke lesions underlying somatosensory deficits.

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Meyer, Sarah; Kessner, Simon S; Cheng, Bastian; Bönstrup, Marlene; Schulz, Robert; Hummel, Friedhelm C; De Bruyn, Nele; Peeters, Andre; Van Pesch, Vincent; Duprez, Thierry; Sunaert, Stefan; Schrooten, Maarten; Feys, Hilde; Gerloff, Christian; Thomalla, Götz; Thijs, Vincent; Verheyden, Geert

2016-01-01

The aim of this study was to investigate the relationship between stroke lesion location and the resulting somatosensory deficit. We studied exteroceptive and proprioceptive somatosensory symptoms and stroke lesions in 38 patients with first-ever acute stroke. The Erasmus modified Nottingham Sensory Assessment was used to clinically evaluate somatosensory functioning in the arm and hand within the first week after stroke onset. Additionally, more objective measures such as the perceptual threshold of touch and somatosensory evoked potentials were recorded. Non-parametric voxel-based lesion-symptom mapping was performed to investigate lesion contribution to different somatosensory deficits in the upper limb. Additionally, structural connectivity of brain areas that demonstrated the strongest association with somatosensory symptoms was determined, using probabilistic fiber tracking based on diffusion tensor imaging data from a healthy age-matched sample. Voxels with a significant association to somatosensory deficits were clustered in two core brain regions: the central parietal white matter, also referred to as the sensory component of the superior thalamic radiation, and the parietal operculum close to the insular cortex, representing the secondary somatosensory cortex. Our objective recordings confirmed findings from clinical assessments. Probabilistic tracking connected the first region to thalamus, internal capsule, brain stem, postcentral gyrus, cerebellum, and frontal pathways, while the second region demonstrated structural connections to thalamus, insular and primary somatosensory cortex. This study reveals that stroke lesions in the sensory fibers of the superior thalamocortical radiation and the parietal operculum are significantly associated with multiple exteroceptive and proprioceptive deficits in the arm and hand.

Vestibular-somatosensory interactions: effects of passive whole-body rotation on somatosensory detection.

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Elisa Raffaella Ferrè

Full Text Available Vestibular signals are strongly integrated with information from several other sensory modalities. For example, vestibular stimulation was reported to improve tactile detection. However, this improvement could reflect either a multimodal interaction or an indirect interaction driven by vestibular effects on spatial attention and orienting. Here we investigate whether natural vestibular activation induced by passive whole-body rotation influences tactile detection. In particular, we assessed the ability to detect faint tactile stimuli to the fingertips of the left and right hand during spatially congruent or incongruent rotations. We found that passive whole-body rotations significantly enhanced sensitivity to faint shocks, without affecting response bias. Critically, this enhancement of somatosensory sensitivity did not depend on the spatial congruency between the direction of rotation and the hand stimulated. Thus, our results support a multimodal interaction, likely in brain areas receiving both vestibular and somatosensory signals.

Reorganization of the Human Somatosensory Cortex in Hand Dystonia

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Maria Jose Catalan

2012-05-01

Full Text Available Background and Purpose: Abnormalities of finger representations in the somatosensory cortex have been identified in patients with focal hand dystonia. Measuring blood flow with positron emission tomography (PET can be use to demonstrate functional localization of receptive fields. Methods: A vibratory stimulus was applied to the right thumb and little finger of six healthy volunteers and six patients with focal hand dystonia to map their receptive fields using H215O PET. Results: The cortical finger representations in the primary somatosensory cortex were closer to each other in patients than in normal subjects. No abnormalities were found in secondary somatosensory cortex, but the somatotopy there is less well distinguished. Conclusions: These data confirm prior electrophysiological and functional neuroimaging observations showing abnormalities of finger representations in somatosensory cortex of patients with focal hand dystonia.

Synaptic and Cellular Organization of Layer 1 of the Developing Rat Somatosensory Cortex

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Shruti eMuralidhar

2014-01-01

Full Text Available We have performed a systematic and quantitative study of the neuronal and synaptic organisation of neocortical layer 1 in the somatosensory cortex in juvenile rats (P13 – P16 using multi-neuron patch-clamp and 3D morphology reconstructions. We used both subjective expert based and objective classification to establish distinct morphological groups. According to expert based subjective classification, the neurons were classified into six morphological types: (1 the dense axon neurogliaform cell (NGC-DA and (2 a sparse axon neurogliaform cell (NGC-SA, (3 the horizontal axon cell (HAC and (4 those with descending axonal colaterals (DAC, (5 the large axon cell (LAC and (6 the small axon cell (SAC. We also used objective supervised and unsupervised analyses that confirmed 4 out of the 6 expert proposed groups, namely, DAC, HAC, LAC and a combined NGC. The cells were also classified into 5 electrophysiological types based on the Petilla convention; classical non-adapting (cNAC, burst non-adapting (bNAC, classical adapting (cAC, classical stuttering (cSTUT and classical irregular spiking (cIR. The most common electrophysiological type was the cNAC type (40% and the most commonly encountered morpho-electrical type of neuron was the NGC-DA - cNAC. Layer 1 cells are connected by GABAergic inhibitory synaptic connections with a 7.9% connection probability, as well gap junctions with 5.2% connection probability. Most synaptic connections were mediated by both GABAA and GABAB receptors (62.6%, as observed from the response characteristics to single pulse and train stimulations. A smaller fraction of synaptic connections were mediated exclusively by GABAA (15.4% or GABAB (21.8% receptors. Based on the morphological reconstructions, we found multi-synapse connections with an average of 9 putative synapses per connection. These putative touches were widely distributed with 39% on somata and 61% on dendrites.

Influence of iron on plutonium absorption by the adult and neonatal rat

International Nuclear Information System (INIS)

Sullivan, M.F.; Ruemmler, P.S.; Buschbom, R.L.

1986-01-01

To determine how iron affects plutonium absorption, adult rats were gavaged with 238 Pu nitrate (pH 2) after they had been fed an iron-deficient diet or treated with iron supplements. Neonatal rats born to dams on an iron-deficient diet were also gavaged with 238 Pu. An iron-deficient diet resulted in enhanced 238 Pu absorption both in the adults and in neonates born to iron-deficient dams. Ferric iron increased 238 Pu absorption 12-fold in adult rats; injected iron-dextran reduced that increase; gavaged ferrous iron reduced 238 Pu absorption to one-third of the control value. Rat neonates absorbed 30 to 40 times as much 238 Pu as adults; absorption was lowered in groups that received iron supplements: Iron-dextran caused a 50% reduction; ferric iron, 95%; and ferrous iron, greater than 95%. The results demonstrate an effect of the oxidation state of iron on plutonium absorption in adult rats different from that observed in suckling rats. The results suggest that the high rate of 238 Pu absorption by neonatal animals is due not only to the permeability of their intestines but also to their high demand for iron

[Subcutaneous transplants of juvenile rat testicular tissues continue to develop and secret androgen in adult rats].

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Yu, Zhou; Wang, Tong; Cui, Jiangbo; Song, Yajuan; Ma, Xianjie; Su, Yingjun; Peng, Pai

2017-12-01

Objective To explore the effects of subcutaneous microenvironment of adult rats on survival, development and androgen secretion of Leydig cells of transplanted juvenile rat testis. Methods Healthy adult SD rats were randomly divided into control group, sham group, castrated group and non-castrated group. Rats in the control group were kept intact, no testis was transplanted subcutaneously after adult recipients were castrated in the sham group; 5-7-day juvenile rat testes were transplanted subcutaneously in the castrated group, with one testis per side; Testes resected from juvenile rats were directly transplanted subcutaneously on both sides of the recipients in the non-castrated group. The grafts were obtained and weighed 4 weeks later. Then the histological features of the grafts were examined by HE staining; the expression and distribution of hydroxysteroid 17-beta dehydrogenase 1 (HSD-17β1) were investigated by immunohistochemistry; and the serum androgen level was determined by ELISA. Results The average mass of grafts obtained from the castrated group was significantly higher than that of the non-castrated group. Immunohistochemistry indicated that Leydig cells were visible in the tissues from both the castrated and non-castrated groups, but the number of HSD-17β1-posotive cells in the castrated group was larger than that in the non-castrated group. ELISA results showed that the serum androgen level was higher in the control group and non-castrated group than in the sham group and castrated group, and compared with the sham group, the serum androgen level in the castrated group was significantly higher. Conclusion The juvenile rat testis subcutaneously transplanted could further develop under the adult recipient rat skin, and the Leydig cells of grafts harbored the ability to produce and secret androgen.

Functional Magnetic Resonance Study of Non-conventional Morphological Brains: malnourished rats

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Martin R.

2015-08-01

Full Text Available Malnutrition during brain development can cause serious problems that can be irreversible. Dysfunctional patterns of brain activity can be detected with functional MRI. We used BOLD functional Magnetic Resonance Imaging (fMRI to investigate region differences of brain activity between control and malnourished rats. The food-competition method was applied to a rat model to induce malnutrition during lactation. A 7T magnet was used to detect changes of the BOLD signal associated with changes in brain activity caused by the trigeminal nerve stimulation in malnourished and control rats. Major neuronal activation was observed in malnourished rats in several brain regions, including cerebellum, somatosensory cortex, hippocampus, and hypothalamus. Statistical analysis of the BOLD signals from various brain areas revealed significant differences in somatosensory cortex between the control and experimental groups, as well as a significant difference between the cerebellum and other structures in the experimental group. This study, particularly in malnourished rats, demonstrates increased BOLD activation in the cerebellum.

Influence of dopaminergically mediated reward on somatosensory decision-making.

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Burkhard Pleger

2009-07-01

Full Text Available Reward-related dopaminergic influences on learning and overt behaviour are well established, but any influence on sensory decision-making is largely unknown. We used functional magnetic resonance imaging (fMRI while participants judged electric somatosensory stimuli on one hand or other, before being rewarded for correct performance at trial end via a visual signal, at one of four anticipated financial levels. Prior to the procedure, participants received either placebo (saline, a dopamine agonist (levodopa, or an antagonist (haloperidol.higher anticipated reward improved tactile decisions. Visually signalled reward reactivated primary somatosensory cortex for the judged hand, more strongly for higher reward. After receiving a higher reward on one trial, somatosensory activations and decisions were enhanced on the next trial. These behavioural and neural effects were all enhanced by levodopa and attenuated by haloperidol, indicating dopaminergic dependency. Dopaminergic reward-related influences extend even to early somatosensory cortex and sensory decision-making.

Descending projections from the dysgranular zone of rat primary somatosensory cortex processing deep somatic input.

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Lee, Taehee; Kim, Uhnoh

2012-04-01

In the mammalian somatic system, peripheral inputs from cutaneous and deep receptors ascend via different subcortical channels and terminate in largely separate regions of the primary somatosensory cortex (SI). How these inputs are processed in SI and then projected back to the subcortical relay centers is critical for understanding how SI may regulate somatic information processing in the subcortex. Although it is now relatively well understood how SI cutaneous areas project to the subcortical structures, little is known about the descending projections from SI areas processing deep somatic input. We examined this issue by using the rodent somatic system as a model. In rat SI, deep somatic input is processed mainly in the dysgranular zone (DSZ) enclosed by the cutaneous barrel subfields. By using biotinylated dextran amine (BDA) as anterograde tracer, we characterized the topography of corticostriatal and corticofugal projections arising in the DSZ. The DSZ projections terminate mainly in the lateral subregions of the striatum that are also known as the target of certain SI cutaneous areas. This suggests that SI processing of deep and cutaneous information may be integrated, to a certain degree, in this striatal region. By contrast, at both thalamic and prethalamic levels as far as the spinal cord, descending projections from DSZ terminate in areas largely distinguishable from those that receive input from SI cutaneous areas. These subcortical targets of DSZ include not only the sensory but also motor-related structures, suggesting that SI processing of deep input may engage in regulating somatic and motor information flow between the cortex and periphery. Copyright © 2011 Wiley-Liss, Inc.

Region and task-specific activation of Arc in primary motor cortex of rats following motor skill learning.

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Hosp, J A; Mann, S; Wegenast-Braun, B M; Calhoun, M E; Luft, A R

2013-10-10

Motor learning requires protein synthesis within the primary motor cortex (M1). Here, we show that the immediate early gene Arc/Arg3.1 is specifically induced in M1 by learning a motor skill. Arc mRNA was quantified using a fluorescent in situ hybridization assay in adult Long-Evans rats learning a skilled reaching task (SRT), in rats performing reaching-like forelimb movement without learning (ACT) and in rats that were trained in the operant but not the motor elements of the task (controls). Apart from M1, Arc expression was assessed within the rostral motor area (RMA), primary somatosensory cortex (S1), striatum (ST) and cerebellum. In SRT animals, Arc mRNA levels in M1 contralateral to the trained limb were 31% higher than ipsilateral (pmotor skill learning in rats. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

In vitro uptake of 75Se-selenite by lens of young and adult rats

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Sladkova, J.; Ostadalova, I.; Babicky, A.; Obenberger, J.

1988-01-01

The uptake was observed of 75 Se-selenite by the lens in Wistar strain rats in adult animals, in 17-day old rats kept with their mothers and in prematurely weaned rats. Also measured was the excretion of 75 Se by the lens of young and adult rats following incubation in the medium with radioselenium. The metabolites were analysed which were discharged by the lens containing 75 Se. In Brattleboro rats the uptake of 75 Se-selenite was also measured by the lens in young and adult rats. The uptake of 75 Se-selenite by the lens in young Wistar rats was found to be 1.6 times higher than by the lens of adult rats and the time course of the radioselenium uptake was slightly different. In the lens of prematurely weaned rats no significant difference was found in the uptake of radioselenium after 4 hours as compared with rats of the same age kept with their mothers. In homozygous Brattleboro rats, a higher uptake of 75 Se-selenite was found as compared with both young and adult heterozygous rats. The time course and the quantity of 75 Se efflux from the lens of young and adult Wistar rats differed significantly after 0.5 hour of pre-incubation. From metabolites containing 75 Se excreted by the lens following preincubation, glutathione selenotrisulfide and a not yet accurately determined fraction with a large share of radioactivity were isolated. The stated results provide yet more proof that selenium cataract is a manifestation of the ontogenic dependence of selenium metabolism in the lens and in the entire organism. (author). 4 tabs., 30 refs

Radiation-induced apoptosis in the neonatal and adult rat spinal cord.

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Li, Y Q; Wong, C S

2000-09-01

This study was designed to characterize radiation-induced apoptosis in the spinal cord of the neonatal and young adult rat. Spinal cords (C2-T2) of 1-, 2- and 10-week-old rats were irradiated with a single dose of 8, 18 or 22 Gy. Apoptosis was assessed histologically according to its specific morphological features or by using the TUNEL assay. Cell proliferation was assessed immunohistochemically using BrdU. Identities of cell types undergoing apoptosis were assessed using immunohistochemistry or in situ hybridization using markers for neurons, glial progenitor cells, microglia, oligodendrocytes and astrocytes. The time course of radiation-induced apoptosis in 1- or 2-week-old rat spinal cord was similar to that in the young adult rat spinal cord. A peak response was observed at about 8 h after irradiation, and the apoptosis index returned to the levels in nonirradiated spinal cords at 24 h. The neonatal rat spinal cord demonstrated increased apoptosis compared to the adult. Values for total yield of apoptosis over 24 h induced by 8 Gy in the neonatal rat spinal cord were significantly greater than that in the adult. Immunohistochemistry studies using Leu7, galactocerebroside, Rip and adenomatous polyposis coli tumor suppressor protein indicated that most apoptotic cells were cells of the oligodendroglial lineage regardless of the age of the animal. No evidence of Gfap or factor VIII-related antigen-positive apoptotic cells was observed, and there was a small number of apoptotic microglial cells (lectin-Rca1 positive) in the neonatal and adult rat spinal cord. In the neonatal but not adult rat spinal cord, about 10% of the apoptotic cells appeared to be neurons and were immunoreactive for synaptophysin. Labeling indices (LI) for BrdU in nonirradiated 1- and 2-week-old rat spinal cord were 20.0 and 16.3%, respectively, significantly greater than the LI of 1.0% in the 10-week-old rat spinal cord. At 8 h after a single dose of 8 Gy, 13.4% of the apoptotic cells were

Index finger somatosensory evoked potentials in blind Braille readers.

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Giriyappa, Dayananda; Subrahmanyam, Roopakala Mysore; Rangashetty, Srinivasa; Sharma, Rajeev

2009-01-01

Traditionally, vision has been considered the dominant modality in our multi-sensory perception of the surrounding world. Sensory input via non-visual tracts becomes of greater behavioural relevance in totally blind individuals to enable effective interaction with the world around them. These include audition and tactile perceptions, leading to an augmentation in these perceptions when compared with normal sighted individuals. The objective of the present work was to study the index finger somatosensory evoked potentials (SEPs) in totally blind and normal sighted individuals. SEPs were recorded in 15 Braille reading totally blind females and compared with 15 age-matched normal sighted females. Latency and amplitudes of somatosensory evoked potential waveforms (N9, N13, and N20) were measured. Amplitude of N20 SEP (a cortical somatosensory evoked potential) was significantly larger in the totally blind than in normal sighted individuals (p Braille reading right index finger. Totally blind Braille readers have larger N20 amplitude, suggestive of greater somatosensory cortical representation of the Braille reading index finger.

Pharmacokinetics of bisphenol A in neonatal and adult Sprague-Dawley rats

International Nuclear Information System (INIS)

Doerge, Daniel R.; Twaddle, Nathan C.; Vanlandingham, Michelle; Fisher, Jeffrey W.

2010-01-01

Bisphenol A (BPA) is an important industrial chemical used in the manufacture of polycarbonate plastic products and epoxy resin-based food can liners. The presence of BPA in urine of > 90% of Americans aged 6-60 suggests ubiquitous and frequent exposure. The current study used LC/MS/MS to measure serum pharmacokinetics of aglycone (active) and conjugated (inactive) BPA in adult and neonatal Sprague-Dawley rats by oral and injection routes. Deuterated BPA was used to avoid issues of background contamination. Linear pharmacokinetics were observed in adult rats treated orally in the range of 0-200 μg/kg bw. Evidence for enterohepatic recirculation of conjugated, but not aglycone, BPA was observed in adult rats. Significant inverse relationships were observed between postnatal age and measures of internal exposures to aglycone BPA and its elimination. In neonatal rats treated orally, internal exposures to aglycone BPA were substantially lower than from subcutaneous injection. The results reinforce the critical role for first-pass Phase II metabolism of BPA in gut and liver after oral exposure that attenuates internal exposure to the aglycone form in rats of all ages. The internal exposures to aglycone BPA observed in adult and neonatal rats following a single oral dose of 100 μg/kg bw are inconsistent with effects mediated by classical estrogen receptors based on binding affinities. However, an impact on alternative estrogen signaling pathways that have higher receptor affinity cannot be excluded in neonatal rats. These findings emphasize the importance of matching aglycone BPA internal dosimetry with receptor affinities in experimental animal studies reporting toxicity.

Human perception of electrical stimulation on the surface of somatosensory cortex.

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Shivayogi V Hiremath

Full Text Available Recent advancement in electrocorticography (ECoG-based brain-computer interface technology has sparked a new interest in providing somatosensory feedback using ECoG electrodes, i.e., cortical surface electrodes. We conducted a 28-day study of cortical surface stimulation in an individual with arm paralysis due to brachial plexus injury to examine the sensation produced by electrical stimulation of the somatosensory cortex. A high-density ECoG grid was implanted over the somatosensory and motor cortices. Stimulation through cortical surface electrodes over the somatosensory cortex successfully elicited arm and hand sensations in our participant with chronic paralysis. There were three key findings. First, the intensity of perceived sensation increased monotonically with both pulse amplitude and pulse frequency. Second, changing pulse width changed the type of sensation based on qualitative description provided by the human participant. Third, the participant could distinguish between stimulation applied to two neighboring cortical surface electrodes, 4.5 mm center-to-center distance, for three out of seven electrode pairs tested. Taken together, we found that it was possible to modulate sensation intensity, sensation type, and evoke sensations across a range of locations from the fingers to the upper arm using different stimulation electrodes even in an individual with chronic impairment of somatosensory function. These three features are essential to provide effective somatosensory feedback for neuroprosthetic applications.

Phantom somatosensory evoked potentials following selective intraneural electrical stimulation in two amputees.

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Granata, Giuseppe; Di Iorio, Riccardo; Romanello, Roberto; Iodice, Francesco; Raspopovic, Stanisa; Petrini, Francesco; Strauss, Ivo; Valle, Giacomo; Stieglitz, Thomas; Čvančara, Paul; Andreu, David; Divoux, Jean-Louis; Guiraud, David; Wauters, Loic; Hiairrassary, Arthur; Jensen, Winnie; Micera, Silvestro; Rossini, Paolo Maria

2018-06-01

The aim of the paper is to objectively demonstrate that amputees implanted with intraneural interfaces are truly able to feel a sensation in the phantom hand by recording "phantom" somatosensory evoked potentials from the corresponding brain areas. We implanted four transverse intrafascicular multichannel electrodes, available with percutaneous connections to a multichannel electrical stimulator, in the median and ulnar nerves of two left trans-radial amputees. Two channels of the implants that were able to elicit sensations during intraneural nerve stimulation were chosen, in both patients, for recording somatosensory evoked potentials. We recorded reproducible evoked responses by stimulating the median and the ulnar nerves in both cases. Latencies were in accordance with the arrival of somatosensory information to the primary somatosensory cortex. Our results provide evidence that sensations generated by intraneural stimulation are truly perceived by amputees and located in the phantom hand. Moreover, our results strongly suggest that sensations perceived in different parts of the phantom hand result in different evoked responses. Somatosensory evoked potentials obtained by selective intraneural electrical stimulation in amputee patients are a useful tool to provide an objective demonstration of somatosensory feedback in new generation bidirectional prostheses. Copyright © 2018. Published by Elsevier B.V.

Somatosensory tinnitus: Current evidence and future perspectives

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Greco, Antonio; Turchetta, Rosaria; Altissimi, Giancarlo; de Vincentiis, Marco; Cianfrone, Giancarlo

2017-01-01

In some individuals, tinnitus can be modulated by specific maneuvers of the temporomandibular joint, head and neck, eyes, and limbs. Neuroplasticity seems to play a central role in this capacity for modulation, suggesting that abnormal interactions between the sensory modalities, sensorimotor systems, and neurocognitive and neuroemotional networks may contribute to the development of somatosensory tinnitus. Current evidence supports a link between somatic disorders and higher modulation of tinnitus, especially in patients with a normal hearing threshold. Patients with tinnitus who have somatic disorders seems to have a higher chance of modulating their tinnitus with somatic maneuvers; consistent improvements in tinnitus symptoms have been observed in patients with temporomandibular joint disease following targeted therapy for temporomandibular disorders. Somatosensory tinnitus is often overlooked by otolaryngologists and not fully investigated during the diagnostic process. Somatic disorders, when identified and treated, can be a valid therapeutic target for tinnitus; however, somatic screening of subjects for somatosensory tinnitus is imperative for correct selection of patients who would benefit from a multidisciplinary somatic approach. PMID:28553764

Somatosensory tinnitus: Current evidence and future perspectives.

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Ralli, Massimo; Greco, Antonio; Turchetta, Rosaria; Altissimi, Giancarlo; de Vincentiis, Marco; Cianfrone, Giancarlo

2017-06-01

In some individuals, tinnitus can be modulated by specific maneuvers of the temporomandibular joint, head and neck, eyes, and limbs. Neuroplasticity seems to play a central role in this capacity for modulation, suggesting that abnormal interactions between the sensory modalities, sensorimotor systems, and neurocognitive and neuroemotional networks may contribute to the development of somatosensory tinnitus. Current evidence supports a link between somatic disorders and higher modulation of tinnitus, especially in patients with a normal hearing threshold. Patients with tinnitus who have somatic disorders seems to have a higher chance of modulating their tinnitus with somatic maneuvers; consistent improvements in tinnitus symptoms have been observed in patients with temporomandibular joint disease following targeted therapy for temporomandibular disorders. Somatosensory tinnitus is often overlooked by otolaryngologists and not fully investigated during the diagnostic process. Somatic disorders, when identified and treated, can be a valid therapeutic target for tinnitus; however, somatic screening of subjects for somatosensory tinnitus is imperative for correct selection of patients who would benefit from a multidisciplinary somatic approach.

Kinetics of lead retention and distribution in suckling and adult rats

International Nuclear Information System (INIS)

Momcilovic, B.; Kostial, K.

1974-01-01

The kinetics of lead distribution was studied in suckling and adult rats 8 days after a single intraperitoneal injection of 203 Pb. Marked differences were observed in the kinetics of lead retention and distribution in suckling as compared to adult rats. The rate of 203 Pb disappearance was lower in the whole body, blood and kidneys, but higher in the liver, while the deposition processes predominated in the brain, femur and teeth of sucklings as compared to adult animals. (auth)

Distribution and morphology of nitridergic neurons across functional domains of the rat primary somatosensory cortex

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Anaelli A Nogueira-Campos

2012-11-01

Full Text Available The rat primary somatosensory cortex (S1 is remarkable for its conspicuous vertical compartmentalization in barrels and septal columns, which are additionally stratified in horizontal layers. Whereas excitatory neurons from each of these compartments perform different types of processing, the role of interneurons is much less clear. Among the numerous types of GABAergic interneurons, those producing nitric oxide (NO are especially puzzling, since this gaseous messenger can modulate neural activity, synaptic plasticity and neurovascular coupling. We used a quantitative morphological approach to investigate whether nitrergic interneurons, which might therefore be considered both as NO volume diffusers and as elements of local circuitry, display features that could relate to barrel cortex architecture. In fixed brain sections, nitrergic interneurons can be revealed by histochemical processing for NADPH-diaphorase (NADPHd. Here, the dendritic arbors of nitrergic neurons from different compartments of area S1 were 3D reconstructed from serial 200-μm thick sections, using 100x objective and the Neurolucida system. Standard morphological parameters were extracted for all individual arbors and compared across columns and layers. Wedge analysis was used to compute dendritic orientation indices. Supragranular layers displayed the highest density of nitrergic neurons, whereas layer IV contained nitrergic neurons with largest soma area. The highest nitrergic neuronal density was found in septa, where dendrites were previously characterized as more extense and ramified than in barrels. Dendritic arbors were not confined to the boundaries of the column nor layer of their respective soma, being mostly double-tufted and vertically oriented, except in supragranular layers. These data strongly suggest that nitrergic interneurons adapt their morphology to the dynamics of processing performed by cortical compartments.

Hypertension after bilateral kidney irradiation in young and adult rats

International Nuclear Information System (INIS)

Jongejan, H.T.; van der Kogel, A.J.; Provoost, A.P.; Molenaar, J.C.

1987-01-01

The mechanism of a rise in blood pressure after kidney irradiation is unclear but most likely of renal origin. We have investigated the role of the renin-angiotensin system and dietary salt restriction in the development of systolic hypertension after bilateral kidney irradiation in young and adult rats. Three to 12 months after a single X-ray dose of 7.5 or 12.5 Gy to both kidneys of young and adult rats, the systolic blood pressure (SBP) and plasma renin concentration (PRC) were measured regularly. A single X-ray dose of 12.5 Gy caused a moderate rise in SBP and a slight reduction in PRC in both young and adult rats. A dose of 7.5 Gy did not significantly alter the SBP or PRC during the follow-up period of 1 year. In a second experiment, the kidneys of young rats received an X-ray dose of 20 Gy. Subsequently, rats were kept on a standard diet (110 mmol sodium/kg) or a sodium-poor diet (10 mmol sodium/kg). On both diets, SBP started to rise rapidly 3 months after kidney irradiation. Sodium balance studies carried out at that time revealed an increased sodium retention in the irradiated rats compared to controls on the same diet. In rats on a low sodium intake, there was neither a delay nor an alleviation in the development of hypertension. Compared to controls, the PRC tended to be lower in irradiated rats up to 4 months after irradiation. Subsequently, malignant hypertension developed in all 20 Gy rats, resulting in pressure natriuresis, stimulating the renin-angiotensin system. Our findings indicated that hypertension after bilateral kidney irradiation was not primarily the result of an activation of the renin-angiotensin system. Although there were some indications that sodium retention played a role, dietary sodium restriction did not influence the development of hypertension

[Effect of tail-suspension on the reproduction of adult male rats].

Science.gov (United States)

Zhou, Dang-xia; Qiu, Shu-dong; Wang, Zhi-yong; Zhang, Jie

2006-04-01

To study the effects on the male reproduction in adult male rats and its mechanisms through simulated weightlessness using tail-suspension, in order to do a basic works of exploring the effects on human being's reproduction in outer space. Forty Spraque-Dawley adult male rats were randomly divided into four groups, two experimental groups and two control groups. Rats in the two experimental groups were tail-suspended for 14 d and 28 d respectively, then we examined the weight and morphology of testis, the quality and amount of sperm, also tested the serum hormone by radioimmunoassay and analyzed apoptosis rate of testicular cells by TUNEL in the experimental rats and control rats. After tail-suspension, the weight of testis, the sperm count and sperm motility significantly decreased (P 0.05). These changes were not significant between two experimental groups (P > 0.05). In addition, the seminiferous tubules became atrophy with the reduction of the layers of seminiferous epithelium, and sperm amount in lumens of seminiferous tubules decreased in experimental groups. The above were more remarkable in the 28 d experimental group. Simulating weightlessness has a harmful effect on reproduction of adult male rats. These may be caused by inducing apoptosis. The blocking apoptosis of testicular cells may be useful in improving the harmful effect.

Reproductive experience modified dendritic spines on cortical pyramidal neurons to enhance sensory perception and spatial learning in rats.

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Chen, Jeng-Rung; Lim, Seh Hong; Chung, Sin-Cun; Lee, Yee-Fun; Wang, Yueh-Jan; Tseng, Guo-Fang; Wang, Tsyr-Jiuan

2017-01-27

Behavioral adaptations during motherhood are aimed at increasing reproductive success. Alterations of hormones during motherhood could trigger brain morphological changes to underlie behavioral alterations. Here we investigated whether motherhood changes a rat's sensory perception and spatial memory in conjunction with cortical neuronal structural changes. Female rats of different statuses, including virgin, pregnant, lactating, and primiparous rats were studied. Behavioral test showed that the lactating rats were most sensitive to heat, while rats with motherhood and reproduction experience outperformed virgin rats in a water maze task. By intracellular dye injection and computer-assisted 3-dimensional reconstruction, the dendritic arbors and spines of the layer III and V pyramidal neurons of the somatosensory cortex and CA1 hippocampal pyramidal neurons were revealed for closer analysis. The results showed that motherhood and reproductive experience increased dendritic spines but not arbors or the lengths of the layer III and V pyramidal neurons of the somatosensory cortex and CA1 hippocampal pyramidal neurons. In addition, lactating rats had a higher incidence of spines than pregnant or primiparous rats. The increase of dendritic spines was coupled with increased expression of the glutamatergic postsynaptic marker protein (PSD-95), especially in lactating rats. On the basis of the present results, it is concluded that motherhood enhanced rat sensory perception and spatial memory and was accompanied by increases in dendritic spines on output neurons of the somatosensory cortex and CA1 hippocampus. The effect was sustained for at least 6 weeks after the weaning of the pups.

Four-dimensional maps of the human somatosensory system.

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Avanzini, Pietro; Abdollahi, Rouhollah O; Sartori, Ivana; Caruana, Fausto; Pelliccia, Veronica; Casaceli, Giuseppe; Mai, Roberto; Lo Russo, Giorgio; Rizzolatti, Giacomo; Orban, Guy A

2016-03-29

A fine-grained description of the spatiotemporal dynamics of human brain activity is a major goal of neuroscientific research. Limitations in spatial and temporal resolution of available noninvasive recording and imaging techniques have hindered so far the acquisition of precise, comprehensive four-dimensional maps of human neural activity. The present study combines anatomical and functional data from intracerebral recordings of nearly 100 patients, to generate highly resolved four-dimensional maps of human cortical processing of nonpainful somatosensory stimuli. These maps indicate that the human somatosensory system devoted to the hand encompasses a widespread network covering more than 10% of the cortical surface of both hemispheres. This network includes phasic components, centered on primary somatosensory cortex and neighboring motor, premotor, and inferior parietal regions, and tonic components, centered on opercular and insular areas, and involving human parietal rostroventral area and ventral medial-superior-temporal area. The technique described opens new avenues for investigating the neural basis of all levels of cortical processing in humans.

Structural and functional changes in the somatosensory cortex in euthymic females with bipolar disorder.

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Minuzzi, Luciano; Syan, Sabrina K; Smith, Mara; Hall, Alexander; Hall, Geoffrey Bc; Frey, Benicio N

2017-12-01

Current evidence from neuroimaging data suggests possible dysfunction of the fronto-striatal-limbic circuits in individuals with bipolar disorder. Somatosensory cortical function has been implicated in emotional recognition, risk-taking and affective responses through sensory modalities. This study investigates anatomy and function of the somatosensory cortex in euthymic bipolar women. In total, 68 right-handed euthymic women (bipolar disorder = 32 and healthy controls = 36) between 16 and 45 years of age underwent high-resolution anatomical and functional magnetic resonance imaging during the mid-follicular menstrual phase. The somatosensory cortex was used as a seed region for resting-state functional connectivity analysis. Voxel-based morphometry was used to evaluate somatosensory cortical gray matter volume between groups. We found increased resting-state functional connectivity between the somatosensory cortex and insular cortex, inferior prefrontal gyrus and frontal orbital cortex in euthymic bipolar disorder subjects compared to healthy controls. Voxel-based morphometry analysis showed decreased gray matter in the left somatosensory cortex in the bipolar disorder group. Whole-brain voxel-based morphometry analysis controlled by age did not reveal any additional significant difference between groups. This study is the first to date to evaluate anatomy and function of the somatosensory cortex in a well-characterized sample of euthymic bipolar disorder females. Anatomical and functional changes in the somatosensory cortex in this population might contribute to the pathophysiology of bipolar disorder.

Effects of Mercury Chloride on the Cerebral Cortex of Adult Wistar Rats

African Journals Online (AJOL)

Mercury is among the heavy metals that have been reported to cause devastating health problem worldwide. The primary site of action of mercury chloride is the central nervous system. This study investigated the effect of mercury chloride on the cerebral cortex of adult wistar rats. Twenty-four (24) adult wistar rats were used ...

Comparison and modification of Pu-239 kinetics in young and adult rats

International Nuclear Information System (INIS)

Volf, V.; Gamer, A.; Laengle, U.

1987-01-01

It is obvious that the biokinetics of bone-seeking radionuclides are influenced by skeletal growth and remodelling, the rate of which in general decreases with increasing age. For plutonium, Mahlum and Sikov (1974) observed that rats injected with Pu-239 as weanlings retained a lower percentage in the liver and more in the bones than the animals injected as adults. However, skeletal Pu-239 was diluted more rapidly in the young rats because of intensive new bone formation and this led to a more pronounced reduction in the accumulation of radiation dose than was the case in adult animals. The aim of the present experiments was to study: a) The age effect on Pu-239 biokinetics in adult rates as influenced by the sex of the animals. b) Early retention and distribution of Pu-239 in the bones of young and adult rats injected with an optimal osteosarcomogenic dose. c) The effectiveness of a delayed prolonged administration of Zn-DTPA in drinking water for the mobilization of injected Pu-239 in rats of various age. 3 refs.; 5 figs.; 1 table

Repeated touch and needle-prick stimulation in the neonatal period increases the baseline mechanical sensitivity and postinjury hypersensitivity of adult spinal sensory neurons.

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van den Hoogen, Nynke J; Patijn, Jacob; Tibboel, Dick; Joosten, Bert A; Fitzgerald, Maria; Kwok, Charlie H T

2018-03-08

Noxious stimulation at critical stages of development has long-term consequences on somatosensory processing in later life, but it is not known whether this developmental plasticity is restricted to nociceptive pathways. Here, we investigate the effect of repeated neonatal noxious or innocuous hind paw stimulation on adult spinal dorsal horn cutaneous mechanical sensitivity. Neonatal Sprague-Dawley rats of both sexes received 4 unilateral left hind paw needle pricks (NPs, n = 13) or 4 tactile (cotton swab touch) stimuli, per day (TC, n = 11) for the first 7 days of life. Control pups were left undisturbed (n = 17). When adult (6-8 weeks), lumbar wide-dynamic-range neuron activity in laminae III-V was recorded using in vivo extracellular single-unit electrophysiology. Spike activity evoked by cutaneous dynamic tactile (brush), pinch and punctate (von Frey hair) stimulation, and plantar receptive field areas were recorded, at baseline and 2 and 5 days after left plantar hind paw incision. Baseline brush receptive fields, von Frey hair, and pinch sensitivity were significantly enhanced in adult NP and TC animals compared with undisturbed controls, although effects were greatest in NP rats. After incision, injury sensitivity of adult wide-dynamic-range neurons to both noxious and dynamic tactile hypersensitivity was significantly greater in NP animals compared with TC and undisturbed controls. We conclude that both repeated touch and needle-prick stimulation in the neonatal period can alter adult spinal sensory neuron sensitivity to both innocuous and noxious mechanical stimulation. Thus, spinal sensory circuits underlying touch and pain processing are shaped by a range of early-life somatosensory experiences.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Somatosensory evoked potentials and dynamic postural assessment in adolescent idiopathic scoliosis

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Dalia Mohamed Ezz El Mikkawy

2016-01-01

Conclusion The study demonstrates abnormal somatosensory and postural function in patients with AIS, and a significant inter-relationship between the scoliotic angle, the somatosensory system, and posture. Thus, optimum assessment and treatment of neurological pathway and balance are important in these patients.

Somatosensory Representations Link the Perception of Emotional Expressions and Sensory Experience.

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Kragel, Philip A; LaBar, Kevin S

2016-01-01

Studies of human emotion perception have linked a distributed set of brain regions to the recognition of emotion in facial, vocal, and body expressions. In particular, lesions to somatosensory cortex in the right hemisphere have been shown to impair recognition of facial and vocal expressions of emotion. Although these findings suggest that somatosensory cortex represents body states associated with distinct emotions, such as a furrowed brow or gaping jaw, functional evidence directly linking somatosensory activity and subjective experience during emotion perception is critically lacking. Using functional magnetic resonance imaging and multivariate decoding techniques, we show that perceiving vocal and facial expressions of emotion yields hemodynamic activity in right somatosensory cortex that discriminates among emotion categories, exhibits somatotopic organization, and tracks self-reported sensory experience. The findings both support embodied accounts of emotion and provide mechanistic insight into how emotional expressions are capable of biasing subjective experience in those who perceive them.

Sub-threshold cross-modal sensory interaction in the thalamus: lemniscal auditory response in the medial geniculate nucleus is modulated by somatosensory stimulation.

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Donishi, T; Kimura, A; Imbe, H; Yokoi, I; Kaneoke, Y

2011-02-03

Recent studies have highlighted cross-modal sensory modulations in the primary sensory areas in the cortex, suggesting that cross-modal sensory interactions occur at early stages in the hierarchy of sensory processing. Multi-modal sensory inputs from non-lemniscal thalamic nuclei and cortical inputs from the secondary sensory and association areas are considered responsible for the modulations. On the other hand, there is little evidence of cross-sensory modal sensitivities in lemniscal thalamic nuclei. In the present study, we were interested in a possibility that somatosensory stimulation may affect auditory response in the ventral division (MGV) of the medial geniculate nucleus (MG), a lemniscal thalamic nucleus that is considered to be dedicated to auditory uni-modal processing. Experiments were performed on anesthetized rats. Transcutaneous electrical stimulation of the hindpaw, which is thought to evoke nociception and seems unrelated to auditory processing, modulated unit discharges in response to auditory stimulation (noise bursts). The modulation was observed in the MGV and non-lemniscal auditory thalamic nuclei such as the dorsal and medial divisions of the MG. The major effect of somatosensory stimulation was suppression. The most robust suppression was induced by electrical stimuli given simultaneously with noise bursts or preceding noise bursts by 10 to 20 ms. The results indicate that the lemniscal (MGV) and non-lemniscal auditory nuclei are subject to somatosensory influence. In everyday experience intense somatosensory stimuli such as pain interrupt our ongoing hearing or interfere with clear recognition of sound. The modulation of lemniscal auditory response by somatosensory stimulation may underlie such cross-modal disturbance of auditory perception as a form of cross-modal switching of attention. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

Discriminability of Single and Multichannel Intracortical Microstimulation within Somatosensory Cortex

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Cynthia Kay Overstreet

2016-12-01

Full Text Available The addition of tactile and proprioceptive feedback to neuroprosthetic limbs is expected to significantly improve the control of these devices. Intracortical microstimulation (ICMS of somatosensory cortex is a promising method of delivering this sensory feedback. To date, the main focus of somatosensory ICMS studies has been to deliver discriminable signals, corresponding to varying intensity, to a single location in cortex. However, multiple independent and simultaneous streams of sensory information will need to be encoded by ICMS to provide functionally relevant feedback for a neuroprosthetic limb (e.g. encoding contact events and pressure on multiple digits.In this study, we evaluated the ability of an awake, behaving non-human primate (Macaca mulatta to discriminate ICMS stimuli delivered on multiple electrodes spaced within somatosensory cortex. We delivered serial stimulation on single electrodes to evaluate the discriminability of sensations corresponding to ICMS of distinct cortical locations. Additionally, we delivered trains of multichannel stimulation, derived from a tactile sensor, synchronously across multiple electrodes. Our results indicate that discrimination of multiple ICMS stimuli is a challenging task, but that discriminable sensory percepts can be elicited by both single and multichannel ICMS on electrodes spaced within somatosensory cortex.

Methylphenidate increases glucose uptake in the brain of young and adult rats.

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Réus, Gislaine Z; Scaini, Giselli; Titus, Stephanie E; Furlanetto, Camila B; Wessler, Leticia B; Ferreira, Gabriela K; Gonçalves, Cinara L; Jeremias, Gabriela C; Quevedo, João; Streck, Emilio L

2015-10-01

Methylphenidate (MPH) is the drug of choice for pharmacological treatment of attention deficit hyperactivity disorder. Studies have pointed to the role of glucose and lactate as well as in the action mechanisms of drugs used to treat these neuropsychiatric diseases. Thus, this study aims to evaluate the effects of MPH administration on lactate release and glucose uptake in the brains of young and adult rats. MPH (1.0, 2.0 and 10.0mg/kg) or saline was injected in young and adult Wistar male rats either acutely (once) or chronically (once daily for 28 days). Then, the levels of lactate release and glucose uptake were assessed in the prefrontal cortex, hippocampus, striatum, cerebellum and cerebral cortex. Chronic MPH treatment increased glucose uptake at the dose of 10.0mg/kg in the prefrontal cortex and striatum, and at the dose of 2.0mg/kg in the cerebral cortex of young rats. In adult rats, an increase in glucose uptake was observed after acute administration of MPH at the dose of 10.0mg/kg in the prefrontal cortex. After chronic treatment, there was an increase in glucose uptake with MPH doses of 2.0 and 10.0mg/kg in the prefrontal cortex, and at an MPH dose of 2.0mg/kg in the striatum of adult rats. The lactate release did not change with either acute or chronic treatments in young or adult rats. These findings indicate that MPH increases glucose consumption in the brain, and that these changes are dependent on age and posology. Copyright © 2015 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Different Astrocytic Activation between Adult Gekko japonicus and Rats during Wound Healing In Vitro.

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Yun Gu

Full Text Available Glial scar formation is a major obstacle to regeneration after spinal cord injury. Moreover, it has been shown that the astrocytic response to injury differs between species. Gekko japonicas is a type of reptile and it shows differential glial activation compared to that of rats. The purpose of the present study was to compare the proliferation and migration of astrocytes in the spinal cords of geckos and rats after injury in vitro. Spinal cord homogenate stimulation and scratch wound models were used to induce astrocytic activation in adult and embryonic rats, as well as in adult geckos. Our results indicated that astrocytes from the adult rat were likely activated by mechanical stimulation, even though they showed lower proliferation abilities than the astrocytes from the gecko under normal conditions. Furthermore, a transcriptome analysis revealed that the differentially expressed genes in astrocytes from adult rats and those from geckos were enriched in pathways involved in proliferation and the response to stimuli. This implies that intrinsic discrepancies in gene expression patterns might contribute to the differential activation of astrocytes between species.

MEG event-related desynchronization and synchronization deficits during basic somatosensory processing in individuals with ADHD

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Wang Frank

2008-02-01

Full Text Available Abstract Background Attention-Deficit/Hyperactivity Disorder (ADHD is a prevalent, complex disorder which is characterized by symptoms of inattention, hyperactivity, and impulsivity. Convergent evidence from neurobiological studies of ADHD identifies dysfunction in fronto-striatal-cerebellar circuitry as the source of behavioural deficits. Recent studies have shown that regions governing basic sensory processing, such as the somatosensory cortex, show abnormalities in those with ADHD suggesting that these processes may also be compromised. Methods We used event-related magnetoencephalography (MEG to examine patterns of cortical rhythms in the primary (SI and secondary (SII somatosensory cortices in response to median nerve stimulation, in 9 adults with ADHD and 10 healthy controls. Stimuli were brief (0.2 ms non-painful electrical pulses presented to the median nerve in two counterbalanced conditions: unpredictable and predictable stimulus presentation. We measured changes in strength, synchronicity, and frequency of cortical rhythms. Results Healthy comparison group showed strong event-related desynchrony and synchrony in SI and SII. By contrast, those with ADHD showed significantly weaker event-related desynchrony and event-related synchrony in the alpha (8–12 Hz and beta (15–30 Hz bands, respectively. This was most striking during random presentation of median nerve stimulation. Adults with ADHD showed significantly shorter duration of beta rebound in both SI and SII except for when the onset of the stimulus event could be predicted. In this case, the rhythmicity of SI (but not SII in the ADHD group did not differ from that of controls. Conclusion Our findings suggest that somatosensory processing is altered in individuals with ADHD. MEG constitutes a promising approach to profiling patterns of neural activity during the processing of sensory input (e.g., detection of a tactile stimulus, stimulus predictability and facilitating our

Operant conditioning of rat navigation using electrical stimulation for directional cues and rewards.

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Lee, Maan-Gee; Jun, Gayoung; Choi, Hyo-Soon; Jang, Hwan Soo; Bae, Yong Chul; Suk, Kyoungho; Jang, Il-Sung; Choi, Byung-Ju

2010-07-01

Operant conditioning is often used to train a desired behavior in an animal. The contingency between a specific behavior and a reward is required for successful training. Here, we compared the effectiveness of two different mazes for training turning behaviors in response to directional cues in Sprague-Dawley rats. Forty-three rats were implanted with electrodes into the medial forebrain bundle and the left and right somatosensory cortices for reward and cues. Among them, thirteen rats discriminated between the left and right somatosensory stimulations to obtain rewards. They were trained to learn ipsilateral turning response to the stimulation of the left or right somatosensory cortex in either the T-maze (Group T) or the E| maze (Group W). Performance was measured by the navigation speed in the mazes. Performances of rats in Group T were enhanced faster than those in Group W. A significant correlation between performances during training and performance in final testing was observed in Group T starting with the fifth training session while such a correlation was not observed in Group W until the tenth training session. The training mazes did not however affect the performances in the final test. These results suggest that a simple maze is better than a complicated maze for training animals to learn directions and direct cortical stimulation can be used as a cue for direction training. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Volumetric localization of somatosensory cortex in children using synthetic aperture magnetometry

International Nuclear Information System (INIS)

Xiang, Jing; Holowka, Stephanie; Chuang, Sylvester; Sharma, Rohit; Hunjan, Amrita; Otsubo, Hiroshi

2003-01-01

Magnetic signal from the human brain can be measured noninvasively by using magnetoencephalography (MEG). This study was designed to localize and reconstruct the neuromagnetic activity in the somatosensory cortex in children Twenty children were studied using a 151-channel MEG system with electrical stimulation applied to median nerves. Data were analyzed using synthetic aperture magnetometry (SAM). A clear deflection (M1) was clearly identified in 18 children (90%, 18/20). Two frequency bands, 30-60 Hz and 60-120 Hz, were found to be related to somatosensory cortex. Magnetic activity was localized in the posterior bank of the central sulcus in 16 children. The extent of the reconstructed neuromagnetic activity of the left hemisphere was significantly larger than that of the right hemisphere (P<0.01). Somatosensory cortex was accurately localized by using SAM. The extent of the reconstructed neuromagnetic activity suggested that the left hemisphere was the dominant side in the somatosensory system in children. We postulate that the volumetric characteristics of the reconstructed neuromagnetic activity are able to indicate the functionality of the brain. (orig.)

Abilities in tactile discrimination of textures in adult rats exposed to enriched or impoverished environments.

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Bourgeon, Stéphanie; Xerri, Christian; Coq, Jacques-Olivier

2004-08-12

In previous studies, we have shown that housing in enriched environment for about 3 months after weaning improved the topographic organization and decreased the size of the receptive fields (RFs) located on the glabrous skin surfaces in the forepaw maps of the primary somatosensory cortex (SI) in rats [Exp. Brain Res. 121 (1998) 191]. In contrast, housing in impoverished environment induced a degradation of the SI forepaw representation, characterized by topographic disruptions, a reduction of the cutaneous forepaw area and an enlargement of the glabrous RFs [Exp. Brain Res. 129 (1999) 518]. Based on these two studies, we postulated that these representational alterations could underlie changes in haptic perception. Therefore, the present study was aimed at determining the influence of housing conditions on the rat's abilities in tactile texture discrimination. After a 2-month exposure to enriched or impoverished environments, rats were trained to perform a discrimination task during locomotion on floorboards of different roughness. At the end of every daily behavioral session, rats were replaced in their respective housing environment. Rats had to discriminate homogeneous (low roughness) from heterogeneous floorboards (combination of two different roughness levels). To determine the maximum performance in texture discrimination, the roughness contrast of the heterogeneous texture was gradually reduced, so that homogeneous and heterogeneous floorboards became harder to differentiate. We found that the enriched rats learned the first steps of the behavioral task faster than the impoverished rats, whereas both groups exhibited similar performances in texture discrimination. An individual "predilection" for either homogeneous or heterogeneous floorboards, presumably reflecting a behavioral strategy, seemed to account for the absence of differences in haptic discrimination between groups. The sensory experience depending on the rewarded texture discrimination task

Dietary modulation of parathion-induced neurotoxicity in adult and juvenile rats.

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Liu, Jing; Karanth, Subramanya; Pope, Carey

2005-06-01

Previous studies indicated that dietary glucose (15% in drinking water) could markedly exacerbate the toxicity of parathion in adult rats. The present study evaluated the effect of consumption of the commonly used sweetener, high fructose corn syrup (HFCS), on parathion toxicity in adult and juvenile rats. Animals were given free access to either water or 15% HFCS in drinking water for a total of 10 days and challenged with parathion (6 or 18 mg/kg, s.c., for juveniles or adults, respectively) on the 4th day. Signs of cholinergic toxicity, body weight and chow/fluid intake were recorded daily. Acetylcholinesterase (AChE) activity and immunoreactivity (AChE-IR) in frontal cortex and diaphragm were measured at 2, 4, and 7 days after parathion. As HFCS was associated with significant reduction in chow intake, adult rats were also pair-fed to evaluate the effect of similar reduced chow intake alone on parathion toxicity. The results indicated that the cholinergic toxicity of parathion was significantly increased by HFCS feeding in both age groups. The excess sugar consumption, however, did not significantly affect parathion-induced AChE inhibition in either tissue or either age group. Enzyme immunoreactivity in frontal cortex was generally not affected in either age group while diaphragm AChE-IR was significantly reduced by parathion and HFCS alone in adult animals at 2 and 4 days timepoints, and more so by the combination of sugar feeding and parathion exposure in both age groups. Food restriction alone did not exacerbate parathion toxicity. While the mechanism(s) remains unclear, we conclude that voluntary consumption of the common sweetener HFCS can markedly amplify parathion acute toxicity in both juvenile and adult rats.

Disruption of behavior and brain metabolism in artificially reared rats.

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Aguirre-Benítez, Elsa L; Porras, Mercedes G; Parra, Leticia; González-Ríos, Jacquelina; Garduño-Torres, Dafne F; Albores-García, Damaris; Avendaño, Arturo; Ávila-Rodríguez, Miguel A; Melo, Angel I; Jiménez-Estrada, Ismael; Mendoza-Garrido, Ma Eugenia; Toriz, César; Diaz, Daniel; Ibarra-Coronado, Elizabeth; Mendoza-Ángeles, Karina; Hernández-Falcón, Jesús

2017-12-01

Early adverse life stress has been associated to behavioral disorders that can manifest as inappropriate or aggressive responses to social challenges. In this study, we analyzed the effects of artificial rearing on the open field and burial behavioral tests and on GFAP, c-Fos immunoreactivity, and glucose metabolism measured in anxiety-related brain areas. Artificial rearing of male rats was performed by supplying artificial milk through a cheek cannula and tactile stimulation, mimicking the mother's licking to rat pups from the fourth postnatal day until weaning. Tactile stimulation was applied twice a day, at morning and at night, by means of a camel brush on the rat anogenital area. As compared to mother reared rats, greater aggressiveness, and boldness, stereotyped behavior (burial conduct) was observed in artificially reared rats which occurred in parallel to a reduction of GFAP immunoreactivity in somatosensory cortex, c-Fos immunoreactivity at the amygdala and primary somatosensory cortex, and lower metabolism in amygdala (as measured by 2-deoxi-2-[ 18 fluoro]-d-glucose uptake, assessed by microPET imaging). These results could suggest that tactile and/or chemical stimuli from the mother and littermates carry relevant information for the proper development of the central nervous system, particularly in brain areas involved with emotions and social relationships of the rat. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1413-1429, 2017. © 2017 Wiley Periodicals, Inc.

Neural mechanisms of selective attention in the somatosensory system.

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Gomez-Ramirez, Manuel; Hysaj, Kristjana; Niebur, Ernst

2016-09-01

Selective attention allows organisms to extract behaviorally relevant information while ignoring distracting stimuli that compete for the limited resources of their central nervous systems. Attention is highly flexible, and it can be harnessed to select information based on sensory modality, within-modality feature(s), spatial location, object identity, and/or temporal properties. In this review, we discuss the body of work devoted to understanding mechanisms of selective attention in the somatosensory system. In particular, we describe the effects of attention on tactile behavior and corresponding neural activity in somatosensory cortex. Our focus is on neural mechanisms that select tactile stimuli based on their location on the body (somatotopic-based attention) or their sensory feature (feature-based attention). We highlight parallels between selection mechanisms in touch and other sensory systems and discuss several putative neural coding schemes employed by cortical populations to signal the behavioral relevance of sensory inputs. Specifically, we contrast the advantages and disadvantages of using a gain vs. spike-spike correlation code for representing attended sensory stimuli. We favor a neural network model of tactile attention that is composed of frontal, parietal, and subcortical areas that controls somatosensory cells encoding the relevant stimulus features to enable preferential processing throughout the somatosensory hierarchy. Our review is based on data from noninvasive electrophysiological and imaging data in humans as well as single-unit recordings in nonhuman primates. Copyright © 2016 the American Physiological Society.

[Neurophysiological investigations of information processing in the somato-sensory system].

Science.gov (United States)

Kunesch, E

2009-08-01

The ability of the human hand to perform complex sensorimotor tasks such as tactile exploration and grasping is based on 1. exact encoding of somatosensory information by cutaneous mechanoreceptors, 2. elaborated processing of afferent signals in somatosensory relay stations and cortex fields, 3. rapid and effective interaction of sensory feedback with motor programs, and 4. different modes of sensory control, which can be switched over. (c) Georg Thieme Verlag KG Stuttgart-New York.

Long-term organ culture of adult rat colon

DEFF Research Database (Denmark)

Shamsuddin, A.K.M.; Barrett, L.A.; Autrup, Herman

1978-01-01

. The effect of in vivo carcinogen pretreatment was also studied. The explant culture from control untreated animals showed good epithelial differentiation with crypts until 6 weeks. In contrast, the explants from animals pretreated with 4 weekly doses of azoxymethane consistently showed epithelial......Colon explants from adult rats were maintained in culture for over 3 months in our laboratories with good epithelial preservation and cellular differentiation. The light and transmission electron microscopic features of rat colon mucosa during the culture period are described. In all the explants...

High serotonin levels during brain development alter the structural input-output connectivity of neural networks in the rat somatosensory layer IV

Directory of Open Access Journals (Sweden)

Stéphanie eMiceli

2013-06-01

Full Text Available Homeostatic regulation of serotonin (5-HT concentration is critical for normal topographical organization and development of thalamocortical (TC afferent circuits. Down-regulation of the serotonin transporter (SERT and the consequent impaired reuptake of 5-HT at the synapse, results in a reduced terminal branching of developing TC afferents within the primary somatosensory cortex (S1. Despite the presence of multiple genetic models, the effect of high extracellular 5-HT levels on the structure and function of developing intracortical neural networks is far from being understood. Here, using juvenile SERT knockout (SERT-/- rats we investigated, in vitro, the effect of increased 5-HT levels on the structural organization of (i the thalamocortical projections of the ventroposteromedial thalamic nucleus towards S1, (ii the general barrel-field pattern and (iii the electrophysiological and morphological properties of the excitatory cell population in layer IV of S1 (spiny stellate and pyramidal cells. Our results confirmed previous findings that high levels of 5-HT during development lead to a reduction of the topographical precision of TCA projections towards the barrel cortex. Also, the barrel pattern was altered but not abolished in SERT-/- rats. In layer IV, both excitatory spiny stellate and pyramidal cells showed a significantly reduced intracolumnar organization of their axonal projections. In addition, the layer IV spiny stellate cells gave rise to a prominent projection towards the infragranular layer Vb. Our findings point to a structural and functional reorganization, of TCAs, as well as early stage intracortical microcircuitry, following the disruption of 5-HT reuptake during critical developmental periods. The increased projection pattern of the layer IV neurons suggests that the intracortical network changes are not limited to the main entry layer IV but may also affect the subsequent stages of the canonical circuits of the barrel

Metabolic and hemodynamic activation of postischemic rat brain by cortical spreading depression.

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Kocher, M

1990-07-01

Following transient ischemia of the brain, the coupling between somatosensory activation and the hemodynamic-metabolic response is abolished for a certain period despite the partial recovery of somatosensory evoked responses. To determine whether this disturbance is due to alterations of the stimulus-induced neuronal excitation or to a breakdown of the coupling mechanisms, cortical spreading depression was used as a metabolic stimulus in rats before and after ischemia. Adult rats were subjected to 30 min of global forebrain ischemia and 3-6 h of recirculation. EEG, cortical direct current (DC) potential, and laser-Doppler flow were continuously recorded. Local CBF (LCBF), local CMRglc (LCMRglc), regional tissue contents of ATP, glucose, and lactate, and regional pH were determined by quantitative autoradiography, substrate-induced bioluminescence, and fluorometry. Amplitude and frequency of the DC shifts did not differ between groups. In control animals, spreading depression induced a 77% rise in cortical glucose consumption, a 66% rise in lactate content, and a drop in tissue pH of 0.3 unit. ATP and glucose contents were not depleted. During the passage of DC shifts, transient increases (less than 2 min) in laser-Doppler flow were observed, followed by a post-spreading depression hypoperfusion. A comparable although less expressed pattern of hemodynamic and metabolic changes was observed in the postischemic rats. Although baseline LCMRglc was depressed after ischemia, it was activated 47% during spreading depression. Lactate increased by 26%, pH decreased by 0.3 unit, and ATP and glucose remained unchanged. The extent of the transient increase in laser-Doppler flow did not differ from that of the control group, and a post-spreading depression hypoperfusion was also found.(ABSTRACT TRUNCATED AT 250 WORDS)

Immature rats show ovulatory defects similar to those in adult rats lacking prostaglandin and progesterone actions

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Sanchez-Criado Jose E

2004-09-01

Full Text Available Abstract Gonadotropin-primed immature rats (GPIR constitute a widely used model for the study of ovulation. Although the equivalence between the ovulatory process in immature and adult rats is generally assumed, the morphological and functional characteristics of ovulation in immature rats have been scarcely considered. We describe herein the morphological aspects of the ovulatory process in GPIR and their response to classical ovulation inhibitors, such as the inhibitor of prostaglandin (PG synthesis indomethacin (INDO and a progesterone (P receptor (PR antagonist (RU486. Immature Wistar rats were primed with equine chorionic gonadotropin (eCG at 21, 23 or 25 days of age, injected with human chorionic gonadotropin (hCG 48 h later, and sacrificed 16 h after hCG treatment, to assess follicle rupture and ovulation. Surprisingly, GPIR showed age-related ovulatory defects close similar to those in adult rats lacking P and PG actions. Rats primed with eCG at 21 or 23 days of age showed abnormally ruptured corpora lutea in which the cumulus-oocyte complex (COC was trapped or had been released to the ovarian interstitum, invading the ovarian stroma and blood and lymphatic vessels. Supplementation of immature rats with exogenous P and/or PG of the E series did not significantly inhibit abnormal follicle rupture. Otherwise, ovulatory defects were practically absent in rats primed with eCG at 25 days of age. GPIR treated with INDO showed the same ovulatory alterations than vehicle-treated ones, although affecting to a higher proportion of follicles. Blocking P actions with RU486 increased the number of COC trapped inside corpora lutea and decreased ovulation. The presence of ovulatory defects in GPIR, suggests that the capacity of the immature ovary to undergo the coordinate changes leading to effective ovulation is not fully established in Wistar rats primed with eCG before 25 days of age.

Intrauterine ethanol exposure results in hypothalamic oxidative stress and neuroendocrine alterations in adult rat offspring.

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Dembele, Korami; Yao, Xing-Hai; Chen, Li; Nyomba, B L Grégoire

2006-09-01

Prenatal ethanol (EtOH) exposure is associated with low birth weight, followed by increased appetite, catch-up growth, insulin resistance, and impaired glucose tolerance in the rat offspring. Because EtOH can induce oxidative stress, which is a putative mechanism of insulin resistance, and because of the central role of the hypothalamus in the regulation of energy homeostasis and insulin action, we investigated whether prenatal EtOH exposure causes oxidative damage to the hypothalamus, which may alter its function. Female rats were given EtOH by gavage throughout pregnancy. At birth, their offspring were smaller than those of non-EtOH rats. Markers of oxidative stress and expression of neuropeptide Y and proopiomelanocortin (POMC) were determined in hypothalami of postnatal day 7 (PD7) and 3-mo-old (adult) rat offspring. In both PD7 and adult rats, prenatal EtOH exposure was associated with decreased levels of glutathione and increased expression of MnSOD. The concentrations of lipid peroxides and protein carbonyls were normal in PD7 EtOH-exposed offspring, but were increased in adult EtOH-exposed offspring. Both PD7 and adult EtOH-exposed offspring had normal neuropeptide Y and POMC mRNA levels, but the adult offspring had reduced POMC protein concentration. Thus only adult offspring preexposed to EtOH had increased hypothalamic tissue damage and decreased levels of POMC, which could impair melanocortin signaling. We conclude that prenatal EtOH exposure causes hypothalamic oxidative stress, which persists into adult life and alters melanocortin action during adulthood. These neuroendocrine alterations may explain weight gain and insulin resistance in rats exposed to EtOH early in life.

Some behavioral aspects of adult rats irradiated prenatally

International Nuclear Information System (INIS)

Vekovishcheva, O.Yu.; Blagova, O.E.; Borovitskaya, A.E.; Evtushenko, V.I.; Khanson, K.P.

1992-01-01

This is a study of the effects of prenatal irradiation on the behavior of rats. The experiments were performed on 42 eighteen month old rats of both sexes. Eight of the males and thirteen females had been irradiated prenatally. The results of this experiment indicated that in general, the activation of behavior, the appearance of aggression and the increase in chaos along with the presence of behavior poses were typical of the suppressed condition of the prenatal irradiated animal. Also, among prenatally irradiated animals, there was a greater degree of anxiety, a slow rate of adjustment to unfamiliar situations and unfriendly relationships between animals of the same sex. These results were compared with the results of behavioral experiments on irradiated adult rats

Independent mediation of unconditioned motor behavior by striatal D1 and D2 receptors in rats depleted of dopamine as neonates.

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Bruno, J P; Byrnes, E M; Johnson, B J

1995-11-01

The effects of systemic administration of DA receptor antagonists suggest that unconditioned motor behavior in rats depleted of DA as neonates continues to be dependent upon dopaminergic transmission, yet the specific contribution of D1 and D2 receptors to these behaviors has been altered. The purpose of the present study was to determine whether these depletion-induced receptor changes are occurring at the level of striatal DA terminals and their targets. The ability of bilateral intrastriatal injections (0.5 microliter) of DA receptor antagonists to induce motoric deficits was determined in adult rats treated with vehicle or 6-OHDA (100 micrograms, intraventricular) on postnatal day 3. Administration of the D1-like antagonist SCH 23390 (0.5-2.0 micrograms) or the D2-like antagonist clebopride (1.0-4.0 micrograms) induced dose-dependent akinesia, catalepsy, and somatosensory neglect in vehicle-treated controls. In contrast, neither antagonist produced deficits in rats depleted of forebrain DA as neonates. However, combined administration of SCH 23390 + clebopride induced similar akinesia, catalepsy, and somatosensory neglect in both controls and DA depleted animals. Animals depleted of DA were more sensitive than controls to the low doses of this combined D1 + D2 antagonism. These results demonstrate that activation of striatal DA receptors remains necessary for unconditioned motor behavior in rats depleted of DA as neonates. However, the specific contributions of D1- and D2-like receptors to these behaviors differ between intact animals and those depleted of DA as neonates. The ability of endogenous DA acting at either D1 or D2 receptors to support spontaneous motor behavior in rats depleted of DA as neonates may contribute to their relative sparing from parkinsonian deficits.

The effect of prenatal methamphetamine exposure on recognition memory in adult rats.

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Fialová, Markéta; Šírová, Jana; Bubeníková-Valešová, Věra; Šlamberová, Romana

2015-01-01

The use of methamphetamine (MA) among pregnant women is an increasing world-wide health problem. Prenatal MA exposure may cause changes in foetus but the exact effects have remained unclear. The aim of this study is to present the effect of prenatal MA exposure on recognition memory in adult rats. Adult female Wistar rats were injected daily with D-methamphetamine HCl (MA; 5 mg/kg, s.c.) during the entire gestation period. Control females were treated with saline in the same regime. Adult male offspring was administrated acutely by MA (1 mg/kg i.p.) or saline 30 minutes before beginning of an experiment. For testing recognition memory two tasks were chosen: Novel Object Recognition Test (NORT) and Object Location Test (OLT). Our results demonstrate that prenatally MA-exposed animals were worse in NORT independently on an acute administration of MA in adulthood. Prenatally MA-exposed rats did not deteriorate in OLT, but after acute administration of MA in adulthood, there was significant worsening compared to appropriate control. Prenatally saline-exposed offspring did not deteriorate in any test even after acute administration of MA. Our data suggest that prenatal MA exposure in rats cause impairment in recognition memory in adult offspring, but not in spatial memory. In addition, acute administration of MA to controls did not deteriorate either recognition or spatial memory.

The Influence of Eye Closure on Somatosensory Discrimination: A Trade-off Between Simple Perception and Discrimination.

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Götz, Theresa; Hanke, David; Huonker, Ralph; Weiss, Thomas; Klingner, Carsten; Brodoehl, Stefan; Baumbach, Philipp; Witte, Otto W

2017-06-01

We often close our eyes to improve perception. Recent results have shown a decrease of perception thresholds accompanied by an increase in somatosensory activity after eye closure. However, does somatosensory spatial discrimination also benefit from eye closure? We previously showed that spatial discrimination is accompanied by a reduction of somatosensory activity. Using magnetoencephalography, we analyzed the magnitude of primary somatosensory (somatosensory P50m) and primary auditory activity (auditory P50m) during a one-back discrimination task in 21 healthy volunteers. In complete darkness, participants were requested to pay attention to either the somatosensory or auditory stimulation and asked to open or close their eyes every 6.5 min. Somatosensory P50m was reduced during a task requiring the distinguishing of stimulus location changes at the distal phalanges of different fingers. The somatosensory P50m was further reduced and detection performance was higher during eyes open. A similar reduction was found for the auditory P50m during a task requiring the distinguishing of changing tones. The function of eye closure is more than controlling visual input. It might be advantageous for perception because it is an effective way to reduce interference from other modalities, but disadvantageous for spatial discrimination because it requires at least one top-down processing stage. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A new psychometric questionnaire for reporting of somatosensory percepts

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Kim, L. H.; McLeod, R. S.; Kiss, Z. H. T.

2018-02-01

Objective. There have been remarkable advances over the past decade in neural prostheses to restore lost motor function. However, restoration of somatosensory feedback, which is essential for fine motor control and user acceptance, has lagged behind. With an increasing interest in using electrical stimulation to restore somatosensory sensations within the peripheral (PNS) and central nervous systems (CNS), it is critical to characterize the percepts evoked by electrical stimulation in a standardized manner with a validated psychometric questionnaire. This will allow comparison of results from applications at various nervous system levels in multiple settings. Approach. We compiled a summary of published reports of somatosensory percepts that were elicited by electrical stimulation in humans and used these to develop a new psychometric questionnaire. Results. This new questionnaire was able to characterize subjective evoked sensations with good test-retest reliability (Spearman’s correlation coefficients ranging 0.716  ⩽  ρ  ⩽  1.000, p  ⩽  0.005) in 13 subjects receiving stimulation through neural implants in both the CNS and PNS. Furthermore, the new questionnaire captured more descriptors (M  =  2.65, SD  =  0.91) that would have been missed by being categorized as ‘other sensations’, using a previous questionnaire (M  =  1.40, SD  =  0.77, t(12)  =  -10.24, p  psychometric questionnaire will aid in establishing consistency and standardization of reporting in future studies of somatosensory neural prostheses.

Theta-Burst Stimulation-Induced Plasticity over Primary Somatosensory Cortex Changes Somatosensory Temporal Discrimination in Healthy Humans

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Conte, Antonella; Rocchi, Lorenzo; Nardella, Andrea; Dispenza, Sabrina; Scontrini, Alessandra; Khan, Nashaba; Berardelli, Alfredo

2012-01-01

Background The somatosensory temporal discrimination threshold (STDT) measures the ability to perceive two stimuli as being sequential. Precisely how the single cerebral structures contribute in controlling the STDT is partially known and no information is available about whether STDT can be modulated by plasticity-inducing protocols. Methodology/Principal Findings To investigate how the cortical and cerebellar areas contribute to the STDT we used transcranial magnetic stimulation and a neuronavigation system. We enrolled 18 healthy volunteers and 10 of these completed all the experimental sessions, including the control experiments. STDT was measured on the left hand before and after applying continuous theta-burst stimulation (cTBS) on the right primary somatosensory area (S1), pre-supplementary motor area (pre-SMA), right dorsolateral prefrontal cortex (DLPFC) and left cerebellar hemisphere. We then investigated whether intermittent theta-burst stimulation (iTBS) on the right S1 improved the STDT. After right S1 cTBS, STDT values increased whereas after iTBS to the same cortical site they decreased. cTBS over the DLPFC and left lateral cerebellum left the STDT statistically unchanged. cTBS over the pre-SMA also left the STDT statistically unchanged, but it increased the number of errors subjects made in distinguishing trials testing a single stimulus and those testing paired stimuli. Conclusions/Significance Our findings obtained by applying TBS to the cortical areas involved in processing sensory discrimination show that the STDT is encoded in S1, possibly depends on intrinsic S1 neural circuit properties, and can be modulated by plasticity-inducing TBS protocols delivered over S1. Our findings, giving further insight into mechanisms involved in somatosensory temporal discrimination, help interpret STDT abnormalities in movement disorders including dystonia and Parkinson's disease. PMID:22412964

Theta-burst stimulation-induced plasticity over primary somatosensory cortex changes somatosensory temporal discrimination in healthy humans.

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Antonella Conte

Full Text Available BACKGROUND: The somatosensory temporal discrimination threshold (STDT measures the ability to perceive two stimuli as being sequential. Precisely how the single cerebral structures contribute in controlling the STDT is partially known and no information is available about whether STDT can be modulated by plasticity-inducing protocols. METHODOLOGY/PRINCIPAL FINDINGS: To investigate how the cortical and cerebellar areas contribute to the STDT we used transcranial magnetic stimulation and a neuronavigation system. We enrolled 18 healthy volunteers and 10 of these completed all the experimental sessions, including the control experiments. STDT was measured on the left hand before and after applying continuous theta-burst stimulation (cTBS on the right primary somatosensory area (S1, pre-supplementary motor area (pre-SMA, right dorsolateral prefrontal cortex (DLPFC and left cerebellar hemisphere. We then investigated whether intermittent theta-burst stimulation (iTBS on the right S1 improved the STDT. After right S1 cTBS, STDT values increased whereas after iTBS to the same cortical site they decreased. cTBS over the DLPFC and left lateral cerebellum left the STDT statistically unchanged. cTBS over the pre-SMA also left the STDT statistically unchanged, but it increased the number of errors subjects made in distinguishing trials testing a single stimulus and those testing paired stimuli. CONCLUSIONS/SIGNIFICANCE: Our findings obtained by applying TBS to the cortical areas involved in processing sensory discrimination show that the STDT is encoded in S1, possibly depends on intrinsic S1 neural circuit properties, and can be modulated by plasticity-inducing TBS protocols delivered over S1. Our findings, giving further insight into mechanisms involved in somatosensory temporal discrimination, help interpret STDT abnormalities in movement disorders including dystonia and Parkinson's disease.

EFFECTS OF EARLY POSTNATAL ANOXIA ON ADULT LEARNING AND EMOTION IN RATS

NARCIS (Netherlands)

BUWALDA, B; NYAKAS, C; VOSSELMAN, HJ; LUITEN, PGM; Vosselman, Henk Jan

Cognitive functioning, behavioural attention and anxiety were studied in adult male Wistar rats after early postnatal anoxia. Spatial memory performance in the holeboard learning task was impaired in anoxic rats when compared with control animals. Attention assessed by the behavioural immobility

Turnover time of Leydig cells and other interstitial cells in testes of adult rats

NARCIS (Netherlands)

Teerds, K. J.; de rooij, D. G.; Rommerts, F. F.; van der Tweel, I.; Wensing, C. J.

1989-01-01

The aim of this study was to investigate the turnover of Leydig cells and other interstitial cells in the adult rat testis. Normal adult rats received injections of [3H]thymidine at 9:00 and 21:00 for 2, 5, or 8 days. The percentage of labeled Leydig cells, which was initially low (0.8% +/- 0.2%),

Beta oscillations define discrete perceptual cycles in the somatosensory domain.

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Baumgarten, Thomas J; Schnitzler, Alfons; Lange, Joachim

2015-09-29

Whether seeing a movie, listening to a song, or feeling a breeze on the skin, we coherently experience these stimuli as continuous, seamless percepts. However, there are rare perceptual phenomena that argue against continuous perception but, instead, suggest discrete processing of sensory input. Empirical evidence supporting such a discrete mechanism, however, remains scarce and comes entirely from the visual domain. Here, we demonstrate compelling evidence for discrete perceptual sampling in the somatosensory domain. Using magnetoencephalography (MEG) and a tactile temporal discrimination task in humans, we find that oscillatory alpha- and low beta-band (8-20 Hz) cycles in primary somatosensory cortex represent neurophysiological correlates of discrete perceptual cycles. Our results agree with several theoretical concepts of discrete perceptual sampling and empirical evidence of perceptual cycles in the visual domain. Critically, these results show that discrete perceptual cycles are not domain-specific, and thus restricted to the visual domain, but extend to the somatosensory domain.

The effect of hypertension on adult hippocampal neurogenesis in young adult spontaneously hypertensive rats and Dahl rats

Czech Academy of Sciences Publication Activity Database

Pištíková, Adéla; Brožka, Hana; Bencze, Michal; Radostová, Dominika; Valeš, Karel; Stuchlík, Aleš

2017-01-01

Roč. 66, č. 5 (2017), s. 881-887 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GBP304/12/G069 Grant - others:Rada Programu interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M200111204 Institutional support: RVO:67985823 Keywords : adult neurogenesis * Captopril * hypertension * Dahl rats * SHR * young animals Subject RIV: FH - Neurology OBOR OECD: Neurosciences (including psychophysiology Impact factor: 1.461, year: 2016

Effect of Consuming Iodized Salt on Fertility Indices in Male Adult Rats

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M. Mehrabani Natanzi

2017-06-01

Full Text Available Introduction: Today about 27.4 percent of female 15-44 years and 1 percent of female in fertility age are affected by infertility. Iodine is a rare element that is essential for the synthesis of thyroid hormones. Concentration of the thyroid hormones in blood under the influence of iodine intake and changes in thyroid hormones levels interact with reproductive system. Today, all the people of Iran consuming iodized salt regardless of iodine status in their body. In this study according to high prevalence of the infertility among young couples, iodized salt intake on fertility in male rats were investigated. Materials and Methods: In this study 20 male and 20 female adult Wistar rats were used. Twenty male adult Wistar rats were randomly divided into 2 groups. Including the control group and treatment group that received iodine and female adult Wistar were fed with a regular diet. Five male rats from each group were killed at the end of the fourth weeks in order to evaluate the possible effect of iodized salt on sperm analysis and weight of testis. After a month, male and female rats were placed in pairs in separate cages and their offspring were investigated in terms of number, gender and health. Results: The result of this study showed that the number of healthy offspring of treated male rats was significantly lower than the control group. Conclusion: Due to the negative effect of excessive iodine intake on fertility rate, it is recommended to couples to perform functional tests of their thyroid glands before intake of iodized salts.

A terrified-sound stress induced proteomic changes in adult male rat hippocampus.

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Yang, Juan; Hu, Lili; Wu, Qiuhua; Liu, Liying; Zhao, Lingyu; Zhao, Xiaoge; Song, Tusheng; Huang, Chen

2014-04-10

In this study, we investigated the biochemical mechanisms in the adult rat hippocampus underlying the relationship between a terrified-sound induced psychological stress and spatial learning. Adult male rats were exposed to a terrified-sound stress, and the Morris water maze (MWM) has been used to evaluate changes in spatial learning and memory. The protein expression profile of the hippocampus was examined using two-dimensional gel electrophoresis (2DE), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and bioinformatics analysis. The data from the MWM tests suggested that a terrified-sound stress improved spatial learning. The proteomic analysis revealed that the expression of 52 proteins was down-regulated, while that of 35 proteins were up-regulated, in the hippocampus of the stressed rats. We identified and validated six of the most significant differentially expressed proteins that demonstrated the greatest stress-induced changes. Our study provides the first evidence that a terrified-sound stress improves spatial learning in rats, and that the enhanced spatial learning coincides with changes in protein expression in rat hippocampus. Copyright © 2014 Elsevier Inc. All rights reserved.

Impaired somatosensory discrimination of shape in Parkinson's disease : Association with caudate nucleus dopaminergic function

NARCIS (Netherlands)

Weder, BJ; Leenders, KL; Vontobel, P; Nienhusmeier, M; Keel, A; Zaunbauer, W; Vonesch, T; Ludin, HP

1999-01-01

Tactile discrimination of macrogeometric objects in a two-alternative forced-choice procedure represents a demanding task involving somatosensory pathways and higher cognitive processing. The objects for somatosensory discrimination, i.e., rectangular parallelepipeds differing only in oblongness,

Extinction of conditioned cues attenuates incubation of cocaine craving in adolescent and adult rats.

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Madsen, Heather B; Zbukvic, Isabel C; Luikinga, Sophia J; Lawrence, Andrew J; Kim, Jee Hyun

2017-09-01

Relapse to drug use is often precipitated by exposure to drug associated cues that evoke craving. Cue-induced drug craving has been observed in both animals and humans to increase over the first few weeks of abstinence and remain high over extended periods, a phenomenon known as 'incubation of craving'. As adolescence represents a period of vulnerability to developing drug addiction, potentially due to persistent reactivity to drug associated cues, we first compared incubation of cocaine craving in adolescent and adult rats. Adolescent (P35) and adult (P70) rats were trained to lever press to obtain intravenous cocaine, with each drug delivery accompanied by a light cue that served as the conditioned stimulus (CS). Following acquisition of stable responding, rats were tested for cue-induced cocaine-seeking after either 1 or 30days of abstinence. Additional groups of rats were also tested after 30days of abstinence, however these rats were subjected to a cue extinction session 1week into the abstinence period. Rats were injected with aripiprazole, a dopamine 2 receptor (D2R)-like partial agonist, or vehicle, 30min prior to cue extinction. We found that adolescent and adult rats acquired and maintained a similar level of cocaine self-administration, and rats of both ages exhibited a higher level of cue-induced cocaine-seeking if they were tested after 30days of abstinence compared to 1day. Incubation of cocaine craving was significantly reduced to 1day levels in both adults and adolescents that received cue extinction training. Administration of aripiprazole prior to cue extinction did not further reduce cue-induced drug-seeking. These results indicate that cue extinction training during abstinence may effectively reduce cue-induced relapse at a time when cue-induced drug craving is usually high. Copyright © 2016 Elsevier Inc. All rights reserved.

In vivo patch-clamp analysis of response properties of rat primary somatosensory cortical neurons responding to noxious stimulation of the facial skin

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Nasu Masanori

2010-05-01

Full Text Available Abstract Background Although it has been widely accepted that the primary somatosensory (SI cortex plays an important role in pain perception, it still remains unclear how the nociceptive mechanisms of synaptic transmission occur at the single neuron level. The aim of the present study was to examine whether noxious stimulation applied to the orofacial area evokes the synaptic response of SI neurons in urethane-anesthetized rats using an in vivo patch-clamp technique. Results In vivo whole-cell current-clamp recordings were performed in rat SI neurons (layers III-IV. Twenty-seven out of 63 neurons were identified in the mechanical receptive field of the orofacial area (36 neurons showed no receptive field and they were classified as non-nociceptive (low-threshold mechanoreceptive; 6/27, 22% and nociceptive neurons. Nociceptive neurons were further divided into wide-dynamic range neurons (3/27, 11% and nociceptive-specific neurons (18/27, 67%. In the majority of these neurons, a proportion of the excitatory postsynaptic potentials (EPSPs reached the threshold, and then generated random discharges of action potentials. Noxious mechanical stimuli applied to the receptive field elicited a discharge of action potentials on the barrage of EPSPs. In the case of noxious chemical stimulation applied as mustard oil to the orofacial area, the membrane potential shifted depolarization and the rate of spontaneous discharges gradually increased as did the noxious pinch-evoked discharge rates, which were usually associated with potentiated EPSP amplitudes. Conclusions The present study provides evidence that SI neurons in deep layers III-V respond to the temporal summation of EPSPs due to noxious mechanical and chemical stimulation applied to the orofacial area and that these neurons may contribute to the processing of nociceptive information, including hyperalgesia.

Reduced somatosensory impairment by piezosurgery during orthognathic surgery of the mandible.

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Brockmeyer, Phillipp; Hahn, Wolfram; Fenge, Stefan; Moser, Norman; Schliephake, Henning; Gruber, Rudolf Matthias

2015-09-01

This clinical trial aimed to test the hypothesis that piezosurgery causes reduced nerval irritations and, thus, reduced somatosensory impairment when used in orthognathic surgery of the mandible. To this end, 37 consecutive patients with Angle Class II and III malocclusion were treated using bilateral sagittal split osteotomies (BSSO) of the mandible. In a split mouth design, randomized one side of the mandible was operated using a conventional saw, while a piezosurgery device was used on the contralateral side. In order to test the individual qualities of somatosensory function, quantitative sensory testings (QSTs) were performed 1 month, 6 months and 1 year after surgery. A comparison of the data using a two-way analysis of variance (ANOVA) revealed a significant reduction in postoperative impairment in warm detection threshold (WDT) (P = 0.046), a decreased dynamic mechanical allodynia (ALL) (P = 0.002) and a decreased vibration detection threshold (VDT) (P = 0.030) on the piezosurgery side of the mandible as opposed to the conventionally operated control side. In the remaining QSTs, minor deviations from the preoperative baseline conditions and a more rapid regression could be observed. Piezosurgery caused reduced somatosensory impairment and a faster recovery of somatosensory functions in the present investigation.

Somatosensory cortices are required for the acquisition of morphine-induced conditioned place preference.

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Zhiqiang Meng

Full Text Available BACKGROUND: Sensory system information is thought to play an important role in drug addiction related responses. However, how somatic sensory information participates in the drug related behaviors is still unclear. Many studies demonstrated that drug addiction represents a pathological usurpation of neural mechanisms of learning and memory that normally relate to the pursuit of rewards. Thus, elucidate the role of somatic sensory in drug related learning and memory is of particular importance to understand the neurobiological mechanisms of drug addiction. PRINCIPAL FINDINGS: In the present study, we investigated the role of somatosensory system in reward-related associative learning using the conditioned place preference model. Lesions were made in somatosensory cortices either before or after conditioning training. We found that lesion of somatosensory cortices before, rather than after morphine conditioning impaired the acquisition of place preference. CONCLUSION: These results demonstrate that somatosensory cortices are necessary for the acquisition but not retention of morphine induced place preference.

Eating high fat chow enhances the locomotor-stimulating effects of cocaine in adolescent and adult female rats.

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Baladi, Michelle G; Koek, Wouter; Aumann, Megan; Velasco, Fortino; France, Charles P

2012-08-01

Dopamine systems vary through development in a manner that can impact drugs acting on those systems. Dietary factors can also impact the effects of drugs acting on dopamine systems. This study examined whether eating high fat chow alters locomotor effects of cocaine (1-56 mg/kg) in adolescent and adult female rats. Cocaine was studied in rats (n = 6/group) with free access to standard (5.7% fat) or high fat (34.3%) chow or restricted access to high fat chow (body weight matched to rats eating standard chow). After 1 week of eating high fat chow (free or restricted access), sensitivity to cocaine was significantly increased in adolescent and adult rats, compared with rats eating standard chow. Sensitivity to cocaine was also increased in adolescent rats with restricted, but not free, access to high fat chow for 4 weeks. When adolescent and adult rats that previously ate high fat chow ate standard chow, sensitivity to cocaine returned to normal. In adolescent and adult female rats eating high fat chow, but not those eating standard chow, sensitivity to cocaine increased progressively over once weekly tests with cocaine (i.e., sensitization) in a manner that was not statistically different between adolescents and adults. These results show that eating high fat chow alters sensitivity of female rats to acutely administered cocaine and also facilitates the development of sensitization to cocaine. That the type of food consumed can increase drug effects might have relevance to vulnerability to abuse cocaine in the female population.

Analysis of testosterone effects on sonic hedgehog signaling in juvenile, adolescent and adult sprague dawley rat penis.

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Bond, Christopher W; Angeloni, Nicholas L; Podlasek, Carol A

2010-03-01

Smooth muscle apoptosis is a major contributing factor to erectile dysfunction (ED) development in prostatectomy and diabetic patients and animal models. A critical regulator of penile smooth muscle and apoptosis is Sonic hedgehog (SHH). The SHH protein is decreased in ED models and SHH treatment of cavernous nerve (CN) injured rats prevents smooth muscle apoptosis. A close association between androgen deficiency and ED has been suggested in the literature, but few studies have examined the molecular effects on penile smooth muscle and on known signaling mechanisms that regulate morphology. Aim. Examine testosterone and SHH interaction in eugonadal adult, adolescent and juvenile rats by performing castration studies and treatment with supraphysiological testosterone. The eugonadal adult Sprague Dawley rats were either treated with testosterone for 7 or 14 days (N = 14) or were castrated for 4 or 7 days (N = 12). The juvenile rats were treated with testosterone for 8 days (N = 7). The adolescent rats were castrated and sacrificed at P88 (N = 8). The control rats had empty vehicle (N = 22) or sham surgery (N = 20). The active form of SHH protein and mRNA were quantified by semi-quantitative immunohistochemical analysis and real-time reverse transcriptase polymerase chain reaction (RT-PCR). Testosterone treatment did not alter SHH signaling in juvenile rats. Shh mRNA increased 3.2-fold and SHH protein increased 1.2-fold in rats castrated during puberty. In adult rats, castration decreased Shh mRNA 3.2-fold but did not alter SHH protein. Testosterone supplement in adult rats increased Shh mRNA 2.3-fold and decreased SHH protein 1.3-fold. SHH signaling is independent of testosterone in normal juvenile rats and is sensitive to testosterone during adolescence, while testosterone supplement in the adult adversely impacts SHH signaling in a very similar manner to that observed with CN injury.

The influence of visual perspective on the somatosensory steady-state response during pain observation

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Dora Linsey Canizales

2013-12-01

Full Text Available The observation and evaluation of other's pain activate part of the neuronal network involved in the actual experience of pain, including those regions subserving the sensori-discriminative dimension of pain. This was largely interpreted as evidence showing that part of the painful experience can be shared vicariously. Here, we investigated the effect of the visual perspective from which other people’s pain is seen on the cortical response to continuous 25 Hz non-painful somatosensory stimulation (somatosensory steady-state response: SSSR. Based on the shared representation framework, we expected first-person visual perspective (1PP to yield more changes in cortical activity than third-person visual perspective (3PP during pain observation. Twenty healthy adults were instructed to rate a series of pseudo-dynamic pictures depicting hands in either painful or non-painful scenarios, presented either in 1PP (0°-45° angle or 3PP (180° angle, while changes in brain activity was measured with a 128-electode EEG system. The ratings demonstrated that the same scenarios were rated on average as more painful when observed from the 1PP than from the 3PP. As expected from previous works, the SSSR response was decreased after stimulus onset over the left caudal part of the parieto-central cortex, contralateral to the stimulation side. Moreover, the difference between the SSSR was of greater amplitude when the painful situations were presented from the 1PP compared to the 3PP. Together, these results suggest that a visuospatial congruence between the viewer and the observed scenarios is associated with both a higher subjective evaluation of pain and an increased modulation in the somatosensory representation of observed pain. These findings are discussed with regards to the potential role of visual perspective in pain communication and empathy.

Effects of prenatal caffeine exposure on glucose homeostasis of adult offspring rats

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Kou, Hao; Wang, Gui-hua; Pei, Lin-guo; Zhang, Li; Shi, Chai; Guo, Yu; Wu, Dong-fang; Wang, Hui

2017-12-01

Epidemiological evidences show that prenatal caffeine exposure (PCE) could induce intrauterine growth retardation (IUGR). The IUGR offspring also present glucose intolerance and type 2 diabetes mellitus after maturity. We have previously demonstrated that PCE induced IUGR and increased susceptibility to adult metabolic syndrome in rats. This study aimed to further investigate the effects of PCE on glucose homeostasis in adult offspring rats. Pregnant rats were administered caffeine (120 mg/kg/day, intragastrically) from gestational days 11 to 20. PCE offspring presented partial catch-up growth pattern after birth, characterizing by the increased body weight gain rates. Meanwhile, PCE had no significant influences on the basal blood glucose and insulin phenotypes of adult offspring but increased the glucose tolerance, glucose-stimulated insulin section and β cell sensitivity to glucose in female progeny. The insulin sensitivity of both male and female PCE offspring were enhanced accompanied with reduced β cell fraction and mass. Western blotting results revealed that significant augmentation in protein expression of hepatic insulin signaling elements of PCE females, including insulin receptor (INSR), insulin receptor substrate 1 (IRS-1) and the phosphorylation of serine-threonine protein kinase (Akt), was also potentiated. In conclusion, we demonstrated that PCE reduced the pancreatic β mass but increased the glucose tolerance in adult offspring rats, especially for females. The adaptive compensatory enhancement of β cell responsiveness to glucose and elevated insulin sensitivity mainly mediated by upregulated hepatic insulin signaling might coordinately contribute to the increased glucose tolerance.

Modulation of Somatosensory Alpha Rhythm by Transcranial Alternating Current Stimulation at Mu-Frequency

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Christopher Gundlach

2017-08-01

Full Text Available Introduction: Transcranial alternating current stimulation (tACS is emerging as an interventional tool to modulate different functions of the brain, potentially by interacting with intrinsic ongoing neuronal oscillations. Functionally different intrinsic alpha oscillations are found throughout the cortex. Yet it remains unclear whether tACS is capable of specifically modulating the somatosensory mu-rhythm in amplitude.Objectives: We used tACS to modulate mu-alpha oscillations in amplitude. When compared to sham stimulation we expected a modulation of mu-alpha oscillations but not visual alpha oscillations by tACS.Methods: Individual mu-alpha frequencies were determined in 25 participants. Subsequently, blocks of tACS with individual mu-alpha frequency and sham stimulation were applied over primary somatosensory cortex (SI. Electroencephalogram (EEG was recorded before and after either stimulation or sham. Modulations of mu-alpha and, for control, visual alpha amplitudes were then compared between tACS and sham.Results: Somatosensory mu-alpha oscillations decreased in amplitude after tACS was applied at participants’ individual mu-alpha frequency. No changes in amplitude were observed for sham stimulation. Furthermore, visual alpha oscillations were not affected by tACS or sham, respectively.Conclusion: Our results demonstrate the capability of tACS to specifically modulate the targeted somatosensory mu-rhythm when the tACS frequency is tuned to the individual endogenous rhythm and applied over somatosensory areas. Our results are in contrast to previously reported amplitude increases of visual alpha oscillations induced by tACS applied over visual cortex. Our results may point to a specific interaction between our stimulation protocol and the functional architecture of the somatosensory system.

Histological changes in the cerebelli of adult wistar rats exposed to ...

African Journals Online (AJOL)

The different constituents of tobacco smoke have been linked to different diseased conditions. In this work, the histological effects of cigarette smoke on the cerebellum of adult male Wistar rats were studied. Sixteen Wistar rats with mean weight of 153.24 ± 4.12 g were grouped equally into four. The Control Group A was ...

Control of Somatosensory Cortical Processing by Thalamic Posterior Medial Nucleus: A New Role of Thalamus in Cortical Function.

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Carlos Castejon

Full Text Available Current knowledge of thalamocortical interaction comes mainly from studying lemniscal thalamic systems. Less is known about paralemniscal thalamic nuclei function. In the vibrissae system, the posterior medial nucleus (POm is the corresponding paralemniscal nucleus. POm neurons project to L1 and L5A of the primary somatosensory cortex (S1 in the rat brain. It is known that L1 modifies sensory-evoked responses through control of intracortical excitability suggesting that L1 exerts an influence on whisker responses. Therefore, thalamocortical pathways targeting L1 could modulate cortical firing. Here, using a combination of electrophysiology and pharmacology in vivo, we have sought to determine how POm influences cortical processing. In our experiments, single unit recordings performed in urethane-anesthetized rats showed that POm imposes precise control on the magnitude and duration of supra- and infragranular barrel cortex whisker responses. Our findings demonstrated that L1 inputs from POm imposed a time and intensity dependent regulation on cortical sensory processing. Moreover, we found that blocking L1 GABAergic inhibition or blocking P/Q-type Ca2+ channels in L1 prevents POm adjustment of whisker responses in the barrel cortex. Additionally, we found that POm was also controlling the sensory processing in S2 and this regulation was modulated by corticofugal activity from L5 in S1. Taken together, our data demonstrate the determinant role exerted by the POm in the adjustment of somatosensory cortical processing and in the regulation of cortical processing between S1 and S2. We propose that this adjustment could be a thalamocortical gain regulation mechanism also present in the processing of information between cortical areas.

Modification Of Cesium Toxicity By Prussian Blue In Adult Male Albino Rats

International Nuclear Information System (INIS)

MANGOOD, S.A.; HAGGAG, A.M.

2009-01-01

The purposes of this study were to asses the toxicological effects of stable cesium chloride, and investigate the possible therapeutic role of Prussian blue (PB) in adult male albino rats.Thirty two adult male albino rats were used in this study and classified to 4 groups (8 rats/group) as follows:1- Group one (G1): rats were considered as controls and kept on the commercial diet without any treatments.2-Group two (G2): treated with daily oral cesium chloride (50 mg/300 g body weight).3-Group three (G3): treated with daily oral Prussian blue (250 mg/rats).4-Group four (G4): treated with cesium chloride at a daily oral dose of 50 mg/300 g body weight + Prussian blue at a daily oral dose of 250 mg/rats.All animals were administered the CsCl and/or PB via intubation tube and the duration of this study was 35 consecutive days. Hemoglobin (Hb), hematocrit (Ht%), red blood cells (RBC), white blood cells (WBC), folic acid, vitamin B12, total protein, albumin, globulin, A/G ratio, ALT, AST, total bilirubin, alkaline phosphatase, blood glucose, urea, creatinine, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), sodium, potassium, calcium and inorganic phosphorous and body weight were determined in all groups.The data obtained revealed that the intake of stable cesium chloride in adult male rats caused significant decreases in the Hb, hematocrit, folic acid, vitamin B12 and potassium contents, with significant increases in WBC count, urea and creatinine levels and no effect on the other parameters. On the other hand, PB as a therapeutic agent caused significant amelioration in the changes produced by CsCl with variable degrees leading to the conclusion that the therapeutic agents might provide a protection against the toxicological effects of CsCl.

Comparison of airway measurements during influenza-induced tachypnea in infant and adult cotton rats

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Prince Gregory A

2009-06-01

Full Text Available Abstract Background Increased respiratory rate (tachypnea is frequently observed as a clinical sign of influenza pneumonia in pediatric patients admitted to the hospital. We previously demonstrated that influenza infection of adult cotton rats (Sigmodon hispidus also results in tachypnea and wanted to establish whether this clinical sign was observed in infected infant cotton rats. We hypothesized that age-dependent differences in lung mechanics result in differences in ventilatory characteristics following influenza infection. Methods Lung tidal volume, dynamic elastance, resistance, and pleural pressure were measured in a resistance and compliance system on mechanically-ventilated anesthestized young (14–28 day old and adult (6–12 week old cotton rats. Animals at the same age were infected with influenza virus, and breathing rates and other respiratory measurements were recorded using a whole body flow plethysmograph. Results Adult cotton rats had significantly greater tidal volume (TV, and lower resistance and elastance than young animals. To evaluate the impact of this increased lung capacity and stiffening on respiratory disease, young and adult animals were infected intra-nasally with influenza A/Wuhan/359/95. Both age groups had increased respiratory rate and enhanced pause (Penh during infection, suggesting lower airway obstruction. However, in spite of significant tachypnea, the infant (unlike the adult cotton rats maintained the same tidal volume, resulting in an increased minute volume. In addition, the parameters that contribute to Penh were different: while relaxation time between breaths and time of expiration was decreased in both age groups, a disproportionate increase in peak inspiratory and expiratory flow contributed to the increase in Penh in infant animals. Conclusion While respiratory rate is increased in both adult and infant influenza-infected cotton rats, the volume of air exchanged per minute (minute volume is

Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

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Zago, A. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Leão, R.M.; Carneiro-de-Oliveira, P.E. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Programa Interinstitucional de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos/Universidade Estadual de São Paulo, Araraquara, SP (Brazil); Marin, M.T.; Cruz, F.C. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Planeta, C.S. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Programa Interinstitucional de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos/Universidade Estadual de São Paulo, Araraquara, SP (Brazil)

2011-11-18

Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although crosssensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9% NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

International Nuclear Information System (INIS)

Zago, A.; Leão, R.M.; Carneiro-de-Oliveira, P.E.; Marin, M.T.; Cruz, F.C.; Planeta, C.S.

2011-01-01

Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although crosssensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9% NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats

Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

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A. Zago

2012-01-01

Full Text Available Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although cross-sensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P 28-37 and adult (P60-67 rats received nicotine (0.4 mg/kg, sc or saline (0.9% NaCl, sc and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

Toluene effects on the motor activity of adolescent, young-adult, middle-age and senescent male Brown Norway rats.

Science.gov (United States)

MacPhail, R C; Farmer, J D; Jarema, K A

2012-01-01

Life stage is an important risk factor for toxicity. Children and aging adults, for example, are more susceptible to certain chemicals than are young adults. In comparison to children, relatively little is known about susceptibility in older adults. Additionally, few studies have compared toxicant susceptibility across a broad range of life stages. Results are presented for behavioral evaluations of male Brown Norway rats obtained as adolescents (1 month), or young (4 months), middle-age (12 months) and senescent (24 months) adults. Motor activity was evaluated in photocell devices during 30-min sessions. Age-related baseline characteristics and sensitivity to toluene (0, 300, 650, or 1000mg/kg, p.o.) were determined. In Experiment 1, young-adult, middle-age and senescent rats were treated with corn-oil vehicle before five weekly test sessions. Baselines of horizontal and vertical activity decreased with age, but each age-group's averages remained stable across weeks of testing. Baseline activity of older rats was more variable than that of the young adults; older rats were also more variable individually from week to week. Toluene (1000mg/kg) increased horizontal activity proportionately more in senescent rats (ca. 300% of control) than in middle-age or young-adult rats (ca.145-175% of control). Experiment 2 established toluene dose-effect functions in individual adolescent, young-adult, middle-age and senescent rats; each rat received all treatments, counterbalanced across four weekly sessions. Toluene produced dose-related increases in horizontal activity that increased proportionately with age. Experiment 3 replicated the effects of toluene (1000mg/kg) in Experiment 1, showing that toluene-induced increases in horizontal activity were greatest in the oldest rats. Collectively, the results show that aging increased susceptibility to toluene and also increased variability in toluene response. Given the rapid growth of the aged population, further research is

Gastrointestinal absorption and retention of polonium in adult and newborn rats and guinea pigs

International Nuclear Information System (INIS)

Haines, J.W.; Naylor, G.P.L.; Pottinger, H.; Harrison, J.D.

1993-01-01

The gastrointestinal absorption of 210 Po was determined by comparing tissue retention after oral and systemic administration. The results indicate an increase in absorption in adult rats for 210 Po administered in liver compared with 210 Po nitrate with estimated absorption of 5 and 13%, respectively. For 210 Po citrate, values of about 7% were obtained in 1-day-old neonate and adult rats while absorption in guinea pigs was estimated to be about 23% in 1-day-old neonates, 17% in 5-day-old neonates, and 9% in adults. Gut retention of ingested 210 Po in neonates was high in rats but not guinea pigs. In adult animals, but not neonates, the liver accounted for a greater proportion of 210 Po reaching the bloodstream after ingestion than after systemic injection. The significance of these results is discussed in relation to current assumptions made in the calculation of doses from 210 Po. (author)

Early life stress impairs social recognition due to a blunted response of vasopressin release within the septum of adult male rats.

Science.gov (United States)

Lukas, Michael; Bredewold, Remco; Landgraf, Rainer; Neumann, Inga D; Veenema, Alexa H

2011-07-01

Early life stress poses a risk for the development of psychopathologies characterized by disturbed emotional, social, and cognitive performance. We used maternal separation (MS, 3h daily, postnatal days 1-14) to test whether early life stress impairs social recognition performance in juvenile (5-week-old) and adult (16-week-old) male Wistar rats. Social recognition was tested in the social discrimination test and defined by increased investigation by the experimental rat towards a novel rat compared with a previously encountered rat. Juvenile control and MS rats demonstrated successful social recognition at inter-exposure intervals of 30 and 60 min. However, unlike adult control rats, adult MS rats failed to discriminate between a previously encountered and a novel rat after 60 min. The social recognition impairment of adult MS rats was accompanied by a lack of a rise in arginine vasopressin (AVP) release within the lateral septum seen during social memory acquisition in adult control rats. This blunted response of septal AVP release was social stimulus-specific because forced swimming induced a rise in septal AVP release in both control and MS rats. Retrodialysis of AVP (1 μg/ml, 3.3 μl/min, 30 min) into the lateral septum during social memory acquisition restored social recognition in adult MS rats at the 60-min interval. These studies demonstrate that MS impairs social recognition performance in adult rats, which is likely caused by blunted septal AVP activation. Impaired social recognition may be linked to MS-induced changes in other social behaviors like aggression as shown previously. Copyright © 2010 Elsevier Ltd. All rights reserved.

SOMATOSENSORY EVOKED POTENTIALS IN DIABETES MELLITUS TYPE - 2

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Rekha

2015-10-01

Full Text Available Diabetes mellitus is the most common metabolic disorder affecting majority of population. It is estimated that over 400 million people throughout the world have diabetes. It has progressed to be a pandemic from an epidemic causing morbidity and mortality in the population. Among the many complications of diabetes, diabetic neuropathies contribute majorly to the morbidity associated with the disease. Axonal conduction is affected by elevated levels of protein kinase c causing neuronal ischemia; decreased ce llular myoinositol affecting sodium potassium ATPase pump leads to decreased nerve conduction; Somatosensory E voked P otentials (SSEPs reflect the activity of somatosensory pathways mediated through the dorsal columns of the spinal cord and the specific so matosensory cortex. Recording of Somatosensory Evoked Potentials in diabetics is done to assess the sensory involvement of spinal cord. Presence of SEPs provides clear evidence for axonal continuity and by using different stimulation sites, the rate of reg eneration can be determined. Both onset and peak latencies of all SEP components are prolonged in patients with diabetes. Present study is done to compare somatosensory evoked potentials in diabetics and normal subjects. MATERIALS AND METHOD S: The present study was undertaken at the Upgraded Department of Physiology, Osmania Medical College, Koti, Hyderabad. The study was conducted on subjects, both male and female in the age group of 45 to 55 years, suffering from type II diabetes excluding other neurologi cal disorders. Non - invasive method of estimation of nerve conduction studies using SFEMG/EP — Electromyography or evoked potential system (Nicolet systems — USA using surface electrodes with automated computerized monitor attached with printer is used. RESUL TS : ANOVA showed statistically significant N9 latency (right & left sides. Latencies of all the components of SSEPs were more significant than amplitudes in Diabetic

Pain from Dental Implant Placement, Inflammatory Pulpitis Pain, and Neuropathic Pain Present Different Somatosensory Profiles.

Science.gov (United States)

Porporatti, André Luís; Bonjardim, Leonardo Rigoldi; Stuginski-Barbosa, Juliana; Bonfante, Estevam Augusto; Costa, Yuri Martins; Rodrigues Conti, Paulo César

2017-01-01

To address the two following questions: (1) What kind of somatosensory abnormalities may be characterized in patients receiving dental implants (IMP), in ongoing inflammatory dental pulpitis (IP) patients, and in neuropathic pain (atypical odontalgia [AO]) patients? and (2) What sort of sensory and neural changes may result from dental implant placement surgery and pulpectomy? A total of 60 subjects were divided into three groups: the IMP (n = 20), IP (n = 20), and AO groups (n = 20). Quantitative sensory testing (QST) was performed preoperatively (baseline) for all three groups and postoperatively at 1 month and 3 months after dental implant placement or pulpectomy (in the IMP group and IP group, respectively). Statistical analyses were completed with one-way and two-way analysis of variance and z score transformations (α = 5%). The main findings of this study indicated that: (1) Elevations in mechanical detection threshold (MDT) and in current perception threshold (CPT) related to C-fiber activation, indicating a loss of function, were found at baseline in IP patients; (2) Somatosensory abnormalities such as allodynia, reduced MDT and mechanical pain threshold (MPT), and impaired pain modulation were found in AO patients; (3) No somatosensory alterations after implant placement were found in the IMP group; and (4) Somatosensory alterations in the form of reduction in the CPT related to C-fiber activation were reported 3 months after pulpectomy in the IP group. This study showed that somatosensory abnormalities were evident in AO and IP patients, and somatosensory alterations were seen in IP patients even 3 months after pulpectomy. However, no somatosensory alterations were seen after implant placement.

Electrical stimulation of the epileptic focus in absence epileptic WAG/RIJ rats: assessment of local and network excitability

NARCIS (Netherlands)

Luttjohann, A.K.; Zhang, S.W.; Peijper, R.A.G. de; Luijtelaar, E.L.J.M. van

2011-01-01

[Objective] The study aims to investigate whether there is a higher excitability in the deep cortical layers of the pen-oral region of the somatosensory cortex as compared to other cortical regions in absence epileptic WAG/Rij rats and whether this is unique for this type of epileptic rats, as would

Electrophysiological Evidence for a Sensory Recruitment Model of Somatosensory Working Memory.

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Katus, Tobias; Grubert, Anna; Eimer, Martin

2015-12-01

Sensory recruitment models of working memory assume that information storage is mediated by the same cortical areas that are responsible for the perceptual processing of sensory signals. To test this assumption, we measured somatosensory event-related brain potentials (ERPs) during a tactile delayed match-to-sample task. Participants memorized a tactile sample set at one task-relevant hand to compare it with a subsequent test set on the same hand. During the retention period, a sustained negativity (tactile contralateral delay activity, tCDA) was elicited over primary somatosensory cortex contralateral to the relevant hand. The amplitude of this component increased with memory load and was sensitive to individual limitations in memory capacity, suggesting that the tCDA reflects the maintenance of tactile information in somatosensory working memory. The tCDA was preceded by a transient negativity (N2cc component) with a similar contralateral scalp distribution, which is likely to reflect selection of task-relevant tactile stimuli at the encoding stage. The temporal sequence of N2cc and tCDA components mirrors previous observations from ERP studies of working memory in vision. The finding that the sustained somatosensory delay period activity varies as a function of memory load supports a sensory recruitment model for spatial working memory in touch. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Effect of Amphetamine on Adult Male and Female Rats Prenatally Exposed to Methamphetamine

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Romana Šlamberová

2014-01-01

Full Text Available The aim of the present study was to examine the cross-sensitization induced by prenatal methamphetamine (MA exposure to adult amphetamine (AMP treatment in male and female rats. Rat mothers received a daily injection of MA (5 mg/kg or saline throughout the gestation period. Adult male and female offspring (prenatally MA- or saline-exposed were administered with AMP (5 mg/kg or saline (1 ml/kg in adulthood. Behaviour in unknown environment was examined in open field test (Laboras, active drug-seeking behaviour in conditioned place preference test (CPP, spatial memory in the Morris water maze (MWM, and levels of corticosterone (CORT were analyzed by enzyme immunoassay (EIA. Our data demonstrate that in Laboras test, AMP treatment in adulthood increased general locomotion (time and distance travelled regardless of the prenatal exposure and sex, while AMP increased exploratory activity (rearing only in prenatally MA-exposed animals. AMP induced sensitization only in male rats, but not in females when tested drug-seeking behaviour in the CPP test. In the spatial memory MWM test, AMP worsened the performance only in females, but not in males. On the other hand, males swam faster after chronic AMP treatment regardless of the prenatal drug exposure. EIA analysis of CORT levels demonstrated higher level in females in all measurement settings. In males, prenatal MA exposure and chronic adult AMP treatment decreased CORT levels. Thus, our data demonstrated that adult AMP treatment affects behaviour of adult rats, their spatial memory and stress response in sex-specific manner. The effect is also influenced by prenatal drug exposure.

Social instability stress differentially affects amygdalar neuron adaptations and memory performance in adolescent and adult rats

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Sheng-Feng eTsai

2014-02-01

Full Text Available Adolescence is a time of developmental changes and reorganization in the brain. It has been hypothesized that stress has a greater neurological impact on adolescents than on adults. However, scientific evidence in support of this hypothesis is still limited. We treated adolescent (4-week-old and adult (8-week-old rats with social instability stress for five weeks and compared the subsequent structural and functional changes to amygdala neurons. In the stress-free control condition, the adolescent group showed higher fear-potentiated startle responses, larger dendritic arborization, more proximal dendritic spine distribution and lower levels of truncated TrkB than the adult rats. Social instability stress exerted opposite effects on fear-potentiated startle responses in these two groups, i.e., the stress period appeared to hamper the performance in adolescents but improved it in adult rats. Furthermore, whilst the chronic social stress applied to adolescent rats reduced their dendritic field and spine density in basal and lateral amygdala neurons, the opposite stress effects on neuron morphology were observed in the adult rats. Moreover, stress in adolescence suppressed the amygdala expression of synaptic proteins, i.e., full-length TrkB and SNAP-25, whereas, in the adult rats, chronic stress enhanced full-length and truncated TrkB expressions in the amygdala. In summary, chronic social instability stress hinders amygdala neuron development in the adolescent brain, while mature neurons in the amygdala are capable of adapting to the stress. The stress induced age-dependent effects on the fear-potentiated memory may occur by altering the BDNF-TrkB signaling and neuroplasticity in the amygdala.

LOCALIZATION OF NMDA AND AMPA RECEPTORS IN RAT BARREL FIELD

NARCIS (Netherlands)

JAARSMA, D; SEBENS, JB; KORF, J

1991-01-01

The aim of this study was to asses the distribution of N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-S-methyl-4-isoxazole propionic acid (AMPA) receptors in the barrel field of rat primary somatosensory (SI) cortex using light-microscopic in vitro autoradiography. NMDA receptors were labeled

Basement membrane chondroitin sulfate proteoglycans: localization in adult rat tissues

DEFF Research Database (Denmark)

McCarthy, K J; Couchman, J R

1990-01-01

Heparan sulfate proteoglycans have been described as the major proteoglycan component of basement membranes. However, previous investigators have also provided evidence for the presence of chondroitin sulfate glycosaminoglycan in these structures. Recently we described the production...... and characterization of core protein-specific monoclonal antibodies (MAb) against a chondroitin sulfate proteoglycan (CSPG) present in Reichert's membrane, a transient extra-embryonic structure of rodents. This CSPG was also demonstrated to be present in adult rat kidney. We report here the tissue distribution...... of epitopes recognized by these MAb. The ubiquitous presence of these epitopes in the basement membranes of nearly all adult rat tissues demonstrates that at least one CSPG is a constituent of most basement membranes, and by virtue of its unique distribution is distinct from other chondroitin and dermatan...

Spatial encoding in spinal sensorimotor circuits differs in different wild type mice strains

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Schouenborg Jens

2008-05-01

Full Text Available Abstract Background Previous studies in the rat have shown that the spatial organisation of the receptive fields of nociceptive withdrawal reflex (NWR system are functionally adapted through experience dependent mechanisms, termed somatosensory imprinting, during postnatal development. Here we wanted to clarify 1 if mice exhibit a similar spatial encoding of sensory input to NWR as previously found in the rat and 2 if mice strains with a poor learning capacity in various behavioural tests, associated with deficient long term potention, also exhibit poor adaptation of NWR. The organisation of the NWR system in two adult wild type mouse strains with normal long term potentiation (LTP in hippocampus and two adult wild type mouse strains exhibiting deficiencies in corresponding LTP were used and compared to previous results in the rat. Receptive fields of reflexes in single hindlimb muscles were mapped with CO2 laser heat pulses. Results While the spatial organisation of the nociceptive receptive fields in mice with normal LTP were very similar to those in rats, the LTP impaired strains exhibited receptive fields of NWRs with aberrant sensitivity distributions. However, no difference was found in NWR thresholds or onset C-fibre latencies suggesting that the mechanisms determining general reflex sensitivity and somatosensory imprinting are different. Conclusion Our results thus confirm that sensory encoding in mice and rat NWR is similar, provided that mice strains with a good learning capability are studied and raise the possibility that LTP like mechanisms are involved in somatosensory imprinting.

Behavioral changes in preweaning and adult rats exposed prenatally to low ionizing radiation

International Nuclear Information System (INIS)

Norton, S.

1986-01-01

Seven behavioral tests were used to evaluate the postnatal behavior of rats after exposure on gestational Day 15 to 0, 25, 50, 75, or 125 r, whole body irradiation of the pregnant rat. Three tests were administered in the first 2 postnatal weeks (righting reflex, negative geotaxis, and reflex suspension); three tests were administered on postnatal Day 21 (modified open field, spatial maze, and continuous corridor). As adults, the rats were retested with the same tests as at 21 days and also in the running wheel. Dose-response decreases in body weight were greater in the younger rats. Some behavioral tests were not altered by irradiation, while others showed clear dose-response relationships, starting as low as 25 r. The early changes were characterized by light body weight, delays in behavioral development and hypoactivity, followed by recovery of some parameters with maturation. Eventually hyperactivity developed in adult rats after gestational irradiation. However, it cannot be concluded that either morphological or behavioral tests are more sensitive than neonatal body weight change for detection of damage from gestational irradiation

Intraoperative intrinsic optical imaging of human somatosensory cortex during neurosurgical operations.

Science.gov (United States)

Sato, Katsushige; Nariai, Tadashi; Momose-Sato, Yoko; Kamino, Kohtaro

2017-07-01

Intrinsic optical imaging as developed by Grinvald et al. is a powerful technique for monitoring neural function in the in vivo central nervous system. The advent of this dye-free imaging has also enabled us to monitor human brain function during neurosurgical operations. We briefly describe our own experience in functional mapping of the human somatosensory cortex, carried out using intraoperative optical imaging. The maps obtained demonstrate new additional evidence of a hierarchy for sensory response patterns in the human primary somatosensory cortex.

Somatosensory evoked potentials in children with autism | Azouz ...

African Journals Online (AJOL)

SSEPs) changesamong children with autism, and their relation to somatosensory manifestations and severity of autism. Subjects: Thirty children with autism aged 2–12 years were included in the study, all of them fulfilling criteria of the Diagnostic ...

Intrauterine programming mechanism for hypercholesterolemia in prenatal caffeine-exposed female adult rat offspring.

Science.gov (United States)

Xu, Dan; Luo, Hanwen W; Hu, Wen; Hu, Shuwei W; Yuan, Chao; Wang, Guihua H; Zhang, Li; Yu, Hong; Magdalou, Jacques; Chen, Liaobin B; Wang, Hui

2018-05-02

Clinical and animal studies have indicated that hypercholesterolemia and its associated diseases have intrauterine developmental origins. Our previous studies showed that prenatal caffeine exposure (PCE) led to fetal overexposure to maternal glucocorticoids (GCs) and increased serum total cholesterol levels in adult rat offspring. This study further confirms the intrauterine programming of PCE-induced hypercholesterolemia in female adult rat offspring. Pregnant Wistar rats were intragastrically administered caffeine (30, 60, and 120 mg/kg/d) from gestational day (GD)9 to 20. Female rat offspring were euthanized at GD20 and postnatal wk 12; several adult rat offspring were additionally subjected to ice-water swimming stimulation to induce chronic stress prior to death. The effects of GCs on cholesterol metabolism and epigenetic regulation were verified using the L02 cell line. The results showed that PCE induced hypercholesterolemia in adult offspring, which manifested as significantly higher levels of serum total cholesterol and LDL cholesterol (LDL-C) as well as higher ratios of LDL-C/HDL cholesterol. We further found that the cholesterol levels were increased in fetal livers but were decreased in fetal blood, accompanied by increased maternal blood cholesterol levels and reduced placental cholesterol transport. Furthermore, analysis of PCE offspring in the uterus and in a postnatal basal/chronic stress state and the results of in vitro experiments showed that hepatic cholesterol metabolism underwent GC-dependent changes and was associated with cholesterol synthase via abnormalities in 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) histone acetylation. We concluded that, to compensate for intrauterine placentally derived decreases in fetal blood cholesterol levels, high intrauterine GC levels activated fetal hepatic CCAAT enhancer binding protein α signaling and down-regulated Sirtuin1 expression, which mediated the high levels of histone acetylation ( via H3K9

Influence of superior cervical ganglionectomy on hippocampal neurogenesis and learning and memory in adult rats

Institute of Scientific and Technical Information of China (English)

Yanping Ding; Baoping Shao; Shiyuan Yu; Shanting Zhao; Jianlin Wang

2009-01-01

BACKGROUND: Studies have shown that neurogenesis in the dentate gyrus plays an important role in learning and memory. However, studies have not determined whether the superior cervical ganglion or the sympathetic nerve system influences hippocampal neurogenesis or learning and memory in adult rats. OBJECTIVE: To observe differences in dentate gyrus neurogenesis, as well as learning and memory, in adult rats following superior cervical ganglionectomy. DESIGN, TIME AND SETTING: A randomized, controlled, animal study was performed at the Immunohistochemistry Laboratory of the School of Life Sciences in Lanzhou University from July 2006 to July 2007.MATERIALS: Doublecortin polyclonal antibody was provided by Santa Cruz Biotechnology, USA;avidin-biotin-peroxidase complex was purchased from Zhongshan Goldenbride Biotechnology, China;Morris water maze was bought from Taimeng Technology, China. METHODS: A total of 20 adult, male, Wistar rats were randomly divided into surgery and control groups, with 10 rats in each group. In the surgery group, the bilateral superior cervical ganglions were transected. In the control group, the superior cervical ganglions were only exposed, but no ganglionectomy was performed. MAIN OUTCOME MEASURES: To examine distribution, morphology, and number of newborn neurons in the dentate gyrus using doublecortin immunohistochemistry at 36 days following surgical procedures. To examine ability of learning and memory in adult rats using the Morris water maze at 30 days following surgical procedures. RESULTS: Doublecortin immunohistochemical results showed that a reduction in the number of doublecortin-positive neurons in the surgery group compared to the control group (P＜0.05), while the distribution of doublecortin-positive neurons was identical in the two groups. The surgery group exhibited significantly worse performance in learning and spatial memory tasks compared to the control group (P＜0.05). CONCLUSION: Superior cervical ganglionectomy

Effects of acute and chronic administration of fenproporex on DNA damage parameters in young and adult rats.

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Gonçalves, Cinara L; Rezin, Gislaine T; Ferreira, Gabriela K; Jeremias, Isabela C; Cardoso, Mariane R; Valvassori, Samira S; Munhoz, Bruna J P; Borges, Gabriela D; Bristot, Bruno N; Leffa, Daniela D; Andrade, Vanessa M; Quevedo, João; Streck, Emilio L

2013-08-01

Obesity is a chronic and multifactorial disease, whose prevalence is increasing in many countries. Pharmaceutical strategies for the treatment of obesity include drugs that regulate food intake, thermogenesis, fat absorption, and fat metabolism. Fenproporex is the second most commonly consumed amphetamine-based anorectic worldwide; this drug is rapidly converted in vivo into amphetamine, which is associated with neurotoxicity. In this context, the present study evaluated DNA damage parameters in the peripheral blood of young and adult rats submitted to an acute administration and chronic administration of fenproporex. In the acute administration, both young and adult rats received a single injection of fenproporex (6.25, 12.5 or 25 mg/kg i.p.) or vehicle. In the chronic administration, both young and adult rats received one daily injection of fenproporex (6.25, 12.5, or 25 mg/kg i.p.) or Tween for 14 days. 2 h after the last injection, the rats were killed by decapitation and their peripheral blood removed for evaluation of DNA damage parameters by alkaline comet assay. Our study showed that acute administration of fenproporex in young and adult rats presented higher levels of damage index and frequency in the DNA. However, chronic administration of fenproporex in young and adult rats did not alter the levels of DNA damage in both parameters of comet assay. The present findings showed that acute administration of fenproporex promoted damage in DNA, in both young and adult rats. Our results are consistent with other reports which showed that other amphetamine-derived drugs also caused DNA damage. We suggest that the activation of an efficient DNA repair mechanism may occur after chronic exposition to fenproporex. Our results are consistent with other reports that showed some amphetamine-derived drugs also caused DNA damage.

Copolymer-1 enhances cognitive performance in young adult rats

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Meneses, Alfredo; Cruz-Martínez, Yolanda; Anaya-Jiménez, Rosa María; Liy-Salmerón, Gustavo; Carvajal, Horacio Guillermo; Ponce-López, Maria Teresa

2018-01-01

Cognitive impairment is a dysfunction observed as a sequel of various neurodegenerative diseases, as well as a concomitant element in the elderly stages of life. In clinical settings, this malfunction is identified as mild cognitive impairment. Previous studies have suggested that cognitive impairment could be the result of a reduction in the expression of brain-derived neurotrophic factor (BDNF) and/or immune dysfunction. Copolymer-1 (Cop-1) is an FDA-approved synthetic peptide capable of inducing the activation of Th2/3 cells, which are able to release BDNF, as well as to migrate and accumulate in the brain. In this study, we evaluated the effect of Cop-1 immunization on improvement of cognition in adult rats. For this purpose, we performed four experiments. We evaluated the effect of Cop-1 immunization on learning/memory using the Morris water maze for spatial memory and autoshaping for associative memory in 3- or 6-month-old rats. BDNF concentrations at the hippocampus were determined by ELISA. Cop-1 immunization induced a significant improvement of spatial memory and associative memory in 6-month-old rats. Likewise, Cop-1 improved spatial memory and associative memory when animals were immunized at 3 months and evaluated at 6 months old. Additionally, Cop-1 induced a significant increase in BDNF levels at the hippocampus. To our knowledge, the present investigation reports the first instance of Cop-1 treatment enhancing cognitive function in normal young adult rats, suggesting that Cop-1 may be a practical therapeutic strategy potentially useful for age- or disease-related cognitive impairment. PMID:29494605

Late emergence of the vibrissa direction selectivity map in the rat barrel cortex.

Science.gov (United States)

Kremer, Yves; Léger, Jean-François; Goodman, Dan; Brette, Romain; Bourdieu, Laurent

2011-07-20

In the neocortex, neuronal selectivities for multiple sensorimotor modalities are often distributed in topographical maps thought to emerge during a restricted period in early postnatal development. Rodent barrel cortex contains a somatotopic map for vibrissa identity, but the existence of maps representing other tactile features has not been clearly demonstrated. We addressed the issue of the existence in the rat cortex of an intrabarrel map for vibrissa movement direction using in vivo two-photon imaging. We discovered that the emergence of a direction map in rat barrel cortex occurs long after all known critical periods in the somatosensory system. This map is remarkably specific, taking a pinwheel-like form centered near the barrel center and aligned to the barrel cortex somatotopy. We suggest that this map may arise from intracortical mechanisms and demonstrate by simulation that the combination of spike-timing-dependent plasticity at synapses between layer 4 and layer 2/3 and realistic pad stimulation is sufficient to produce such a map. Its late emergence long after other classical maps suggests that experience-dependent map formation and refinement continue throughout adult life.

Skill-Specific Changes in Somatosensory Nogo Potentials in Baseball Players.

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Koya Yamashiro

Full Text Available Athletic training is known to induce neuroplastic alterations in specific somatosensory circuits, which are reflected by changes in somatosensory evoked potentials and event-related potentials. The aim of this study was to clarify whether specific athletic training also affects somatosensory Nogo potentials related to the inhibition of movements. The Nogo potentials were recorded at nine cortical electrode positions (Fz, Cz, Pz, F3, F4, C3, C4, P3 and P4 in 12 baseball players (baseball group and in 12 athletes in sports, such as track and field events and swimming, that do not require response inhibition, such as batting for training or performance (sports group. The Nogo potentials and Go/Nogo reaction times (Go/Nogo RTs were measured under a somatosensory Go/Nogo paradigm in which subjects were instructed to rapidly push a button in response to stimulus presentation. The Nogo potentials were obtained by subtracting the Go trial from the Nogo trial. The peak Nogo-N2 was significantly shorter in the baseball group than that in the sports group. In addition, the amplitude of Nogo-N2 in the frontal area was significantly larger in the baseball group than that in the sports group. There was a significant positive correlation between the latency of Nogo-N2 and Go/Nogo RT. Moreover, there were significant correlations between the Go/Nogo RT and both the amplitude of Nogo-N2 and Nogo-P3 (i.e., amplitude of the Nogo-potentials increases with shorter RT. Specific athletic training regimens may induce neuroplastic alterations in sensorimotor inhibitory processes.

Advanced Restoration Therapies in Spinal Cord Injury

Science.gov (United States)

2016-05-01

improve functional outcome post-SCI. SCI was induced at segment T9 in adult rats . The sensory and motor functions were evaluated in the weeks following...the injury. 2) Specific objectives: We tested the outcome of TMS therapy on sensory and motor functions in three groups: SCI rats that received TMS...acute- TMS) have shown greater sensory responses in primary somatosensory cortex of HL representation compared to rats that did not receive any TMS

Aging-Dependent Changes in the Radiation Response of the Adult Rat Brain

International Nuclear Information System (INIS)

Schindler, Matthew K.; Forbes, M. Elizabeth; Robbins, Mike E.; Riddle, David R.

2008-01-01

Purpose: To assess the impact of aging on the radiation response in the adult rat brain. Methods and Materials: Male rats 8, 18, or 28 months of age received a single 10-Gy dose of whole-brain irradiation (WBI). The hippocampal dentate gyrus was analyzed 1 and 10 weeks later for sensitive neurobiologic markers associated with radiation-induced damage: changes in density of proliferating cells, immature neurons, total microglia, and activated microglia. Results: A significant decrease in basal levels of proliferating cells and immature neurons and increased microglial activation occurred with normal aging. The WBI induced a transient increase in proliferation that was greater in older animals. This proliferation response did not increase the number of immature neurons, which decreased after WBI in young rats, but not in old rats. Total microglial numbers decreased after WBI at all ages, but microglial activation increased markedly, particularly in older animals. Conclusions: Age is an important factor to consider when investigating the radiation response of the brain. In contrast to young adults, older rats show no sustained decrease in number of immature neurons after WBI, but have a greater inflammatory response. The latter may have an enhanced role in the development of radiation-induced cognitive dysfunction in older individuals

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Indian Academy of Sciences (India)

Unknown

primary somatosensory cortex or area 3b of owl monkeys is deprived of its ... of these observations by extending them to visual, auditory and motor systems, to .... M and Ebner F F 1998 Experience-dependent plasticity of adult rat S1 cortex.

Tooth movement characteristics in relation to root resorption in young and adult rats.

NARCIS (Netherlands)

Ren, Y.; Maltha, J.C.; Kuijpers-Jagtman, A.M.

2007-01-01

The aim of this study was to investigate tooth movement characteristics in relation to root resorption in young and adult rats. Two groups of 30 rats each (aged 6 wk and 9-12 months, respectively) were used. Standardized orthodontic appliances were placed to move the maxillary molars mesially.

Tooth movement characteristics in relation to root resorption in young and adult rats

NARCIS (Netherlands)

Ren, Yijin; Maltha, Jaap C.; Kuijpers-Jagtman, Anne Marie

2007-01-01

The aim of this study was to investigate tooth movement characteristics in relation to root resorption in young and adult rats. Two groups of 30 rats each (aged 6 wk and 9-12 months, respectively) were used. Standardized orthodontic appliances were placed to move the maxillary molars mesially.

Bilateral somatosensory evoked potentials following intermittent theta-burst repetitive transcranial magnetic stimulation.

Science.gov (United States)

Premji, Azra; Ziluk, Angela; Nelson, Aimee J

2010-08-05

Intermittent theta-burst stimulation (iTBS) is a form of repetitive transcranial magnetic stimulation that may alter cortical excitability in the primary somatosensory cortex (SI). The present study investigated the effects of iTBS on subcortical and early cortical somatosensory evoked potentials (SEPs) recorded over left, iTBS stimulated SI and the right-hemisphere non-stimulated SI. SEPs were recorded before and at 5, 15, and 25 minutes following iTBS. Compared to pre-iTBS, the amplitude of cortical potential N20/P25 was significantly increased for 5 minutes from non-stimulated SI and for 15 to 25 minutes from stimulated SI. Subcortical potentials recorded bilaterally remained unaltered following iTBS. We conclude that iTBS increases the cortical excitability of SI bilaterally and does not alter thalamocortical afferent input to SI. ITBS may provide one avenue to induce cortical plasticity in the somatosensory cortex.

Enhancement of Median Nerve Regeneration by Mesenchymal Stem Cells Engraftment in an Absorbable Conduit: Improvement of Peripheral Nerve Morphology with Enlargement of Somatosensory Cortical Representation.

Directory of Open Access Journals (Sweden)

Julia Teixeira Oliveira

2014-10-01

Full Text Available We studied the morphology and the cortical representation of the median nerve (MN, 10 weeks after a transection immediately followed by treatment with tubulization using a polycaprolactone (PCL conduit with or without bone marrow-derived mesenchymal stem cell (MSC transplant. In order to characterize the cutaneous representation of MN inputs in primary somatosensory cortex (S1, electrophysiological cortical mapping of the somatosensory representation of the forepaw and adjacent body parts was performed after acute lesion of all brachial plexus nerves, except for the MN. This was performed in ten adult male Wistar rats randomly assigned in 3 groups: MN Intact (n=4, PCL-Only (n=3 and PCL+MSC (n=3. Ten weeks before mapping procedures in animals from PCL-Only and PCL+MSC groups, animal were subjected to MN transection with removal of a 4-mm-long segment, immediately followed by suturing a PCL conduit to the nerve stumps with (PCL+MSC group or without (PCL-Only group injection of MSC into the conduit. After mapping the representation of the MN in S1, animals had a segment of the regenerated nerve processed for light and transmission electron microscopy. For histomorphometric analysis of the nerve segment, sample size was increased to 5 animals per experimental group. The PCL+MSC group presented a higher number of myelinated fibers and a larger cortical representation of MN inputs in S1 (3,383±390 fibers; 2.3 mm2, respectively than the PCL-Only group (2,226±575 fibers; 1.6 mm2. In conclusion, MSC-based therapy associated with PCL conduits can improve MN regeneration. This treatment seems to rescue the nerve representation in S1, thus minimizing the stabilization of new representations of adjacent body parts in regions previously responsive to the MN.

Ghrelin modulates testicular germ cells apoptosis and proliferation in adult normal rats

International Nuclear Information System (INIS)

Kheradmand, Arash; Dezfoulian, Omid; Alirezaei, Masoud; Rasoulian, Bahram

2012-01-01

Highlights: ► Spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. ► Numerous studies have documented the direct action of ghrelin in the modulation of apoptosis in different cell types. ► Ghrelin may be considered as a modulator of spermatogenesis in normal adult rats. ► Ghrelin may be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors. -- Abstract: Under normal condition in the most mammals, spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. The present study was designed to determine the effects of ghrelin treatment on in vivo quality and quantity expression of apoptosis and proliferation specific indices in rat testicular germ cells. Twenty eight adult normal rats were subdivided into equal control and treatment groups. Treatment group received 3 nmol of ghrelin as subcutaneous injection for 30 consecutive days or vehicle to the control animals. The rats from each group (n = 7) were killed on days 10 and 30 and their testes were taken for immunocytochemical evaluation and caspase-3 assay. Immunohistochemical analysis indicated that the accumulations of Bax and PCNA peptides are generally more prominent in spermatocytes and spermatogonia of both groups. Likewise, the mean percentage of immunoreactive spermatocytes against Bax increased (P 0.05). Upstream of Bax substance parallel to down-regulation of PCNA demonstrate that ghrelin may prevent massive accumulation of germ cells during normal spermatogenesis. These observations also indicate that ghrelin may be considered as a modulator of spermatogenesis in normal adult rats and could be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors.

Substance P Differentially Modulates Firing Rate of Solitary Complex (SC) Neurons from Control and Chronic Hypoxia-Adapted Adult Rats

Science.gov (United States)

Nichols, Nicole L.; Powell, Frank L.; Dean, Jay B.; Putnam, Robert W.

2014-01-01

NK1 receptors, which bind substance P, are present in the majority of brainstem regions that contain CO2/H+-sensitive neurons that play a role in central chemosensitivity. However, the effect of substance P on the chemosensitive response of neurons from these regions has not been studied. Hypoxia increases substance P release from peripheral afferents that terminate in the caudal nucleus tractus solitarius (NTS). Here we studied the effect of substance P on the chemosensitive responses of solitary complex (SC: NTS and dorsal motor nucleus) neurons from control and chronic hypoxia-adapted (CHx) adult rats. We simultaneously measured intracellular pH and electrical responses to hypercapnic acidosis in SC neurons from control and CHx adult rats using the blind whole cell patch clamp technique and fluorescence imaging microscopy. Substance P significantly increased the basal firing rate in SC neurons from control and CHx rats, although the increase was smaller in CHx rats. However, substance P did not affect the chemosensitive response of SC neurons from either group of rats. In conclusion, we found that substance P plays a role in modulating the basal firing rate of SC neurons but the magnitude of the effect is smaller for SC neurons from CHx adult rats, implying that NK1 receptors may be down regulated in CHx adult rats. Substance P does not appear to play a role in modulating the firing rate response to hypercapnic acidosis of SC neurons from either control or CHx adult rats. PMID:24516602

Can prenatal low-dose irradiation affect behavior of adult rats?

International Nuclear Information System (INIS)

Smajda, B.; Tomasova, L.; Kokocova, N.

2011-01-01

The aim of our study was to determine whether exposure of very low dose gamma-rays during the critical phase of brain development affects some selected behavioral parameters in adult rats. Pregnant female Wistar rats were irradiated with 1 Gy gamma-rays from a cobalt source at 17 th day of pregnancy. The progeniture of irradiated as well as non-irradiated females have undergone behavioral tests at the age of 3 months. Irradiated animals exhibited lower locomotor and exploratory activity in the open field test. (authors)

Airway somatosensory deficits and dysphagia in Parkinson's disease.

Science.gov (United States)

Hammer, Michael J; Murphy, Caitlin A; Abrams, Trisha M

2013-01-01

Individuals with Parkinson's disease (PD) often experience substantial impairment of swallow control, and are typically unaware of the presence or severity of their impairments suggesting that these individuals may also experience airway sensory deficits. However, the degree to which impaired swallow function in PD may relate to airway sensory deficits has yet to be formally tested. The purpose of this study was to examine whether airway sensory function is associated with swallow impairment in PD. Eighteen PD participants and 18 healthy controls participated in this study and underwent endoscopic assessment of airway somatosensory function, endoscopic assessment of swallow function, and clinical ratings of swallow and disease severity. PD participants exhibited abnormal airway somatosensory function and greater swallow impairment compared with healthy controls. Swallow and sensory deficits in PD were correlated with disease severity. Moreover, PD participants reported similar self-rated swallow function as healthy controls, and swallow deficits were correlated with sensory function suggesting an association between impaired sensory function and poor self-awareness of swallow deficits in PD. These results suggest that control of swallow is influenced by airway somatosensory function, that swallow-related deficits in PD are related to abnormal somatosensation, and that swallow and airway sensory function may degrade as a function of disease severity. Therefore, the basal ganglia and related neural networks may play an important role to integrate airway sensory input for swallow-related motor control. Furthermore, the airway deficits observed in PD suggest a disintegration of swallow-related sensory and motor control.

Regional gray matter volume increases following 7days of voluntary wheel running exercise: a longitudinal VBM study in rats.

Science.gov (United States)

Sumiyoshi, Akira; Taki, Yasuyuki; Nonaka, Hiroi; Takeuchi, Hikaru; Kawashima, Ryuta

2014-09-01

The effects of physical exercise on brain morphology in rodents have been well documented in histological studies. However, to further understand when and where morphological changes occur in the whole brain, a noninvasive neuroimaging method allowing an unbiased, comprehensive, and longitudinal investigation of brain morphology should be used. In this study, we investigated the effects of 7days of voluntary wheel running exercise on regional gray matter volume (rGMV) using longitudinal voxel-based morphometry (VBM) in rats. Eighteen pairs of adult male naïve Wistar rats were randomized to the exercise or control condition (one rat for each condition from each pair). Each rat was scanned in a 7.0-T MRI scanner at three time points: before exercise, after 7days of exercise, and after 7days of follow-up. The T2-weighted MRI images were segmented using the rat brain tissue priors that were recently published by our laboratory, and the intra- and inter-subject template creation steps were followed. Longitudinal VBM analysis revealed significant increases in rGMV in the motor, somatosensory, association, and visual cortices in the exercise group. Among these brain regions, rGMV changes in the motor cortex were positively correlated with the total distance that was run during the 7days of exercise. In addition, the effects of 7days of exercise on rGMV persisted after 7days of follow-up. These results support the utility of a longitudinal VBM study in rats and provide new insights into experience-dependent structural brain plasticity in naïve adult animals. Copyright © 2014 Elsevier Inc. All rights reserved.

Acute and Chronic Effects of Dietary Lactose in Adult Rats Are not Explained by Residual Intestinal Lactase Activity.

Science.gov (United States)

van de Heijning, Bert J M; Kegler, Diane; Schipper, Lidewij; Voogd, Eline; Oosting, Annemarie; van der Beek, Eline M

2015-07-08

Neonatal rats have a high intestinal lactase activity, which declines around weaning. Yet, the effects of lactose-containing products are often studied in adult animals. This report is on the residual, post-weaning lactase activity and on the short- and long-term effects of lactose exposure in adult rats. Acutely, the postprandial plasma response to increasing doses of lactose was studied, and chronically, the effects of a 30% lactose diet fed from postnatal (PN) Day 15 onwards were evaluated. Intestinal lactase activity, as assessed both in vivo and in vitro, was compared between both test methods and diet groups (lactose vs. control). A 50%-75% decreased digestive capability towards lactose was observed from weaning into adulthood. Instillation of lactose in adult rats showed disproportionally low increases in plasma glucose levels and did not elicit an insulin response. However, gavages comprising maltodextrin gave rise to significant plasma glucose and insulin responses, indicative of a bias of the adult GI tract to digest glucose polymers. Despite the residual intestinal lactase activity shown, a 30% lactose diet was poorly digested by adult rats: the lactose diet rendered the animals less heavy and virtually devoid of body fat, whereas their cecum tripled in size, suggesting an increased bacterial fermentation. The observed acute and chronic effects of lactose exposure in adult rats cannot be explained by the residual intestinal lactase activity assessed.

Inhibition of somatosensory-evoked cortical responses by a weak leading stimulus.

Science.gov (United States)

Nakagawa, Kei; Inui, Koji; Yuge, Louis; Kakigi, Ryusuke

2014-11-01

We previously demonstrated that auditory-evoked cortical responses were suppressed by a weak leading stimulus in a manner similar to the prepulse inhibition (PPI) of startle reflexes. The purpose of the present study was to investigate whether a similar phenomenon was present in the somatosensory system, and also whether this suppression reflected an inhibitory process. We recorded somatosensory-evoked magnetic fields following stimulation of the median nerve and evaluated the extent by which they were suppressed by inserting leading stimuli at an intensity of 2.5-, 1.5-, 1.1-, or 0.9-fold the sensory threshold (ST) in healthy participants (Experiment 1). The results obtained demonstrated that activity in the secondary somatosensory cortex in the hemisphere contralateral to the stimulated side (cSII) was significantly suppressed by a weak leading stimulus with the intensity larger than 1.1-fold ST. This result implied that the somatosensory system had an inhibitory process similar to that of PPI. We then presented two successive leading stimuli before the test stimulus, and compared the extent of suppression between the test stimulus-evoked responses and those obtained with the second prepulse alone and with two prepulses (first and second) (Experiment 2). When two prepulses were preceded, cSII responses to the second prepulse were suppressed by the first prepulse, whereas the ability of the second prepulse to suppress the test stimulus remained unchanged. These results suggested the presence of at least two individual pathways; response-generating and inhibitory pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

On the presence of high-order interactions among somatosensory neurons and their effect on information transmission

International Nuclear Information System (INIS)

Ince, Robin A A; Montani, Fernando; Panzeri, Stefano; Arabzadeh, Ehsan; Diamond, Mathew E

2009-01-01

In order to understand how populations of neurons encode information about external correlates, it is important to develop minimal models of the probability of neural population responses which capture all the salient changes of neural responses with stimuli. In this context, it is particularly useful to determine whether interactions among neurons responding to stimuli can be described by a pairwise interaction model, or whether a higher order interaction model is needed. To address this question, we compared real neural population activity obtained from the rat somatosensory cortex to maximum-entropy models which take into account only interaction of up any given order. By performing these comparisons, we found that interactions of order two were sufficient to explain a large amount of observed stimulus-response distributions, but not all of them. Triple-wise interactions were necessary to fully explain the data. We then used Shannon information to compute the impact of high order correlations on the amount of somatosensory information transmitted by the neural population. We found that correlations of order two gave a good approximation of information carried by the neural population, within 4% of the true value. Third order correlations gave an even better approximation, within 2% of the true value. Taken together, these results suggest that higher order interactions exist and shape the dynamics of cortical networks, but play a quantitatively minor role in determining the information capacity of neural populations.

On the presence of high-order interactions among somatosensory neurons and their effect on information transmission

Energy Technology Data Exchange (ETDEWEB)

Ince, Robin A A [Faculty of Life Science, University of Manchester, 3.431 Stopford Building, Oxford Road, Manchester M13 9PL (United Kingdom); Montani, Fernando; Panzeri, Stefano [Robotics, Brain, and Cognitive Sciences Department, Italian Institute of Technology, Via Morego 30, 16163 Genova (Italy); Arabzadeh, Ehsan [School of Psychology, University of New South Wales, Sydney, New South Wales (Australia); Diamond, Mathew E, E-mail: stefano.panzeri@iit.i [Cognitive Neuroscience Sector, International School for Advanced Studies, Trieste (Italy) and the SISSA Unit, Italian Institute of Technology, Trieste (Italy)

2009-12-01

In order to understand how populations of neurons encode information about external correlates, it is important to develop minimal models of the probability of neural population responses which capture all the salient changes of neural responses with stimuli. In this context, it is particularly useful to determine whether interactions among neurons responding to stimuli can be described by a pairwise interaction model, or whether a higher order interaction model is needed. To address this question, we compared real neural population activity obtained from the rat somatosensory cortex to maximum-entropy models which take into account only interaction of up any given order. By performing these comparisons, we found that interactions of order two were sufficient to explain a large amount of observed stimulus-response distributions, but not all of them. Triple-wise interactions were necessary to fully explain the data. We then used Shannon information to compute the impact of high order correlations on the amount of somatosensory information transmitted by the neural population. We found that correlations of order two gave a good approximation of information carried by the neural population, within 4% of the true value. Third order correlations gave an even better approximation, within 2% of the true value. Taken together, these results suggest that higher order interactions exist and shape the dynamics of cortical networks, but play a quantitatively minor role in determining the information capacity of neural populations.

Multidimensional MRI-CT atlas of the naked mole-rat brain

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Fumiko eSeki

2013-12-01

Full Text Available Naked mole-rats have a variety of distinctive features such as the organisation of a hierarchical society (known as eusociality, extraordinary longevity, and cancer resistance; thus, it would be worthwhile investigating these animals in detail. One important task is the preparation of a brain atlas database that provide comprehensive information containing multidimensional data with various image contrasts, which can be achievable using a magnetic resonance imaging (MRI. Advanced MRI techniques such as diffusion tensor imaging (DTI, which generates high contrast images of fibre structures, can characterise unique morphological properties in addition to conventional MRI. To obtain high spatial resolution images, MR histology, DTI, and X-ray computed tomography (CT were performed on the fixed adult brain. Skull and brain structures were segmented as well as reconstructed in stereotaxic coordinates. Data were also acquired for the neonatal brain to allow developmental changes to be observed. Moreover, in vivo imaging of naked mole-rats was established as an evaluation tool of live animals. The data obtained comprised three-dimensional (3D images with high tissue contrast as well as stereotaxic coordinates. Developmental differences in the visual system were highlighted in particular by DTI. Although it was difficult to delineate optic nerves in the mature adult brain, parts of them could be distinguished in the immature neonatal brain. From observation of cortical thickness, possibility of high somatosensory system development replaced to the visual system was indicated. 3D visualisation of brain structures in the atlas as well as the establishment of in vivo imaging would promote neuroimaging researches towards detection of novel characteristics of eusocial naked mole-rats.

Inhibitory rTMS applied on somatosensory cortex in Wilson's disease patients with hand dystonia.

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Lozeron, Pierre; Poujois, Aurélia; Meppiel, Elodie; Masmoudi, Sana; Magnan, Thierry Peron; Vicaut, Eric; Houdart, Emmanuel; Guichard, Jean-Pierre; Trocello, Jean-Marc; Woimant, France; Kubis, Nathalie

2017-10-01

Hand dystonia is a common complication of Wilson's disease (WD), responsible for handwriting difficulties and disability. Alteration of sensorimotor integration and overactivity of the somatosensory cortex have been demonstrated in dystonia. This study investigated the immediate after effect of an inhibitory repetitive transcranial magnetic stimulation (rTMS) applied over the somatosensory cortex on the writing function in WD patients with hand dystonia. We performed a pilot prospective randomized double-blind sham-controlled crossover rTMS study. A 20-min 1-Hz rTMS session, stereotaxically guided, was applied over the left somatosensory cortex in 13 WD patients with right dystonic writer's cramp. After 3 days, each patient was crossed-over to the alternative treatment. Patients were clinically evaluated before and immediately after each rTMS session with the Unified Wilson's Disease rating scale (UWDRS), the Writers' Cramp Rating Scale (WCRS), a specifically designed scale for handwriting difficulties in Wilson's disease patients (FAR, flow, accuracy, and rhythmicity evaluation), and a visual analog scale (VAS) for handwriting discomfort. No significant change in UWDRS, WCRS, VAS, or FAR scores was observed in patients treated with somatosensory inhibitory rTMS compared to the sham protocol. The FAR negatively correlated with UWDRS (r = -0.6; P = 0.02), but not with the WCRS score, disease duration, MRI diffusion lesions, or with atrophy scores. In our experimental conditions, a single inhibitory rTMS session applied over somatosensory cortex did not improve dystonic writer cramp in WD patients.

Reliability of Visual and Somatosensory Feedback in Skilled Movement: The Role of the Cerebellum.

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Mizelle, J C; Oparah, Alexis; Wheaton, Lewis A

2016-01-01

The integration of vision and somatosensation is required to allow for accurate motor behavior. While both sensory systems contribute to an understanding of the state of the body through continuous updating and estimation, how the brain processes unreliable sensory information remains to be fully understood in the context of complex action. Using functional brain imaging, we sought to understand the role of the cerebellum in weighting visual and somatosensory feedback by selectively reducing the reliability of each sense individually during a tool use task. We broadly hypothesized upregulated activation of the sensorimotor and cerebellar areas during movement with reduced visual reliability, and upregulated activation of occipital brain areas during movement with reduced somatosensory reliability. As specifically compared to reduced somatosensory reliability, we expected greater activations of ipsilateral sensorimotor cerebellum for intact visual and somatosensory reliability. Further, we expected that ipsilateral posterior cognitive cerebellum would be affected with reduced visual reliability. We observed that reduced visual reliability results in a trend towards the relative consolidation of sensorimotor activation and an expansion of cerebellar activation. In contrast, reduced somatosensory reliability was characterized by the absence of cerebellar activations and a trend towards the increase of right frontal, left parietofrontal activation, and temporo-occipital areas. Our findings highlight the role of the cerebellum for specific aspects of skillful motor performance. This has relevance to understanding basic aspects of brain functions underlying sensorimotor integration, and provides a greater understanding of cerebellar function in tool use motor control.

Competition among oxidizable substrates in brains of young and adult rats. Dissociated cells.

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Roeder, L M; Tildon, J T; Holman, D C

1984-01-01

The rates of conversion of D-(-)-3-hydroxy[3-14C]butyrate, [3-14C]acetoacetate, [6-14C]glucose and [U-14C]glutamine into 14CO2 were measured in the presence and absence of alternative oxidizable substrates in intact dissociated cells from the brains of young and adult rats. When unlabelled glutamine was added to [6-14C]glucose or unlabelled glucose was added to [U-14C]glutamine, the rate of 14CO2 production was decreased in both young and adult rats. The rate of oxidation of 3-hydroxy[3-14C]b...

Bilateral somatosensory evoked potentials following intermittent theta-burst repetitive transcranial magnetic stimulation

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Ziluk Angela

2010-08-01

Full Text Available Abstract Background Intermittent theta-burst stimulation (iTBS is a form of repetitive transcranial magnetic stimulation that may alter cortical excitability in the primary somatosensory cortex (SI. The present study investigated the effects of iTBS on subcortical and early cortical somatosensory evoked potentials (SEPs recorded over left, iTBS stimulated SI and the right-hemisphere non-stimulated SI. SEPs were recorded before and at 5, 15, and 25 minutes following iTBS. Results Compared to pre-iTBS, the amplitude of cortical potential N20/P25 was significantly increased for 5 minutes from non-stimulated SI and for 15 to 25 minutes from stimulated SI. Subcortical potentials recorded bilaterally remained unaltered following iTBS. Conclusion We conclude that iTBS increases the cortical excitability of SI bilaterally and does not alter thalamocortical afferent input to SI. ITBS may provide one avenue to induce cortical plasticity in the somatosensory cortex.

Long-term effects of 239Pu injection in adult, weanling, newborn and fetal rats

International Nuclear Information System (INIS)

Sikov, M.R.; Mahlum, D.D.; Hess, J.O.; Carr, D.B.

1979-01-01

We have completed biological evaluations comparing long-term effects in rats exposed to 239 Pu citrate as adults, weanlings, newborns, or late fetuses, and statistical analyses have been initiated. In rats exposed postnatally, statistically significant alterations in terminal body weight and in weights of several organs were found at higher doses. Survivorship decreased with increasing dose in the postnatal groups, but not in rats exposed prenatally

Influence of body position on cortical pain-related somatosensory processing: an ERP study.

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Chiara Spironelli

Full Text Available BACKGROUND: Despite the consistent information available on the physiological changes induced by head down bed rest, a condition which simulates space microgravity, our knowledge on the possible perceptual-cortical alterations is still poor. The present study investigated the effects of 2-h head-down bed rest on subjective and cortical responses elicited by electrical, pain-related somatosensory stimulation. METHODOLOGY/PRINCIPAL FINDINGS: Twenty male subjects were randomly assigned to two groups, head-down bed rest (BR or sitting control condition. Starting from individual electrical thresholds, Somatosensory Evoked Potentials were elicited by electrical stimuli administered randomly to the left wrist and divided into four conditions: control painless condition, electrical pain threshold, 30% above pain threshold, 30% below pain threshold. Subjective pain ratings collected during the EEG session showed significantly reduced pain perception in BR compared to Control group. Statistical analysis on four electrode clusters and sLORETA source analysis revealed, in sitting controls, a P1 component (40-50 ms in the right somatosensory cortex, whereas it was bilateral and differently located in BR group. Controls' N1 (80-90 ms had widespread right hemisphere activation, involving also anterior cingulate, whereas BR group showed primary somatosensory cortex activation. The P2 (190-220 ms was larger in left-central locations of Controls compared with BR group. CONCLUSIONS/SIGNIFICANCE: Head-down bed rest was associated to an overall decrease of pain sensitivity and an altered pain network also outside the primary somatosensory cortex. Results have implications not only for astronauts' health and spaceflight risks, but also for the clinical aspects of pain detection in bedridden patients at risk of fatal undetected complications.

Somatosensory impairment and its association with balance limitation in people with multiple sclerosis.

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Jamali, Akram; Sadeghi-Demneh, Ebrahim; Fereshtenajad, Niloufar; Hillier, Susan

2017-09-01

Somatosensory impairments are common in multiple sclerosis. However, little data are available to characterize the nature and frequency of these problems in people with multiple sclerosis. To investigate the frequency of somatosensory impairments and identify any association with balance limitations in people with multiple sclerosis. The design was a prospective cross-sectional study, involving 82 people with multiple sclerosis and 30 healthy controls. Tactile and proprioceptive sensory acuity were measured using the Rivermead Assessment of Somatosensory Performance. Vibration duration was assessed using a tuning fork. Duration for the Timed Up and Go Test and reaching distance of the Functional Reach Test were measured to assess balance limitations. The normative range of sensory modalities was defined using cut-off points in the healthy participants. The multivariate linear regression was used to identify the significant predictors of balance in people with multiple sclerosis. Proprioceptive impairments (66.7%) were more common than tactile (60.8%) and vibration impairments (44.9%). Somatosensory impairments were more frequent in the lower limb (78.2%) than the upper limb (64.1%). All sensory modalities were significantly associated with the Timed Up and Go and Functional Reach tests (plimitation. Copyright © 2017 Elsevier B.V. All rights reserved.

Substance P differentially modulates firing rate of solitary complex (SC neurons from control and chronic hypoxia-adapted adult rats.

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Nicole L Nichols

Full Text Available NK1 receptors, which bind substance P, are present in the majority of brainstem regions that contain CO2/H(+-sensitive neurons that play a role in central chemosensitivity. However, the effect of substance P on the chemosensitive response of neurons from these regions has not been studied. Hypoxia increases substance P release from peripheral afferents that terminate in the caudal nucleus tractus solitarius (NTS. Here we studied the effect of substance P on the chemosensitive responses of solitary complex (SC: NTS and dorsal motor nucleus neurons from control and chronic hypoxia-adapted (CHx adult rats. We simultaneously measured intracellular pH and electrical responses to hypercapnic acidosis in SC neurons from control and CHx adult rats using the blind whole cell patch clamp technique and fluorescence imaging microscopy. Substance P significantly increased the basal firing rate in SC neurons from control and CHx rats, although the increase was smaller in CHx rats. However, substance P did not affect the chemosensitive response of SC neurons from either group of rats. In conclusion, we found that substance P plays a role in modulating the basal firing rate of SC neurons but the magnitude of the effect is smaller for SC neurons from CHx adult rats, implying that NK1 receptors may be down regulated in CHx adult rats. Substance P does not appear to play a role in modulating the firing rate response to hypercapnic acidosis of SC neurons from either control or CHx adult rats.

Influx mechanisms in the embryonic and adult rat choroid plexus

DEFF Research Database (Denmark)

Saunders, Norman R; Dziegielewska, Katarzyna M; Møllgård, Kjeld

2015-01-01

The transcriptome of embryonic and adult rat lateral ventricular choroid plexus, using a combination of RNA-Sequencing and microarray data, was analyzed by functional groups of influx transporters, particularly solute carrier (SLC) transporters. RNA-Seq was performed at embryonic day (E) 15 and a...

Changes in Binding of [123I]CLINDE, a High-Affinity Translocator Protein 18 kDa (TSPO) Selective Radioligand in a Rat Model of Traumatic Brain Injury

DEFF Research Database (Denmark)

Donat, Cornelius K; Gaber, Khaled; Meixensberger, Jürgen

2016-01-01

, somatosensory and parietal cortex, as well as in the hippocampus and thalamus. Interestingly, binding was also significantly elevated in the contralateral M1 motor cortex following TBI. Craniotomy without TBI caused a less marked increase in [(123)I]CLINDE binding, restricted to the ipsilateral hemisphere...... studies using single-photon emission computed tomography to image the neuroinflammatory response after stroke. In this study, we used the same tracer in a rat model of TBI to determine changes in TSPO expression. Adult Sprague-Dawley rats were subjected to moderate controlled cortical impact injury...... and sacrificed at 6, 24, 72 h and 28 days post surgery. TSPO expression was assessed in brain sections employing [(123)I]CLINDE in vitro autoradiography. From 24 h to 28 days post surgery, injured animals exhibited a marked and time-dependent increase in [(123)I]CLINDE binding in the ipsilateral motor...

Differential effects of magnetic field exposure from domestic power supply on loco motor and exploratory behavior of an adult rat

International Nuclear Information System (INIS)

Anandavadivel, A.; Caleo, M.

2011-01-01

In the present study, we have examined the low intense magnetic field exposed on adult rats to understand effect of several behavioral parameters. The rats are tested in the open field and spontaneous alternation task after either a single or chronic exposure to the magnetic field. We found that magnetic field exposure had no effect on locomotor behavior in the adult. However, the exploratory behavior of adult rats in the open field was significantly affected. Indeed, we found a consistent increase in behavior performance viz. exploration time and number of exploration events in rats exposed to magnetic field. Our results demonstrate behavioral changes after magnetic field exposure in adult subjects. This also suggests possible deleterious effects of magnetic field exposure in the brain. (author)

The interaction between felt touch and tactile consequences of observed actions: an action-based somatosensory congruency paradigm.

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Deschrijver, Eliane; Wiersema, Jan R; Brass, Marcel

2016-07-01

Action observation leads to a representation of both the motor aspect of an observed action (motor simulation) and its somatosensory consequences (action-based somatosensory simulation) in the observer's brain. In the current electroencephalography-study, we investigated the neuronal interplay of action-based somatosensory simulation and felt touch. We presented index or middle finger tapping movements of a human or a wooden hand, while simultaneously presenting 'tap-like' tactile sensations to either the corresponding or non-corresponding fingertip of the participant. We focused on an early stage of somatosensory processing [P50, N100 and N140 sensory evoked potentials (SEPs)] and on a later stage of higher-order processing (P3-complex). The results revealed an interaction effect of animacy and congruency in the early P50 SEP and an animacy effect in the N100/N140 SEPs. In the P3-complex, we found an interaction effect indicating that the influence of congruency was larger in the human than in the wooden hand. We argue that the P3-complex may reflect higher-order self-other distinction by signaling simulated action-based touch that does not match own tactile information. As such, the action-based somatosensory congruency paradigm might help understand higher-order social processes from a somatosensory point of view. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

The rate of cerebral utilization of glucose, ketone bodies, and oxygen: a comparative in vivo study of infant and adult rats.

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Dahlquist, G; Persson, B

1976-11-01

Cerebral blood flow (CBF) was measured by means of Celabeled microspheres in infant (20-day-old) and adult (3-month-old) rats, anesthetised with Na-5-ethyl-5-(1-methylpropyl)2-thiobarbituric acid. Cerebral arteriovenous differences of acetoacetate, D-beta-hydroxybutyrate, glucose, lactate, and oxygen and brain DNA content were determined in other groups of similarly treated infant and adult animals fed or starved for 48 or 72 hr. The mean CBF values of 0.48+/-0.04 and 0.62+/-0.07 ml/(g X min), +/- SEM, in infant and adult animals, respectively, were not significantly different. CBF was unaffected by starvation. At any given arterial concentration the cerebral arteriovenous difference of acetoacetate was significantly higher in infant than adult rats. The same was true for D-beta-hydroxybutyrate at arterial concentrations above 1 mmol/liter. There was an approximately linear relationship between arterial concentration of acetoacetate and its cerebral arteriovenous difference in both infant and adult rats. A similar relationship was found for D-beta-hydroxybutyrate only in infant animals. In the fed state, the cerebral uptake of glucose and ketone bodies (micromoles per (mg DNA X min)) was not different in infant and adult rats. During starvation, cerebral uptake of ketone bodies expressed as micromoles per (mg DNA X min) was higher in infant than adult rats, indicating a higher rate of utilization of ketone bodies per cell in these animals. For glucose, no such difference was found in either fed or starved groups (Table 3). The average percentage of the total cerebral uptake of substrates (micromoles per min) accounted for by ketone bodies increased in both infant and adult rats during starvation. This percentage value was clearly higher in infant than adult rats during starvation. After 72 hr of starvation the values were 38.8% and 15.2% in infant and adult rats, respectively (Fig. 3). Calculated cerebral metabolic rate for oxygen (CMRO2), assuming complete

Rapid reorganization of adult rat motor cortex somatic representation patterns after motor nerve injury.

OpenAIRE

Sanes, J N; Suner, S; Lando, J F; Donoghue, J P

1988-01-01

The potential for peripheral nerve injury to reorganize motor cortical representations was investigated in adult rats. Maps reflecting functional connections between the motor cortex and somatic musculature were generated with intracortical electrical stimulation techniques. Comparison of cortical somatotopic maps obtained in normal rats with maps generated from rats with a facial nerve lesion indicated that the forelimb and eye/eyelid representations expanded into the normal vibrissa area. R...

Sexual odor discrimination and physiological profiles in adult male rats after a neonatal, short term, reversible nasal obstruction.

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Thornton, S N; Padzys, G S; Trabalon, M

2014-05-01

The present study was designed to examine behavioral responses (interpreted as preferences) to olfactory cues (nest bedding odor and odors of estrous and anestrus females) in adult male rats after they had a short term reversible, bilateral, nasal obstruction (RbNO) as developing rat pups. These results were compared to behavior of control (untreated) and sham operated male littermates. Behavioral tests and physiological parameters were analyzed 90 days after recovery of nasal breathing. Experiments investigated the time spent in arms or the center of a maze of male rats in response to odors from the nest bedding or from adult females. There were no differences in responses between untreated, sham and RbNO adult male rats to fresh and nest bedding odors. RbNO males spent more time in the center of the maze when given a choice of estrus or anestrus female odors, or bedding odors from untreated or sham operated female rats. In contrast untreated and sham male rats preferred the odors of estrous females and of untreated or sham females. Plasma corticosterone levels in the males increased during the behavioral tests. Plasma testosterone levels were significantly lower in RbNO males compared to untreated males and did not increase during the behavioral tests compared to sham operated males. Males from all groups had similar preferences for the odor of bedding from adult RbNO females. Plasma levels of cholesterol and triglycerides were increased in RbNO adults. In conclusion, short term nasal obstruction in males while juvenile has long term consequences on hormones and behavioral preferences, thus potential partner selection when adult. Copyright © 2014 Elsevier Inc. All rights reserved.

Genetic influence demonstrated for MEG-recorded somatosensory evoked responses

NARCIS (Netherlands)

van 't Ent, D.; van Soelen, I.L.C.; Stam, K.J.; de Geus, E.J.C.; Boomsma, D.I.

2010-01-01

We tested for a genetic influence on magnetoencephalogram (MEG)-recorded somatosensory evoked fields (SEFs) in 20 monozygotic (MZ) and 14 dizygotic (DZ) twin pairs. Previous electroencephalogram (EEG) studies that demonstrated a genetic contribution to evoked responses generally focused on

In vivo and in vitro dermal penetration of 2,4,5,2',4', 5'-hexachlorobiphenyl in young and adult rats

International Nuclear Information System (INIS)

Shah, P.V.; Sumler, M.R.; Fisher, H.L.; Hall, L.L.

1989-01-01

Penetration of 2,4,5,2',4',5'-[ 14 C]hexachlorobiphenyl (HCB) through skin of young (33 days) and adult (82 days) female Fischer 344 rats was determined in vivo and by two in vitro methods. In vivo dermal penetration at 120 hr was 45% in young and 43% in adults. At 72 hr in vivo dermal penetration was 35% in young and 26% in adults compared to 1.5% for young and 1.0% for adult as measured with a continuous flow in vitro system and 2.9% for young and 1.9% for adults as measured with a static in vitro system. Most of the dermally absorbed HCB remained in the body as only 4.9 and 2.6% of that absorbed was excreted by young and adult rats, respectively, at the end of 120 hr. Significant differences in dermal penetration and kinetics of HCB between young and adult female rats were observed. The elimination of ECB-derived material was approximately six times higher in feces than in urine. A physiological pharmacokinetic model was fitted to the organ and tissue radioactivity distribution data. Parameters in the model determined from dermal dosing of female Fischer 344 rats were in reasonable agreement with those reported in the literature for adult male Sprague-Dawley rats (iv dose). The rate constant for dermal penetration was 0.83 x 10 -4 min -1 for adults and 0.96 x 10 -4 min -1 for young. The delay or lag time parameter for dermal penetration was 4.4 hr in adults and 1.1 hr in young

Adolescent TBI-induced hypopituitarism causes sexual dysfunction in adult male rats.

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Greco, Tiffany; Hovda, David A; Prins, Mayumi L

2015-02-01

Adolescents are at greatest risk for traumatic brain injury (TBI) and repeat TBI (RTBI). TBI-induced hypopituitarism has been documented in both adults and juveniles and despite the necessity of pituitary function for normal physical and brain development, it is still unrecognized and untreated in adolescents following TBI. TBI induced hormonal dysfunction during a critical developmental window has the potential to cause long-term cognitive and behavioral deficits and the topic currently remains unaddressed. The purpose of this study was to determine if four mild TBIs delivered to adolescent male rats disrupts testosterone production and adult behavioral outcomes. Plasma testosterone was quantified from 72 hrs preinjury to 3 months postinjury and pubertal onset, reproductive organ growth, erectile function and reproductive behaviors were assessed at 1 and 2 months postinjury. RTBI resulted in both acute and chronic decreases in testosterone production and delayed onset of puberty. Significant deficits were observed in reproductive organ growth, erectile function and reproductive behaviors in adult rats at both 1 and 2 months postinjury. These data suggest adolescent RTBI-induced hypopituitarism underlies abnormal behavioral changes observed during adulthood. The impact of undiagnosed hypopituitarism following RTBI in adolescence has significance not only for growth and puberty, but also for brain development and neurobehavioral function as adults. © 2014 Wiley Periodicals, Inc.

Using constellation pharmacology to define comprehensively a somatosensory neuronal subclass

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Teichert, Russell W.; Memon, Tosifa; Aman, Joseph W.; Olivera, Baldomero M.

2014-01-01

Change is intrinsic to nervous systems; change is required for learning and conditioning and occurs with disease progression, normal development, and aging. To better understand mammalian nervous systems and effectively treat nervous-system disorders, it is essential to track changes in relevant individual neurons. A critical challenge is to identify and characterize the specific cell types involved and the molecular-level changes that occur in each. Using an experimental strategy called constellation pharmacology, we demonstrate that we can define a specific somatosensory neuronal subclass, cold thermosensors, across different species and track changes in these neurons as a function of development. Cold thermosensors are uniformly responsive to menthol and innocuous cool temperature (17 °C), indicating that they express TRPM8 channels. A subset of cold thermosensors expressed α7 nicotinic acetylcholine receptors (nAChRs) but not other nAChR subtypes. Differences in temperature threshold of cold thermosensors correlated with functional expression of voltage-gated K channels Kv1.1/1.2: Relatively higher expression of KV1.1/1.2 channels resulted in a higher threshold response to cold temperature. Other signaling components varied during development and between species. In cold thermosensors of neonatal mice and rats, ATP receptors were functionally expressed, but the expression disappeared with development. This developmental change occurred earlier in low-threshold than high-threshold cold thermosensors. Most rat cold thermosensors expressed TRPA1 channels, whereas mouse cold thermosensors did not. The broad implications of this study are that it is now feasible to track changes in receptor and ion-channel expression in individual neuronal subclasses as a function of development, learning, disease, or aging. PMID:24469798

Adult neurogenesis and its anatomical context in the hippocampus of three mole-rat species

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Irmgard eAmrein

2014-05-01

Full Text Available African mole-rats (family Bathyergidae are small to medium sized, long-lived and strictly subterranean rodents that became valuable animal models as a result of their longevity and diversity in social organization. The formation and integration of new hippocampal neurons in adult mammals (adult hippocampal neurogenesis, AHN correlates negatively with age and positively with habitat complexity. Here we present quantitative data on AHN in wild-derived mole-rats of one year and older, and briefly describe its anatomical context including markers of neuronal function (calbindin and parvalbumin. Solitary Cape mole-rats (Georychus capensis, social highveld mole-rats (Cryptomys hottentotus pretoriae, and eusocial naked mole-rats (Heterocephalus glaber were assessed. Compared to other rodents, the hippocampal formation in mole-rats is small, but shows a distinct cytoarchitecture in the dentate gyrus and CA1. Distributions of the calcium-binding proteins differ from those seen in rodents; e.g., calbindin in CA3 of naked mole-rats distributes similar to the pattern seen in early primate development, and calbindin staining extends into the stratum lacunosum-moleculare of Cape mole-rats. Proliferating cells and young neurons are found in low numbers in the hippocampus of all three mole-rat species. Resident granule cell numbers are low as well. Proliferating cells expressed as a percentage of resident granule cells are in the range of other rodents, while the percentage of young neurons is lower than that observed in surface dwelling rodents. Between mole-rat species, we observed no difference in the percentage of proliferating cells. The percentages of young neurons are high in social highveld and naked mole-rats, and low in solitary Cape mole-rats. The findings support that proliferation is regulated independently of average life expectancy and habitat. Instead, neuronal differentiation reflects species-specific demands, which appear lower in subterranean

Adult neurogenesis and its anatomical context in the hippocampus of three mole-rat species.

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Amrein, Irmgard; Becker, Anton S; Engler, Stefanie; Huang, Shih-Hui; Müller, Julian; Slomianka, Lutz; Oosthuizen, Maria K

2014-01-01

African mole-rats (family Bathyergidae) are small to medium sized, long-lived, and strictly subterranean rodents that became valuable animal models as a result of their longevity and diversity in social organization. The formation and integration of new hippocampal neurons in adult mammals (adult hippocampal neurogenesis, AHN) correlates negatively with age and positively with habitat complexity. Here we present quantitative data on AHN in wild-derived mole-rats of 1 year and older, and briefly describe its anatomical context including markers of neuronal function (calbindin and parvalbumin). Solitary Cape mole-rats (Georychus capensis), social highveld mole-rats (Cryptomys hottentotus pretoriae), and eusocial naked mole-rats (Heterocephalus glaber) were assessed. Compared to other rodents, the hippocampal formation in mole-rats is small, but shows a distinct cytoarchitecture in the dentate gyrus and CA1. Distributions of the calcium-binding proteins differ from those seen in rodents; e.g., calbindin in CA3 of naked mole-rats distributes similar to the pattern seen in early primate development, and calbindin staining extends into the stratum lacunosum-moleculare of Cape mole-rats. Proliferating cells and young neurons are found in low numbers in the hippocampus of all three mole-rat species. Resident granule cell numbers are low as well. Proliferating cells expressed as a percentage of resident granule cells are in the range of other rodents, while the percentage of young neurons is lower than that observed in surface dwelling rodents. Between mole-rat species, we observed no difference in the percentage of proliferating cells. The percentages of young neurons are high in social highveld and naked mole-rats, and low in solitary Cape mole-rats. The findings support that proliferation is regulated independently of average life expectancy and habitat. Instead, neuronal differentiation reflects species-specific demands, which appear lower in subterranean rodents.

Morphometric golgi study of some cortical locations in wag/rij and aci rat strains

NARCIS (Netherlands)

Karpova, A.V.; Bikbaev, A.F.; Coenen, A.M.L.; Luijtelaar, E.L.J.M. van; Luijtelaar, E.L.J.M. van; Kuznetsova, G.D.; Coenen, A.M.L.; Chepurnov, S.A.

2004-01-01

The present study was aimed to investigate the neuronal organization of two neocortical frontal zones using a Golgi staining technique in genetic epileptic rats, WAG/Rij's. One cortical zone was a specific part of the somatosensory cortex, which was recently proposed to contain a cortical epileptic

COMMUNICATION Designing a somatosensory neural prosthesis: percepts evoked by different patterns of thalamic stimulation

Science.gov (United States)

Heming, Ethan; Sanden, Andrew; Kiss, Zelma H. T.

2010-12-01

Although major advances have been made in the development of motor prostheses, fine motor control requires intuitive somatosensory feedback. Here we explored whether a thalamic site for a somatosensory neural prosthetic could provide natural somatic sensation to humans. Different patterns of electrical stimulation (obtained from thalamic spike trains) were applied in patients undergoing deep brain stimulation surgery. Changes in pattern produced different sensations, while preserving somatotopic representation. While most percepts were reported as 'unnatural', some stimulations produced more 'natural' sensations than others. However, the additional patterns did not elicit more 'natural' percepts than high-frequency (333 Hz) electrical stimulation. These features suggest that despite some limitations, the thalamus may be a feasible site for a somatosensory neural prosthesis and different stimulation patterns may be useful in its development.

Neonatal tobacco smoke reduces thermogenesis capacity in brown adipose tissue in adult rats

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T.C. Peixoto

2018-04-01

Full Text Available Maternal smoking is a risk factor for progeny obesity. We have previously shown, in a rat model of neonatal tobacco smoke exposure, a mild increase in food intake and a considerable increase in visceral adiposity in the adult offspring. Males also had secondary hyperthyroidism, while females had only higher T4. Since brown adipose tissue (BAT hypofunction is related to obesity, here we tested the hypothesis that higher levels of thyroid hormones are not functional in BAT, suggesting a lower metabolic rate. We evaluated autonomic nerve activity in BAT and its function in adult rats that were exposed to tobacco smoke during lactation. At birth, litters were adjusted to 3 male and 3 female pups/litter. From postnatal day (PND 3 to 21, Wistar lactating rats and their pups were divided into SE group, smoke-exposed in a cigarette smoking machine (4 times/day and C group, exposed to filtered air. Offspring were sacrificed at PND180. Adult SE rats of both genders had lower interscapular BAT autonomic nervous system activity, with higher BAT mass but no change in morphology. BAT UCP1 and CPT1a protein levels were decreased in the SE groups of both genders. Male SE rats had lower β3-AR, TRα1, and TRβ1 expression while females showed lower PGC1α expression. BAT Dio2 mRNA and hypothalamic POMC and MC4R levels were similar between groups. Hypothalamic pAMPK level was higher in SE males and lower in SE females. Thus, neonatal cigarette smoke exposure induces lower BAT thermogenic capacity, which can be obesogenic at adulthood.

Neonatal tobacco smoke reduces thermogenesis capacity in brown adipose tissue in adult rats.

Science.gov (United States)

Peixoto, T C; Moura, E G; Oliveira, E; Younes-Rapozo, V; Soares, P N; Rodrigues, V S T; Santos, T R; Peixoto-Silva, N; Carvalho, J C; Calvino, C; Conceição, E P S; Guarda, D S; Claudio-Neto, S; Manhães, A C; Lisboa, P C

2018-01-01

Maternal smoking is a risk factor for progeny obesity. We have previously shown, in a rat model of neonatal tobacco smoke exposure, a mild increase in food intake and a considerable increase in visceral adiposity in the adult offspring. Males also had secondary hyperthyroidism, while females had only higher T4. Since brown adipose tissue (BAT) hypofunction is related to obesity, here we tested the hypothesis that higher levels of thyroid hormones are not functional in BAT, suggesting a lower metabolic rate. We evaluated autonomic nerve activity in BAT and its function in adult rats that were exposed to tobacco smoke during lactation. At birth, litters were adjusted to 3 male and 3 female pups/litter. From postnatal day (PND) 3 to 21, Wistar lactating rats and their pups were divided into SE group, smoke-exposed in a cigarette smoking machine (4 times/day) and C group, exposed to filtered air. Offspring were sacrificed at PND180. Adult SE rats of both genders had lower interscapular BAT autonomic nervous system activity, with higher BAT mass but no change in morphology. BAT UCP1 and CPT1a protein levels were decreased in the SE groups of both genders. Male SE rats had lower β3-AR, TRα1, and TRβ1 expression while females showed lower PGC1α expression. BAT Dio2 mRNA and hypothalamic POMC and MC4R levels were similar between groups. Hypothalamic pAMPK level was higher in SE males and lower in SE females. Thus, neonatal cigarette smoke exposure induces lower BAT thermogenic capacity, which can be obesogenic at adulthood.

Effects of chronic fluoxetine treatment on neurogenesis and tryptophan hydroxylase expression in adolescent and adult rats.

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Klomp, Anne; Václavů, Lena; Meerhoff, Gideon F; Reneman, Liesbeth; Lucassen, Paul J

2014-01-01

The antidepressant drug fluoxetine (Prozac) has been increasingly prescribed to children and adolescents with depressive disorders despite a lack of thorough understanding of its therapeutic effects in the paediatric population and of its putative neurodevelopmental effects. Within the framework of PRIOMEDCHILD ERA-NET, we investigated; a) effects of chronic fluoxetine treatment on adult hippocampal neurogenesis, a structural readout relevant for antidepressant action and hippocampal development; b) effects on tryptophan hydroxylase (TPH) expression, a measure of serotonin synthesis; c) whether treatment effects during adolescence differed from treatment at an adult age, and d) whether they were subregion-specific. Stereological quantification of the number of proliferating (Ki-67+) cells and of the number of young migratory neurons (doublecortin+), revealed a significant age-by-treatment interaction effect, indicating that fluoxetine affects both proliferation and neurogenesis in adolescent-treated rats differently than it does in adult-treated rats. In terms of subregional differences, fluoxetine enhanced proliferation mainly in the dorsal parts of the hippocampus, and neurogenesis in both the suprapyramidal and infrapyramidal blades of the dentate gyrus in adolescent-treated rats, while no such differences were seen in adult-treated rats. Fluoxetine exerted similar age-by-treatment interaction effects on TPH cells mainly in the ventral portion of the dorsal raphe nucleus. We conclude that fluoxetine exerts divergent effects on structural plasticity and serotonin synthesis in adolescent versus adult-treated rats. These preliminary data indicate a differential sensitivity of the adolescent brain to this drug and thus warrant further research into their behavioural and translational aspects. Together with recent related findings, they further call for caution in prescribing these drugs to the adolescent population.

Effects of chronic fluoxetine treatment on neurogenesis and tryptophan hydroxylase expression in adolescent and adult rats.

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Anne Klomp

Full Text Available The antidepressant drug fluoxetine (Prozac has been increasingly prescribed to children and adolescents with depressive disorders despite a lack of thorough understanding of its therapeutic effects in the paediatric population and of its putative neurodevelopmental effects. Within the framework of PRIOMEDCHILD ERA-NET, we investigated; a effects of chronic fluoxetine treatment on adult hippocampal neurogenesis, a structural readout relevant for antidepressant action and hippocampal development; b effects on tryptophan hydroxylase (TPH expression, a measure of serotonin synthesis; c whether treatment effects during adolescence differed from treatment at an adult age, and d whether they were subregion-specific. Stereological quantification of the number of proliferating (Ki-67+ cells and of the number of young migratory neurons (doublecortin+, revealed a significant age-by-treatment interaction effect, indicating that fluoxetine affects both proliferation and neurogenesis in adolescent-treated rats differently than it does in adult-treated rats. In terms of subregional differences, fluoxetine enhanced proliferation mainly in the dorsal parts of the hippocampus, and neurogenesis in both the suprapyramidal and infrapyramidal blades of the dentate gyrus in adolescent-treated rats, while no such differences were seen in adult-treated rats. Fluoxetine exerted similar age-by-treatment interaction effects on TPH cells mainly in the ventral portion of the dorsal raphe nucleus. We conclude that fluoxetine exerts divergent effects on structural plasticity and serotonin synthesis in adolescent versus adult-treated rats. These preliminary data indicate a differential sensitivity of the adolescent brain to this drug and thus warrant further research into their behavioural and translational aspects. Together with recent related findings, they further call for caution in prescribing these drugs to the adolescent population.

Behavioral cross-sensitization between testosterone and fenproporex in adolescent and adult rats.

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Conceição, C Q; Engi, S A; Cruz, F C; Planeta, C S

2017-11-17

The abuse of psychoactive drugs is considered a global health problem. During the last years, a relevant number of studies have investigated the relationship between anabolic-androgenic steroids (AAS) and other psychoactive drugs. AAS, such as testosterone, can cause a dependence syndrome that shares many features with the classical dependence to psychoactive substances. Pre-clinical evidence shows that there are interactions between testosterone and psychoactive drugs, such as cocaine. However, few studies have been performed to investigate the effect of repeated testosterone treatment on behavioral effects of amphetamine derivatives, such as fenproporex. The purpose of the present study was to investigate the effects of repeated testosterone administration on fenproporex-induced locomotor activity in adolescent and adult rats. Adolescent male Wistar rats were injected with testosterone (10 mg/kg sc for 10 days). After 3 days, animals received an acute injection of fenproporex (3.0 mg/kg ip) and the locomotor activity was recorded during 40 min. Thirty days later, the same animals received the same treatment with testosterone followed by a fenproporex challenge injection as described above. Our results demonstrated that repeated testosterone induced behavioral sensitization to fenproporex in adolescent but not in adult rats. These findings suggest that repeated AAS treatment might increase the dependence vulnerability to amphetamine and its derivatives in adolescent rats.

Early Effects of a Low Fat, Fructose-Rich Diet on Liver Metabolism, Insulin Signaling, and Oxidative Stress in Young and Adult Rats

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Raffaella Crescenzo

2018-04-01

Full Text Available The increase in the use of refined food, which is rich in fructose, is of particular concern in children and adolescents, since the total caloric intake and the prevalence of metabolic syndrome are increasing continuously in these populations. Nevertheless, the effects of high fructose diet have been mostly investigated in adults, by focusing on the effect of a long-term fructose intake. Notably, some reports evidenced that even short-term fructose intake exerts detrimental effects on metabolism. Therefore, the aim of this study was to compare the metabolic changes induced by the fructose-rich diet in rats of different age, i.e., young (30 days old and adult (90 days old rats. The fructose-rich diet increased whole body lipid content in adult, but not in young rats. The analysis of liver markers of inflammation suggests that different mechanisms depending on the age might be activated after the fructose-rich diet. In fact, a pro-inflammatory gene-expression analysis showed just a minor activation of macrophages in young rats compared to adult rats, while other markers of low-grade metabolic inflammation (TNF-alpha, myeloperoxidase, lipocalin, haptoglobin significantly increased. Inflammation was associated with oxidative damage to hepatic lipids in young and adult rats, while increased levels of hepatic nitrotyrosine and ceramides were detected only in young rats. Interestingly, fructose-induced hepatic insulin resistance was evident in young but not in adult rats, while whole body insulin sensitivity decreased both in fructose-fed young and adult rats. Taken together, the present data indicate that young rats do not increase their body lipids but are exposed to metabolic perturbations, such as hepatic insulin resistance and hepatic oxidative stress, in line with the finding that increased fructose intake may be an important predictor of metabolic risk in young people, independently of weight status. These results indicate the need of corrective

Adult naked mole-rat brain retains the NMDA receptor subunit GluN2D associated with hypoxia tolerance in neonatal mammals.

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Peterson, Bethany L; Park, Thomas J; Larson, John

2012-01-11

Adult naked mole-rats show a number of systemic adaptations to a crowded underground habitat that is low in oxygen and high in carbon dioxide. Remarkably, brain slice tissue from adult naked mole-rats also is extremely tolerant to oxygen deprivation as indicated by maintenance of synaptic transmission under hypoxic conditions as well as by a delayed neuronal depolarization during anoxia. These characteristics resemble hypoxia tolerance in brain slices from neonates in a variety of mammal species. An important component of neonatal tolerance to hypoxia involves the subunit composition of NMDA receptors. Neonates have a high proportion of NMDA receptors with GluN2D subunits which are protective because they retard calcium entry into neurons during hypoxic episodes. Therefore, we hypothesized that adult naked mole-rats retain a protective, neonatal-like, NMDA receptor subunit profile. We used immunoblotting to assess age-related changes in NMDA receptor subunits in naked mole-rats and mice. The results show that adult naked mole-rat brain retains a much greater proportion of the hypoxia-protective GluN2D subunit compared to adult mice. However, age-related changes in other subunits (GluN2A and GluN2B) from the neonatal period to adulthood were comparable in mice and naked mole-rats. Hence, adult naked mole-rat brain only retains the neonatal NMDA receptor subunit that is associated with hypoxia tolerance. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Keeping in Touch With the Visual System: Spatial Alignment and Multisensory Integration of Visual-Somatosensory Inputs

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Jeannette Rose Mahoney

2015-08-01

Full Text Available Correlated sensory inputs coursing along the individual sensory processing hierarchies arrive at multisensory convergence zones in cortex where inputs are processed in an integrative manner. The exact hierarchical level of multisensory convergence zones and the timing of their inputs are still under debate, although increasingly, evidence points to multisensory integration at very early sensory processing levels. The objective of the current study was to determine, both psychophysically and electrophysiologically, whether differential visual-somatosensory integration patterns exist for stimuli presented to the same versus opposite hemifields. Using high-density electrical mapping and complementary psychophysical data, we examined multisensory integrative processing for combinations of visual and somatosensory inputs presented to both left and right spatial locations. We assessed how early during sensory processing visual-somatosensory (VS interactions were seen in the event-related potential and whether spatial alignment of the visual and somatosensory elements resulted in differential integration effects. Reaction times to all VS pairings were significantly faster than those to the unisensory conditions, regardless of spatial alignment, pointing to engagement of integrative multisensory processing in all conditions. In support, electrophysiological results revealed significant differences between multisensory simultaneous VS and summed V+S responses, regardless of the spatial alignment of the constituent inputs. Nonetheless, multisensory effects were earlier in the aligned conditions, and were found to be particularly robust in the case of right-sided inputs (beginning at just 55ms. In contrast to previous work on audio-visual and audio-somatosensory inputs, the current work suggests a degree of spatial specificity to the earliest detectable multisensory integrative effects in response to visual-somatosensory pairings.

A comparative study on the effect of high cholesterol diet on the hippocampal CA1 area of adult and aged rats.

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Abo El-Khair, Doaa M; El-Safti, Fatma El-Nabawia A; Nooh, Hanaa Z; El-Mehi, Abeer E

2014-06-01

Dementia is one of the most important problems nowadays. Aging is associated with learning and memory impairments. Diet rich in cholesterol has been shown to be detrimental to cognitive performance. This work was carried out to compare the effect of high cholesterol diet on the hippocampus of adult and aged male albino rats. Twenty adult and twenty aged male rats were used in this study. According to age, the rats were randomly subdivided into balanced and high cholesterol diet fed groups. The diet was 15 g/rat/day for adult rats and 20 g/rat/day for aged rats for eight weeks. Serial coronal sections of hippocampus and blood samples were taken from each rat. For diet effect evaluation, Clinical, biochemical, histological, immunohistochemical, and morphometric assessments were done. In compare to a balanced diet fed rat, examination of Cornu Ammonis 1 (CA 1) area in the hippocampus of the high cholesterol diet adult rats showed degeneration, a significant decrease of the pyramidal cells, attenuation and/or thickening of small blood vessels, apparent increase of astrocytes and apparent decrease of Nissl's granules content. Moreover, the high cholesterol diet aged rats showed aggravation of senility changes of the hippocampus together with Alzheimer like pathological changes. In conclusion, the high cholesterol diet has a significant detrimental effect on the hippocampus and aging might pronounce this effect. So, we should direct our attention to limit cholesterol intake in our food to maintain a healthy life style for a successful aging.

Multidimensional MRI-CT atlas of the naked mole-rat brain (Heterocephalus glaber).

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Seki, Fumiko; Hikishima, Keigo; Nambu, Sanae; Okanoya, Kazuo; Okano, Hirotaka J; Sasaki, Erika; Miura, Kyoko; Okano, Hideyuki

2013-01-01

Naked mole-rats have a variety of distinctive features such as the organization of a hierarchical society (known as eusociality), extraordinary longevity, and cancer resistance; thus, it would be worthwhile investigating these animals in detail. One important task is the preparation of a brain atlas database that provide comprehensive information containing multidimensional data with various image contrasts, which can be achievable using a magnetic resonance imaging (MRI). Advanced MRI techniques such as diffusion tensor imaging (DTI), which generates high contrast images of fiber structures, can characterize unique morphological properties in addition to conventional MRI. To obtain high spatial resolution images, MR histology, DTI, and X-ray computed tomography were performed on the fixed adult brain. Skull and brain structures were segmented as well as reconstructed in stereotaxic coordinates. Data were also acquired for the neonatal brain to allow developmental changes to be observed. Moreover, in vivo imaging of naked mole-rats was established as an evaluation tool of live animals. The data obtained comprised three-dimensional (3D) images with high tissue contrast as well as stereotaxic coordinates. Developmental differences in the visual system were highlighted in particular by DTI. Although it was difficult to delineate optic nerves in the mature adult brain, parts of them could be distinguished in the immature neonatal brain. From observation of cortical thickness, possibility of high somatosensory system development replaced to the visual system was indicated. 3D visualization of brain structures in the atlas as well as the establishment of in vivo imaging would promote neuroimaging researches towards detection of novel characteristics of eusocial naked mole-rats.

Reorganization of auditory map and pitch discrimination in adult rats chronically exposed to low-level ambient noise

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Weimin eZheng

2012-09-01

Full Text Available Behavioral adaption to a changing environment is critical for an animal’s survival. How well the brain can modify its functional properties based on experience essentially defines the limits of behavioral adaptation. In adult animals the extent to which experience shapes brain function has not been fully explored. Moreover, the perceptual consequences of experience-induced changes in the brains of adults remain unknown. Here we show that the tonotopic map in the primary auditory cortex of adult rats living with low-level ambient noise underwent a dramatic reorganization. Behaviorally, chronic noise-exposure impaired fine, but not coarse pitch discrimination. When tested in a noisy environment, the noise-exposed rats performed as well as in a quiet environment whereas the control rats performed poorly. This suggests that noise-exposed animals had adapted to living in a noisy environment. Behavioral pattern analyses revealed that stress or distraction engendered by the noisy background could not account for the poor performance of the control rats in a noisy environment. A reorganized auditory map may therefore have served as the neural substrate for the consistent performance of the noise-exposed rats in a noisy environment.

Evaluation of various somatosensory stimulations for functional MRI

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Hara, Kazushi; Nakasato, Nobukazu; Mizoi, Kazuo; Yoshimoto, Takashi; Shimizu, Hiroaki.

1997-01-01

The aim of this functional magnetic resonance imaging (fMRI) study was to test detectability of activated area using various somatosensory stimulations. The following stimulations were performed in normal volunteers: regular or irregular electrical median nerve stimulation (n=5, each), tactile stimulation to the palm and fingers (n=8), pain stimulation to the index finger (n=5) or to the palm and fingers (n=5). fMRI was acquired with a spoiled gradient echo sequence at 1.5 T. Detectability of activated area was the highest when the pain stimulation was applied to the palm and fingers (80%). A successful rate for the tactile stimulation was 25%, and the other stimulations failed to demonstrate any activation. When successful, the highest signal activation on fMRI was seen on a sulcus, which presumably arose from a vein. The sulcus was defined as the central sulcus by somatosensory evoked field using a median nerve stimulation. Our study indicates that the pain stimulation to the palm and fingers may be a choice for the sensory fMRI. (author)

Effects of dimethylarsinic and dimethylarsinous acid on evoked synaptic potentials in hippocampal slices of young and adult rats

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Krueger, Katharina; Repges, Hendrik; Hippler, Joerg; Hartmann, Louise M.; Hirner, Alfred V.; Straub, Heidrun; Binding, Norbert; Musshoff, Ulrich

2007-01-01

In this study, the effects of pentavalent dimethylarsinic acid ((CH 3 ) 2 AsO(OH); DMA V ) and trivalent dimethylarsinous acid ((CH 3 ) 2 As(OH); DMA III ) on synaptic transmission generated by the excitatory Schaffer collateral-CA1 synapse were tested in hippocampal slices of young (14-21 day-old) and adult (2-4 month-old) rats. Both compounds were applied in concentrations of 1 to 100 μmol/l. DMA V had no effect on the amplitudes of evoked fEPSPs or the induction of LTP recorded from the CA1 dendritic region either in adult or in young rats. However, application of DMA III significantly reduced the amplitudes of evoked fEPSPs in a concentration-dependent manner with a total depression following application of 100 μmol/l DMA III in adult and 10 μmol/l DMA III in young rats. Moreover, DMA III significantly affected the LTP-induction. Application of 10 μmol/l DMA III resulted in a complete failure of the postsynaptic potentiation of the fEPSP amplitudes in slices taken both from adult and young rats. The depressant effect was not reversible after a 30-min washout of the DMA III . In slices of young rats, the depressant effects of DMA III were more pronounced than in those taken from adult ones. Compared to the (absent) effect of DMA V on synaptic transmission, the trivalent compound possesses a considerably higher neurotoxic potential

Synergistic effect of estradiol and fluoxetine in young adult and middle-aged female rats in two models of experimental depression.

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Récamier-Carballo, Soledad; Estrada-Camarena, Erika; Reyes, Rebeca; Fernández-Guasti, Alonso

2012-08-01

The antidepressant effect of estrogens combined with antidepressants is controversial: some preclinical data showed that estrogens facilitate the effect of antidepressants in the forced swimming test (FST) in young adult rats, while others failed to find such effect in middle-aged rats in the chronic mild stress (CMS) model. In clinics similar differences were reported and may be due to the compounds, the depression model or type of depression, the experimental design, and the age of the subjects or the women's menopause stage. The objective of this study was to analyze the antidepressant-like effect of the combination of 17β-estradiol (E(2)) and fluoxetine (FLX) in young adults (2-4 months) and middle-aged (12-14 months) ovariectomized (OVX) rats in two experimental models: FST and CMS. E(2) (5 and 10 μg/rat) and FLX (2.5 and 10 mg/kg) per se dose-dependently reduced immobility in both age groups and, in young adults both compounds increased swimming, whereas in middle-aged rats they increased swimming and climbing. Analysis of the antidepressant-like effect of the combination of suboptimal doses of FLX (1.25 mg/kg) and E(2) (2.5 μg/rat) showed a decrease in immobility and an increase in swimming in both age groups. In the CMS, chronic E(2) (2.5 μg/rat) with FLX (1.25 mg/kg) augmented relative sucrose intake, but middle-aged rats responded 2 weeks earlier than young adults. These results show that the antidepressant-like effect of the combination of E(2) and FLX in young adult and middle-aged female rats is evidenced in the two animal models of depression: FST and CMS. Copyright © 2012 Elsevier B.V. All rights reserved.

The expression of NFATc1 in adult rat skeletal muscle fibres.

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Mutungi, Gabriel

2008-03-01

Although numerous studies have recently implicated the calcineurin-nuclear factor of activated T-cells (Cn-NFAT) signalling pathway in the regulation of activity-dependent fibre type switching in adult mammalian skeletal muscles, little is known about the endogenous expression of NFAT proteins in the various fibre types present in these muscles. In this study, the immunolocalization of NFATc1 (also known as NFATc or NFAT2) in the extensor digitorum longus (EDL; a mainly fast-twitch muscle) and the soleus (a predominantly slow-twitch muscle) muscles of adult ( approximately 90-day-old) Wistar rats was investigated. The results show that NFATc1 is expressed only in oxidative fibres (i.e. type I and type IIA fibres) that stain intensely for succinate dehydrogenase activity irrespective of whether they are from the fast- or slow-twitch muscle. Thus, 99 +/- 4% (n = 7 rats) of the muscle fibres in the soleus and 42 +/- 2% (n = 7 rats) of those in the EDL expressed NFATc1. In the soleus muscle fibres, NFATc1 was localized mainly in the fibre nuclei, whereas in the EDL fibres it was localized in both the cytoplasm and the nuclei. However, no difference in its localization was observed between type I and type IIA fibres in both muscles. Western blot experiments showed that the soleus expressed more NFATc1 proteins than the EDL. From these results, we suggest that NFATc1 controls the number and distribution of both type I and type IIA fibres, as well as the oxidative capacity of adult mammalian skeletal muscles.

Dobutamine stress echocardiography in healthy adult male rats

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Couet Jacques

2005-10-01

Full Text Available Abstract Background Dobutamine stress echocardiography is used to investigate a wide variety of heart diseases in humans. Dobutamine stress echocardiography has also been used in animal models of heart disease despite the facts that the normal response of healthy rat hearts to this type of pharmacological stress testing is unknown. This study was performed to assess this normal response. Methods 15 normal adult male Wistar rats were evaluated. Increasing doses of dobutamine were infused intravenously under continuous imaging of the heart by a 12 MHz ultrasound probe. Results Dobutamine stress echocardiography reduced gradually LV diastolic and systolic dimensions. Ejection fraction increased by a mean of +24% vs. baseline. Heart rate increased progressively without reaching a plateau. Changes in LV dimensions and ejection fraction reached a plateau after a mean of 4 minutes at a constant infusion rate. Conclusion DSE can be easily performed in rats. The normal response is an increase in heart rate and ejection fraction and a decrease in LV dimensions. A plateau in echocardiographic measurements is obtained after 4 minutes of a constant infusion rate in most animals.

Somatosensory BOLD fMRI reveals close link between salient blood pressure changes and the murine neuromatrix.

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Reimann, Henning Matthias; Todiras, Mihail; Hodge, Russ; Huelnhagen, Till; Millward, Jason Michael; Turner, Robert; Seeliger, Erdmann; Bader, Michael; Pohlmann, Andreas; Niendorf, Thoralf

2018-05-15

The neuromatrix, or "pain matrix", is a network of cortical brain areas which is activated by noxious as well as salient somatosensory stimulation. This has been studied in mice and humans using blood oxygenation level-dependent (BOLD) fMRI. Here we demonstrate that BOLD effects observed in the murine neuromatrix in response to salient somatosensory stimuli are prone to reflect mean arterial blood pressure (MABP) changes, rather than neural activity. We show that a standard electrostimulus typically used in murine somatosensory fMRI can induce substantial elevations in MABP. Equivalent drug-induced MABP changes - without somatosensory stimulation - evoked BOLD patterns in the neuromatrix strikingly similar to those evoked by electrostimulation. This constitutes a serious caveat for murine fMRI. The regional specificity of these BOLD patterns can be attributed to the co-localization of the neuromatrix with large draining veins. Based on these findings we propose a cardiovascular support mechanism whereby abrupt elevations in MABP provide additional energy supply to the neuromatrix and other essential brain areas in fight-or-flight situations. Copyright © 2018 Elsevier Inc. All rights reserved.

Alexithymia and Somatosensory Amplification Link Perceived Psychosocial Stress and Somatic Symptoms in Outpatients with Psychosomatic Illness

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Mutsuhiro Nakao

2018-05-01

Full Text Available Background: Psychosomatic patients often complain of a variety of somatic symptoms. We sought to clarify the role of clinical predictors of complaints of somatic symptoms. Methods: We enrolled 604 patients visiting a psychosomatic outpatient clinic. The outcome was the total number of somatic symptoms, and the candidate clinical predictors were perceived psychosocial stress, alexithymia, somatosensory amplification, adaptation, anxiety, and depression. All participants completed questionnaires assessing the outcome and the predictors. Results: The average number of reported somatic symptoms was 4.8; the most frequent was fatigue (75.3%, followed by insomnia (56.1%, low-back pain (49.5%, headache (44.7%, and palpitations (43.1%. Multiple regression analysis showed that the total number of somatic symptoms was significantly associated with the degree of perceived psychosocial stress, alexithymia, somatosensory amplification, and depression. Also, structural equation models indicated links between excessive adaptation (via perceived psychosocial stress, alexithymia, and somatosensory amplification and the total number of somatic symptoms. Conclusion: The results suggested that the association between psychosocial stress and reported somatic symptoms is mediated by alexithymia and somatosensory amplification in psychosomatic patients.

Use of the light/dark test for anxiety in adult and adolescent male rats.

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Arrant, Andrew E; Schramm-Sapyta, Nicole L; Kuhn, Cynthia M

2013-11-01

The light/dark (LD) test is a commonly used rodent test of unconditioned anxiety-like behavior that is based on an approach/avoidance conflict between the drive to explore novel areas and an aversion to brightly lit, open spaces. We used the LD test to investigate developmental differences in behavior between adolescent (postnatal day (PN) 28-34) and adult (PN67-74) male rats. We investigated whether LD behavioral measures reflect anxiety-like behavior similarly in each age group using factor analysis and multiple regression. These analyses showed that time in the light compartment, percent distance in the light, rearing, and latency to emerge into the light compartment were measures of anxiety-like behavior in each age group, while total distance traveled and distance in the dark compartment provided indices of locomotor activity. We then used these measures to assess developmental differences in baseline LD behavior and the response to anxiogenic drugs. Adolescent rats emerged into the light compartment more quickly than adults and made fewer pokes into the light compartment. These age differences could reflect greater risk taking and less risk assessment in adolescent rats than adults. Adolescent rats were less sensitive than adults to the anxiogenic effects of the benzodiazepine inverse agonist N-methyl-β-carboline-3-carboxamide (FG-7142) and the α₂ adrenergic antagonist yohimbine on anxiety-like behaviors validated by factor analysis, but locomotor variables were similarly affected. These data support the results of the factor analysis and indicate that GABAergic and noradrenergic modulation of LD anxiety-like behavior may be immature during adolescence. Copyright © 2013 Elsevier B.V. All rights reserved.

Abstinence environment contributes to age differences in reinstatement of cocaine seeking between adolescent and adult male rats.

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Li, Chen; Frantz, Kyle J

2017-07-01

Extinction responding and cue-induced reinstatement of cocaine seeking after 60-days of forced abstinence are attenuated in male rats that self-administered cocaine during adolescence, compared with adults. Given that environmental enrichment during abstinence decreases reinstatement among adults, a possible explanation for attenuated reinstatement among adolescents is that standard pair-housing in prior studies creates a more stimulating environment for younger rats. Therefore, we tested whether standard pair-housing is necessary for the attenuated reinstatement among adolescents by determining whether an impoverished environment during abstinence would increase reinstatement among adolescents, up to adult levels. Conversely, we also tested whether environmental enrichment could further decrease reinstatement among adolescents, and whether we could replicate effects of environmental enrichment to decrease reinstatement among adults down to adolescent levels (positive controls). Adolescent and adult male Wistar rats self-administered cocaine intravenously for 12days (fixed ratio 1; 0.36mg/kg per infusion; 2h sessions). Rats were then moved into enriched (grouped, large cages, novel toys), standard (pair-housed, shoebox cages), or impoverished (isolated, hanging cages) housing conditions. After 60days, extinction and cue-induced reinstatement of cocaine seeking were tested, followed by drug-primed reinstatement (0, 5, 10mg/kg cocaine, i.p.). Consistent with previous results, extinction and cue-induced reinstatement were attenuated in adolescent-onset groups compared with adults; this age difference also extended to drug-primed reinstatement. In support of the present hypothesis, an impoverished environment during abstinence increased reinstatement among adolescents to levels that were not different from adult standard-housing levels. These data suggest that abstinence environment influences the enduring effects of cocaine among adolescents as well as adults

Ehlers-Danlos Syndrome, Hypermobility Type: Impact of Somatosensory Orthoses on Postural Control (A Pilot Study

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Emma G. Dupuy

2017-06-01

Full Text Available Elhers-Danlos syndrome (EDS is the clinical manifestation of connective tissue disorders, and comprises several clinical forms with no specific symptoms and selective medical examinations which result in a delay in diagnosis of about 10 years. The EDS hypermobility type (hEDS is characterized by generalized joint hypermobility, variable skin hyperextensibility and impaired proprioception. Since somatosensory processing and multisensory integration are crucial for both perception and action, we put forth the hypothesis that somatosensory deficits in hEDS patients may lead, among other clinical symptoms, to misperception of verticality and postural instability. Therefore, the purpose of this study was twofold: (i to assess the impact of somatosensory deficit on subjective visual vertical (SVV and postural stability; and (ii to quantify the effect of wearing somatosensory orthoses (i.e., compressive garments and insoles on postural stability. Six hEDS patients and six age- and gender-matched controls underwent a SVV (sitting, standing, lying on the right side evaluation and a postural control evaluation on a force platform (Synapsys, with or without visual information (eyes open (EO/eyes closed (EC. These two latter conditions performed either without orthoses, or with compression garments (CG, or insoles, or both. Results showed that patients did not exhibit a substantial perceived tilt of the visual vertical in the direction of the body tilt (Aubert effect as did the control subjects. Interestingly, such differential effects were only apparent when the rod was initially positioned to the left of the vertical axis (opposite the longitudinal body axis. In addition, patients showed greater postural instability (sway area than the controls. The removal of vision exacerbated this instability, especially in the mediolateral (ML direction. The wearing of orthoses improved postural stability, especially in the eyes-closed condition, with a particularly

Effects of monomethylarsonic and monomethylarsonous acid on evoked synaptic potentials in hippocampal slices of adult and young rats

International Nuclear Information System (INIS)

Krueger, Katharina; Straub, Heidrun; Hirner, Alfred V.; Hippler, Joerg; Binding, Norbert; Musshoff, Ulrich

2009-01-01

Arsenite and its metabolites, dimethylarsinic or dimethylarsinous acid, have previously been shown to disturb synaptic transmission in hippocampal slices of rats (Krueger, K., Gruner, J., Madeja, M., Hartmann, L.M., Hirner, A.V., Binding, N., Muβhoff, U., 2006a. Blockade and enhancement of glutamate receptor responses in Xenopus oocytes by methylated arsenicals. Arch. Toxicol. 80, 492-501, Krueger, K., Straub, H., Binding, N., Muβhoff, U., 2006b. Effects of arsenite on long-term potentiation in hippocampal slices from adult and young rats. Toxicol. Lett. 165, 167-173, Krueger, K., Repges, H., Hippler, J., Hartmann, L.M., Hirner, A.V., Straub, H., Binding, N., Muβhoff, U., 2007. Effects of dimethylarsinic and dimethylarsinous acid on evoked synaptic potentials in hippocampal slices of young and adult rats. Toxicol. Appl. Pharmacol. 225, 40-46). The present experiments investigate, whether the important arsenic metabolites monomethylarsonic acid (MMA V ) and monomethylarsonous acid (MMA III ) also influence the synaptic functions of the hippocampus. In hippocampal slices of young (14-21 days-old) and adult (2-4 months-old) rats, evoked synaptic field potentials from the Schaffer collateral-CA1 synapse were measured under control conditions and during and after 30 and 60 min of application of the arsenic compounds. MMA V had no effect on the synapse functions neither in slices of adult nor in those from young rats. However, MMA III strongly influenced the synaptic transmission: it totally depressed the amplitudes of fEPSPs at concentrations of 50 μmol/l (adult rats) and 25 μmol/l (young rats) and LTP amplitudes at concentrations of 25 μmol/l (adult rats) and 10 μmol/l (young rats), respectively. In contrast, application of 1 μmol/l MMA III led to an enhancement of the LTP amplitude in young rats, which is interpretable by an enhancing effect on NMDA receptors and a lack of the blocking effect on AMPA receptors at this concentration (Krueger, K., Gruner, J

HISTOLOGICAL STUDIES OF THE EFFECTS OF RED PEPPER ON THE STOMACH OF ADULT WISTAR RATS

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Josiah O. Adjene

2007-01-01

Full Text Available Histological effects of red pepper commonly used as spice in food on the stomach of adult wistar rats were carefully investigated. The rats of both sexes (n=24, average weight of 200g were randomly assigned into two treatments (n=16 and control (n=6 groups. The rats in the treatments groups received 1g and 2g of red pepper thoroughly mixed with 20g of their feeds for 7 and 14 days, while the control rats received equal amounts of feeds without the red pepper added. The rats were fed with grower's mash purchased from Edo feeds and flour mill Ltd, Ewu, Edo State and were given water liberally. The rats were sacrificed on day eight and fifteen of the experiment respectively.The stomach was carefully dissected out and quickly fixed in 10% formol saline for routine histological procedure after H & E method.The histological findings after H&E methods indicated that the treated sections of the stomach showed some level of cellular hypertrophy, congestion of blood vessels degenerative changes disruption and distortion of the cytoarchitecture of the stomach.These findings indicate that red pepper may have some deleterious effects on the microanatomy of the stomach of adult wistar rat at higher doses. It is recommended that further studies aimed at corroborating these findings be carried out.

Behavioral cross-sensitization between testosterone and fenproporex in adolescent and adult rats

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C.Q. Conceição

2017-11-01

Full Text Available The abuse of psychoactive drugs is considered a global health problem. During the last years, a relevant number of studies have investigated the relationship between anabolic-androgenic steroids (AAS and other psychoactive drugs. AAS, such as testosterone, can cause a dependence syndrome that shares many features with the classical dependence to psychoactive substances. Pre-clinical evidence shows that there are interactions between testosterone and psychoactive drugs, such as cocaine. However, few studies have been performed to investigate the effect of repeated testosterone treatment on behavioral effects of amphetamine derivatives, such as fenproporex. The purpose of the present study was to investigate the effects of repeated testosterone administration on fenproporex-induced locomotor activity in adolescent and adult rats. Adolescent male Wistar rats were injected with testosterone (10 mg/kg sc for 10 days. After 3 days, animals received an acute injection of fenproporex (3.0 mg/kg ip and the locomotor activity was recorded during 40 min. Thirty days later, the same animals received the same treatment with testosterone followed by a fenproporex challenge injection as described above. Our results demonstrated that repeated testosterone induced behavioral sensitization to fenproporex in adolescent but not in adult rats. These findings suggest that repeated AAS treatment might increase the dependence vulnerability to amphetamine and its derivatives in adolescent rats.

Preconception paternal bisphenol A exposure induces sex-specific anxiety and depression behaviors in adult rats.

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Ying Fan

Full Text Available Bisphenol A (BPA, an environmental endocrine-disrupting compound, has drawn a great attention for its adverse effect on behavioral development. Maternal exposure to this compound has been reported to induce anxiety and depression in offspring, but the effect of its paternal exposure is rarely discussed. This study investigated whether preconception paternal BPA exposure can affect the emotions of male rats and their offspring. Eighteen adult male rats (F0 received either a vehicle or 50 μg/kg/day BPA diet for 21 weeks and were then mated with non-exposed females to produce offspring (F1. The affective behaviors of F0 and F1 rats were evaluated in the open-field test, the elevated-plus maze and the forced swimming test, and their serum corticosterone were then examined. BPA exposure induced increased anxiety behaviors along with increased serum corticosterone in F0 rats. This paternal exposure also led to increased anxiety behaviors in F1 females and aggravated depression behaviors in both sexes of F1 rats. Furthermore, only F1 females exhibited increased serum corticosterone. Overall, these data indicate that preconception paternal exposure to a low dose of BPA may induce transgenerational sex-specific impairments in the affection of adult rats.

Effects of amphetamine administration on neurogenesis in adult rats

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Tomasz Stępień

2017-12-01

Full Text Available In our study expression of phospho-(Ser-10-histone H3 (pH3S10, a marker for the early stage of neurogenesis, and cellular early response genes were investigated using c-Fos protein as an example of a transcription factor in the neurogenic process in rats. Neurogenesis in the adult brain is regulated by endo- and exogenous factors, which influence the proliferation potential of progenitor cells and accelerate the dendritic development of newborn neurons. D-amphetamine, a psychoactive substance, is one of the exogenous factors able to influence the process of neurogenesis. The rats were injected with D-amphetamine at a dose of 1.5 mg/kg/body weight (b.w. under one administration scheme. Analysis of the pH3S10 and c-Fos expression levels in the group of D-amphetamine administered rats provided evidence of enhanced expression of these proteins in the regions of neurogenesis occurrence in rats. However, conclusions concerning stimulant effects of amphetamine on neurogenesis should be formulated with great caution, taking into account amphetamine dosage and the administration scheme. It should also be remembered that doses of psychoactive substances used in animal models can be lethal to humans.

α-Lipoic Acid Mitigates Arsenic-Induced Hematological Abnormalities in Adult Male Rats

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Sonali Ghosh

2017-05-01

Full Text Available Background: Arsenic toxicity is a major global health problem and exposure via contaminated drinking water has been associated with hematological and other systemic disorders. The present investigation has been conducted in adult male rats to evaluate the protective ability of α-lipoic acid (ALA against such hematological disorders. Methods: Twenty-four adult male Wister rats (b.wt.130±10g were grouped and accordingly group I (control received the normal diet, group II (treated was given arsenic orally for 28 consecutive days as arsenic trioxide (3 mg/kgbw/rat/day whereas group III (supplemented received the same dose of arsenic along with ALA (25 mg/kgbw/rat/day as oral supplement. Hematological profile, plasma oxidant/antioxidant status, and erythrocyte morphology were assessed. Statistical analysis was done by one-way ANOVA using SPSS software (version 16.0. Results: Arsenic exposure caused reduction of erythrocyte (P=0.021, leucocyte (P<0.001, and hemoglobin (P=0.031 associated with echinocytic transformation as evidenced by light and scanning electron microscopic studies. The other significantly altered parameters include increased mean corpuscular volume (P=0.041 and lymphocytopenia (P<0.001 with insignificant neutropenia and eosinophilia. Altered serum oxidative balance as evidenced by decreased TAS (P<0.001 and increased TOS (P<0.001 with OSI (P<0.001 was also noted. The dietary supplementation of ALA has a beneficial effect against the observed (P<0.05 arsenic toxicities. It brings about the protection by restoring the hematological redox and inflammatory status near normal in treated rats. Arsenic-induced morphological alteration of erythrocytes was also partially attenuated by ALA supplementation. Conclusion: It is concluded that arsenicosis is associated with hematological alterations and ALA co-supplementation can partially alleviate these changes in an experimental male rat model.

Importance of neural mechanisms in colonic mucosal and muscular dysfunction in adult rats following neonatal colonic irritation

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Chaloner, A.; Rao, A.; Al-Chaer, E.D.; Meerveld, B. Greenwood-Van

2009-01-01

Previous studies have shown that early life trauma induced by maternal separation or colonic irritation leads to hypersensitivity to colorectal distension in adulthood. We tested the hypothesis that repetitive colorectal distension in neonates leads to abnormalities in colonic permeability and smooth muscle function in the adult rat. In neonatal rats, repetitive colorectal distension was performed on days 8, 10, and 12. As adults, stool consistency was graded from 0 (formed stool) to 3 (liqui...

Effect of norbinaltorphimine on ∆⁹-tetrahydrocannabinol (THC)-induced taste avoidance in adolescent and adult Sprague-Dawley rats.

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Flax, Shaun M; Wakeford, Alison G P; Cheng, Kejun; Rice, Kenner C; Riley, Anthony L

2015-09-01

The aversive effects of ∆(9)-tetrahydrocannabinol (THC) are mediated by activity at the kappa opioid receptor (KOR) as assessed in adult animals; however, no studies have assessed KOR involvement in the aversive effects of THC in adolescents. Given that adolescents have been reported to be insensitive to the aversive effects induced by KOR agonists, a different mechanism might mediate the aversive effects of THC in this age group. The present study was designed to assess the impact of KOR antagonism on the aversive effects of THC in adolescent and adult rats using the conditioned taste avoidance (CTA) procedure. Following a single pretreatment injection of norbinaltorphimine (norBNI; 15 mg/kg), CTAs induced by THC (0, 0.56, 1.0, 1.8, and 3.2 mg/kg) were assessed in adolescent (n = 84) and adult (n = 83) Sprague-Dawley rats. The KOR antagonist, norBNI, had weak and inconsistent effects on THC-induced taste avoidance in adolescent rats in that norBNI both attenuated and strengthened taste avoidance dependent on dose and trial. norBNI had limited impact on the final one-bottle avoidance and no effects on the two-bottle preference test. Interestingly, norBNI had no effect on THC-induced taste avoidance in adult rats as well. That norBNI had no significant effect on THC-induced avoidance in adults, and a minor and inconsistent effect in adolescents demonstrates that the aversive effects of THC are not mediated by KOR activity as assessed by the CTA design in Sprague-Dawley rats.

Encoding of Touch Intensity But Not Pleasantness in Human Primary Somatosensory Cortex

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Laubacher, Claire M.; Olausson, Håkan; Wang, Binquan; Spagnolo, Primavera A.; Bushnell, M. Catherine

2016-01-01

Growing interest in affective touch has delineated a neural network that bypasses primary somatosensory cortex (S1). Several recent studies, however, have cast doubt on the segregation of touch discrimination and affect, suggesting that S1 also encodes affective qualities. We used functional magnetic resonance imaging (fMRI) and repetitive transcranial magnetic stimulation (rTMS) to examine the role of S1 in processing touch intensity and pleasantness. Twenty-six healthy human adults rated brushing on the hand during fMRI. Intensity ratings significantly predicted activation in S1, whereas pleasantness ratings predicted activation only in the anterior cingulate cortex. Nineteen subjects also received inhibitory rTMS over right hemisphere S1 and the vertex (control). After S1 rTMS, but not after vertex rTMS, sensory discrimination was reduced and subjects with reduced sensory discrimination rated touch as more intense. In contrast, rTMS did not alter ratings of touch pleasantness. Our findings support divergent neural processing of touch intensity and pleasantness, with affective touch encoded outside of S1. SIGNIFICANCE STATEMENT Growing interest in affective touch has identified a neural network that bypasses primary somatosensory cortex (S1). Several recent studies, however, cast doubt on the separation of touch discrimination and affect. We used functional magnetic resonance imaging and repetitive transcranial magnetic stimulation to demonstrate the representation of touch discrimination and intensity in S1, but the representation of pleasantness in the anterior cingulate cortex, not S1. Our findings support divergent neural processing of touch intensity and pleasantness, with affective touch encoded outside of S1. Our study contributes to growing delineation of the affective touch system, a crucial step in understanding its dysregulation in numerous clinical conditions such as autism, eating disorders, depression, and chronic pain. PMID:27225773

Locomotor activity and catecholamine receptor binding in adult normotensive and spontaneously hypertensive rats

International Nuclear Information System (INIS)

Hellstrand, K.; Engel, J.

1980-01-01

The binding of 3 H-WB 4101, an α 1 -adrenoceptor antagonist, the membranes of the cerebral cortex, the hypothalamus, and the lower brainstem was examined in adult spontaneously hypertensive (SH) rats and in normotensive Wistar Kyoto (WK) controls. The specific binding of 3 H-WB 4101 (0.33 nM) was significantly higher in homogenates from the cerebral cortex of SH rats as compared to WK rats. No differences were detected between SH and WK rats in the specific binding of 3 H-spiroperidol (0.25 nM), a dopamine receptor antagonist, to membranes from the corpus striatum and the limbic forebrain. The locomotor activity was significantly higher in SH rats as compared to WK controls, in all probability due to a lack of habituation to environmental change. It is suggested that the high reactivity of SH rats is related to a disfunction in the noradrenergic neurons in the central nervous system. (author)

The satiating hormone amylin enhances neurogenesis in the area postrema of adult rats

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Claudia G. Liberini

2016-10-01

Full Text Available Objective: Adult neurogenesis in the subgranular zone and subventricular zone is generally accepted, but its existence in other brain areas is still controversial. Circumventricular organs, such as the area postrema (AP have recently been described as potential neurogenic niches in the adult brain. The AP is the major site of action of the satiating hormone amylin. Amylin has been shown to promote the formation of neuronal projections originating from the AP in neonatal rodents but the role of amylin in adult neurogenesis remains unknown. Methods: To test this, we first performed an RNA-sequencing of the AP of adult rats acutely injected with either amylin (20 μg/kg, amylin plus the amylin receptor antagonist AC187 (500 μg/kg or vehicle. Second, animals were subcutaneously equipped with minipumps releasing either amylin (50 μg/kg/day or vehicle for 3 weeks to assess cell proliferation and differentiation with the 5′-bromo-2-deoxyuridine (BrdU technique. Results: Acute amylin injections affected genes involved in pathways and processes that control adult neurogenesis. Amylin consistently upregulated NeuroD1 transcript and protein in the adult AP, and this effect was blocked by the co-administration of AC187. Further, chronic amylin treatment increased the number of newly proliferated AP-cells and significantly promoted their differentiation into neurons rather than astrocytes. Conclusion: Our findings revealed a novel role of the satiating hormone amylin in promoting neurogenesis in the AP of adult rats. Keywords: Amylin, Adult neurogenesis, Area postrema, BrdU, Circumventricular organs

Impairment of male reproduction in adult rats exposed to hydroxyprogesterone caproate in utero

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Pushpalatha, T.; Ramachandra Reddy, P.; Sreenivasula Reddy, P.

Hydroxyprogesterone caproate is one of the most effective and widely used drugs for the treatment of uterine bleeding and threatened miscarriage in women. Hydroxyprogesterone caproate was administered to pregnant rats in order to assess the effect of intraperitoneal exposure to supranormal levels of hydroxyprogesterone caproate on the male reproductive potential in the first generation. The cauda epididymal sperm count and motility decreased significantly in rats exposed to hydroxyprogesterone caproate during embryonic development, when compared with control rats. The levels of serum testosterone decreased with an increase in follicle stimulating hormone and luteinizing hormone in adult rats exposed to hydroxyprogesterone caproate during the embryonic stage. It was suggested that the impairment of male reproductive performance could be mediated through the inhibition of testosterone production.

Acquisition of i.v. cocaine self-administration in adolescent and adult male rats selectively bred for high and low saccharin intake.

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Perry, Jennifer L; Anderson, Marissa M; Nelson, Sarah E; Carroll, Marilyn E

2007-05-16

Adolescence and excessive intake of saccharin have each been previously associated with enhanced vulnerability to drug abuse. In the present study, we focused on the relationship between these two factors using male adolescent and adult rats selectively bred for high (HiS) and low (LoS) levels of saccharin intake. On postnatal day 25 (adolescents) or 150 (adults), rats were implanted with an intravenous catheter and trained to self-administer cocaine (0.4 mg/kg) using an autoshaping procedure that consisted of two 6-h sessions. In the first 6 h, rats were given non-contingent cocaine infusions at random intervals 10 times per hour, and during the second 6-h session, rats were allowed to self-administer cocaine under a fixed ratio 1 (FR 1) lever-response contingency. Acquisition was defined as a total of at least 250 infusions over 5 consecutive days, and rats were given 30 days to meet the acquisition criterion. Subsequently, saccharin phenotype scores were determined by comparing 24-h saccharin and water consumption in two-bottle tests to verify HiS/LoS status. Adolescent LoS rats had a faster rate of acquisition of cocaine self-administration than adult LoS rats; however, adolescent and adult HiS rats acquired at the same rate. Both HiS and LoS adolescents had significantly higher saccharin phenotype scores than HiS and LoS adults, respectively. Additionally, saccharin score was negatively correlated with the number of days to meet the acquisition criterion for cocaine self-administration, but this was mostly accounted for by the HiS adolescents. These results suggest that during adolescence, compared with adulthood, rats have both an increased avidity for sweets and vulnerability to initiate drug abuse.

Novel assessment of cortical response to somatosensory stimuli in children with hemiparetic cerebral palsy.

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Maitre, Nathalie L; Barnett, Zachary P; Key, Alexandra P F

2012-10-01

The brain's response to somatosensory stimuli is essential to experience-driven learning in children. It was hypothesized that advances in event-related potential technology could quantify the response to touch in somatosensory cortices and characterize the responses of hemiparetic children. In this prospective study of 8 children (5-8 years old) with hemiparetic cerebral palsy, both event-related potential responses to sham or air puff trials and standard functional assessments were used. Event-related potential technology consistently measured signals reflecting activity in the primary and secondary somatosensory cortices as well as complex cognitive processing of touch. Participants showed typical early responses but less efficient perceptual processes. Significant differences between affected and unaffected extremities correlated with sensorimotor testing, stereognosis, and 2-point discrimination (r > 0.800 and P = .001 for all). For the first time, a novel event-related potential paradigm shows that hemiparetic children have slower and less efficient tactile cortical perception in their affected extremities.

Repeated exposure to methamphetamine induces sex-dependent hypersensitivity to ischemic injury in the adult rat heart.

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Boyd R Rorabaugh

Full Text Available We previously reported that adult female, but not male rats that were prenatally exposed to methamphetamine exhibit myocardial hypersensitivity to ischemic injury. However, it is unknown whether hypersensitivity to ischemic injury develops when rats are exposed to methamphetamine during adulthood. The goal of this study was to determine whether methamphetamine exposure during adulthood sensitizes the heart to ischemic injury.Adult male and female rats received daily injections of methamphetamine (5 mg/kg or saline for 10 days. Their hearts were isolated on day 11 and subjected to a 20 min ischemic insult on a Langendorff isolated heart apparatus. Cardiac contractile function was measured by an intraventricular balloon, and infarct size was measured by triphenyltetrazolium chloride staining.Hearts from methamphetamine-treated females exhibited significantly larger infarcts and suppressed postischemic recovery of contractile function compared to hearts from saline-treated females. In contrast, methamphetamine had no effect on infarct size or contractile recovery in male hearts. Subsequent experiments demonstrated that hypersensitivity to ischemic injury persisted in female hearts following a 1 month period of abstinence from methamphetamine. Myocardial protein kinase C-ε expression, Akt phosphorylation, and ERK phosphorylation were unaffected by adult exposure to methamphetamine.Exposure of adult rats to methamphetamine sex-dependently increases the extent of myocardial injury following an ischemic insult. These data suggest that women who have a heart attack might be at risk of more extensive myocardial injury if they have a recent history of methamphetamine abuse.

Repeated exposure to methamphetamine induces sex-dependent hypersensitivity to ischemic injury in the adult rat heart

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Seeley, Sarah L.; Stoops, Thorne S.; D’Souza, Manoranjan S.

2017-01-01

Background We previously reported that adult female, but not male rats that were prenatally exposed to methamphetamine exhibit myocardial hypersensitivity to ischemic injury. However, it is unknown whether hypersensitivity to ischemic injury develops when rats are exposed to methamphetamine during adulthood. The goal of this study was to determine whether methamphetamine exposure during adulthood sensitizes the heart to ischemic injury. Methods Adult male and female rats received daily injections of methamphetamine (5 mg/kg) or saline for 10 days. Their hearts were isolated on day 11 and subjected to a 20 min ischemic insult on a Langendorff isolated heart apparatus. Cardiac contractile function was measured by an intraventricular balloon, and infarct size was measured by triphenyltetrazolium chloride staining. Results Hearts from methamphetamine-treated females exhibited significantly larger infarcts and suppressed postischemic recovery of contractile function compared to hearts from saline-treated females. In contrast, methamphetamine had no effect on infarct size or contractile recovery in male hearts. Subsequent experiments demonstrated that hypersensitivity to ischemic injury persisted in female hearts following a 1 month period of abstinence from methamphetamine. Myocardial protein kinase C-ε expression, Akt phosphorylation, and ERK phosphorylation were unaffected by adult exposure to methamphetamine. Conclusions Exposure of adult rats to methamphetamine sex-dependently increases the extent of myocardial injury following an ischemic insult. These data suggest that women who have a heart attack might be at risk of more extensive myocardial injury if they have a recent history of methamphetamine abuse. PMID:28575091

Aversive effects of ethanol in adolescent versus adult rats: potential causes and implication for future drinking.

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Schramm-Sapyta, Nicole L; DiFeliceantonio, Alexandra G; Foscue, Ethan; Glowacz, Susan; Haseeb, Naadeyah; Wang, Nancy; Zhou, Cathy; Kuhn, Cynthia M

2010-12-01

Many people experiment with alcohol and other drugs of abuse during their teenage years. Epidemiological evidence suggests that younger initiates into drug taking are more likely to develop problematic drug seeking behavior, including binge and other high-intake behaviors. The level of drug intake for any individual depends on the balance of rewarding and aversive effects of the drug in that individual. Multiple rodent studies have demonstrated that aversive effects of drugs of abuse are reduced in adolescent compared to adult animals. In this study, we addressed 2 key questions: First, do reduced aversive effects of ethanol in younger rats correlate with increased ethanol consumption? Second, are the reduced aversive effects in adolescents attributable to reduced sensitivity to ethanol's physiologic effects? Adolescent and adult rats were tested for ethanol conditioned taste aversion (CTA) followed by a voluntary drinking period, including postdeprivation consumption. Multivariate regression was used to assess correlations. In separate experiments, adolescent and adult rats were tested for their sensitivity to the hypothermic and sedative effects of ethanol, and for blood ethanol concentrations (BECs). We observed that in adolescent rats but not adults, taste aversion was inversely correlated with postdeprivation consumption. Adolescents also exhibited a greater increase in consumption after deprivation than adults. Furthermore, the age difference in ethanol CTA was not attributable to differences in hypothermia, sedation, or BECs. These results suggest that during adolescence, individuals that are insensitive to aversive effects are most likely to develop problem drinking behaviors. These results underscore the importance of the interaction between developmental stage and individual variation in sensitivity to alcohol. Copyright © 2010 by the Research Society on Alcoholism.

Negative Effect of Zinc on Testes, Testosterone and Gonadotrophins Levels in Adult Male Wistar Rats

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D. Sohrabi

2008-10-01

Full Text Available Background and ObjectivesThe toxic effects of zinc leading to sebaceous gland closure, skin eczema and blister have been previously demonstrated in other studies. The aim of this study is to determine the chronic effects of zinc chloride (ZnCl2 on testicular tissues, testosterone and gonadotrophins in adult male Wistar rats.Methods Twenty four Adult male Wistar rats were divided in to two groups of study and control with each group consisting of 12 rats. Study group rats received 10 mg/kg interaperitoneal Zinc chloride in normal saline (N.S every other day for 30 days. Control group rats received N.S during this time. Blood sample for hormonal evaluation were collected from hearts of these rats. The rats were destroyed and their testes were removed and fixed in a 10% formaldehyde and glutaraldehyde solution.ResultsThe results of this study showed a significant decrease in the level of LH and testosterone hormone among the rats in the study group compared to the control group with p< 0.001 and p< 0.01 respectively. Study of fine structure of testicular cells and tissues in the study group rats revealed swelling of mitochondria, increase in smooth endoplasmic reticulum vacuolization and lysosomic granules (Autophagic vacuoles in cytosol of their germinal cells.ConclusionBased on the results of this study consumption of large amount of compounds which contain zinc should be controlled and limited among men. There is a need for further studies to evaluate and determine the reversibility of most hormonal and physiological changes due to usage of zinc containing compounds.Keywords: Zinc Chloride; Testis; Testosterone; Gonadotrophins

Spinal N13 versus cortical N20 and dermatomal somatosensory ...

African Journals Online (AJOL)

Mohamed Imam

2013-04-06

Apr 6, 2013 ... Spinal N13 versus cortical N20 and dermatomal somatosensory .... recording point for the right upper limb stimulation and the. C40 for the left upper limb stimulation. The reference ..... Brain 1992;115:1209–34. 298. M. Imam ...

Reduced resting state functional connectivity of the somatosensory cortex predicts psychopathological symptoms in women with bulimia nervosa

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Luca eLavagnino

2014-08-01

Full Text Available BackgroundAlterations in the resting state functional connectivity (rs-FC of several brain networks have been demonstrated in eating disorders. However, very few studies are currently available on brain network dysfunctions in bulimia nervosa (BN. The somatosensory network is central in processing body-related stimuli and it may be altered in BN. The present study therefore aimed to investigate rs-FC in the somatosensory network in bulimic women. MethodsSixteen medication-free women with BN (age=23±5 years and 18 matched controls (age=23±3 years underwent a functional magnetic resonance resting state scan and assessment of eating disorder symptoms. Within-network and seed-based functional connectivity analyses were conducted to assess rs-FC within the somatosensory network and to other areas of the brain. ResultsBN patients showed a decreased resting state functional connectivity both within the somatosensory network (t=9.0, df=1, P=0.005 and with posterior cingulate cortex (PCC and two visual areas (the right middle occipital gyrus and the right cuneus(P=0.05 corrected for multiple comparison. The region in the right middle occipital gyrus is implicated in body processing and is known as extrastriate body area, or EBA. The rs-FC of the left paracentral lobule with the EBA correlated with psychopathology measures like bulimia (r=-0.4; P=0.02 and interoceptive awareness (r=-0.4; P=0.01. Analyses were conducted using age, BMI (body mass index and depressive symptoms as covariates. ConclusionsOur findings show a specific alteration of the rs-FC of the somatosensory cortex in BN patients, which correlates with eating disorder symptoms. The connectivity between the somatosensory cortex and the EBA might be related to dysfunctions in body image processing. The results should be considered preliminary due to the small sample size.

Reduced resting-state functional connectivity of the somatosensory cortex predicts psychopathological symptoms in women with bulimia nervosa.

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Lavagnino, Luca; Amianto, Federico; D'Agata, Federico; Huang, Zirui; Mortara, Paolo; Abbate-Daga, Giovanni; Marzola, Enrica; Spalatro, Angela; Fassino, Secondo; Northoff, Georg

2014-01-01

Alterations in the resting-state functional connectivity (rs-FC) of several brain networks have been demonstrated in eating disorders. However, very few studies are currently available on brain network dysfunctions in bulimia nervosa (BN). The somatosensory network is central in processing body-related stimuli and it may be altered in BN. The present study therefore aimed to investigate rs-FC in the somatosensory network in bulimic women. Sixteen medication-free women with BN (age = 23 ± 5 years) and 18 matched controls (age = 23 ± 3 years) underwent a functional magnetic resonance resting-state scan and assessment of eating disorder symptoms. Within-network and seed-based functional connectivity analyses were conducted to assess rs-FC within the somatosensory network and to other areas of the brain. Bulimia nervosa patients showed a decreased rs-FC both within the somatosensory network (t = 9.0, df = 1, P = 0.005) and with posterior cingulate cortex and two visual areas (the right middle occipital gyrus and the right cuneus) (P = 0.05 corrected for multiple comparison). The rs-FC of the left paracentral lobule with the right middle occipital gyrus correlated with psychopathology measures like bulimia (r = -0.4; P = 0.02) and interoceptive awareness (r = -0.4; P = 0.01). Analyses were conducted using age, BMI (body mass index), and depressive symptoms as covariates. Our findings show a specific alteration of the rs-FC of the somatosensory cortex in BN patients, which correlates with eating disorder symptoms. The region in the right middle occipital gyrus is implicated in body processing and is known as extrastriate body area (EBA). The connectivity between the somatosensory cortex and the EBA might be related to dysfunctions in body image processing. The results should be considered preliminary due to the small sample size.

Magnetoencephalographic Imaging of Auditory and Somatosensory Cortical Responses in Children with Autism and Sensory Processing Dysfunction

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Carly Demopoulos

2017-05-01

Full Text Available This study compared magnetoencephalographic (MEG imaging-derived indices of auditory and somatosensory cortical processing in children aged 8–12 years with autism spectrum disorder (ASD; N = 18, those with sensory processing dysfunction (SPD; N = 13 who do not meet ASD criteria, and typically developing control (TDC; N = 19 participants. The magnitude of responses to both auditory and tactile stimulation was comparable across all three groups; however, the M200 latency response from the left auditory cortex was significantly delayed in the ASD group relative to both the TDC and SPD groups, whereas the somatosensory response of the ASD group was only delayed relative to TDC participants. The SPD group did not significantly differ from either group in terms of somatosensory latency, suggesting that participants with SPD may have an intermediate phenotype between ASD and TDC with regard to somatosensory processing. For the ASD group, correlation analyses indicated that the left M200 latency delay was significantly associated with performance on the WISC-IV Verbal Comprehension Index as well as the DSTP Acoustic-Linguistic index. Further, these cortical auditory response delays were not associated with somatosensory cortical response delays or cognitive processing speed in the ASD group, suggesting that auditory delays in ASD are domain specific rather than associated with generalized processing delays. The specificity of these auditory delays to the ASD group, in addition to their correlation with verbal abilities, suggests that auditory sensory dysfunction may be implicated in communication symptoms in ASD, motivating further research aimed at understanding the impact of sensory dysfunction on the developing brain.

Lavandula angustifolia Extract Improves the Result of Human Umbilical Mesenchymal Wharton's Jelly Stem Cell Transplantation after Contusive Spinal Cord Injury in Wistar Rats

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Yaghoobi, Kayvan; Kaka, Gholamreza; Mansouri, Korosh; Davoodi, Shaghayegh; Sadraie, Seyed Homayoon; Hosseini, Seyed Ruhollah

2016-01-01

Introduction. The primary trauma of spinal cord injury (SCI) results in severe damage to nervous functions. At the cellular level, SCI causes astrogliosis. Human umbilical mesenchymal stem cells (HUMSCs), isolated from Wharton's jelly of the umbilical cord, can be easily obtained. Previously, we showed that the neuroprotective effects of Lavandula angustifolia can lead to improvement in a contusive SCI model in rats. Objective. The aim of this study was to investigate the effect of L. angustifolia (Lav) on HUMSC transplantation after acute SCI. Materials and Methods. Sixty adult female rats were randomly divided into eight groups. Every week after SCI onset, all animals were evaluated for behavior outcomes. H&E staining was performed to examine the lesions after injury. GFAP expression was assessed for astrogliosis. Somatosensory evoked potential (SEP) testing was performed to detect the recovery of neural conduction. Results. Behavioral tests showed that the HUMSC group improved in comparison with the SCI group, but HUMSC + Lav 400 was very effective, resulting in a significant increase in locomotion activity. Sensory tests and histomorphological and immunohistochemistry analyses verified the potentiation effects of Lav extract on HUMSC treatment. Conclusion. Transplantation of HUMSCs is beneficial for SCI in rats, and Lav extract can potentiate the functional and cellular recovery with HUMSC treatment in rats after SCI. PMID:27057171

Effects of physical exercise on object recognition memory in adult rats of postnatal isoflurane exposures

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Xiao-yan FANG

2017-08-01

Full Text Available Objective To investigate effects of physical exercise (PE on object recognition memory in adult rats of postnatal isoflurane (Iso exposures. Methods One hundred and ten postnatal 7-day SD rats (P7 were randomly divided into four groups: normal control group (Naive, Naive+PE group (received physical exercise in P21: a treadmill exercise 30min each day, 5 times/week, for 6 weeks, Iso group (three times of 2-hour Iso exposure in P7, P9, and P11, and Iso+PE group (received PE in P21 after postnatal Iso exposures. In P67, behavioral testing was conducted including open field and object recognition task (ORT, recording the time (Discrimination Ratios, DR that rats spent on exploring each object, evaluating effects of PE on object recognition memory. Results There was no significant difference in influence of PE on open field testing in all of the groups (P>0.05. Compared with Naive, there was no group difference in DR (P>0.05 for all groups, but the DR of Iso male rats was significantly higher than that of Naive female rats in P67, with significant difference (P=0.034. Compared with non-PE groups, whether or not postnatal Iso exposures, the DR of PE male groups was significantly higher (compared with Naive and Iso group: P67, P=0.050, P=0.017; P95, P=0.037, P=0.019; in female rats, the DR for ISO+PE group was lower than that of Iso group in P67 (P=0.036, but the DR of Naive+PE group was higher than that of Naive group in P95 (P=0.004. Compared with male rats, the DR of non-PE female rats was significantly higher in P67 (vis. Naive and Iso group: P=0.022, P=0.011; but in P95, the DR of non- Iso female groups was significantly higher than that of male groups (vis. Naive and Naive+PE: P=0.008, P=0.017. Conclusions There is no obvious impact of postnatal Iso exposures on object recognition memory of adult rats. These results also indicate that postnatal PE could improve object recognition memory of non-spatial learning in adult rats. In addition, exercise

Auditory-somatosensory temporal sensitivity improves when the somatosensory event is caused by voluntary body movement

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Norimichi Kitagawa

2016-12-01

Full Text Available When we actively interact with the environment, it is crucial that we perceive a precise temporal relationship between our own actions and sensory effects to guide our body movements.Thus, we hypothesized that voluntary movements improve perceptual sensitivity to the temporal disparity between auditory and movement-related somatosensory events compared to when they are delivered passively to sensory receptors. In the voluntary condition, participants voluntarily tapped a button, and a noise burst was presented at various onset asynchronies relative to the button press. The participants made either 'sound-first' or 'touch-first' responses. We found that the performance of temporal order judgment (TOJ in the voluntary condition (as indexed by the just noticeable difference was significantly better (M=42.5 ms ±3.8 s.e.m than that when their finger was passively stimulated (passive condition: M=66.8 ms ±6.3 s.e.m. We further examined whether the performance improvement with voluntary action can be attributed to the prediction of the timing of the stimulation from sensory cues (sensory-based prediction, kinesthetic cues contained in voluntary action, and/or to the prediction of stimulation timing from the efference copy of the motor command (motor-based prediction. When the participant’s finger was moved passively to press the button (involuntary condition and when three noise bursts were presented before the target burst with regular intervals (predictable condition, the TOJ performance was not improved from that in the passive condition. These results suggest that the improvement in sensitivity to temporal disparity between somatosensory and auditory events caused by the voluntary action cannot be attributed to sensory-based prediction and kinesthetic cues. Rather, the prediction from the efference copy of the motor command would be crucial for improving the temporal sensitivity.

Prenatal zinc reduces stress response in adult rat offspring exposed to lipopolysaccharide during gestation.

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Galvão, Marcella C; Chaves-Kirsten, Gabriela P; Queiroz-Hazarbassanov, Nicolle; Carvalho, Virgínia M; Bernardi, Maria M; Kirsten, Thiago B

2015-01-01

Previous investigations by our group have shown that prenatal treatment with lipopolysaccharide (LPS; 100 μg/kg, intraperitoneally) on gestation day (GD) 9.5 in rats, which mimics infections by Gram-negative bacteria, induces short- and long-term behavioral and neuroimmune changes in the offspring. Because LPS induces hypozincemia, dams were treated with zinc after LPS in an attempt to prevent or ameliorate the impairments induced by prenatal LPS exposure. LPS can also interfere with hypothalamic-pituitary-adrenal (HPA) axis development; thus, behavioral and neuroendocrine parameters linked to HPA axis were evaluated in adult offspring after a restraint stress session. We prenatally exposed Wistar rats to LPS (100 μg/kg, intraperitoneally, on GD 9.5). One hour later they received zinc (ZnSO4, 2 mg/kg, subcutaneously). Adult female offspring that were in metestrus/diestrus were submitted to a 2 h restraint stress session. Immediately after the stressor, 22 kHz ultrasonic vocalizations, open field behavior, serum corticosterone and brain-derived neurotrophic factor (BDNF) levels, and striatal and hypothalamic neurotransmitter and metabolite levels were assessed. Offspring that received prenatal zinc after LPS presented longer periods in silence, increased locomotion, and reduced serum corticosterone and striatal norepinephrine turnover compared with rats treated with LPS and saline. Prenatal zinc reduced acute restraint stress response in adult rats prenatally exposed to LPS. Our findings suggest a potential beneficial effect of prenatal zinc, in which the stress response was reduced in offspring that were stricken with infectious/inflammatory processes during gestation. Copyright © 2014 Elsevier Inc. All rights reserved.

The Processing of Somatosensory Information shifts from an early parallel into a serial processing mode: a combined fMRI/MEG study.

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Carsten Michael Klingner

2016-12-01

Full Text Available The question regarding whether somatosensory inputs are processed in parallel or in series has not been clearly answered. Several studies that have applied dynamic causal modeling (DCM to fMRI data have arrived at seemingly divergent conclusions. However, these divergent results could be explained by the hypothesis that the processing route of somatosensory information changes with time. Specifically, we suggest that somatosensory stimuli are processed in parallel only during the early stage, whereas the processing is later dominated by serial processing. This hypothesis was revisited in the present study based on fMRI analyses of tactile stimuli and the application of DCM to magnetoencephalographic (MEG data collected during sustained (260 ms tactile stimulation. Bayesian model comparisons were used to infer the processing stream. We demonstrated that the favored processing stream changes over time. We found that the neural activity elicited in the first 100 ms following somatosensory stimuli is best explained by models that support a parallel processing route, whereas a serial processing route is subsequently favored. These results suggest that the secondary somatosensory area (SII receives information regarding a new stimulus in parallel with the primary somatosensory area (SI, whereas later processing in the SII is dominated by the preprocessed input from the SI.

The Processing of Somatosensory Information Shifts from an Early Parallel into a Serial Processing Mode: A Combined fMRI/MEG Study.

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Klingner, Carsten M; Brodoehl, Stefan; Huonker, Ralph; Witte, Otto W

2016-01-01

The question regarding whether somatosensory inputs are processed in parallel or in series has not been clearly answered. Several studies that have applied dynamic causal modeling (DCM) to fMRI data have arrived at seemingly divergent conclusions. However, these divergent results could be explained by the hypothesis that the processing route of somatosensory information changes with time. Specifically, we suggest that somatosensory stimuli are processed in parallel only during the early stage, whereas the processing is later dominated by serial processing. This hypothesis was revisited in the present study based on fMRI analyses of tactile stimuli and the application of DCM to magnetoencephalographic (MEG) data collected during sustained (260 ms) tactile stimulation. Bayesian model comparisons were used to infer the processing stream. We demonstrated that the favored processing stream changes over time. We found that the neural activity elicited in the first 100 ms following somatosensory stimuli is best explained by models that support a parallel processing route, whereas a serial processing route is subsequently favored. These results suggest that the secondary somatosensory area (SII) receives information regarding a new stimulus in parallel with the primary somatosensory area (SI), whereas later processing in the SII is dominated by the preprocessed input from the SI.

Chronic intermittent hypoxia promotes expression of 3-mercaptopyruvate sulfurtransferase in adult rat medulla oblongata.

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Li, Mingqiang; Nie, Lihong; Hu, Yajie; Yan, Xiang; Xue, Lian; Chen, Li; Zhou, Hua; Zheng, Yu

2013-12-01

The present experiments were carried out to investigate the expression of 3-mercaptopyruvate sulfurtransferase (3MST) in medulla oblongata of rats and effects of chronic intermittent hypoxia (CIH) on its expression. Sprague Dawley adult rats were randomly divided into two groups, including control (Con) group and CIH group. The endogenous production of hydrogen sulfide (H2S) in medulla oblongata tissue homogenates was measured using the methylene blue assay method, 3MST mRNA and protein expression were analyzed by RT-PCR and Western blotting, respectively, and the expression of 3MST in the neurons of respiratory-related nuclei in medulla oblongata of rats was investigated with immunohistochemical technique. CIH elevated the endogenous H2S production in rat medulla oblongata (Pmedulla oblongata of rats and CIH promoted their expression (P<0.01). Immunohistochemical staining indicated that 3MST existed in the neurons of pre-Bötzinger complex (pre-BötC), hypoglossal nucleus (12N), ambiguous nucleus (Amb), facial nucleus (FN) and nucleus tractus solitarius (NTS) in the animals and the mean optical densities of 3MST-positive neurons in the pre-BötC, 12N and Amb, but not in FN and NTS, were significantly increased in CIH group (P<0.05). In conclusion, 3MST exists in the neurons of medullary respiratory nuclei and its expression can be up-regulated by CIH in adult rat, suggesting that 3MST-H2S pathway may be involved in regulation of respiration and protection on medullary respiratory centers from injury induced by CIH. © 2013.

Electroacupuncture Ameliorates Cognitive Deficit and Improves Hippocampal Synaptic Plasticity in Adult Rat with Neonatal Maternal Separation

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Lili Guo

2018-01-01

Full Text Available Exposure to adverse early-life events is thought to be the risk factors for the development of psychiatric and altered cognitive function in adulthood. The purpose of this study was to investigate whether electroacupuncture (EA treatment in young adult rat would improve impaired cognitive function and synaptic plasticity in adult rat with neonatal maternal separation (MS. Wistar rats were randomly divided into four groups: control group, MS group, MS with EA treatment (MS + EA group, and MS with Sham-EA treatment (MS + Sham-EA group. We evaluated the cognitive function by using Morris water maze and fear conditioning tests. Electrophysiology experiment used in vivo long-term potentiation (LTP at Schaffer Collateral-CA1 synapses was detected to assess extent of synaptic plasticity. Repeated EA stimulation at Baihui (GV 20 and Yintang (GV 29 during postnatal 9 to 11 weeks was identified to significantly ameliorate poor performance in behavior tests and improve the impaired LTP induction detected at Schaffer Collateral-CA1 synapse in hippocampus. Collectively, the findings suggested that early-life stress due to MS may induce adult cognitive deficit associated with hippocampus, and EA in young adult demonstrated that its therapeutic efficacy may be via ameliorating deficit of hippocampal synaptic plasticity.

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

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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.

Multimodal and widespread somatosensory abnormalities in persistent shoulder pain in the first 6 months after stroke: an exploratory study

NARCIS (Netherlands)

Roosink, M.; van Dongen, R.T.; Buitenweg, J.R.; Renzenbrink, G.J.; Geurts, A.C.H.; IJzerman, M.J.

2012-01-01

Roosink M, Van Dongen RT, Buitenweg JR, Renzenbrink GJ, Geurts AC, IJzerman MJ. Multimodal and widespread somatosensory abnormalities in persistent shoulder pain in the first 6 months after stroke: an exploratory study. OBJECTIVE: To explore the role of multimodal and widespread somatosensory

A comparative study of myosin and its subunits in adult and neonatal-rat hearts and in rat heart cells from young and old cultures.

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Ghanbari, H A; McCarl, R L

1980-01-01

A possible explanation for the decrease in myosin Ca2+-dependent ATPase activity as rat heart cells age in culture is presented. The subunit structure and enzyme kinetics of myosin from adult and neonatal rat hearts and from rat heart cells of young and old cultures are compared. These studies indicate that the loss in Ca-ATPase activity of myosin from older cultures was an intrinsic property of the myosin itself. Myofibrillar fractions from the indicated four sources showed no qualitative or...

Negative Effect of Zinc on Testes, Testosterone and Gonadotrophins Levels in Adult Male Wistar Rats

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D Sohrabi

2012-05-01

Full Text Available

Background and Objectives

The toxic effects of zinc leading to sebaceous gland closure, skin eczema and blister have been previously demonstrated in other studies. The aim of this study is to determine the chronic effects of zinc chloride (ZnCl₂   on testicular tissues, testosterone and gonadotrophins in adult male Wistar rats.

Methods

Twenty four Adult male Wistar rats were divided in to two groups of study and control with each group consisting of 12 rats. Study group rats received 10 mg/kg interaperitoneal Zinc chloride in normal saline (N.S every other day for 30 days. Control group rats received N.S during this time. Blood sample for hormonal evaluation were collected from hearts of these rats. The rats were destroyed and their testes were removed and fixed in a 10% formaldehyde and glutaraldehyde solution.

Results

The results of this study showed a significant decrease in the level of LH and testosterone hormone among the rats in the study group compared to the control group with p< 0.001  and

p< 0.01 respectively. Study of fine structure of testicular cells and tissues in the study group rats  revealed swelling of mitochondria, increase in smooth endoplasmic reticulum vacuolization and lysosomic granules (Autophagic vacuoles in cytosol of their germinal cells.

Conclusion

Based on the results of this study consumption of large amount of compounds which contain zinc should be controlled and limited among men. There is a need for further studies to evaluate and determine the reversibility of most hormonal and physiological changes due to usage of zinc containing compounds.

Vibration and muscle contraction affect somatosensory evoked potentials

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Cohen, LG; Starr, A

1985-01-01

We recorded potentials evoked by specific somatosensory stimuli over peripheral nerve, spinal cord, and cerebral cortex. Vibration attenuated spinal and cerebral potentials evoked by mixed nerve and muscle spindle stimulation; in one subject that was tested, there was no effect on cutaneous input. Presynaptic inhibition of Ia input in the spinal cord and muscle spindle receptor occupancy are probably the responsible mechanisms. In contrast, muscle contraction attenuated cerebral potentials to...

Analgesia for early-life pain prevents deficits in adult anxiety and stress in rats.

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Victoria, Nicole C; Karom, Mary C; Murphy, Anne Z

2015-01-01

Previous studies in rats have established that inflammatory pain experienced on the day of birth (P0) decreases sensitivity to acute noxious, anxiety- and stress-provoking stimuli. However, to date, the impact of early-life pain on adult responses to chronic stress is not known. Further, the ability of morphine, administered at the time of injury, to mitigate changes in adult behavioral and hormonal responses to acute or chronic stressors has not been examined. P0 male and female Sprague-Dawley rat pups were given an intraplantar injection of 1% carrageenan or handled in an identical manner in the presence or absence of morphine. As adults, rats that experienced early-life pain displayed decreased sensitivity to acute stressors, as indicated by increased time in the inner area of the Open Field, and increased latency to immobility and decreased time immobile in the Forced Swim Test (FST). An accelerated return of corticosterone to baseline was also observed. Morphine administration at the time of injury completely reversed this 'hyporesponsive' phenotype. By contrast, following 7 days of chronic variable stress, injured animals displayed a 'hyperresponsive' phenotype in that they initiated immobility and spent significantly more time immobile in the FST than controls. Responses to chronic stress were also rescued in animals that received morphine at the time of injury. These data suggest that analgesia for early-life pain prevents adult hyposensitivity to acute anxiety- and stress-provoking stimuli and increased vulnerability to chronic stress, and have important clinical implications for the management of pain in infants. © 2014 S. Karger AG, Basel.

Eating high fat chow decreases dopamine clearance in adolescent and adult male rats but selectively enhances the locomotor stimulating effects of cocaine in adolescents.

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Baladi, Michelle G; Horton, Rebecca E; Owens, William A; Daws, Lynette C; France, Charles P

2015-03-24

Feeding conditions can influence dopamine neurotransmission and impact behavioral and neurochemical effects of drugs acting on dopamine systems. This study examined whether eating high fat chow alters the locomotor effects of cocaine and dopamine transporter activity in adolescent (postnatal day 25) and adult (postnatal day 75) male Sprague-Dawley rats. Dose-response curves for cocaine-induced locomotor activity were generated in rats with free access to either standard or high fat chow or restricted access to high fat chow (body weight matched to rats eating standard chow). Compared with eating standard chow, eating high fat chow increased the sensitivity of adolescent, but not adult, rats to the acute effects of cocaine. When tested once per week, sensitization to the locomotor effects of cocaine was enhanced in adolescent rats eating high fat chow compared with adolescent rats eating standard chow. Sensitization to cocaine was not different among feeding conditions in adults. When adolescent rats that previously ate high fat chow ate standard chow, sensitivity to cocaine returned to normal. As measured by chronoamperometry, dopamine clearance rate in striatum was decreased in both adolescent and adult rats eating high fat chow compared with age-matched rats eating standard chow. These results suggest that high fat diet-induced reductions in dopamine clearance rate do not always correspond to increased sensitivity to the locomotor effects of cocaine, suggesting that mechanisms other than dopamine transporter might play a role. Moreover, in adolescent but not adult rats, eating high fat chow increases sensitivity to cocaine and enhances the sensitization that develops to cocaine. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Vestibular-Somatosensory Convergence in Head Movement Control During Locomotion after Long-Duration Space Flight

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Mulavara, Ajitkumar; Ruttley, Tara; Cohen, Helen; Peters, Brian; Miller, Chris; Brady, Rachel; Merkle, Lauren; Bloomberg, Jacob

2010-01-01

Exposure to the microgravity conditions of space flight induces adaptive modification in the control of vestibular-mediated reflexive head movement during locomotion after space flight. Space flight causes astronauts to be exposed to somatosensory adaptation in both the vestibular and body load-sensing (BLS) systems. The goal of these studies was to examine the contributions of vestibular and BLS-mediated somatosensory influences on head movement control during locomotion after long-duration space flight. Subjects were asked to walk on a treadmill driven at 1.8 m/s while performing a visual acuity task. Data were collected using the same testing protocol from three independent subject groups; 1) normal subjects before and after exposure to 30 minutes of 40% bodyweight unloaded treadmill walking, 2) bilateral labyrinthine deficient (LD) patients and 3) astronauts who performed the protocol before and after long duration space flight. Motion data from head and trunk segmental motion data were obtained to calculate the angular head pitch (HP) movements during walking trials while subjects performed the visual task, to estimate the contributions of vestibular reflexive mechanisms in HP movements. Results showed that exposure to unloaded locomotion caused a significant increase in HP movements, whereas in the LD patients the HP movements were significantly decreased. Astronaut subjects results showed a heterogeneous response of both increases and decreases in the amplitude of HP movement. We infer that BLS-mediated somatosensory input centrally modulates vestibular input and can adaptively modify head-movement control during locomotion. Thus, space flight may cause a central adaptation mediated by the converging vestibular and body load-sensing somatosensory systems.

Disruption of visuospatial and somatosensory functional connectivity in anorexia nervosa.

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Favaro, Angela; Santonastaso, Paolo; Manara, Renzo; Bosello, Romina; Bommarito, Giulia; Tenconi, Elena; Di Salle, Francesco

2012-11-15

Although body image disturbance is considered one of the core characteristics of anorexia nervosa (AN), the exact nature of this complex feature is poorly understood. Task-related functional magnetic resonance imaging studies can only partially explore the multimodal complexity of body consciousness, which is a complex cognition underpinned by aspects of visual perception, proprioception, and touch. The aim of the present study was to explore the functional connectivity of networks involved in visuospatial and somatosensory processing in AN. Twenty-nine subjects with AN, 16 women who had recovered from it, and 26 healthy women underwent a resting-state functional magnetic resonance imaging scan and neuropsychological assessment of their visuospatial abilities using the Rey-Osterrieth Complex Figure Test. Both AN groups showed areas of decreased connectivity in the ventral visual network, a network involved in the "what?" pathway of visual perception. Even more interestingly, the AN group, but not the recovered AN group, displayed increased coactivation in the left parietal cortex, encompassing the somatosensory cortex, in an area implicated in long-term multimodal spatial memory and representation, even in the absence of visual information. A neuropsychological assessment of visuospatial abilities revealed that aspects of detail processing and global integration (central coherence) showed correlations with connectivity of this brain area in the AN group. Our findings show that AN is associated with double disruption of brain connectivity, which shows a specific association with visuospatial difficulties and may explain the failure of the integration process between visual and somatosensory perceptual information that might sustain body image disturbance. Copyright © 2012 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Neuroprotective Effect of Melatonin Against PCBs Induced Behavioural, Molecular and Histological Changes in Cerebral Cortex of Adult Male Wistar Rats.

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Bavithra, S; Selvakumar, K; Sundareswaran, L; Arunakaran, J

2017-02-01

There is ample evidence stating Polychlorinated biphenyls (PCBs) as neurotoxins. In the current study, we have analyzed the behavioural impact of PCBs exposure in adult rats and assessed the simultaneous effect of antioxidant melatonin against the PCBs action. The rats were grouped into four and treated intraperitoneally with vehicle, PCBs, PCBs + melatonin and melatonin alone for 30 days, respectively. After the treatment period the rats were tested for locomotor activity and anxiety behaviour analysis. We confirmed the neuronal damage in the cerebral cortex by molecular and histological analysis. Our data indicates that there is impairment in locomotor activity and behaviour of PCBs treated rats compared to control. The simultaneous melatonin treated rat shows increased motor coordination and less anxiety like behaviour compared to PCBs treated rats. Molecular and histological analysis supports that, the impaired motor coordination in PCBs treated rats is due to neurodegeneration in motor cortex region. The results proved that melatonin treatment improved the motor co-ordination and reduced anxiety behaviour, prevented neurodegeneration in the cerebral cortex of PCBs-exposed adult male rats.

HISTOLOGICAL STUDIES OF THE EFFECTS OF MONOSODIUM GLUTAMATE ON THE INFERIOR COLLICULUS OF ADULT WISTAR RATS.

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A.O. Eweka.

2008-01-01

Full Text Available Histological effects of Monosodium glutamate (MSG commonly used as food additive on the inferior colliculus (IC of adult Wistar rats were carefully studied. The rats of both sexes (n=24, average weight of 185g were randomly assigned into two treatments (n=16 and control (n=8 groups. The rats in the treatment groups received 3g and 6g of MSG thoroughly mixed with their feeds for fourteen days, while the control rats received equal amounts of feeds without MSG added. The rats were fed with growers' mash purchased from Edo Feeds and Flour Mill Ltd, Ewu, Edo State and were given water liberally. The rats were sacrificed on day fifteen of the experiment. The inferior colliculus was carefully dissected out and quickly fixed in 10% formal saline for routine histological study after H&E method.The histological findings after H&E methods indicated that the treated sections of the inferior colliculus showed some cellular degenerative changes, cellular hypertrophy, and autophagic vacuoles with some intercellular vacuolations appearing in the stroma, and some degree of neuronal hypertrophy when compared to the control sections.These findings indicate that MSG consumption may have a deleterious effect on the neurons of the inferior colliculus (IC. MSG may probably have adverse effects on the auditory sensibilities by its deleterious effects on the nerve cells of the IC of adult Wistar rats. It is recommended that further studies aimed at corroborating these observations be carried out.

HISTOLOGICAL EFFECTS OF CHRONIC CONSUMPTION OF NUTMEG ON THE LATERAL GENICULATE BODY OF ADULT WISTAR RATS.

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J.O. Adjene

2010-01-01

Full Text Available The effects of chronic consumption of nutmeg commonly used as a spice in various dishes, as components of teas and soft drinks or mixed in milk and alcohol on the lateral geniculate body of adult wistar rats was studied.The rats of both sexes, with average weight of 200g were randomly assigned into treatment and control groups. The rats in the treatment group (n=8 received 2g of nutmeg thoroughly mixed with the feeds on a daily basis for thirty-two days. The control group (n=8 received equal amount of feeds daily without nutmeg added for thirty-two days. The growers mash feeds was obtained from Edo Feeds and Flour Mill Limited, Ewu, Edo State, Nigeria and the rats were given water liberally. The rats were sacrificed on the thirty-three day of the experiment. The lateral geniculate body was carefully dissected out and quickly fixed in 10% formal saline for histological study.The findings indicate that rats in the treated group showed some cellular degenerative changes like sparse cellular population, pyknotic nuclei with some microcystic changes, edema and vacuolations in the stroma of the treated lateral geniculate body as compared to that of the control group.Chronic consumption of nutmeg may therefore have an adverse effect on the visual sensibilities by affecting the microanatomy of the lateral geniculate body of adult wistar rats. It is recommended for further studies aimed at corroborating these observations.

Cortex-dependent recovery of unassisted hindlimb locomotion after complete spinal cord injury in adult rats

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Manohar, Anitha; Foffani, Guglielmo; Ganzer, Patrick D; Bethea, John R; Moxon, Karen A

2017-01-01

After paralyzing spinal cord injury the adult nervous system has little ability to ‘heal’ spinal connections, and it is assumed to be unable to develop extra-spinal recovery strategies to bypass the lesion. We challenge this assumption, showing that completely spinalized adult rats can recover unassisted hindlimb weight support and locomotion without explicit spinal transmission of motor commands through the lesion. This is achieved with combinations of pharmacological and physical therapies that maximize cortical reorganization, inducing an expansion of trunk motor cortex and forepaw sensory cortex into the deafferented hindlimb cortex, associated with sprouting of corticospinal axons. Lesioning the reorganized cortex reverses the recovery. Adult rats can thus develop a novel cortical sensorimotor circuit that bypasses the lesion, probably through biomechanical coupling, to partly recover unassisted hindlimb locomotion after complete spinal cord injury. DOI: http://dx.doi.org/10.7554/eLife.23532.001 PMID:28661400

Ghrelin modulates testicular germ cells apoptosis and proliferation in adult normal rats

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Kheradmand, Arash, E-mail: arashkheradmand@yahoo.com [Department of Clinical Sciences, School of Veterinary Medicine, Lorestan University, P.O. Box: 465, Khorram Abad (Iran, Islamic Republic of); Dezfoulian, Omid [Department of Pathobiology, School of Veterinary Medicine, Lorestan University, Khorram Abad (Iran, Islamic Republic of); Alirezaei, Masoud [Division of Biochemistry, School of Veterinary Medicine, Lorestan University, P.O. Box: 465, Khorram Abad (Iran, Islamic Republic of); Rasoulian, Bahram [Razi Herbal Medicine Research Center, Lorestan University of Medical Sciences, Khorram Abad (Iran, Islamic Republic of)

2012-03-09

Highlights: Black-Right-Pointing-Pointer Spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. Black-Right-Pointing-Pointer Numerous studies have documented the direct action of ghrelin in the modulation of apoptosis in different cell types. Black-Right-Pointing-Pointer Ghrelin may be considered as a modulator of spermatogenesis in normal adult rats. Black-Right-Pointing-Pointer Ghrelin may be potentially implicated for abnormal spermatogenesis in some testicular germ cell tumors. -- Abstract: Under normal condition in the most mammals, spermatogenesis is closely associated with the balance between germ cells proliferation and apoptosis. The present study was designed to determine the effects of ghrelin treatment on in vivo quality and quantity expression of apoptosis and proliferation specific indices in rat testicular germ cells. Twenty eight adult normal rats were subdivided into equal control and treatment groups. Treatment group received 3 nmol of ghrelin as subcutaneous injection for 30 consecutive days or vehicle to the control animals. The rats from each group (n = 7) were killed on days 10 and 30 and their testes were taken for immunocytochemical evaluation and caspase-3 assay. Immunohistochemical analysis indicated that the accumulations of Bax and PCNA peptides are generally more prominent in spermatocytes and spermatogonia of both groups. Likewise, the mean percentage of immunoreactive spermatocytes against Bax increased (P < 0.01) in the ghrelin-treated group on day 10, while despite of 30% increment in the Bax level of spermatocytes in the treated rats on day 30, however, it was not statistically significant. During the experimental period, only a few spermatogonia represented Bax expression and the changes of Bax immunolabling cells were negligible upon ghrelin treatment. Likewise, there were immunostaining cells against Bcl-2 in each germ cell neither in the control nor in the treated animals. In fact

Persistent changes in ability to express long-term potentiation/depression in the rat hippocampus after juvenile/adult stress.

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Maggio, Nicola; Segal, Menahem

2011-04-15

The ventral hippocampus (VH) was recently shown to express lower magnitude long-term potentiation (LTP) compared with the dorsal hippocampus (DH). Exposure to acute stress reversed this difference, and VH slices from stressed rats expressed larger LTP than that produced in the DH, which was reduced by stress. Stressful experience in adolescence has been shown to produce long-lasting effects on animal behavior and on ability to express LTP/long-term depression (LTD) of reactivity to afferent stimulation in the adult. We are interested in possible interactions between juvenile and adult stress in their effects of adult plasticity. We studied the effects of a composite juvenile (28-30 days) stress, followed by a reminder stressful experience in the young adult (60 days) rat, on the ability to produce LTP and LTD in CA1 region of slices of the VH and DH. Juvenile or adult stress produced a transient decrease in ability to express LTP in DH and a parallel increase in LTP in VH. Stress in the young adult after juvenile stress produced a striking prolongation of the DH/VH disparity with respect to the ability to express both LTP and LTD into the adulthood of the rat. These results have important implications for the impact of juvenile stress on adult neuronal plasticity and on the understanding the functions of the different sectors of the hippocampus. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Visuotactile motion congruence enhances gamma-band activity in visual and somatosensory cortices.

Science.gov (United States)

Krebber, Martin; Harwood, James; Spitzer, Bernhard; Keil, Julian; Senkowski, Daniel

2015-08-15

When touching and viewing a moving surface our visual and somatosensory systems receive congruent spatiotemporal input. Behavioral studies have shown that motion congruence facilitates interplay between visual and tactile stimuli, but the neural mechanisms underlying this interplay are not well understood. Neural oscillations play a role in motion processing and multisensory integration. They may also be crucial for visuotactile motion processing. In this electroencephalography study, we applied linear beamforming to examine the impact of visuotactile motion congruence on beta and gamma band activity (GBA) in visual and somatosensory cortices. Visual and tactile inputs comprised of gratings that moved either in the same or different directions. Participants performed a target detection task that was unrelated to motion congruence. While there were no effects in the beta band (13-21Hz), the power of GBA (50-80Hz) in visual and somatosensory cortices was larger for congruent compared with incongruent motion stimuli. This suggests enhanced bottom-up multisensory processing when visual and tactile gratings moved in the same direction. Supporting its behavioral relevance, GBA was correlated with shorter reaction times in the target detection task. We conclude that motion congruence plays an important role for the integrative processing of visuotactile stimuli in sensory cortices, as reflected by oscillatory responses in the gamma band. Copyright © 2015 Elsevier Inc. All rights reserved.

Mitogen response of B cells, but not T cells, is impaired in adult vitamin A-deficient rats

NARCIS (Netherlands)

van Bennekum, A. M.; Wong Yen Kong, L. R.; Gijbels, M. J.; Tielen, F. J.; Roholl, P. J.; Brouwer, A.; Hendriks, H. F.

1991-01-01

The effect of vitamin A deficiency on the mitogen response of splenic B and T lymphocytes was determined in adult vitamin A-deficient rats. Female weanling Brown Norway/Billingham-Rijswijk (BN/BiRij) and Sprague-Dawley rats were fed a semipurified, essentially vitamin A-free diet, which resulted in

A combined phytohemagglutinin and a-ketoglutarate pharmacology study of gut morphology and growth in older adult rats

DEFF Research Database (Denmark)

Filip, R.; Harrison, Adrian Paul; Pierzynowski, S.G.

2008-01-01

This study has evaluated the effect of phytohaemagglutinin (PHA) in combination with alpha-ketoglutaric acid (AKG), on GI-tract morphology and N balance in adult rats. Rats, aged approx. 15 months, were assigned to one of four experimental groups, (1) Control group, (2) AKG group, (3) AKG+PHA 100...

Detection of optogenetic stimulation in somatosensory cortex by non-human primates--towards artificial tactile sensation.

Science.gov (United States)

May, Travis; Ozden, Ilker; Brush, Benjamin; Borton, David; Wagner, Fabien; Agha, Naubahar; Sheinberg, David L; Nurmikko, Arto V

2014-01-01

Neuroprosthesis research aims to enable communication between the brain and external assistive devices while restoring lost functionality such as occurs from stroke, spinal cord injury or neurodegenerative diseases. In future closed-loop sensorimotor prostheses, one approach is to use neuromodulation as direct stimulus to the brain to compensate for a lost sensory function and help the brain to integrate relevant information for commanding external devices via, e.g. movement intention. Current neuromodulation techniques rely mainly of electrical stimulation. Here we focus specifically on the question of eliciting a biomimetically relevant sense of touch by direct stimulus of the somatosensory cortex by introducing optogenetic techniques as an alternative to electrical stimulation. We demonstrate that light activated opsins can be introduced to target neurons in the somatosensory cortex of non-human primates and be optically activated to create a reliably detected sensation which the animal learns to interpret as a tactile sensation localized within the hand. The accomplishment highlighted here shows how optical stimulation of a relatively small group of mostly excitatory somatosensory neurons in the nonhuman primate brain is sufficient for eliciting a useful sensation from data acquired by simultaneous electrophysiology and from behavioral metrics. In this first report to date on optically neuromodulated behavior in the somatosensory cortex of nonhuman primates we do not yet dissect the details of the sensation the animals exerience or contrast it to those evoked by electrical stimulation, issues of considerable future interest.

Detection of optogenetic stimulation in somatosensory cortex by non-human primates--towards artificial tactile sensation.

Directory of Open Access Journals (Sweden)

Travis May

Full Text Available Neuroprosthesis research aims to enable communication between the brain and external assistive devices while restoring lost functionality such as occurs from stroke, spinal cord injury or neurodegenerative diseases. In future closed-loop sensorimotor prostheses, one approach is to use neuromodulation as direct stimulus to the brain to compensate for a lost sensory function and help the brain to integrate relevant information for commanding external devices via, e.g. movement intention. Current neuromodulation techniques rely mainly of electrical stimulation. Here we focus specifically on the question of eliciting a biomimetically relevant sense of touch by direct stimulus of the somatosensory cortex by introducing optogenetic techniques as an alternative to electrical stimulation. We demonstrate that light activated opsins can be introduced to target neurons in the somatosensory cortex of non-human primates and be optically activated to create a reliably detected sensation which the animal learns to interpret as a tactile sensation localized within the hand. The accomplishment highlighted here shows how optical stimulation of a relatively small group of mostly excitatory somatosensory neurons in the nonhuman primate brain is sufficient for eliciting a useful sensation from data acquired by simultaneous electrophysiology and from behavioral metrics. In this first report to date on optically neuromodulated behavior in the somatosensory cortex of nonhuman primates we do not yet dissect the details of the sensation the animals exerience or contrast it to those evoked by electrical stimulation, issues of considerable future interest.

Pattern of chondroitin sulfate proteoglycan expression after ablation of the sensorimotor cortex of the neonatal and adult rat brain

Directory of Open Access Journals (Sweden)

Dacić Sanja

2008-01-01

Full Text Available The central nervous system has a limited capacity for self-repair after damage. However, the neonatal brain has agreater capacity for recovery than the adult brain. These differences in the regenerative capability depend on local environmental factors and the maturational stage of growing axons. Among molecules which have both growth-promoting and growth-inhibiting activities is the heterogeneous class of chondroitin sulfate proteoglycans (CSPGs. In this paper, we investigated the chondroitin-4 and chondroitin-6 sulfate proteoglycan expression profile after left sensorimotor cortex ablation of the neonatal and adult rat brain. Immunohistochemical analysis revealed that compared to the normal uninjured cortex, lesion provoked up regulation of CSPGs showing a different pattern of expression in the neonatal vs. the adult brain. Punctuate and membrane-bound labeling was predominate after neonatal lesion, where as heavy deposition of staining in the extracellular matrix was observed after adult lesion. Heavy deposition of CSPG immunoreactivity around the lesionsite in adult rats, in contrast to a less CSPG-rich environment in neonatal rats, indicated that enhancement of the recovery process after neonatal injury is due to amore permissive environment.

Somatosensory sensitivity in patients with persistent idiopathic orofacial pain is associated with pain relief from hypnosis and relaxation.

Science.gov (United States)

Baad-Hansen, Lene; Abrahamsen, Randi; Zachariae, Robert; List, Thomas; Svensson, Peter

2013-06-01

In a recent study hypnosis has been found to relieve persistent idiopathic orofacial pain. Quantitative sensory testing (QST) is widely used to evaluate somatosensory sensitivity, which has been suggested as a possible predictor of management outcome. The objectives of this study were to examine: (1) possible associations between clinical pain relief and baseline somatosensory sensitivity and (2) the effect of hypnosis management on QST parameters. Forty-one patients with persistent idiopathic orofacial pain completed this randomized controlled study in 1 of 2 groups: hypnosis (hypnotic analgesia suggestions) or control (relaxation). QST at 2 intraoral (pain region and contralateral mirror image region) and 3 extraoral (hand and both cheeks) sites was performed at baseline and after the hypnosis/control management, together with pressure pain thresholds and pressure pain tolerance thresholds determined bilaterally at the masseter and temporalis muscles, the temporomandibular joints, and the third finger. Degree of pain relief was negatively correlated with a summary statistic of baseline somatosensory sensitivity (summed z-score), that is, high baseline somatosensory sensitivity was associated with low pain relief (r=-0.372, P=0.020). Hypnosis had no major effect on any QST measure compared with relaxation (P>0.063). High pain sensitivity at baseline may predict poor pain management outcome. In addition, despite clear clinical pain relief, hypnosis did not significantly or specifically influence somatosensory sensitivity. Future studies should further explore QST measures as possible predictors of different management response in orofacial pain conditions.

Electroconvulsive Stimulation, but not Chronic Restraint Stress, Causes Structural Alterations in Adult Rat Hippocampus

DEFF Research Database (Denmark)

Olesen, Mikkel V.; Wörtwein, Gitta; Pakkenberg, Bente

2015-01-01

The neurobiological mechanisms underlying depression are not fully understood. Only a few previous studies have used validated stereological methods to test how stress and animal paradigms of depression affect adult hippocampal neurogenesis and whether antidepressant therapy can counteract possible...... changes in an animal model. Thus, in this study we applied methods that are state of the art in regard to stereological cell counting methods. Using a validated rat model of depression in combination with a clinically relevant schedule of electroconvulsive stimulation, we estimated the total number...... of newly formed neurons in the hippocampal subgranular zone. Also estimated were the total number of neurons and the volume of the granule cell layer in adult rats subjected to chronic restraint stress and electroconvulsive stimulation either alone or in combination. We found that chronic restraint stress...

A functional MRI study of somatotopic representation of somatosensory stimulation in the cerebellum

Energy Technology Data Exchange (ETDEWEB)

Takanashi, M.; Abe, K.; Yanagihara, T.; Sakoda, S. [Dept. of Neurology D4, Osaka Univ. Graduate School of Medicine, Suita City, Osaka (Japan); Tanaka, H.; Hirabuki, N.; Nakamura, H.; Fujita, N. [Dept. of Radiology, Osaka Univ. Graduate School of Medicine, Suita City, Osaka (Japan)

2003-03-01

Somatotopic representation in the cerebral cortex of somatosensory stimulation has been widely reported, but that in the cerebellum has not. We investigated the latter in the human cerebellum by functional MRI (fMRI). Using a 1.5 tesla imager, we obtained multislice blood oxygen level-dependent fMRI with single-shot gradient-echo echoplanar imaging in seven right-handed volunteers during electrical stimulation of the left index finger and big toe. In the anterior and posterior cerebellum, activated pixels for the index finger were separate from those for the toe. This suggests that somatosensory stimulation of different parts of the body may involve distinct areas of in the cerebellum as well as the cerebral cortex. (orig.)

A functional MRI study of somatotopic representation of somatosensory stimulation in the cerebellum

International Nuclear Information System (INIS)

Takanashi, M.; Abe, K.; Yanagihara, T.; Sakoda, S.; Tanaka, H.; Hirabuki, N.; Nakamura, H.; Fujita, N.

2003-01-01

Somatotopic representation in the cerebral cortex of somatosensory stimulation has been widely reported, but that in the cerebellum has not. We investigated the latter in the human cerebellum by functional MRI (fMRI). Using a 1.5 tesla imager, we obtained multislice blood oxygen level-dependent fMRI with single-shot gradient-echo echoplanar imaging in seven right-handed volunteers during electrical stimulation of the left index finger and big toe. In the anterior and posterior cerebellum, activated pixels for the index finger were separate from those for the toe. This suggests that somatosensory stimulation of different parts of the body may involve distinct areas of in the cerebellum as well as the cerebral cortex. (orig.)

Trading new neurons for status: Adult hippocampal neurogenesis in eusocial Damaraland mole-rats.

Science.gov (United States)

Oosthuizen, M K; Amrein, I

2016-06-02

Diversity in social structures, from solitary to eusocial, is a prominent feature of subterranean African mole-rat species. Damaraland mole-rats are eusocial, they live in colonies that are characterized by a reproductive division of labor and a subdivision into castes based on physiology and behavior. Damaraland mole-rats are exceptionally long lived and reproductive animals show delayed aging compared to non-reproductive animals. In the present study, we described the hippocampal architecture and the rate of hippocampal neurogenesis of wild-derived, adult Damaraland mole-rats in relation to sex, relative age and social status or caste. Overall, Damaraland mole-rats were found to have a small hippocampus and low rates of neurogenesis. We found no correlation between neurogenesis and sex or relative age. Social status or caste was the most prominent modulator of neurogenesis. An inverse relationship between neurogenesis and social status was apparent, with queens displaying the lowest neurogenesis while the worker mole-rats had the most. As there is no natural progression from one caste to another, social status within a colony was relatively stable and is reflected in the level of neurogenesis. Our results correspond to those found in the naked mole-rat, and may reflect an evolutionary and environmentally conserved trait within social mole-rat species. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Neonatal bee venom exposure induces sensory modality-specific enhancement of nociceptive response in adult rats.

Science.gov (United States)

Li, Mengmeng; Chen, Huisheng; Tang, Jiaguang; Chen, Jun

2014-06-01

Previous studies have shown that inflammatory pain at the neonatal stage can produce long-term structural and functional changes in nociceptive pathways, resulting in altered pain perception in adulthood. However, the exact pattern of altered nociceptive response and associated neurochemical changes in the spinal cord in this process is unclear. In this study, we used an experimental paradigm in which each rat first received intraplantar bee venom (BV) or saline injection on postnatal day 1, 4, 7, 14, 21, or 28. This was followed 2 months later by a second intraplantar bee venom injection in the same rats to examine the difference in nociceptive responses. We found that neonatal inflammatory pain induced by the first BV injection significantly reduced baseline paw withdrawal mechanical threshold, but not baseline paw withdrawal thermal latency, when rats were examined 2 months from the first BV injection. Neonatal inflammatory pain also exacerbated mechanical, but not thermal, hyperalgesia in response to the second BV injection in these same rats. Rats exposed to neonatal inflammation also showed up-regulation of spinal NGF, TrkA receptor, BDNF, TrkB receptor, IL-1β, and COX-2 expression following the second BV injection, especially with prior BV exposure on postnatal day 21 or 28. These results indicate that neonatal inflammation produces sensory modality-specific changes in nociceptive behavior and alters neurochemistry in the spinal cord of adult rats. These results also suggest that a prior history of inflammatory pain during the developmental period might have an impact on clinical pain in highly susceptible adult patients. Wiley Periodicals, Inc.

Hypothyroidism in the adult rat causes incremental changes in brain-derived neurotrophic factor, neuronal and astrocyte apoptosis, gliosis, and deterioration of postsynaptic density.

Science.gov (United States)

Cortés, Claudia; Eugenin, Eliseo; Aliaga, Esteban; Carreño, Leandro J; Bueno, Susan M; Gonzalez, Pablo A; Gayol, Silvina; Naranjo, David; Noches, Verónica; Marassi, Michelle P; Rosenthal, Doris; Jadue, Cindy; Ibarra, Paula; Keitel, Cecilia; Wohllk, Nelson; Court, Felipe; Kalergis, Alexis M; Riedel, Claudia A

2012-09-01

Adult hypothyroidism is a highly prevalent condition that impairs processes, such as learning and memory. Even though tetra-iodothyronine (T(4)) treatment can overcome the hypothyroidism in the majority of cases, it cannot fully recover the patient's learning capacity and memory. In this work, we analyzed the cellular and molecular changes in the adult brain occurring with the development of experimental hypothyroidism. Adult male Sprague-Dawley rats were treated with 6-propyl-2-thiouracil (PTU) for 20 days to induce hypothyroidism. Neuronal and astrocyte apoptosis were analyzed in the hippocampus of control and hypothyroid adult rats by confocal microscopy. The content of brain-derived neurotrophic factor (BDNF) was analyzed using enzyme-linked immunosorbent assay (ELISA) and in situ hybridization. The glutamatergic synapse and the postsynaptic density (PSD) were analyzed by electron microscopy. The content of PSD proteins like tyrosine receptor kinase B (TrkB), p75, and N-methyl-D-aspartate receptor (NMDAr) were analyzed by immunoblot. We observed that the hippocampus of hypothyroid adult rats displayed increased apoptosis levels in neurons and astrocyte and reactive gliosis compared with controls. Moreover, we found that the amount of BDNF mRNA was higher in the hippocampus of hypothyroid rats and the content of TrkB, the receptor for BDNF, was reduced at the PSD of the CA3 region of hypothyroid rats, compared with controls. We also observed that the glutamatergic synapses from the stratum radiatum of CA3 from hypothyroid rats, contained thinner PSDs than control rats. This observation was in agreement with a reduced content of NMDAr subunits at the PSD in hypothyroid animals. Our data suggest that adult hypothyroidism affects the hippocampus by a mechanism that alters the composition of PSD, reduces neuronal and astrocyte survival, and alters the content of the signaling neurotrophic factors, such as BDNF.

Percutaneous absorption of triadimefon in the adult and young male and female rat

International Nuclear Information System (INIS)

Knaak, J.B.; Yee, K.; Ackerman, C.R.; Zweig, G.; Wilson, B.W.

1984-01-01

The percutaneous absorption of 14 C-phenoxy ring labeled triadimefon was studied in adult and young male and female Sprague-Dawley rats. Triadimefon was applied (41.1 to 46.4 micrograms/cm2) in 0.2 ml of acetone to areas comprising 3% of the body surface (7.0 to 14.5 cm2). Thirty-six animals were treated at the initiation of each study. Groups of three animals were subsequently killed at 1, 4, 8, 12, 24, 48, 72, 96, 120, 144, 168, and 192 hr after treatment. Skin from the treated area as well as blood, heart, liver, kidneys, remaining carcass, urine, and feces were analyzed for 14 C by scintillation counting techniques. Based on 14 C counts, triadimefon was lost more rapidly from the skin of young animals (t 1/2, 20 to 25 hr) than from the skin of adult animals (t 1/2, 29 to 53 hr). Recovery studies indicated that adult males, adult females, young males, and young females, respectively, absorbed 53, 82, 57, and 52% of the dose. The rest of the dose based on material balance was presumably lost by evaporation. Approximately 2.5 to 3.9% of the dose penetrated the skin in one hour and was available for absorption. The rate of entry triadimefon into blood was 2 to 2.5 times faster for young than that observed in adult animals. Elimination of it from blood was faster in the case of the young animals. Triadimefon was absorbed through the skins of the adult male, adult female, young male, and young female rats, respectively, at rates of 0.20, 0.50, 0.58, and 0.48 micrograms/hr/cm2 of skin

Attentional Modulation of Somatosensory Processing During the Anticipation of Movements Accompanying Pain: An Event-Related Potential Study.

Science.gov (United States)

Clauwaert, Amanda; Torta, Diana M; Danneels, Lieven; Van Damme, Stefaan

2018-02-01

Attending to pain-relevant information is crucial to protect us from physical harm. Behavioral studies have already suggested that during anticipation of pain somatosensory input at the body location under threat is prioritized. However, research using daily life cues for pain, especially movements, is lacking. Furthermore, to our knowledge, no studies have investigated cortical processing associated with somatosensory processing during threatened movements. The current study aims to investigate whether movements accompanying pain automatically steer attention toward somatosensory input at the threatened location, affecting somatosensory evoked potentials (SEPs). Healthy volunteers were cued to perform movements with the left or the right hand, and one of these movements could be accompanied by pain on the moving hand. During movement anticipation, a task-irrelevant tactile stimulus was presented to the threatened or pain-free hand to evoke SEPs. During anticipation of movements accompanying pain, the N120 component was increased for tactile stimuli at the threatened relative to the hand without pain. Moreover, the P200 SEP was enhanced during anticipation of movements accompanying pain relative to movements without pain, irrespective of which hand was stimulated. These findings show that the anticipation of pain-accompanying movements may affect the processing of somatosensory input, and that this is likely to be driven by attentional processes. This study shows that the anticipation of pain-related movements automatically biases attention toward stimuli at a pain-related location, measured according to SEPs. The present study provides important new insights in the interplay between pain and attention, and its consequences at the cortical level. Copyright © 2017 The American Pain Society. Published by Elsevier Inc. All rights reserved.

Teaching Adult Rats Spinalized as Neonates to Walk Using Trunk Robotic Rehabilitation: Elements of Success, Failure, and Dependence.

Science.gov (United States)

Udoekwere, Ubong I; Oza, Chintan S; Giszter, Simon F

2016-08-10

Robot therapy promotes functional recovery after spinal cord injury (SCI) in animal and clinical studies. Trunk actions are important in adult rats spinalized as neonates (NTX rats) that walk autonomously. Quadrupedal robot rehabilitation was tested using an implanted orthosis at the pelvis. Trunk cortical reorganization follows such rehabilitation. Here, we test the functional outcomes of such training. Robot impedance control at the pelvis allowed hindlimb, trunk, and forelimb mechanical interactions. Rats gradually increased weight support. Rats showed significant improvement in hindlimb stepping ability, quadrupedal weight support, and all measures examined. Function in NTX rats both before and after training showed bimodal distributions, with "poor" and "high weight support" groupings. A total of 35% of rats initially classified as "poor" were able to increase their weight-supported step measures to a level considered "high weight support" after robot training, thus moving between weight support groups. Recovered function in these rats persisted on treadmill with the robot both actuated and nonactuated, but returned to pretraining levels if they were completely disconnected from the robot. Locomotor recovery in robot rehabilitation of NTX rats thus likely included context dependence and/or incorporation of models of robot mechanics that became essential parts of their learned strategy. Such learned dependence is likely a hurdle to autonomy to be overcome for many robot locomotor therapies. Notwithstanding these limitations, trunk-based quadrupedal robot rehabilitation helped the rats to visit mechanical states they would never have achieved alone, to learn novel coordinations, and to achieve major improvements in locomotor function. Neonatal spinal transected rats without any weight support can be taught weight support as adults by using robot rehabilitation at trunk. No adult control rats with neonatal spinal transections spontaneously achieve similar changes

A cognitive neuroprosthetic that uses cortical stimulation for somatosensory feedback

Science.gov (United States)

Klaes, Christian; Shi, Ying; Kellis, Spencer; Minxha, Juri; Revechkis, Boris; Andersen, Richard A.

2014-10-01

Objective. Present day cortical brain-machine interfaces (BMIs) have made impressive advances using decoded brain signals to control extracorporeal devices. Although BMIs are used in a closed-loop fashion, sensory feedback typically is visual only. However medical case studies have shown that the loss of somesthesis in a limb greatly reduces the agility of the limb even when visual feedback is available. Approach. To overcome this limitation, this study tested a closed-loop BMI that utilizes intracortical microstimulation to provide ‘tactile’ sensation to a non-human primate. Main result. Using stimulation electrodes in Brodmann area 1 of somatosensory cortex (BA1) and recording electrodes in the anterior intraparietal area, the parietal reach region and dorsal area 5 (area 5d), it was found that this form of feedback can be used in BMI tasks. Significance. Providing somatosensory feedback has the poyential to greatly improve the performance of cognitive neuroprostheses especially for fine control and object manipulation. Adding stimulation to a BMI system could therefore improve the quality of life for severely paralyzed patients.

CHRONIC ALCOHOLISM ON THE SEMINAL VESICLE AND TESTIS WEIGHT OF ADULT RATS (Rattus norvegicus)

OpenAIRE

Martinez, F. E.; Martinez, M.; Cagnon, V. H. A.; Mello Junior, W.; Padovani, C. R.; Garcia, P. J.

1997-01-01

Effects of experimental chronic alcoholism on the accessory sexual glands weight and testes weight were studied. Male adult albino rats received only sugar cane brandy at 30 Gay Lussac (v/v), while the controls received tap water. After periods of 60, 120, 180 and 240 days, rats from each group were anesthetized, weighed and sacrificed. Alterations in mean daily solid food intake and liquid, mean daily weight gain, mean prostate weight, mean seminal vesicle and coagulating gland weights and t...

Somatosensory amplification mediates sex differences in psychological distress among cardioverter-defibrillator patients

DEFF Research Database (Denmark)

Versteeg, Henneke; Baumert, Jens; Kolb, Christof

2010-01-01

The present study examined whether female patients with an implantable cardioverter defibrillator (ICD) report more psychological distress than male patients, and whether somatosensory amplification mediates this relationship. Design: Consecutive ICD patients (N = 241; 33% women) participating in...

Expression of developmental myosin and morphological characteristics in adult rat skeletal muscle following exercise-induced injury.

Science.gov (United States)

Smith, H K; Plyley, M J; Rodgers, C D; McKee, N H

1999-07-01

The extent and stability of the expression of developmental isoforms of myosin heavy chain (MHCd), and their association with cellular morphology, were determined in adult rat skeletal muscle fibres following injury induced by eccentrically-biased exercise. Adult female Wistar rats [274 (10) g] were either assigned as non-exercised controls or subjected to 30 min of treadmill exercise (grade, -16 degrees; speed, 15 m x min(-1)), and then sacrificed following 1, 2, 4, 7, or 12 days of recovery (n = 5-6 per group). Histologically and immunohistologically stained serial, transverse cryosections of the soleus (S), vastus intermedius (VI), and tibialis anterior (TA) muscles were examined using light microscopy and digital imaging. Fibres staining positively for MHCd (MHCd+) were seldom detected in the TA. In the VI and S, higher proportions of MHCd+ fibres (0.8% and 2.5%, respectively) were observed in rats at 4 and 7 days post-exercise, in comparison to all other groups combined (0.2%, 1.2%; P < or = 0.01). In S, MHCd+ fibres were observed less frequently by 12 days (0.7%) than at 7 days (2.6%) following exercise. The majority (85.1%) of the MHCd+ fibres had morphological characteristics indicative of either damage, degeneration, repair or regeneration. Most of the MHCd+ fibres also expressed adult slow, and/or fast myosin heavy chain. Quantitatively, the MHCd+ fibres were smaller (< 2500 microm2) and more angular than fibres not expressing MHCd. Thus, there was a transient increase in a small, but distinct population of MHCd+ fibres following unaccustomed, functional exercise in adult rat S and VI muscles. The observed close coupling of MHCd expression with morphological changes within muscle fibres suggests that these characteristics have a common, initial exercise-induced injury-related stimulus.

Quantifying interhemispheric symmetry of somatosensory evoked potentials with the intraclass correlation coefficient

NARCIS (Netherlands)

van de Wassenberg, Wilma J. G.; van der Hoeven, Johannes H.; Leenders, Klaus L.; Maurits, Natasha M.

Although large intersubject variability is reported for cortical somatosensory evoked potentials (SEPs), variability between hemispheres within one subject is thought to be small. Therefore, interhemispheric comparison of SEP waveforms might be clinically useful to detect unilateral abnormalities in

Inhibition of acetylcholinesterase activity in brain and behavioral analysis in adult rats after chronic administration of fenproporex.

Science.gov (United States)

Rezin, Gislaine T; Scaini, Giselli; Ferreira, Gabriela K; Cardoso, Mariane R; Gonçalves, Cinara L; Constantino, Larissa S; Deroza, Pedro F; Ghedim, Fernando V; Valvassori, Samira S; Resende, Wilson R; Quevedo, João; Zugno, Alexandra I; Streck, Emilio L

2012-12-01

Fenproporex is an amphetamine-based anorectic and it is rapidly converted in vivo into amphetamine. It elevates the levels of extracellular dopamine in the brain. Acetylcholinesterase is a regulatory enzyme which is involved in cholinergic synapses and may indirectly modulate the release of dopamine. Thus, we investigated whether the effects of chronic administration of fenproporex in adult rats alters acquisition and retention of avoidance memory and acetylcholinesterase activity. Adult male Wistar rats received repeated (14 days) intraperitoneal injection of vehicle or fenproporex (6.25, 12.5 or 25 mg/kg i.p.). For behavioral assessment, animals were submitted to inhibitory avoidance (IA) tasks and continuous multiple trials step-down inhibitory avoidance (CMIA). Acetylcholinesterase activity was measured in the prefrontal cortex, hippocampus, hypothalamus and striatum. The administration of fenproporex (6.25, 12.5 and 25 mg/kg) did not induce impairment in short and long-term IA or CMIA retention memory in rats. In addition, longer periods of exposure to fenproporex administration decreased acetylcholinesterase activity in prefrontal cortex and striatum of rats, but no alteration was verified in the hippocampus and hypothalamus. In conclusion, the present study showed that chronic fenproporex administration decreased acetylcholinesterase activity in the rat brain. However, longer periods of exposure to fenproporex did not produce impairment in short and long-term IA or CMIA retention memory in rats.

Relationship between somatosensory event-related potential N140 aberrations and hemispatial agnosia in patients with stroke: a preliminary study.

Science.gov (United States)

Ueno, Tomoyuki; Hada, Yasushi; Shimizu, Yukiyo; Yamada, Thoru

2018-06-01

The somatosensory event-related potential N140 is thought to be related to selective attention. This study aimed to compare the somatosensory event-related potential N140 in healthy subjects to that in patients with stroke to determine whether N140 and attentiveness are associated in patients with stroke with or without hemispatial agnosia. Normal somatosensory event-related potential N140 values were determined using data from ten healthy subjects. Fifteen patients with stroke were divided into two groups based on the presence of hemispatial neglect. Somatosensory event-related potential N140 components were compared between the two groups. Stimulation of the affected limb in the hemispatial agnosia group resulted in significantly longer N140 latency at the contralateral vs. the ipsilateral electrode. This was the inverse of the relationship observed in normal subjects, with stimulation of the intact side in patients with hemispatial agnosia, and with stimulation of both the intact and affected sides in patients without agnosia. In the hemispatial agnosia group, the peak latency of N140 following stimulation of the affected side was significantly longer than it was following stimulation of the intact side and when compared to that in patients without agnosia. In addition, abnormal N140 peak latencies were observed at the Cz and ipsilateral electrodes in patients with hemispatial agnosia following stimulation of the intact side. These findings suggest that somatosensory event-related potential N140 is independently generated in each hemisphere and may reflect cognitive attention.

Developmental vitamin D deficiency alters MK 801-induced hyperlocomotion in the adult rat: An animal model of schizophrenia.

Science.gov (United States)

Kesby, James P; Burne, Thomas H J; McGrath, John J; Eyles, Darryl W

2006-09-15

Developmental vitamin D (DVD) deficiency has been proposed as a risk factor for schizophrenia. The behavioral phenotype of adult rats subjected to transient low prenatal vitamin D is characterized by spontaneous hyperlocomotion but normal prepulse inhibition of acoustic startle (PPI). The aim of this study was to examine the impact of selected psychotropic agents and one well-known antipsychotic agent on the behavioral phenotype of DVD deplete rats. Control versus DVD deplete adult rats were assessed on holeboard, open field and PPI. In the open field, animals were given MK-801 and/or haloperidol. For PPI, the animals were given apomorphine or MK-801. DVD deplete rats had increased baseline locomotion on the holeboard task and increased locomotion in response to MK-801 compared to control rats. At low doses, haloperidol antagonized the MK-801 hyperactivity of DVD deplete rats preferentially and, at a high dose, resulted in a more pronounced reduction in spontaneous locomotion in DVD deplete rats. DVD depletion did not affect either baseline or drug-mediated PPI response. These results suggest that DVD deficiency is associated with a persistent alteration in neuronal systems associated with motor function but not those associated with sensory motor gating. In light of the putative association between low prenatal vitamin D and schizophrenia, the discrete behavioral differences associated with the DVD model may help elucidate the neurobiological correlates of schizophrenia.

Thyroxine binding to serum thyronine-binding globulin in thyroidectomized adult and normal neonatal rats

International Nuclear Information System (INIS)

Young, R.A.; Meyers, B.; Alex, S.; Fang, S.L.; Braverman, L.E.

1988-01-01

The amount of tracer [125I]T4 bound to serum thyronine-binding globulin (TBG) was measured by polyacrylamide gel electrophoresis in adult thyroidectomized (TX) rats and normal 1-day to 4-week-old rat puts. Thyroidectomy was associated with the appearance of significant amounts of [125I]T4 binding to serum TBG in lean rats, but not in obese Zucker rats. Treatment of the TX rats in vivo with replacement doses of T4 prevented this increase in TBG binding, but enrichment of serum from TX rats with T4 did not. Significant amounts of tracer [125I]T4 binding to TBG was present in serum from 1- to 3-week-old normal rat pups, but not in 1-day- or 4-week-old pups. There were significantly higher levels of TBG binding of [125I]T4 in serum from 2-week-old rat pups raised in litters of 16 pups compared to those raised in litters of 4 pups. All manipulations that result in the appearance of TBG in rat serum also result in either weight loss or a slowing in the rate of growth, suggesting that the appearance of TBG in rat serum has a nutritional component. This possibility is further supported by the observations that increases in TBG binding of [125I]T4 are not found in obese Zucker rats fed a low protein-high carbohydrate diet for 14 days or fasted for 7 days, or after thyroidectomy, perhaps owing to the large stores of fuel in the obese rat

The functional and anatomical dissection of somatosensory subpopulations using mouse genetics

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Claire E Le Pichon

2014-04-01

Full Text Available The word somatosensation comes from joining the Greek word for body (soma with a word for perception (sensation. Somatosensory neurons comprise the largest sensory system in mammals and have nerve endings coursing throughout the skin, viscera, muscle, and bone. Their cell bodies reside in a chain of ganglia adjacent to the dorsal spinal cord (the dorsal root ganglia and at the base of the skull (the trigeminal ganglia. While the neuronal cell bodies are intermingled within the ganglia, the somatosensory system is in reality composed of numerous sub-systems, each specialized to detect distinct stimuli, such as temperature and touch. Historically, somatosensory neurons have been classified using a diverse host of anatomical and physiological parameters, such as the size of the cell body, degree of myelination, histological labeling with markers, specialization of the nerve endings, projection patterns in the spinal cord and brainstem, receptive tuning, and conduction velocity of their action potentials. While useful, the picture that emerged was one of heterogeneity, with many markers at least partially overlapping. More recently, by capitalizing on advances in molecular techniques, researchers have identified specific ion channels and sensory receptors expressed in subsets of sensory neurons. These studies have proved invaluable as they allow genetic access to small subsets of neurons for further molecular dissection. Data being generated from transgenic mice favor the model whereby an array of dedicated neurons is responsible for selectively encoding different modalities. Here we review the current knowledge of the different sensory neuron subtypes in the mouse, the markers used to study them, and the neurogenetic strategies used to define their anatomical projections and functional roles.

Lavandula angustifolia Extract Improves the Result of Human Umbilical Mesenchymal Wharton’s Jelly Stem Cell Transplantation after Contusive Spinal Cord Injury in Wistar Rats

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Kayvan Yaghoobi

2016-01-01

Full Text Available Introduction. The primary trauma of spinal cord injury (SCI results in severe damage to nervous functions. At the cellular level, SCI causes astrogliosis. Human umbilical mesenchymal stem cells (HUMSCs, isolated from Wharton’s jelly of the umbilical cord, can be easily obtained. Previously, we showed that the neuroprotective effects of Lavandula angustifolia can lead to improvement in a contusive SCI model in rats. Objective. The aim of this study was to investigate the effect of L. angustifolia (Lav on HUMSC transplantation after acute SCI. Materials and Methods. Sixty adult female rats were randomly divided into eight groups. Every week after SCI onset, all animals were evaluated for behavior outcomes. H&E staining was performed to examine the lesions after injury. GFAP expression was assessed for astrogliosis. Somatosensory evoked potential (SEP testing was performed to detect the recovery of neural conduction. Results. Behavioral tests showed that the HUMSC group improved in comparison with the SCI group, but HUMSC + Lav 400 was very effective, resulting in a significant increase in locomotion activity. Sensory tests and histomorphological and immunohistochemistry analyses verified the potentiation effects of Lav extract on HUMSC treatment. Conclusion. Transplantation of HUMSCs is beneficial for SCI in rats, and Lav extract can potentiate the functional and cellular recovery with HUMSC treatment in rats after SCI.

The effect of water immersion on short-latency somatosensory evoked potentials in human

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Sato Daisuke

2012-01-01

Full Text Available Abstract Background Water immersion therapy is used to treat a variety of cardiovascular, respiratory, and orthopedic conditions. It can also benefit some neurological patients, although little is known about the effects of water immersion on neural activity, including somatosensory processing. To this end, we examined the effect of water immersion on short-latency somatosensory evoked potentials (SEPs elicited by median nerve stimuli. Short-latency SEP recordings were obtained for ten healthy male volunteers at rest in or out of water at 30°C. Recordings were obtained from nine scalp electrodes according to the 10-20 system. The right median nerve at the wrist was electrically stimulated with the stimulus duration of 0.2 ms at 3 Hz. The intensity of the stimulus was fixed at approximately three times the sensory threshold. Results Water immersion significantly reduced the amplitudes of the short-latency SEP components P25 and P45 measured from electrodes over the parietal region and the P45 measured by central region. Conclusions Water immersion reduced short-latency SEP components known to originate in several cortical areas. Attenuation of short-latency SEPs suggests that water immersion influences the cortical processing of somatosensory inputs. Modulation of cortical processing may contribute to the beneficial effects of aquatic therapy. Trial Registration UMIN-CTR (UMIN000006492

Paradigms for restoration of somatosensory feedback via stimulation of the peripheral nervous system.

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Pasluosta, Cristian; Kiele, Patrick; Stieglitz, Thomas

2018-04-01

The somatosensory system contributes substantially to the integration of multiple sensor modalities into perception. Tactile sensations, proprioception and even temperature perception are integrated to perceive embodiment of our limbs. Damage of somatosensory networks can severely affect the execution of daily life activities. Peripheral injuries are optimally corrected via direct interfacing of the peripheral nerves. Recent advances in implantable devices, stimulation paradigms, and biomimetic sensors enabled the restoration of natural sensations after amputation of the limb. The refinement of stimulation patterns to deliver natural feedback that can be interpreted intuitively such to prescind from long-learning sessions is crucial to function restoration. For this review, we collected state-of-the-art knowledge on the evolution of stimulation paradigms from single fiber stimulation to the eliciting of multisensory sensations. Data from the literature are structured into six sections: (a) physiology of the somatosensory system; (b) stimulation of single fibers; (c) restoral of multisensory percepts; (d) closure of the control loop in hand prostheses; (e) sensory restoration and the sense of embodiment, and (f) methodologies to assess stimulation outcomes. Full functional recovery demands further research on multisensory integration and brain plasticity, which will bring new paradigms for intuitive sensory feedback in the next generation of limb prostheses. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Low maternal care exacerbates adult stress susceptibility in the chronic mild stress rat model of depression

DEFF Research Database (Denmark)

Henningsen, Kim; Johannesen, Mads Dyrvig; Bouzinova, Elena

2012-01-01

In the present study we report the finding that the quality of maternal care, in early life, increased the susceptibility to stress exposure in adulthood, when rats were exposed to the chronic mild stress paradigm. Our results indicate that high, as opposed to low maternal care, predisposed rats...... to a differential stress-coping ability. Thus rats fostered by low maternal care dams became more prone to adopt a stress-susceptible phenotype developing an anhedonic-like condition. Moreover, low maternal care offspring had lower weight gain and lower locomotion, with no additive effect of stress. Subchronic...... exposure to chronic mild stress induced an increase in faecal corticosterone metabolites, which was only significant in rats from low maternal care dams. Examination of glucocorticoid receptor exon 17 promoter methylation in unchallenged adult, maternally characterized rats, showed an insignificant...

Protein-Energy Malnutrition Causes Deficits in Motor Function in Adult Male Rats.

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Alaverdashvili, Mariam; Li, Xue; Paterson, Phyllis G

2015-11-01

Adult protein-energy malnutrition (PEM) often occurs in combination with neurological disorders affecting hand use and walking ability. The independent effects of PEM on motor function are not well characterized and may be obscured by these comorbidities. Our goal was to undertake a comprehensive evaluation of sensorimotor function with the onset and progression of PEM in an adult male rat model. In Expt. 1 and Expt. 2, male Sprague-Dawley rats (14-15 wk old) were assigned ad libitum access for 4 wk to normal-protein (NP) or low-protein (LP) diets containing 12.5% and 0.5% protein, respectively. Expt. 1 assessed muscle strength, balance, and skilled walking ability on days 2, 8, and 27 by bar-holding, cylinder, and horizontal ladder walking tasks, respectively. In addition to food intake and body weight, nutritional status was determined on days 3, 9, and 28 by serum acute-phase reactant and corticosterone concentrations and liver lipids. Expt. 2 addressed the effect of an LP diet on hindlimb muscle size. PEM evolved over time in rats consuming the LP diet. Total food intake decreased by 24% compared with the NP group. On day 28, body weight and serum albumin decreased by 31% and 26%, respectively, and serum α2-macroglobulin increased by 445% (P malnutrition. This model can be used in combination with disease models of sensorimotor deficits to examine the interactions between nutritional status, other treatments, and disease progression. © 2015 American Society for Nutrition.

Ultrafine Particulate Matter Combined With Ozone Exacerbates Lung Injury in Mature Adult Rats With Cardiovascular Disease.

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Wong, Emily M; Walby, William F; Wilson, Dennis W; Tablin, Fern; Schelegle, Edward S

2018-05-01

Particulate matter (PM) and ozone (O3) are dominant air pollutants that contribute to development and exacerbation of multiple cardiopulmonary diseases. Mature adults with cardiovascular disease (CVD) are particularly susceptible to air pollution-related cardiopulmonary morbidities and mortalities. The aim was to investigate the biologic potency of ultrafine particulate matter (UFPM) combined with O3 in the lungs of mature adult normotensive and spontaneously hypertensive (SH) Wistar-Kyoto rats. Conscious, mature adult male normal Wistar-Kyoto (NW) and SH rats were exposed to one of the following atmospheres: filtered air (FA); UFPM (∼ 250 μg/m3); O3 (1.0 ppm); or UFPM + O3 (∼ 250 μg/m3 + 1.0 ppm) combined for 6 h, followed by an 8 h FA recovery period. Lung sections were evaluated for lesions in the large airways, terminal bronchiolar/alveolar duct regions, alveolar parenchyma, and vasculature. NW and SH rats were similarly affected by the combined-pollutant exposure, displaying severe injury in both large and small airways. SH rats were particularly susceptible to O3 exposure, exhibiting increased injury scores in terminal bronchioles and epithelial degeneration in large airways. UFPM-exposure groups had minimal histologic changes. The chemical composition of UFPM was altered by the addition of O3, indicating that ozonolysis promoted compound degradation. O3 increased the biologic potency of UFPM, resulting in greater lung injury following exposure. Pathologic manifestations of CVD may confer susceptibility to air pollution by impairing normal lung defenses and responses to exposure.

Effect of extradural morphine on somatosensory evoked potentials to dermatomal stimulation

DEFF Research Database (Denmark)

Lund, C; Selmar, P; Hansen, O B

1987-01-01

The effect of the extradural (L2-3) administration of morphine 6 mg on early (less than 0.5 s) somatosensory evoked cortical potentials (SEP) to electrical stimulation of the L1- and S1-dermatomes was examined in eight patients. Extradural morphine did not influence SEP amplitude. SEP latency did...

Neurochemical and neuroanatomic effects of 3,4-methylenedioxymethamphetamine (MDMA) in rats

International Nuclear Information System (INIS)

Virus, R.; Commins, D.; Vosmer, G.; Woolverton, W.; Schuster, C.; Seiden, L.

1986-01-01

Rats injected s.c. twice daily for 4 consecutive days with 10,20, or 40 mg/kg MDMA or saline and sacrificed 2 weeks after the last injection showed dose-dependent reductions in serotonin (5-HT) concentrations in hypothalamus, hippocampus (HIP), striatum (STR), somatosensory cortex (SC) and other cortical areas (CTX). 5-HT depletion was maximal in HIP (11.5 +/- 1.7%) and SC (15.3 +/- 3.2%, p 3 H)5-HT uptake sites (V/sub max/ 35.2% of control) without affecting the affinity (K/sub m/) in HIP. Fink-Heimer staining showed that rats injected s.c. twice daily for 2 days with 80 mg/kg MDMA had greater degeneration of nerve terminals in STR (p<0.005) and pyramidal cells in Layer III of SC (p<0.01) than did control rats. These results clearly suggest that repeated exposure to MDMA selectively damages serotonergic neurons in the central nervous system of rats

Functional MRI activation of somatosensory and motor cortices in a hand-grafted patient with early clinical sensorimotor recovery

International Nuclear Information System (INIS)

Neugroschl, C.; Denolin, V.; Schuind, F.; Holder, C. van; David, P.; Baleriaux, D.; Metens, T.

2005-01-01

The aim of this study was to investigate somatosensory and motor cortical activity with functional MRI (fMRI) in a hand-grafted patient with early clinical recovery. The patient had motor fMRI examinations before transplantation, and motor and passive tactile stimulations after surgery. His normal hand and a normal group were studied for comparison. A patient with complete brachial plexus palsy was studied to assess the lack of a fMRI signal in somatosensory areas in the case of total axonal disconnection. Stimulating the grafted hand revealed significant activation in the contralateral somatosensory cortical areas in all fMRI examinations. The activation was seen as early as 10 days after surgery; this effect cannot be explained by the known physiological mechanisms of nerve regeneration. Although an imagination effect cannot be excluded, the objective clinical recovery of sensory function led us to formulate the hypothesis that a connection to the somatosensory cortex was rapidly established. Additional cases and fundamental studies are needed to assess this hypothesis, but several observations were compatible with this explanation. Before surgery, imaginary motion of the amputated hand produced less intense responses than executed movements of the intact hand, whereas the normal activation pattern for right-handed subjects was found after surgery, in agreement with the good clinical motor recovery. (orig.)

Risk factors affecting somatosensory function after sagittal split osteotomy

DEFF Research Database (Denmark)

Thygesen, Torben Henrik; Jensen, Allan Bardow; Helleberg, M

2008-01-01

Purpose The aim of this study was to evaluate potential individual and intraoperative risk factors associated with bilateral sagittal split osteotomy (BSSO) and to correlate the findings with postoperative changes in somatosensory function. Patients and Methods A total of 18 men and 29 women (mean...... and free dissection of the inferior alveolar nerve during BSSO increased self-reported changes in lower lip sensation and lower lip tactile threshold after BSSO (P discrimination (P

Effect of endothelin-1 on the excitability of rat cortical and hippocampal slices in vitro

Czech Academy of Sciences Publication Activity Database

Konopková, Renata; Világi, I.; Borbély, S.; Kubová, Hana; Otáhal, Jakub

2012-01-01

Roč. 61, č. 2 (2012), s. 215-219 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LC554; GA AV ČR(CZ) 1QS501210509; GA ČR(CZ) GD305/08/H037 Institutional research plan: CEZ:AV0Z50110509 Keywords : Endothelin-1 * excitability * hippocampus * somatosensory cortex * rat * epileptogenesis Subject RIV: FH - Neurology Impact factor: 1.531, year: 2012

Effects of thiamine deficiency on food intake and body weight increment in adult female and growing rats.

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Bâ, Abdoulaye

2012-09-01

The present study compared the effects of thiamine (vitamin B1) deficiency (TD) on the patterns of food intake and body weight in adult female and neonatal Wistar rats. The adults weighed 250-270 g at the start and were fed for 60 days either with a synthetic TD diet (211 B1) or with the same synthetic diet+thiamine (210 B1). TD led to a marked reduction in food intake and the body weight set point, both recovering rapidly to their initial level in only 3 days after dietetic reversion. The effects of TD in developing rats were evaluated by subjecting pregnant rats to thiamine restriction during different time windows: prenatal (3 days before mating to parturition); perinatal (7 days after mating to the 10th postnatal day); and postnatal (from parturition to weaning). The effect of TD on the occurrence of low birth weight and ponderal growth retardation was examined from postnatal days 1 to 45. Only perinatal TD significantly decreased birth weight relative to untreated or pair-fed controls. Moreover, compared with the control treatments, ponderal growth retardation was not induced by prenatal TD, whereas induction of TD from perinatal into postnatal periods did cause ponderal growth retardation, with long-lasting effects persisting in adulthood. The results suggest a major physiological role of thiamine in the homeostasis of body weight programming, increment, and set point regulation in both offspring and adult female rats.

Peripubertal castration of male rats, adult open field ambulation and partner preference behavior.

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Brand, T; Slob, A K

1988-09-15

The validity of the hypothesis put forward earlier, that testicular secretions during puberty have an organizing effect on open field ambulation was examined. Male rats were castrated or sham-operated at days 21, 43 or 70. At the age of 17 weeks the males were tested in an automated, octagonal open field (3 consecutive days, 3 min/day) for locomotor activity. Male rats castrated at day 21 or day 43 ambulated more than sham-castrated controls. Males castrated at day 70 did not differ from sham-castrated controls. It thus appears that pubertal testicular secretion(s) organize adult open field locomotor activity in male rats. From 18 weeks of age partner preference behavior was tested in the same open field apparatus with one adjacent cage containing an ovariectomized female and an opposite one containing an ovariectomized female brought into heat. The females in the adjacent cages were separated from the experimental males in the octagonal cage by wire mesh. Peripubertally castrated males did not show a clear-cut partner preference, whereas the intact males preferred the vicinity of the estrous female. There were no differences among the males castrated either before, during or after puberty. Testosterone treatment (crystalline T in silastic capsules) caused peripubertally castrated males to prefer the estrous female. Thus, adult partner preference behavior does not seem to be organized by peripubertal testicular androgens.

Cutaneous and periodontal inputs to the cerebellum of the naked mole-rat (Heterocephalus glaber).

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Sarko, Diana K; Leitch, Duncan B; Catania, Kenneth C

2013-01-01

The naked mole-rat (Heterocephalus glaber) is a small fossorial rodent with specialized dentition that is reflected by the large cortical area dedicated to representation of the prominent incisors. Due to naked mole-rats' behavioral reliance on the incisors for digging and for manipulating objects, as well as their ability to move the lower incisors independently, we hypothesized that expanded somatosensory representations of the incisors would be present within the cerebellum in order to accommodate a greater degree of proprioceptive, cutaneous, and periodontal input. Multiunit electrophysiological recordings targeting the ansiform lobule were used to investigate tactile inputs from receptive fields on the entire body with a focus on the incisors. Similar to other rodents, a fractured somatotopy appeared to be present with discrete representations of the same receptive fields repeated within each folium of the cerebellum. These findings confirm the presence of somatosensory inputs to a large area of the naked mole-rat cerebellum with particularly extensive representations of the lower incisors and mystacial vibrissae. We speculate that these extensive inputs facilitate processing of tactile cues as part of a sensorimotor integration network that optimizes how sensory stimuli are acquired through active exploration and in turn adjusts motor outputs (such as independent movement of the lower incisors). These results highlight the diverse sensory specializations and corresponding brain organizational schemes that have evolved in different mammals to facilitate exploration of and interaction with their environment.

Neonatal programming with testosterone propionate reduces dopamine transporter expression in nucleus accumbens and methylphenidate-induced locomotor activity in adult female rats.

Science.gov (United States)

Dib, Tatiana; Martínez-Pinto, Jonathan; Reyes-Parada, Miguel; Torres, Gonzalo E; Sotomayor-Zárate, Ramón

2018-07-02

Research in programming is focused on the study of stimuli that alters sensitive periods in development, such as prenatal and neonatal stages, that can produce long-term deleterious effects. These effects can occur in various organs or tissues such as the brain, affecting brain circuits and related behaviors. Our laboratory has demonstrated that neonatal programming with sex hormones affects the mesocorticolimbic circuitry, increasing the synthesis and release of dopamine (DA) in striatum and nucleus accumbens (NAcc). However, the behavioral response to psychostimulant drugs such as methylphenidate and the possible mechanism(s) involved have not been studied in adult rats exposed to sex hormones during the first hours of life. Thus, the aim of this study was to examine the locomotor activity induced by methylphenidate (5mg/kg i.p.) and the expression of the DA transporter (DAT) in NAcc of adult rats exposed to a single dose of testosterone propionate (TP: 1mg/50μLs.c.) or estradiol valerate (EV: 0.1mg/50μLs.c.) at postnatal day 1. Our results demonstrated that adult female rats treated with TP have a lower methylphenidate-induced locomotor activity compared to control and EV-treated adult female rats. This reduction in locomotor activity is related with a lower NAcc DAT expression. However, neither methylphenidate-induced locomotor activity nor NAcc DAT expression was affected in EV or TP-treated adult male rats. Our results suggest that early exposure to sex hormones affects long-term dopaminergic brain areas involved in the response to psychostimulants, which could be a vulnerability factor to favor the escalating doses of drugs of abuse. Copyright © 2017 Elsevier B.V. All rights reserved.

Study of the effects of a prenatal or postnatal irradiation of 150 rads in adult rats

International Nuclear Information System (INIS)

Coffigny, H.; Pasquier, C.

Pregnant females and newborn rats were exposed to a gamma irradiation of 150 rads. The stage of gestation at the time of irradiation varied from 14 to 21 days. The newborn rats were irradiated at 0, 1 and 2 days of age. The effect of irradiation of foetus and newborn rats depends on the age of the animal at the time of irradiation. This effect was specially important at the beginning of the foetal life. Neonatal mortality, growth of body weight and adult brain development were investigated. A modification of germ cell radiosensitivity during the period studied, was emphasized [fr

Adult and newborn rat inner retinal oxygenation during carbogen and 100% oxygen breathing. Comparison using magnetic resonance imaging delta Po2 mapping.

Science.gov (United States)

Berkowitz, B A

1996-09-01

To test the hypothesis that breathing carbogen (95% O2-5% CO2) oxygenates the inner retina better than breathing 100% oxygen using an magnetic resonance imaging (MRI) method that noninvasively measures inner retinal oxygenation in normal adult and newborn rats. Urethane-anesthetized adult and newborn (day 18) rats were studied. Sequential images were acquired in room air combined with either 100% oxygen or carbogen breathing. Normalized vitreous signal intensity changes were converted to oxygen tension changes (delta PO2) either on a pixel-by-pixel basis or in specific regions of interest. Systemic levels of hyperoxia during carbogen or 100% oxygen breathing were not significantly different (P > 0.05). In the adult rat, a significant difference (P = 0.017) was found in the preretinal vitreous delta PO2 during the breathing of either carbogen (130 +/- 9 mm Hg, mean +/- SEM; n = 5) or 100% oxygen (88 +/- 16 mm Hg; n = 5). Agreement was found between the MRI-determined delta PO2 values and literature oxygen microelectrodes data. In the newborn rat, significant differences (P delta PO2 were found during carbogen (164 +/- 23 mm Hg; n = 3) and oxygen breathing (91 +/- 8 mm Hg; n = 3). MRI delta PO2 mapping demonstrated for the first time that in the normal adult and newborn rat eye, carbogen breathing oxygenates the inner retina better than 100% oxygen breathing.

Brownian Optogenetic-Noise-Photostimulation on the Brain Amplifies Somatosensory-Evoked Field Potentials

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Nayeli Huidobro

2017-08-01

Full Text Available Stochastic resonance (SR is an inherent and counter-intuitive mechanism of signal-to-noise ratio (SNR facilitation in biological systems associated with the application of an intermediate level of noise. As a first step to investigate in detail this phenomenon in the somatosensory system, here we examined whether the direct application of noisy light on pyramidal neurons from the mouse-barrel cortex expressing a light-gated channel channelrhodopsin-2 (ChR2 can produce facilitation in somatosensory evoked field potentials. Using anesthetized Thy1-ChR2-YFP transgenic mice, and a new neural technology, that we called Brownian optogenetic-noise-photostimulation (BONP, we provide evidence for how BONP directly applied on the barrel cortex modulates the SNR in the amplitude of whisker-evoked field potentials (whisker-EFP. In all transgenic mice, we found that the SNR in the amplitude of whisker-EFP (at 30% of the maximal whisker-EFP exhibited an inverted U-like shape as a function of the BONP level. As a control, we also applied the same experimental paradigm, but in wild-type mice, as expected, we did not find any facilitation effects. Our results show that the application of an intermediate intensity of BONP on the barrel cortex of ChR2 transgenic mice amplifies the SNR of somatosensory whisker-EFPs. This result may be relevant to explain the improvements found in sensory detection in humans produced by the application of transcranial-random-noise-stimulation (tRNS on the scalp.

Laterodorsal nucleus of the thalamus: A processor of somatosensory inputs.

Science.gov (United States)

Bezdudnaya, Tatiana; Keller, Asaf

2008-04-20

The laterodorsal (LD) nucleus of the thalamus has been considered a "higher order" nucleus that provides inputs to limbic cortical areas. Although its functions are largely unknown, it is often considered to be involved in spatial learning and memory. Here we provide evidence that LD is part of a hitherto unknown pathway for processing somatosensory information. Juxtacellular and extracellular recordings from LD neurons reveal that they respond to vibrissa stimulation with short latency (median = 7 ms) and large magnitude responses (median = 1.2 spikes/stimulus). Most neurons (62%) had large receptive fields, responding to six and more individual vibrissae. Electrical stimulation of the trigeminal nucleus interpolaris (SpVi) evoked short latency responses (median = 3.8 ms) in vibrissa-responsive LD neurons. Labeling produced by anterograde and retrograde neuroanatomical tracers confirmed that LD neurons receive direct inputs from SpVi. Electrophysiological and neuroanatomical analyses revealed also that LD projects upon the cingulate and retrosplenial cortex, but has only sparse projections to the barrel cortex. These findings suggest that LD is part of a novel processing stream involved in spatial orientation and learning related to somatosensory cues. (c) 2008 Wiley-Liss, Inc.

Mild Thyroid Hormone Insufficiency During Development Compromises Activity-Dependent Neuroplasticity in the Hippocampus of Adult Male Rats

Data.gov (United States)

U.S. Environmental Protection Agency — behavioral measures of learning and memory in adult offspring of rats treated with thyroid hormone synthesis inhibitor, propylthiouracil. Electrophysiological...

Effects of chronic isoproterenol administration of β1-adrenoceptors and growth of pancreas of young and adult rats

International Nuclear Information System (INIS)

Schneyer, C.A.; Humphreys-Beher, M.

1988-01-01

[ 3 H]Dihydroalprenolol (DHA) binding of membranes of adult pancreas differed from that of pancreas of young rats, and the DHA binding in the presence of atenolol or butoxamine also was different in the two age groups. The adult pancreas had 93% β 2 - and 7% β 1 -adrenoceptors and did not exhibit an increased incorporation of [ 3 H]thymidine into deoxyribonucleic acid (DNA) following 2 days of DL-isoproterenol (ISO) administration; in contrast, pancreas of the 20-day-old rat had 71% β 2 -adrenoceptors and 27% β 1 -adrenoceptors and exhibited a 34-fold increase over that of adult, and a 6-fold increase over that of the control 20-day-old pancreas. Acinar cell differentiation was also accelerated by a 7-day regimen of ISO administration from 13 to 20 days of age. These growth responses to ISO appear to be β 1 mediated. The lack of β 1 -adrenoceptors in the adult may account for the failure of the adult pancreas to exhibit a growth response to ISO

Neonatal stress tempers vulnerability of acute stress response in adult socially isolated rats

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Mariangela Serra

2014-06-01

Full Text Available Adverse experiences occurred in early life and especially during childhood and adolescence can have negative impact on behavior later in life and the quality of maternal care is considered a critical moment that can considerably influence the development and the stress responsiveness in offspring. This review will assess how the association between neonatal and adolescence stressful experiences such as maternal separation and social isolation, at weaning, may influence the stress responsiveness and brain plasticity in adult rats. Three hours of separation from the pups (3-14 postnatal days significantly increased frequencies of maternal arched-back nursing and licking-grooming by dams across the first 14 days postpartum and induced a long-lasting increase in their blood levels of corticosterone. Maternal separation, which per sedid not modified brain and plasma allopregnanolone and corticosterone levels in adult rats, significantly reduced social isolation-induced decrease of the levels of these hormones. Moreover, the enhancement of corticosterone and allopregnanolone levels induced by foot shock stress in socially isolated animals that were exposed to maternal separation was markedly reduced respect to that observed in socially isolated animals. Our results suggest that in rats a daily brief separation from the mother during the first weeks of life, which per se did not substantially alter adult function and reactivity of hypothalamic-pituitary-adrenal (HPA axis, elicited a significant protection versus the subsequent long-term stressful experience such that induced by social isolation from weaning. Proceedings of the 10th International Workshop on Neonatology · Cagliari (Italy · October 22nd-25th, 2014 · The last ten years, the next ten years in NeonatologyGuest Editors: Vassilios Fanos, Michele Mussap, Gavino Faa, Apostolos Papageorgiou

Thymoquinone supplementation ameliorates lead-induced testis function impairment in adult rats.

Science.gov (United States)

Mabrouk, Aymen; Ben Cheikh, Hassen

2016-06-01

This study was realized to investigate the possible beneficial effect of thymoquinone (TQ), the major active component of volatile oil of Nigella sativa seeds, against lead (Pb)-induced inhibition of rat testicular functions. Adult rats were randomized into four groups: a control group receiving no treatment; a Pb group exposed to 2000 parts per million (ppm) of Pb acetate in drinking water; a Pb-TQ group co-treated with Pb (as in Pb group) plus TQ (5 mg/kg body weight (b.w.)/day, per orally (p.o.)); and a TQ group receiving TQ (5 mg/kg b.w./day, p.o.). All treatments were for 5 weeks. No significant differences were observed for the body weight gain or for relative testes weight among the four groups of animals. Testicular Pb content significantly increased in metal-intoxicated rats compared with that in control rats. TQ supplementation had no effect on this testicular Pb accumulation. Interestingly, when coadministrated with Pb, TQ significantly improved the low plasma testosterone level and the decreased epididymal sperm count caused by Pb. In conclusion, the results suggest, for the first time, that TQ protects against Pb-induced impairment of testicular steroidogenic and spermatogenic functions. This study will open new perspectives for the clinical use of TQ in Pb intoxication. © The Author(s) 2014.

The impact of adult vitamin D deficiency on behaviour and brain function in male Sprague-Dawley rats.

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Jacqueline H Byrne

Full Text Available BACKGROUND: Vitamin D deficiency is common in the adult population, and this has been linked to depression and cognitive outcomes in clinical populations. The aim of this study was to investigate the effects of adult vitamin D (AVD deficiency on behavioural tasks of relevance to neuropsychiatric disorders in male Sprague-Dawley rats. METHODS: Ten-week old male Sprague-Dawley rats were fed a control or vitamin D deficient diet for 6 weeks prior to, and during behavioural testing. We first examined a range of behavioural domains including locomotion, exploration, anxiety, social behaviour, learned helplessness, sensorimotor gating, and nociception. We then assessed locomotor response to the psychomimetic drugs, amphetamine and MK-801. Attention and vigilance were assessed using the 5 choice serial reaction time task (5C-SRT and the 5 choice continuous performance task (5C-CPT and, in a separate cohort, working memory was assessed using the delay match to sample (DMTS task. We also examined excitatory and inhibitory neurotransmitters in prefrontal cortex and striatum. RESULTS: AVD-deficient rats were deficient in vitamin D3 (<10 nM and had normal calcium and phosphate levels after 8-10 weeks on the diet. Overall, AVD deficiency was not associated with an altered phenotype across the range of behavioural domains tested. On the 5C-SRT AVD-deficient rats made more premature responses and more head entries during longer inter-trial intervals (ITI than control rats. On the 5C-CPT AVD-deficient rats took longer to make false alarm (FA responses than control rats. AVD-deficient rats had increases in baseline GABA levels and the ratio of DOPAC/HVA within the striatum. CONCLUSIONS: AVD-deficient rats exhibited no major impairments in any of the behavioural domains tested. Impairments in premature responses in AVD-deficient rats may indicate that these animals have specific alterations in striatal systems governing compulsive or reward-seeking behaviour.

Sex-Specific Skeletal Muscle Fatigability and Decreased Mitochondrial Oxidative Capacity in Adult Rats Exposed to Postnatal Hyperoxia

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Laura H. Tetri

2018-03-01

Full Text Available Premature birth affects more than 10% of live births, and is characterized by relative hyperoxia exposure in an immature host. Long-term consequences of preterm birth include decreased aerobic capacity, decreased muscular strength and endurance, and increased prevalence of metabolic diseases such as type 2 diabetes mellitus. Postnatal hyperoxia exposure in rodents is a well-established model of chronic lung disease of prematurity, and also recapitulates the pulmonary vascular, cardiovascular, and renal phenotype of premature birth. The objective of this study was to evaluate whether postnatal hyperoxia exposure in rats could recapitulate the skeletal and metabolic phenotype of premature birth, and to characterize the subcellular metabolic changes associated with postnatal hyperoxia exposure, with a secondary aim to evaluate sex differences in this model. Compared to control rats, male rats exposed to 14 days of postnatal hyperoxia then aged to 1 year demonstrated higher skeletal muscle fatigability, lower muscle mitochondrial oxidative capacity, more mitochondrial damage, and higher glycolytic enzyme expression. These differences were not present in female rats with the same postnatal hyperoxia exposure. This study demonstrates detrimental mitochondrial and muscular outcomes in the adult male rat exposed to postnatal hyperoxia. Given that young adults born premature also demonstrate skeletal muscle dysfunction, future studies are merited to determine whether this dysfunction as well as reduced aerobic capacity is due to reduced mitochondrial oxidative capacity and metabolic dysfunction.

Glutamate-Mediated Primary Somatosensory Cortex Excitability Correlated with Circulating Copper and Ceruloplasmin

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Franca Tecchio

2011-01-01

Full Text Available Objective. To verify whether markers of metal homeostasis are related to a magnetoencephalographic index representative of glutamate-mediated excitability of the primary somatosensory cortex. The index is identified as the source strength of the earliest component (M20 of the somatosensory magnetic fields (SEFs evoked by right median nerve stimulation at wrist. Method. Thirty healthy right-handed subjects (51±22 years were enrolled in the study. A source reconstruction algorithm was applied to assess the amount of synchronously activated neurons subtending the M20 and the following SEF component (M30, which is generated by two independent contributions of gabaergic and glutamatergic transmission. Serum copper, ceruloplasmin, iron, transferrin, transferrin saturation, and zinc levels were measured. Results. Total copper and ceruloplasmin negatively correlated with the M20 source strength. Conclusion. This pilot study suggests that higher level of body copper reserve, as marked by ceruloplasmin variations, parallels lower cortical glutamatergic responsiveness.

"Lacking warmth": Alexithymia trait is related to warm-specific thermal somatosensory processing.

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Borhani, Khatereh; Làdavas, Elisabetta; Fotopoulou, Aikaterini; Haggard, Patrick

2017-09-01

Alexithymia is a personality trait involving deficits in emotional processing. The personality construct has been extensively validated, but the underlying neural and physiological systems remain controversial. One theory suggests that low-level somatosensory mechanisms act as somatic markers of emotion, underpinning cognitive and affective impairments in alexithymia. In two separate samples (total N=100), we used an established Quantitative Sensory Testing (QST) battery to probe multiple neurophysiological submodalities of somatosensation, and investigated their associations with the widely-used Toronto Alexithymia Scale (TAS-20). Experiment one found reduced sensitivity to warmth in people with higher alexithymia scores, compared to individuals with lower scores, without deficits in other somatosensory submodalities. Experiment two replicated this result in a new group of participants using a full-sample correlation between threshold for warm detection and TAS-20 scores. We discuss the relations between low-level thermoceptive function and cognitive processing of emotion. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Effect of sex on ethanol consumption and conditioned taste aversion in adolescent and adult rats.

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Schramm-Sapyta, Nicole L; Francis, Reynold; MacDonald, Andrea; Keistler, Colby; O'Neill, Lauren; Kuhn, Cynthia M

2014-04-01

Vulnerability to alcoholism is determined by many factors, including the balance of pleasurable vs. aversive alcohol-induced sensations: pleasurable sensations increase intake, while aversive sensations decrease it. Female sex and adolescent age are associated with lower sensitivity to intake-reducing effects and more rapid development of alcohol abuse. This study assessed voluntary drinking and the aversive effects of alcohol to determine whether these measures are inversely related across the sexes and development. Voluntary drinking of 20 % ethanol in an every-other-day (EOD) availability pattern and the dose-response relationship of ethanol conditioned taste aversion (CTA) were assessed in male and female adolescent and adult rats. CTA was sex specific in adult but not adolescent rats, with adult females exhibiting less aversion. Voluntary ethanol consumption varied according to age and individual differences but was not sex specific. Adolescents initially drank more than adults, exhibited greater day-to-day variation in consumption, were more susceptible to the alcohol deprivation effect, and took longer to establish individual differences in consumption patterns. These results show that the emergence of intake patterns differs between adolescents and adults. Adolescents as a group initiate drinking at high levels but decrease intake as they mature. A subset of adolescents maintained high drinking levels into adulthood. In contrast, most adults consumed at steady, low levels, but a small subset quickly established and maintained high-consumption patterns. Adolescents also showed marked deprivation-induced increases. Sex differences were not observed in EOD drinking during either adolescence or adulthood.

Effect of 8 weeks Resistance Training on BDNF and TrkB in the Hippocampus of Adult Male Rats

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S Mojtahedi

2014-08-01

Full Text Available Background & aim: Exercise enhances the synaptic plasticity and neuroprotective effects in the adult brain. However, it remains unknown that how plasticity molecules change following types of training. The purpose of this study was to determine the effect of eight weeks resistance training on protein levels of Brain Derived Neurotrophic Factor(BDNF and receptor of TrkB, in the hippocampus of adult male rats. Methods: In this experimental study, twelve adult male rats, 8 weeks of age, with an average weight of 200 to 225 grams were randomly divided into two groups, control and exercise respectively. The exercise was to increase the weight on the ladder. 24 hours after their last training session. The animals were killed and the hippocampus was removed for further testing. ELISA determined changes in protein levels. Data were analyzed by independent t test. Results: There was a significant difference between train and control groups In protein level of variables statically (p≤0.05. In addition, protein levels of BDNF and TrkB in the hippocampus of rats increased. Conclusion: Resistance training is beneficial for promoting hippocampal plasticity associated with BDNF signaling and consequently functional and cognitive benefits.

Prenatal exposure to vapors of gasoline-ethanol blends causes few cognitive deficits in adult rats

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Developmental exposure to inhaled ethanol-gasoline fuel blends is a potential public health concern. Here we assessed cognitive functions in adult offspring of pregnant rats that were exposed to vapors of gasoline blended with a range of ethanol concentrations, including gasoli...

The effects of gonadectomy and binge-like ethanol exposure during adolescence on open field behaviour in adult male rats.

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Yan, Wensheng; Kang, Jie; Zhang, Guoliang; Li, Shuangcheng; Kang, Yunxiao; Wang, Lei; Shi, Geming

2015-09-14

Binge drinking ethanol exposure during adolescence can lead to long-term neurobehavioural damage. It is not known whether the pubertal surge in testosterone that occurs during adolescence might impact the neurobehavioural effects of early ethanol exposure in adult animals. We examined this hypothesis by performing sham or gonadectomy surgeries on Sprague-Dawley rats around postnatal day (P) 23. From P28-65,the rats were administered 3.0g/kg ethanol using a binge-like model of exposure. Dependent measurements included tests of open field behaviour, blood ethanol concentrations, and testosterone levels. As adults, significant decreases in open field activity were observed in the GX rats. The open field behaviour of the GX rats was restored after testosterone administration. Binge-like ethanol exposure altered most of the parameters of the open field behaviour, suggestive of alcohol-induced anxiety, but rats treated with alcohol in combination with gonadectomy showed less motor behaviour and grooming behaviour and an increase in immobility, suggesting ethanol-induced depression. These results indicated that testosterone is required for ethanol-induced behavioural changes and that testicular hormones are potent stimulators of ethanol-induced behaviours. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Differentiated effects of deep brain stimulation and medication on somatosensory processing in Parkinson's disease.

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Sridharan, Kousik Sarathy; Højlund, Andreas; Johnsen, Erik Lisbjerg; Sunde, Niels Aagaard; Johansen, Lars Gottfried; Beniczky, Sándor; Østergaard, Karen

2017-07-01

Deep brain stimulation (DBS) and dopaminergic medication effectively alleviate the motor symptoms in Parkinson's disease (PD) patients, but their effects on the sensory symptoms of PD are still not well understood. To explore early somatosensory processing in PD, we recorded magnetoencephalography (MEG) from thirteen DBS-treated PD patients and ten healthy controls during median nerve stimulation. PD patients were measured during DBS-treated, untreated and dopaminergic-medicated states. We focused on early cortical somatosensory processing as indexed by N20m, induced gamma augmentation (31-45Hz and 55-100Hz) and induced beta suppression (13-30Hz). PD patients' motor symptoms were assessed by UPDRS-III. Using Bayesian statistics, we found positive evidence for differentiated effects of treatments on the induced gamma augmentation (31-45Hz) with highest gamma in the dopaminergic-medicated state and lowest in the DBS-treated and untreated states. In contrast, UPDRS-III scores showed beneficial effects of both DBS and dopaminergic medication on the patients' motor symptoms. Furthermore, treatments did not affect the amplitude of N20m. Our results suggest differentiated effects of DBS and dopaminergic medication on cortical somatosensory processing in PD patients despite consistent ameliorating effects of both treatments on PD motor symptoms. The differentiated effect suggests differences in the effect mechanisms of the two treatments. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Seeing is not feeling: posterior parietal but not somatosensory cortex engagement during touch observation.

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Chan, Annie W-Y; Baker, Chris I

2015-01-28

Observing touch has been reported to elicit activation in human primary and secondary somatosensory cortices and is suggested to underlie our ability to interpret other's behavior and potentially empathy. However, despite these reports, there are a large number of inconsistencies in terms of the precise topography of activation, the extent of hemispheric lateralization, and what aspects of the stimulus are necessary to drive responses. To address these issues, we investigated the localization and functional properties of regions responsive to observed touch in a large group of participants (n = 40). Surprisingly, even with a lenient contrast of hand brushing versus brushing alone, we did not find any selective activation for observed touch in the hand regions of somatosensory cortex but rather in superior and inferior portions of neighboring posterior parietal cortex, predominantly in the left hemisphere. These regions in the posterior parietal cortex required the presence of both brush and hand to elicit strong responses and showed some selectivity for the form of the object or agent of touch. Furthermore, the inferior parietal region showed nonspecific tactile and motor responses, suggesting some similarity to area PFG in the monkey. Collectively, our findings challenge the automatic engagement of somatosensory cortex when observing touch, suggest mislocalization in previous studies, and instead highlight the role of posterior parietal cortex. Copyright © 2015 the authors 0270-6474/15/351468-13$15.00/0.

Importance of neural mechanisms in colonic mucosal and muscular dysfunction in adult rats following neonatal colonic irritation.

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Chaloner, A; Rao, A; Al-Chaer, E D; Greenwood-Van Meerveld, B

2010-02-01

Previous studies have shown that early life trauma induced by maternal separation or colonic irritation leads to hypersensitivity to colorectal distension in adulthood. We tested the hypothesis that repetitive colorectal distension in neonates leads to abnormalities in colonic permeability and smooth muscle function in the adult rat. In neonatal rats, repetitive colorectal distension was performed on days 8, 10, and 12. As adults, stool consistency was graded from 0 (formed stool) to 3 (liquid stool). Colonic tissue was isolated for histology and myeloperoxidase levels. The colonic mucosa was placed in modified Ussing chambers for measurements of permeability and short-circuit current responses to forskolin, electrical field stimulation, and carbachol. Segments of colonic musculature were placed in organ baths and contractile response to potassium chloride, electrical field stimulation, and carbachol were determined. In adult rats that experienced neonatal colonic irritation, no significant changes in colonic histology or myeloperoxidase activity were observed; however, stool consistency scores were increased. Mucosal permeability, measured as an increase in basal conductance, was significantly increased but no changes in short-circuit current responses were observed. In adulthood, rats that underwent colorectal distension as neonates exhibited an elevated smooth muscle contractile response to potassium chloride, but no changes in response to electrical field stimulation or carbachol. In summary, neonatal colonic irritation, shown previously to produce colonic hypersensitivity, leads to significant alterations in colonic mucosal and smooth muscle function characterized by loose stools, increased mucosal permeability, and increased smooth muscle contractility in the absence of colon inflammation in adulthood. Published by Elsevier Ltd.

Protein synthesis in the rat brain: a comparative in vivo and in vitro study in immature and adult animals

International Nuclear Information System (INIS)

Shahbazian, F.M.

1985-01-01

Rates of protein synthesis of CNS and other organs were compared in immature and adult rats by in vivo and slice techniques with administration of flooding doses of labeled precursor. The relationship between synthesis and brain region, cell type, subcellular fraction, or MW was examined. Incorporation of [ 14 C]valine into protein of CNS regions in vivo was about 1.2% per hour for immature rats and 0.6% for adults. For slices, the rates decreased significantly more in adults. In adult organs, the highest synthesis rate in vivo was found in liver (2.2% per hour) followed by kidney, spleen, lung, heart, brain, and muscle (0.5% per hour). In immature animals synthesis was highest in liver and spleen (2.5% per hour) and lowest in muscle (0.9% per hour). Slices all showed lower rates than in vivo, especially in adults. In vivo, protein synthesis rates of immature neurons and astrocytes and adult neurons exceeded those of whole brain, while that in adult astrocytes was the same. These results demonstrate a developmental difference of protein synthesis (about double in immature animals) in all brain cells, cell fractions and most brain protein. Similarly the decreased synthesis in brain slices - especially in adults, affects most proteins and structural elements

Mechanosensor Channels in Mammalian Somatosensory Neurons

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Patrick Delmas

2007-09-01

Full Text Available Mechanoreceptive sensory neurons innervating the skin, skeletal muscles andviscera signal both innocuous and noxious information necessary for proprioception, touchand pain. These neurons are responsible for the transduction of mechanical stimuli intoaction potentials that propagate to the central nervous system. The ability of these cells todetect mechanical stimuli impinging on them relies on the presence of mechanosensitivechannels that transduce the external mechanical forces into electrical and chemical signals.Although a great deal of information regarding the molecular and biophysical properties ofmechanosensitive channels in prokaryotes has been accumulated over the past two decades,less is known about the mechanosensitive channels necessary for proprioception and thesenses of touch and pain. This review summarizes the most pertinent data onmechanosensitive channels of mammalian somatosensory neurons, focusing on theirproperties, pharmacology and putative identity.

Impact of experimental hypothyroidism on monoamines level in discrete brain regions and other peripheral tissues of young and adult male rats.

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Hassan, Wafaa A; Aly, Mona S; Rahman, Taghride Abdel; Shahat, Asmaa S

2013-06-01

The levels of dopamine (DA), norepinephrine (NE) and serotonin (5-HT) in different brain regions as well as in blood plasma, cardiac muscle and adrenal gland of young and adult male albino rats were measured following experimentally induced hypothyroidism. Hypothyroidism induced by daily oral administration of propylthiouracil (PTU, 5mg/kg body wt) caused a significant reduction in DA levels in most of the tissues examined of both young and adult rats after 21 and 28 days, in NE levels after all the time intervals studied in young rats, and after 21 and 28 days in adult rats. 5-HT exhibited a significant reduction in the selected brain regions and blood plasma after 21 and 28 days and in cardiac muscle after all the time intervals in the two age groups of animals. It may be suggested that the changes in monoamine levels induced by hypothyroidism may be due to disturbance in the synthesis and release of these amines through the neurons impairment or may be due to an alteration pattern of their synthesizing and/or degradative enzymes. Copyright © 2013 ISDN. Published by Elsevier Ltd. All rights reserved.

Acquisition of i.v. cocaine self-administration in adolescent and adult male rats selectively bred for high and low saccharin intake

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Perry, Jennifer L.; Anderson, Marissa M.; Nelson, Sarah E.; Carroll, Marilyn E.

2007-01-01

Adolescence and excessive intake of saccharin have each been previously associated with enhanced vulnerability to drug abuse. In the present study, we focused on the relationship between these two factors using male adolescent and adult rats bred for high (HiS) and low (LoS) levels of saccharin intake. On postnatal day 25 (adolescents) or 150 (adults), rats were implanted with an intravenous catheter and trained to self-administer cocaine (0.4 mg/kg) using an autoshaping procedure that consis...

Expression of Lymphatic Markers in the Adult Rat Spinal Cord.

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Kaser-Eichberger, Alexandra; Schroedl, Falk; Bieler, Lara; Trost, Andrea; Bogner, Barbara; Runge, Christian; Tempfer, Herbert; Zaunmair, Pia; Kreutzer, Christina; Traweger, Andreas; Reitsamer, Herbert A; Couillard-Despres, Sebastien

2016-01-01

Under physiological conditions, lymphatic vessels are thought to be absent from the central nervous system (CNS), although they are widely distributed within the rest of the body. Recent work in the eye, i.e., another organ regarded as alymphatic, revealed numerous cells expressing lymphatic markers. As the latter can be involved in the response to pathological conditions, we addressed the presence of cells expressing lymphatic markers within the spinal cord by immunohistochemistry. Spinal cord of young adult Fisher rats was scrutinized for the co-expression of the lymphatic markers PROX1 and LYVE-1 with the cell type markers Iba1, CD68, PGP9.5, OLIG2. Rat skin served as positive control for the lymphatic markers. PROX1-immunoreactivity was detected in many nuclei throughout the spinal cord white and gray matter. These nuclei showed no association with LYVE-1. Expression of LYVE-1 could only be detected in cells at the spinal cord surface and in cells closely associated with blood vessels. These cells were found to co-express Iba1, a macrophage and microglia marker. Further, double labeling experiments using CD68, another marker found in microglia and macrophages, also displayed co-localization in the Iba1+ cells located at the spinal cord surface and those apposed to blood vessels. On the other hand, PROX1-expressing cells found in the parenchyma were lacking Iba1 or PGP9.5, but a significant fraction of those cells showed co-expression of the oligodendrocyte lineage marker OLIG2. Intriguingly, following spinal cord injury, LYVE-1-expressing cells assembled and reorganized into putative pre-vessel structures. As expected, the rat skin used as positive controls revealed classical lymphatic vessels, displaying PROX1+ nuclei surrounded by LYVE-1-immunoreactivity. Classical lymphatics were not detected in adult rat spinal cord. Nevertheless, numerous cells expressing either LYVE-1 or PROX1 were identified. Based on their localization and overlapping expression with

Enriched housing enhances recovery of limb placement ability and reduces aggrecan-containing perineuronal nets in the rat somatosensory cortex after experimental stroke.

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Alexandre Madinier

Full Text Available Stroke causes life long disabilities where few therapeutic options are available. Using electrical and magnetic stimulation of the brain and physical rehabilitation, recovery of brain function can be enhanced even late after stroke. Animal models support this notion, and housing rodents in an enriched environment (EE several days after experimental stroke stimulates lost brain function by multisensory mechanisms. We studied the dynamics of functional recovery of rats with a lesion to the fore and hind limb motor areas induced by photothrombosis (PT, and with subsequent housing in either standard (STD or EE. In this model, skilled motor function is not significantly enhanced by enriched housing, while the speed of recovery of sensori-motor function substantially improves over the 9-week study period. In particular, this stroke lesion completely obliterates the fore and hind limb placing ability when visual and whisker guidance is prevented, a deficit that persists for up to 9 weeks of recovery, but that is markedly restored within 2 weeks by enriched housing. Enriched housing after stroke also leads to a significant loss of perineuronal net (PNN immunoreactivity; detection of aggrecan protein backbone with AB1031 antibody was decreased by 13-22%, and labelling of a glycan moiety of aggrecan with Cat-315 antibody was reduced by 25-30% in the peri-infarct area and in the somatosensory cortex, respectively. The majority of these cells are parvalbumin/GABA inhibitory interneurons that are important in sensori-information processing. We conclude that damage to the fore and hind limb motor areas provides a model of loss of limb placing response without visual guidance, a deficit also seen in more than 50% of stroke patients. This loss is amenable to recovery induced by multiple sensory stimulation and correlates with a decrease in aggrecan-containing PNNs around inhibitory interneurons. Modulating the PNN structure after ischemic damage may provide new

Transfer RNA methylases in rat placenta

International Nuclear Information System (INIS)

Jagtiani, S.K.; Narurkar, L.M.; Narurkar, M.V.

1977-01-01

Presence of tRNA methylases (5-adenosylmethionine : tRNA methyltransferases) was demonstrated at various stages of gestation in rat placenta, the enzyme being 50-100% higher than that of adult rat liver during early gestation. Placental tRNA methylases were shown to differ from those of liver in the extent of methylation. Glycine methyltransferase (S-adenosylmethionine : glycine methyltransferase), a regulatory enzyme in adult rat liver, was absent in placenta throughout gestation. The placental tRNA methylases could be inhibited in vitro by semipurified glycine methyltransferase from adult rat liver. The high placental tRNA methylase activity was comparable with the inhibitor-free enzyme activity of the adult rat liver. S-adenosyl-[Me- 14 C]-methionine was used in the investigation. (author)

Responses of vibrissa-sensitive cortical neurons in normal and prenatally x-irradiated rat

International Nuclear Information System (INIS)

Ito, M.; Kawabata, M.; Shoji, R.

1979-01-01

Rats were irradiated by 200 R of x ray on day 17 of gestation through the body wall of the mother. When they underwent the following electrophysiological tests at the age of 3 to 4 month, the somatosensory cortex showed a lack of layers II, III, IV, and Va. Spike responses to quick whisker deflections were recorded from single cells in the somatosenory cortex of normal and prenatally x-irradiated rats. For the irradiated rats the response latency was prolonged when compared to the normal controls. Cortical laminar analysis of field potentials revealed that there was no difference in the latency of these potentials between the two groups, suggesting that vibrissal sensory signals reach the cortical level normally even in the irradiated rats. The prolonged latency of the irradiated cortical neuronal response could thus be ascribed to an abnormal intracortical delay, which was most likely associated with the failure of development of layer IV stellate cells in these preparations

Effects of Chronic Exposure to Triclosan on Reproductive and Thyroid Endpoints in the Adult Wistar Female Rat

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U.S. Environmental Protection Agency — This dataset includes the results of a long term adult female rat oral exposure to triclosan and includes hormone, estrous cyclicity, thyroid histology and liver...

Acute Appendicitis, Somatosensory Disturbances ("Head Zones"), and the Differential Diagnosis of Anterior Cutaneous Nerve Entrapment Syndrome (ACNES).

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Roumen, Rudi M H; Vening, Wouter; Wouda, Rosanne; Scheltinga, Marc M

2017-06-01

Anterior cutaneous nerve entrapment syndrome (ACNES) is a neuropathic abdominal wall pain syndrome typically characterized by locally altered skin sensations. On the other hand, visceral disease may also be associated with similar painful and altered skin sensations ("Head zones"). Aim of the study was to determine if patients with acute appendicitis demonstrated somatosensory disturbances in the corresponding right lower quadrant Head zone. The presence of somatosensory disturbances such as hyperalgesia, hypoesthesia, altered cool perception, or positive pinch test was determined in 100 patients before and after an appendectomy. Potential associations between altered skin sensations and various items including age, sex, history, body temperature, C-reactive protein (CRP), leukocyte count, and type of appendicopathy (normal, inflamed, necrotic, or perforated) were assessed. A total of 39 patients demonstrated at least one right lower abdominal quadrant skin somatosensory disturbance before the laparoscopic appendectomy. However, locoregional skin sensation normalized in all but 2 patients 2 weeks postoperatively. No differences were found concerning patient characteristics or type of appendicopathy between populations with or without altered lower abdominal skin sensations. A substantial portion of patients with acute appendicitis demonstrate right lower abdominal somatosensory disturbances that are similar as observed in acute ACNES. Both may be different sides of the same coin and are possibly expressions of segmental phenomena as described by Head. McBurney's point, a landmark area of maximum pain in acute appendicitis, is possibly a trigger point within a Head zone. Differentiating acute appendicitis from acute ACNES is extremely difficult, but imaging and observation may aid in the diagnostic process.

Impaired verbal memory in Parkinson disease: relationship to prefrontal dysfunction and somatosensory discrimination

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Weniger Dorothea

2009-12-01

Full Text Available Abstract Objective To study the neurocognitive profile and its relationship to prefrontal dysfunction in non-demented Parkinson's disease (PD with deficient haptic perception. Methods Twelve right-handed patients with PD and 12 healthy control subjects underwent thorough neuropsychological testing including Rey complex figure, Rey auditory verbal and figural learning test, figural and verbal fluency, and Stroop test. Test scores reflecting significant differences between patients and healthy subjects were correlated with the individual expression coefficients of one principal component, obtained in a principal component analysis of an oxygen-15-labeled water PET study exploring somatosensory discrimination that differentiated between the two groups and involved prefrontal cortices. Results We found significantly decreased total scores for the verbal learning trials and verbal delayed free recall in PD patients compared with normal volunteers. Further analysis of these parameters using Spearman's ranking correlation showed a significantly negative correlation of deficient verbal recall with expression coefficients of the principal component whose image showed a subcortical-cortical network, including right dorsolateral-prefrontal cortex, in PD patients. Conclusion PD patients with disrupted right dorsolateral prefrontal cortex function and associated diminished somatosensory discrimination are impaired also in verbal memory functions. A negative correlation between delayed verbal free recall and PET activation in a network including the prefrontal cortices suggests that verbal cues and accordingly declarative memory processes may be operative in PD during activities that demand sustained attention such as somatosensory discrimination. Verbal cues may be compensatory in nature and help to non-specifically enhance focused attention in the presence of a functionally disrupted prefrontal cortex.

The Effects of Early-Life Predator Stress on Anxiety- and Depression-Like Behaviors of Adult Rats

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Lu-jing Chen

2014-01-01

Full Text Available Childhood emotional trauma contributes significantly to certain psychopathologies, such as post-traumatic stress disorder. In experimental animals, however, whether or not early-life stress results in behavioral abnormalities in adult animals still remains controversial. Here, we investigated both short-term and long-term changes of anxiety- and depression-like behaviors of Wistar rats after being exposed to chronic feral cat stress in juvenile ages. The 2-week predator stress decreased spontaneous activities immediately following stress but did not increase depression- or anxiety-like behaviors 4 weeks after the stimulation in adulthood. Instead, juvenile predator stress had some protective effects, though not very obvious, in adulthood. We also exposed genetic depression model rats, Wistar Kyoto (WKY rats, to the same predator stress. In WKY rats, the same early-life predator stress did not enhance anxiety- or depression-like behaviors in both the short-term and long-term. However, the stressed WKY rats showed slightly reduced depression-like behaviors in adulthood. These results indicate that in both normal Wistar rats and WKY rats, early-life predator stress led to protective, rather than negative, effects in adulthood.

The Effects of Early-Life Predator Stress on Anxiety- and Depression-Like Behaviors of Adult Rats

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Chen, Lu-jing; Shen, Bing-qing; Liu, Dan-dan; Li, Sheng-tian

2014-01-01

Childhood emotional trauma contributes significantly to certain psychopathologies, such as post-traumatic stress disorder. In experimental animals, however, whether or not early-life stress results in behavioral abnormalities in adult animals still remains controversial. Here, we investigated both short-term and long-term changes of anxiety- and depression-like behaviors of Wistar rats after being exposed to chronic feral cat stress in juvenile ages. The 2-week predator stress decreased spontaneous activities immediately following stress but did not increase depression- or anxiety-like behaviors 4 weeks after the stimulation in adulthood. Instead, juvenile predator stress had some protective effects, though not very obvious, in adulthood. We also exposed genetic depression model rats, Wistar Kyoto (WKY) rats, to the same predator stress. In WKY rats, the same early-life predator stress did not enhance anxiety- or depression-like behaviors in both the short-term and long-term. However, the stressed WKY rats showed slightly reduced depression-like behaviors in adulthood. These results indicate that in both normal Wistar rats and WKY rats, early-life predator stress led to protective, rather than negative, effects in adulthood. PMID:24839560

Effect of Nigella sativa Linn oil on tramadol-induced hepato- and nephrotoxicity in adult male albino rats

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A. Elkhateeb

2015-01-01

Full Text Available The present study was carried out to evaluate the role of Nigella sativa Linn (NsL oil against subacute tramadol-induced hepatotoxicity, nephrotoxicity as well as oxidative stress in adult male albino rats. Sixty adult male albino rats were divided into four groups. Group I: control group; 30 rats equally subdivided into: Ia; −ve control group, Ib; +ve control group received saline, Ic; +ve control group received corn oil. Group II: 10 rats received NsL oil; 1 mg/kg in 1 ml corn oil/day, group III: 10 rats received tramadol; 30 mg/kg/day, group IV: 10 rats received tramadol + NsL oil in the previous doses. Treatments were given by gavage for 30 days. Then rats were sacrificed and specimens from the livers and kidneys were taken for biochemical and histopathological study. Biochemical data showed elevated liver enzymes; alanine transaminase (ALT, aspartate transaminase (AST, gamma glutamyltransferase (GGT, bilirubin as well as urea and creatinine in tramadol group. A significant increase in hepatic and renal malondialdehyde (MDA and a decrease in glutathione peroxidase (GPx levels were also noticed. Histological analysis of the liver showed vacuolated hepatocyte cytoplasm indicating hydropic degeneration with binucleated cells, apoptotic nuclei, congested central veins, cellular infiltration and hemorrhage. Kidney sections revealed atrophied glomeruli with collapsed tufts and wide Bowman's space, degenerated tubules, hemorrhage and mononuclear cellular infiltration. There was also an increase in area % of collagen fibers in both organs. Concomitant use of NsL oil with tramadol induced partial improvement in the hepato- and nephrotoxic effects. In conclusion, this study suggested that concomitant use of NsL oil with tramadol proved to be capable of ameliorating tramadol-induced hepato- and nephrotoxicity which might be due to its antioxidant potential.

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject.

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Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe; Saridis, George A; Gjedde, Albert; Ptito, Maurice; Kupers, Ron

2013-01-01

Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA) 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong, and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI) revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

Physiological slowing and upregulation of inhibition in cortex are correlated with behavioral deficits in protein malnourished rats.

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Rahul Chaudhary

Full Text Available Protein malnutrition during early development has been correlated with cognitive and learning disabilities in children, but the neuronal deficits caused by long-term protein deficiency are not well understood. We exposed rats from gestation up to adulthood to a protein-deficient (PD diet, to emulate chronic protein malnutrition in humans. The offspring exhibited significantly impaired performance on the 'Gap-crossing' (GC task after reaching maturity, a behavior that has been shown to depend on normal functioning of the somatosensory cortex. The physiological state of the somatosensory cortex was examined to determine neuronal correlates of the deficits in behavior. Extracellular multi-unit recording from layer 4 (L4 neurons that receive direct thalamocortical inputs and layers 2/3 (L2/3 neurons that are dominated by intracortical connections in the whisker-barrel cortex of PD rats exhibited significantly low spontaneous activity and depressed responses to whisker stimulation. L4 neurons were more severely affected than L2/3 neurons. The response onset was significantly delayed in L4 cells. The peak response latency of L4 and L2/3 neurons was delayed significantly. In L2/3 and L4 of the barrel cortex there was a substantial increase in GAD65 (112% over controls and much smaller increase in NMDAR1 (12-20%, suggesting enhanced inhibition in the PD cortex. These results show that chronic protein deficiency negatively affects both thalamo-cortical and cortico-cortical transmission during somatosensory information processing. The findings support the interpretation that sustained protein deficiency interferes with features of cortical sensory processing that are likely to underlie the cognitive impairments reported in humans who have suffered from prolonged protein deficiency.

An evaluation of the somatosensory profile of hemiparetic individuals

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R.S. Mota

2010-01-01

Full Text Available The purpose of this study was to evaluate the somatosensory profile of 18 hemiparetic spastic victims of stroke with and without blocking vision. Maximal isometric contraction test was used for flexor and extensor muscles of the hip and knee, and flexor plantar muscles. The number of cycles per minute on stationary bike was also measured with eyes opened and closed. Significant differences were found suggesting the existence of miscommunication between sensory-motor neural mechanisms responsible for voluntary motor actions in these individuals.

Neurochemical Changes after Acute Binge Toluene Inhalation in Adolescent and Adult Rats: A High-Resolution Magnetic Resonance Spectroscopy Study

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O'Leary-Moore, Shonagh K.; Galloway, Matthew P.; McMechan, Andrew P.; Irtenkauf, Susan; Hannigan, John H.; Bowen, Scott E.

2009-01-01

Inhalant abuse in young people is a growing public health concern. We reported previously that acute toluene intoxication in young rats, using a pattern of exposures that approximate abuse patterns of inhalant use in humans, significantly altered neurochemical measures in select brain regions. In this study, adolescent and young adult rats were exposed similarly to an acute (2 × 15 min), high dose (8000 − 12000 ppm) of toluene and high-resolution magic angle spinning proton magnetic resonance spectroscopy (HR-MAS 1H-MRS) was used to assess neurochemical profiles of tissue samples from a number of brain regions collected immediately following solvent exposure. The current investigation focused on N-acetyl-aspartate (NAA), choline-containing compounds, creatine, glutamate, GABA, and glutamine. Contrary to our predictions, no significant alterations were found in levels of NAA, choline, creatine, glutamate, or glutamine in adolescent animals. In contrast to these minimal effects in adolescents, binge toluene exposure altered several neurochemical parameters in young adult rats, including decreased levels of choline and GABA in the frontal cortex and striatum and lowered glutamine and NAA levels in the frontal cortex. One of the more robust findings was a wide-ranging increase in lactate after toluene exposure in adult animals, an effect not observed in adolescents. These age-dependent effects of toluene are distinct from those reported previously in juvenile rats and suggest a developmental difference in vulnerability to the effects of inhalants. Specifically, the results suggest that the neurochemical response to toluene in adolescents is attenuated compared to adults, and imply an association between these neurochemical differences and age-influenced differences in solvent abuse in humans. PMID:19628036

Beneficial Effects of Coenzyme Q10 in Reduction of Testicular Tissue Alteration Following Induction of Diabetes in Adult Rats

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Kianifard Davoud

2015-03-01

Full Text Available Background and Aims: Various types of infertility are associated with uncontrolled hyperglycemia and diabetes. Development of oxidative stress is one the most important factors in the alteration of spermatogenesis in diabetic conditions. Consequently, the reduction of oxidative stress with antioxidant compounds can be effective in the reduction of tissue alterations. The aim of this study was to evaluate the efficacy of coenzyme Q10 in improvement of spermatogenesis in adult diabetic rats. Material and Methods: 32 adult rats were divided into four groups of control and treatment. Coenzyme Q10 (10 mg/kg body weight - b.w. was administrated to one control and one diabetic (intraperitoneal injection of 45 mg/kg b.w. of Streptozotocin groups. Blood concentrations of FSH, LH and Testosterone were measured. Histology of testicular tissue and sperm analysis were considered for evaluation of spermatogenesis. Results: Administration of Coenzyme Q10 led to increase of pituitary gonadotropins levels in diabetic rats. Testosterone levels were not changed significantly. Testicular morphology, spermatogenic indices and sperm analysis were improved in treated diabetic rats. Conclusions: The results of this study suggest that the use of Coenzyme Q10 has positive effects in reduction of spermatogenic alterations following induction of experimental diabetes in rats.

Impact of chronic exposure to the pesticide chlorpyrifos on respiratory parameters and sleep apnea in juvenile and adult rats.

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Walaa Darwiche

Full Text Available The widely used organophosphorus pesticide chlorpyrifos (CPF is often detected in food. CPF inhibits acetylcholinesterase and can modify muscle contractility and respiratory patterns. We studied the effects of chronic exposure to CPF on respiratory parameters and diaphragm contractility in 21- and 60-days old rats. Pregnant rats were exposed to oral CPF (1 or 5 mg/ kg /day: CPF-1 or CPF-5 groups vs vehicle: controls from gestation onset up to weaning of the pups that were individually gavaged (CPF or vehicle thereafter. Two developmental time points were studied: weaning (day 21 and adulthood (day 60. Whole-body plethysmography was used to score breathing patterns and apnea index during sleep. Then, diaphragm strips were dissected for the assessment of contractility and acetylcholinesterase activity. Results showed that the sleep apnea index was higher in CPF-exposed rats than in controls. In adult rats, the expiratory time and tidal volume were higher in CPF-exposed animals than in controls. At both ages, the diaphragm's amplitude of contraction and fatigability index were higher in the CPF-5 group, due to lower acetylcholinesterase activity. We conclude that chronic exposure to CPF is associated with higher sleep apnea index and diaphragm contractility, and modifies respiratory patterns in sleeping juvenile and adult rats.

Effects of chronic prenatal MK-801 treatment on object recognition, cognitive flexibility, and drug-induced locomotor activity in juvenile and adult rat offspring.

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Gallant, S; Welch, L; Martone, P; Shalev, U

2017-06-15

Patients with schizophrenia display impaired cognitive functioning and increased sensitivity to psychomimetic drugs. The neurodevelopmental hypothesis of schizophrenia posits that disruption of the developing brain predisposes neural networks to lasting structural and functional abnormalities resulting in the emergence of such symptoms in adulthood. Given the critical role of the glutamatergic system in early brain development, we investigated whether chronic prenatal exposure to the glutamate NMDA receptor antagonist, MK-801, induces schizophrenia-like behavioural and neurochemical changes in juvenile and adult rats. Pregnant Long-Evans rats were administered saline or MK-801 (0.1mg/kg; s.c.) at gestation day 7-19. Object recognition memory and cognitive flexibility were assessed in the male offspring using a novel object preference task and a maze-based set-shifting procedure, respectively. Locomotor-activating effects of acute amphetamine and MK-801 were also assessed. Adult, but not juvenile, prenatally MK-801-treated rats failed to show novel object preference after a 90min delay, suggesting that object recognition memory may have been impaired. In addition, the set-shifting task revealed impaired acquisition of a new rule in adult prenatally MK-801-treated rats compared to controls. This deficit appeared to be driven by regression to the previously learned behaviour. There were no significant differences in drug-induced locomotor activity in juvenile offspring or in adult offspring following acute amphetamine challenges. Unexpectedly, MK-801-induced locomotor activity in adult prenatally MK-801-treated rats was lower compared to controls. Glutamate transmission dysfunction during early development may modify behavioural parameters in adulthood, though these parameters do not appear to model deficits observed in schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

Astrocytes from adult Wistar rats aged in vitro show changes in glial functions.

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Souza, Débora Guerini; Bellaver, Bruna; Raupp, Gustavo Santos; Souza, Diogo Onofre; Quincozes-Santos, André

2015-11-01

Astrocytes, the most versatile cells of the central nervous system, play an important role in the regulation of neurotransmitter homeostasis, energy metabolism, antioxidant defenses and the anti-inflammatory response. Recently, our group characterized cortical astrocyte cultures from adult Wistar rats. In line with that work, we studied glial function using an experimental in vitro model of aging astrocytes (30 days in vitro after reaching confluence) from newborn (NB), adult (AD) and aged (AG) Wistar rats. We evaluated metabolic parameters, such as the glucose uptake, glutamine synthetase (GS) activity, and glutathione (GSH) content, as well as the GFAP, GLUT-1 and xCT expression. AD and AG astrocytes take up less glucose than NB astrocytes and had decreased GLUT1 expression levels. Furthermore, AD and AG astrocytes exhibited decreased GS activity compared to NB cells. Simultaneously, AD and AG astrocytes showed an increase in GSH levels, along with an increase in xCT expression. NB, AD and AG astrocytes presented similar morphology; however, differences in GFAP levels were observed. Taken together, these results improve the knowledge of cerebral senescence and represent an innovative tool for brain studies of aging. Copyright © 2015 Elsevier Ltd. All rights reserved.

11beta-hydroxysteroid dehydrogenase type 2 expression in the newly formed Leydig cells after ethane dimethanesulphonate treatment of adult rats.

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Katerina Georgieva

2008-01-01

Full Text Available The enzyme 11beta-hydroxysteroid dehydrogenase (11beta-HSD catalyzes the reversible conversion of physiologically active corticosterone to the biologically inert 11beta-dehydrocorticosterone in rat testis and protect the Leydig cells (LCs against the suppressive effect of glucocorticoids. The developmental pathway of the adult LCs population is accompanied with an increase in the 11beta-HDS activity. Thus, 11beta-HDS together with its role in controlling the toxicological effect of glucocorticoids on LCs can be used as a marker for their functional maturity. Ethane 1,2-dimethanesulphonate (EDS treatment of adult rats become unique appropriate model, which enable to answer many questions related to the differentiation of adult LCs in the prepubertal rat testis. The aim of the present study was to investigate the specific changes in the 11beta-HDS type 2 immunoreactivity in tandem with the expression of androgen receptor (AR during renewal of LCs population after EDS treatment. In the present study, we observed the first appearance of immunostaining for 11beta-HSD2 in new LCs population on day 14 after EDS administration when the progenitor LCs were detected. Our immunohistochemical analysis revealed progressive increases in the 11beta-HSD2 reaction intensity on 21 days after EDS treatment and reached a maximum on day 35. AR immunoexpression was found in new LCs on day 14 and 21 after EDS injection with an increasing curve of intensity. The most prominent AR immunostaining in new population LCs was evident by 35 days after EDS and that coincided with the increased number of LCs and restoration of adult LCs population. Our results demonstrated similar pattern of immunoreactivity for 11beta-HSD2 and AR in new LCs population after EDS treatment and suggested that the changes in 11beta-HSD2 expression can be used for evaluation of adult LCs differentiation in rat testis.

Adenosine A1 receptor antagonist mitigates deleterious effects of sleep deprivation on adult neurogenesis and spatial reference memory in rats.

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Chauhan, G; Ray, K; Sahu, S; Roy, K; Jain, V; Wadhwa, M; Panjwani, U; Kishore, K; Singh, S B

2016-11-19

Sleep deprivation (SD) upsurges intracellular levels of adenosine, impairs adult neuronal cell proliferation (NCP) and cognition while caffeine, a non-selective adenosine A1 receptor (A1R) antagonist improves cognition and adult NCP during SD. We examined the selective antagonistic effects of adenosine A1R using 8-cyclopentyl-1,3-dimethylxanthine (8-CPT) on impairment of spatial reference memory and adult NCP during 48h SD. Adult male Sprague Dawley rats were sleep deprived for 48h, using an automatic cage vibrating stimulus based on animal activity. Spatial reference memory was tested as a measure of cognitive performance employing Morris Water Maze. Rats were given 8-CPT dissolved in 50% dimethyl sulfoxide (DMSO), twice daily (10mg/kg, i.p.) along with 5-bromo-2-deoxyuridine (BrdU) (50mg/kg/day, i.p.). The rats treated with 8-CPT showed significantly short mean latency and path-length to reach the platform compared to the SD rats. Consistent with these findings, 8-CPT-treated group was found to have significantly increased the number of BrdU, Ki-67 and doublecortin (DCX) positive cells. However, no significant difference was seen in NeuN expression in the Dentate Gyrus (DG). Brain-derived neurotropic factor (BDNF) expression in the DG and CA1 region was observed to decrease significantly after SD and be rescued by 8-CPT treatment. Furthermore, latency to reach platform showed a negative correlation with number of BrdU, DCX type-1 cells and BDNF expression in DG. Thus, it may be concluded that treatment with 8-CPT, an adenosine A1R antagonist during SD mitigates SD induced decline in spatial reference memory and adult NCP possibly via up regulation of BDNF levels in DG and CA1 regions. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Spiking in primary somatosensory cortex during natural whisking in awake head-restrained rats is cell-type specific

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de Kock, C.P.J.; Sakmann, B.

2009-01-01

Sensation involves active movement of sensory organs, but it remains unknown how position or movement of sensory organs is encoded in cortex. In the rat whisker system, each whisker is represented by an individual cortical (barrel) column. Here, we quantified in awake, head-fixed rats the impact of

Neurological assessments after treatment with the antimalarial β-arteether in neonatal and adult rats.

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Erickson, R I; Defensor, E B; Fairchild, D G; Mirsalis, J C; Steinmetz, K L

2011-08-01

The World Health Organization currently recommends combinatorial treatment including artemisinins as first-line therapy against drug-resistant Plasmodium falciparum malaria. Although highly efficacious, artemisinin and its derivatives, including β-arteether (βAE), are associated with ototoxicity, tremors, and other autonomic and motor impairments in the clinic. Similar neurological symptoms, as well as brainstem lesions, have been observed in adult laboratory species (mice, rats, dogs, and non human primates) following acute treatment with βAE; however, few long-term, nonclinical studies have been conducted. Furthermore, the majority of deaths attributed to malarial infection occur in children under age five, yet no laboratory studies have been initiated in neonatal or juvenile animals. In the current study, neonatal 7-day-old rats were administered intramuscular doses of 1-90 mg/kg βAE in sesame oil for up to eight treatment cycles (one cycle=7 days treatment+7 days without treatment). Neonates were tested for changes in sensorimotor function, and the same animals were tested as adults in the Functional Observational Battery, for motor activity, and in the 8-arm radial maze. Pups receiving a single cycle of 60 or 90 mg/kg died within a week of treatment but had few behavioral changes and no brainstem pathology. In the long-term study, behavioral and motor changes and brainstem lesions were observed in a dose- and time-related manner. Rats given repeated cycles of 1 or 5mg/kg βAE showed subtle motor abnormalities (e.g., slight loss of righting reflex) while repeated cycles of 10mg/kg βAE treatment resulted in obvious motor and behavioral changes. Rats receiving 1mg/kg βAE had no brainstem lesions whereas some rats treated with 5mg/kg βAE and all rats treated with 10 mg/kg βAE had brainstem lesions. Brainstem lesions were observed after as few as five cycles and were characterized by gliosis, satellitosis and progressive necrosis in motor neurons of the

The Role of Attention in Somatosensory Processing: A Multi-Trait, Multi-Method Analysis

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Wodka, Ericka L.; Puts, Nicolaas A. J.; Mahone, E. Mark; Edden, Richard A. E.; Tommerdahl, Mark; Mostofsky, Stewart H.

2016-01-01

Sensory processing abnormalities in autism have largely been described by parent report. This study used a multi-method (parent-report and measurement), multi-trait (tactile sensitivity and attention) design to evaluate somatosensory processing in ASD. Results showed multiple significant within-method (e.g., parent report of different…

Effects of Maternal Behavior Induction and Pup Exposure on Neurogenesis in Adult, Virgin Female Rats

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Furuta, Miyako; Bridges, Robert S.

2009-01-01

The states of pregnancy and lactation bring about a range of physiological and behavioral changes in the adult mammal that prepare the mother to care for her young. Cell proliferation increases in the subventricular zone (SVZ) of the female rodent brain during both pregnancy and lactation when compared to that in cycling, diestrous females. In the present study, the effects of maternal behavior induction and pup exposure on neurogenesis in nulliparous rats were examined in order to determine whether maternal behavior itself, independent of pregnancy and lactation, might affect neurogenesis. Adult, nulliparous, Sprague-Dawley, female rats were exposed daily to foster young in order to induce maternal behavior. Following the induction of maternal behavior each maternal subject plus females that were exposed to pups for a comparable number of test days, but did not display maternal behavior, and subjects that had received no pup exposure were injected with bromodeoxyuridine (BrdU, 90 mg/kg, i.v.). Brain sections were double-labeled for BrdU and the neural marker, NeuN, to examine the proliferating cell population. Increases in the number of double-labeled cells were found in the maternal virgin brain when compared with the number of double-labeled cells present in non-maternal, pup-exposed nulliparous rats and in females not exposed to young. No changes were evident in the dentate gyrus of the hippocampus as a function of maternal behavior. These data indicate that in nulliparous female rats maternal behavior itself is associated with the stimulation of neurogenesis in the SVZ. PMID:19712726

Modality-Based Organization of Ascending Somatosensory Axons in the Direct Dorsal Column Pathway

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Niu, Jingwen; Ding, Long; Li, Jian J.; Kim, Hyukmin; Liu, Jiakun; Li, Haipeng; Moberly, Andrew; Badea, Tudor C.; Duncan, Ian D.; Son, Young-Jin; Scherer, Steven S.

2013-01-01

The long-standing doctrine regarding the functional organization of the direct dorsal column (DDC) pathway is the “somatotopic map” model, which suggests that somatosensory afferents are primarily organized by receptive field instead of modality. Using modality-specific genetic tracing, here we show that ascending mechanosensory and proprioceptive axons, two main types of the DDC afferents, are largely segregated into a medial–lateral pattern in the mouse dorsal column and medulla. In addition, we found that this modality-based organization is likely to be conserved in other mammalian species, including human. Furthermore, we identified key morphological differences between these two types of afferents, which explains how modality segregation is formed and why a rough “somatotopic map” was previously detected. Collectively, our results establish a new functional organization model for the mammalian direct dorsal column pathway and provide insight into how somatotopic and modality-based organization coexist in the central somatosensory pathway. PMID:24198362

Laminar pattern of cholinergic and adrenergic receptors in rat visual cortex using quantitative receptor autoradiography

International Nuclear Information System (INIS)

Schliebs, R.; Walch, C.

1989-01-01

The laminar distribution of muscarinic acetylcholine receptors, including the M1-receptor subtype, of beta-adrenergic receptors, and noradrenaline uptake sites, was studied in the adult rat visual, frontal, somatosensory and motor cortex, using quantitative receptor autoradiography. In the visual cortex, the highest density of muscarinic acetylcholine receptors was found in layer I. From layer II/III to layer V binding decreases continueously reaching a constant binding level in layers V and VI. This laminar pattern of muscarinic receptor density differs somewhat from that observed in the non-visual cortical regions examined: layer II/III contained the highest receptor density followed by layer I and IV: lowest density was found in layer V and VI. The binding profile of the muscarinic cholinergic M1-subtype through the visual cortex shows a peak in cortical layer II and in the upper part of layer VI, whereas in the non-visual cortical regions cited the binding level was high in layer II/III, moderate in layer I and IV, and low in layer VI. Layers I to IV of the visual cortex contained the highest beta-adrenergic receptor densities, whereas only low binding levels were observed in the deeper layers. A similar laminar distribution was found also in the frontal, somatosensory and motor cortex. The density of noradrenaline uptake sites was high in all layers of the cortical regions studied, but with noradrenaline uptake sites somewhat more concentrated in the superficial layers than in deeper ones. The distinct laminar pattern of cholinergic and noradrenergic receptor sites indicates a different role for acetylcholine and noradrenaline in the functional anatomy of the cerebral cortex, and in particular, the visual cortex. (author)

Laminar pattern of cholinergic and adrenergic receptors in rat visual cortex using quantitative receptor autoradiography

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Schliebs, R; Walch, C [Leipzig Univ. (German Democratic Republic). Bereich Medizin; Stewart, M G [Open Univ., Milton Keynes (UK)

1989-01-01

The laminar distribution of muscarinic acetylcholine receptors, including the M1-receptor subtype, of beta-adrenergic receptors, and noradrenaline uptake sites, was studied in the adult rat visual, frontal, somatosensory and motor cortex, using quantitative receptor autoradiography. In the visual cortex, the highest density of muscarinic acetylcholine receptors was found in layer I. From layer II/III to layer V binding decreases continueously reaching a constant binding level in layers V and VI. This laminar pattern of muscarinic receptor density differs somewhat from that observed in the non-visual cortical regions examined: layer II/III contained the highest receptor density followed by layer I and IV: lowest density was found in layer V and VI. The binding profile of the muscarinic cholinergic M1-subtype through the visual cortex shows a peak in cortical layer II and in the upper part of layer VI, whereas in the non-visual cortical regions cited the binding level was high in layer II/III, moderate in layer I and IV, and low in layer VI. Layers I to IV of the visual cortex contained the highest beta-adrenergic receptor densities, whereas only low binding levels were observed in the deeper layers. A similar laminar distribution was found also in the frontal, somatosensory and motor cortex. The density of noradrenaline uptake sites was high in all layers of the cortical regions studied, but with noradrenaline uptake sites somewhat more concentrated in the superficial layers than in deeper ones. The distinct laminar pattern of cholinergic and noradrenergic receptor sites indicates a different role for acetylcholine and noradrenaline in the functional anatomy of the cerebral cortex, and in particular, the visual cortex. (author).

Auditory-somatosensory bimodal stimulation desynchronizes brain circuitry to reduce tinnitus in guinea pigs and humans.

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Marks, Kendra L; Martel, David T; Wu, Calvin; Basura, Gregory J; Roberts, Larry E; Schvartz-Leyzac, Kara C; Shore, Susan E

2018-01-03

The dorsal cochlear nucleus is the first site of multisensory convergence in mammalian auditory pathways. Principal output neurons, the fusiform cells, integrate auditory nerve inputs from the cochlea with somatosensory inputs from the head and neck. In previous work, we developed a guinea pig model of tinnitus induced by noise exposure and showed that the fusiform cells in these animals exhibited increased spontaneous activity and cross-unit synchrony, which are physiological correlates of tinnitus. We delivered repeated bimodal auditory-somatosensory stimulation to the dorsal cochlear nucleus of guinea pigs with tinnitus, choosing a stimulus interval known to induce long-term depression (LTD). Twenty minutes per day of LTD-inducing bimodal (but not unimodal) stimulation reduced physiological and behavioral evidence of tinnitus in the guinea pigs after 25 days. Next, we applied the same bimodal treatment to 20 human subjects with tinnitus using a double-blinded, sham-controlled, crossover study. Twenty-eight days of LTD-inducing bimodal stimulation reduced tinnitus loudness and intrusiveness. Unimodal auditory stimulation did not deliver either benefit. Bimodal auditory-somatosensory stimulation that induces LTD in the dorsal cochlear nucleus may hold promise for suppressing chronic tinnitus, which reduces quality of life for millions of tinnitus sufferers worldwide. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

The effects of cinnamon on glycemic indexes and insulin resistance in adult male diabetic rats with streptozotocin

OpenAIRE

SEbrahim Hosseini; STaereh Shojaei; SAli Hosseini

2015-01-01

Background: Diabetes is a common disease that for its treatment and control different methods are recommended such as the use of natural remedies and lifestyle modification. Since the use of herbal medicines have less side effects than many chemical drugs, hence, this study aimed to investigate the effect of cinnamon extract on blood glucose, insulin and insulin resistance in diabetic rats with streptozotocin. Materials and Methods: This experimental study was conducted on 40 adult male rats,...

Neuropeptide Y (NPY) and peptide YY (PYY) receptors in rat brain

International Nuclear Information System (INIS)

Ohkubo, T.; Niwa, M.; Yamashita, K.; Kataoka, Y.; Shigematsu, K.

1990-01-01

1. Specific binding sites for neuropeptide Y (NPY) and peptide YY (PYY) were investigated in rat brain areas using quantitative receptor autoradiography with 125 I-Bolton-Hunter NPY ( 125 I-BH-NPY) and 125 I-PYY, radioligands for PP-fold family peptides receptors. 2. There were no differences between localization of 125 I-BH-NPY and 125 I-PYY binding sites in the rat brain. High densities of the binding sites were present in the anterior olfactory nucleus, lateral septal nucleus, stratum radiatum of the hippocampus, posteromedial cortical amygdaloid nucleus, and area postrema. 3. In cold ligand-saturation experiments done in the presence of increasing concentrations of unlabeled NPY and PYY, 125 I-BH-NPY and 125 I-PYY binding to the stratum radiatum of the hippocampus, layer I of the somatosensory frontoparietal cortex, molecular layer of the cerebellum, and area postrema was single and of a high affinity. There was a significant difference between the affinities of 125 I-BH-NPY (Kd = 0.96 nM) and 125 I-PYY binding (Kd = 0.05 nM) to the molecular layer of the cerebellum. The binding of the two radioligands to the other areas examined had the same affinities. 4. When comparing the potency of unlabeled rat pancreatic polypeptide (rPP), a family peptide of NPY and PYY, to inhibit the binding to the areas examined, rPP displaced 125 I-BH-NPY and 125 I-PYY binding to the area postrema more potently than it did the binding to the stratum radiatum of the hippocampus, layer I of the somatosensory frontoparietal cortex, and molecular layer of the cerebellum. 5. Thus, the quantitative receptor autoradiographic method with 125 I-BH-NPY and 125 I-PYY revealed differences in binding characteristics of specific NPY and PYY binding sites in different areas of the rat brain. The results provide further evidence for the existence of multiple NPY-PYY receptors in the central nervous system

Toxicity Induced after Subchronic Administration of the Synthetic Food Dye Tartrazine in Adult Rats, Role of Oxidative Stress

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Narges El Golli

2016-04-01

Full Text Available The present study was conducted to evaluate the toxic potential of tartrazine, a food color, in different tissues in adult rat: blood, liver, kidneys, and spleen. Tartrazine was administered orally at a dose of 300 mg/kg of body weight to adult male Wistar rats during a period of 30 days. Tartrazine treatment led to an increase in platelets count, a reduction in peripheral lymphocytes and in spleen T CD8-lymphocytes. Furthermore, tartrazine increased the activities of hepatocellular enzymes and promoted changes in kidney biomarkers. In order to explore the possible mechanism involved, oxidative-stress assessment was performed. Results identified critical oxidative alterations in all tested organs, as shown by the promotion of lipid peroxidation and the modification of endogenous antioxidant-defense enzymes. Thus, tartrazine is able to induce in adult rats’ hematotoxicity, immunotoxicity, and liver and kidney injuries by changing the whole balance between oxidants and antioxidants.

Effect of single x-irradiation on glucocorticoid function of adrenal glands of adult and old rats

International Nuclear Information System (INIS)

Gorban', Je.M.; Topol'nyikova, N.V.

2001-01-01

The peculiarities of short-term (1 h, 1 day) adrenal glucocorticoid function in adult and old rats after single x-irradiation at different doses was studied. changes in the glucocorticoid function of the adrenal glands at studied terms after single x-irradiation at used doses were observed in adult but not in old animals. This testifies to an age-related decrease in the range of adaptive possibilities of this link of the organism adaptive system to x-irradiation effects

Effects of face/head and whole body cooling during passive heat stress on human somatosensory processing.

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Nakata, Hiroki; Namba, Mari; Kakigi, Ryusuke; Shibasaki, Manabu

2017-06-01

We herein investigated the effects of face/head and whole body cooling during passive heat stress on human somatosensory processing recorded by somatosensory-evoked potentials (SEPs) at C4' and Fz electrodes. Fourteen healthy subjects received a median nerve stimulation at the left wrist. SEPs were recorded at normothermic baseline (Rest), when esophageal temperature had increased by ~1.2°C (heat stress: HS) during passive heating, face/head cooling during passive heating (face/head cooling: FHC), and after HS (whole body cooling: WBC). The latencies and amplitudes of P14, N20, P25, N35, P45, and N60 at C4' and P14, N18, P22, and N30 at Fz were evaluated. Latency indicated speed of the subcortical and cortical somatosensory processing, while amplitude reflected the strength of neural activity. Blood flow in the internal and common carotid arteries (ICA and CCA, respectively) and psychological comfort were recorded in each session. Increases in esophageal temperature due to HS significantly decreased the amplitude of N60, psychological comfort, and ICA blood flow in the HS session, and also shortened the latencies of SEPs (all, P body temperature. Copyright © 2017 the American Physiological Society.

Stress-induced locomotor sensitization to amphetamine in adult, but not in adolescent rats, is associated with increased expression of ΔFosB in the nucleus accumbens.

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Paulo Eduardo Carneiro de Oliveira

2016-09-01

Full Text Available While clinical and pre-clinical evidence suggests that adolescence is a risk period for the development of addiction, the underlying neural mechanisms are largely unknown. Stress during adolescence has a huge influence on drug addiction. However, little is known about the mechanisms related to the interaction among stress, adolescence and addiction. Studies point to ΔFosB as a possible target for this phenomenon. In the present study, adolescent and adult rats (postnatal day 28 and 60, respectively were restrained for 2 hours once a day for 7 days. Three days after their last exposure to stress, the animals were challenged with saline or amphetamine (1.0 mg/kg i.p. and amphetamine-induced locomotion was recorded. Immediately after the behavioral tests, rats were decapitated and the nucleus accumbens was dissected to measure ΔFosB protein levels. We found that repeated restraint stress increased amphetamine-induced locomotion in both adult and adolescent rats. Furthermore, in adult rats, stress-induced locomotor sensitization was associated with increased expression of ΔFosB in the nucleus accumbens. Our data suggest that ΔFosB may be involved in some of the neuronal plasticity changes associated with stress induced-cross sensitization with amphetamine in adult rats.

Anti-dopamine beta-hydroxylase immunotoxin-induced sympathectomy in adult rats

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Picklo, M. J.; Wiley, R. G.; Lonce, S.; Lappi, D. A.; Robertson, D.

1995-01-01

Anti-dopamine beta-hydroxylase immunotoxin (DHIT) is an antibody-targeted noradrenergic lesioning tool comprised of a monoclonal antibody against the noradrenergic enzyme, dopamine beta-hydroxylase, conjugated to saporin, a ribosome-inactivating protein. Noradrenergic-neuron specificity and completeness and functionality of sympathectomy were assessed. Adult, male Sprague-Dawley rats were given 28.5, 85.7, 142 or 285 micrograms/kg DHIT i.v. Three days after injection, a 6% to 73% decrease in the neurons was found in the superior cervical ganglia of the animals. No loss of sensory, nodose and dorsal root ganglia, neurons was observed at the highest dose of DHIT. In contrast, the immunotoxin, 192-saporin (142 micrograms/kg), lesioned all three ganglia. To assess the sympathectomy, 2 wk after treatment (285 micrograms/kg), rats were anesthetized with urethane (1 g/kg) and cannulated in the femoral artery and vein. DHIT-treated animals' basal systolic blood pressure and heart rate were significantly lower than controls. Basal plasma norepinephrine levels were 41% lower in DHIT-treated animals than controls. Tyramine-stimulated release of norepinephrine in DHIT-treated rats was 27% of controls. Plasma epinephrine levels of DHIT animals were not reduced. DHIT-treated animals exhibited a 2-fold hypersensitivity to the alpha-adrenergic agonist phenylephrine. We conclude that DHIT selectively delivered saporin to noradrenergic neurons resulting in destruction of these neurons. Anti-dopamine beta-hydroxylase immunotoxin administration produces a rapid, irreversible sympathectomy.

Effect of surgery on sensory threshold and somatosensory evoked potentials after skin stimulation

DEFF Research Database (Denmark)

Lund, C; Hansen, O B; Kehlet, H

1990-01-01

We have studied the effect of surgical injury on cutaneous sensitivity and somatosensory evoked potentials (SSEP) to dermatomal electrical stimulation in 10 patients undergoing hysterectomy. Forty-eight hours after surgery, sensory threshold increased from 2.2 (SEM 0.3) mA to 4.4 (1.1) mA (P less...

Gestational Protein Restriction Increases Cardiac Connexin 43 mRNA levels in male adult rat offspring

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Rossini, Kamila Fernanda; de Oliveira, Camila Andrea; Rebelato, Hércules Jonas; Esquisatto, Marcelo Augusto Marreto; Catisti, Rosana

2017-01-01

Background The dietary limitation during pregnancy influences the growth and development of the fetus and offspring and their health into adult life. The mechanisms underlying the adverse effects of gestational protein restriction (GPR) in the development of the offspring hearts are not well understood. Objectives The aim of this study was to evaluate the effects of GPR on cardiac structure in male rat offspring at day 60 after birth (d60). Methods Pregnant Wistar rats were fed a normal-protein (NP, 17% casein) or low-protein (LP, 6% casein) diet. Blood pressure (BP) values from 60-day-old male offspring were measured by an indirect tail-cuff method using an electro sphygmomanometer. Hearts (d60) were collected for assessment of connexin 43 (Cx43) mRNA expression and morphological and morphometric analysis. Results LP offspring showed no difference in body weight, although they were born lighter than NP offspring. BP levels were significantly higher in the LP group. We observed a significant increase in the area occupied by collagen fibers, a decrease in the number of cardiomyocytes by 104 µm2, and an increase in cardiomyocyte area associated with an increased Cx43 expression. Conclusion GPR changes myocardial levels of Cx43 mRNA in male young adult rats, suggesting that this mechanism aims to compensate the fibrotic process by the accumulation of collagen fibers in the heart interstitium. PMID:28678925

Nitrous Oxide Induces Prominent Cell Proliferation in Adult Rat Hippocampal Dentate Gyrus

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Farah Chamaa

2018-05-01

Full Text Available The identification of distinct and more efficacious antidepressant treatments is highly needed. Nitrous oxide (N2O is an N-methyl-D-aspartic acid (NMDA antagonist that has been reported to exhibit antidepressant effects in treatment-resistant depression (TRD patients. Yet, no studies have investigated the effects of sub-anesthetic dosages of N2O on hippocampal cell proliferation and neurogenesis in adult brain rats. In our study, adult male Sprague-Dawley rats were exposed to single or multiple exposures to mixtures of 70% N2O and 30% oxygen (O2. Sham groups were exposed to 30% O2 and the control groups to atmospheric air. Hippocampal cell proliferation was assessed by bromodeoxyuridine (BrdU incorporation, and BrdU-positive cells were counted in the dentate gyrus (DG using confocal microscopy. Results showed that while the rates of hippocampal cell proliferation were comparable between the N2O and sham groups at day 1, levels increased by 1.4 folds at day 7 after one session exposure to N2O. Multiple N2O exposures significantly increased the rate of hippocampal cell proliferation to two folds. Therefore, sub-anesthetic doses of N2O, similar to ketamine, increase hippocampal cell proliferation, suggesting that there will ultimately be an increase in neurogenesis. Future studies should investigate added N2O exposures and their antidepressant behavioral correlates.

Repeated whisker stimulation evokes invariant neuronal responses in the dorsolateral striatum of anesthetized rats: a potential correlate of sensorimotor habits

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Mowery, Todd M.; Harrold, Jon B.; Alloway, Kevin D.

2011-01-01

The dorsolateral striatum (DLS) receives extensive projections from primary somatosensory cortex (SI), but very few studies have used somesthetic stimulation to characterize the sensory coding properties of DLS neurons. In this study, we used computer-controlled whisker deflections to characterize the extracellular responses of DLS neurons in rats lightly anesthetized with isoflurane. When multiple whiskers were synchronously deflected by rapid back-and-forth movements, whisker-sensitive neur...

Repeated exposure of adult rats to transient oxidative stress induces various long-lasting alterations in cognitive and behavioral functions.

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Yoshio Iguchi

Full Text Available Exposure of neonates to oxidative stress may increase the risk of psychiatric disorders such as schizophrenia in adulthood. However, the effects of moderate oxidative stress on the adult brain are not completely understood. To address this issue, we systemically administrated 2-cyclohexen-1-one (CHX to adult rats to transiently reduce glutathione levels. Repeated administration of CHX did not affect the acquisition or motivation of an appetitive instrumental behavior (lever pressing rewarded by a food outcome under a progressive ratio schedule. In addition, response discrimination and reversal learning were not affected. However, acute CHX administration blunted the sensitivity of the instrumental performance to outcome devaluation, and this effect was prolonged in rats with a history of repeated CHX exposure, representing pro-depression-like phenotypes. On the other hand, repeated CHX administration reduced immobility in forced swimming tests and blunted acute cocaine-induced behaviors, implicating antidepressant-like effects. Multivariate analyses segregated a characteristic group of behavioral variables influenced by repeated CHX administration. Taken together, these findings suggest that repeated administration of CHX to adult rats did not cause a specific mental disorder, but it induced long-term alterations in behavioral and cognitive functions, possibly related to specific neural correlates.

Effect of Ruta graveolens and Cannabis sativa alcoholic extract on spermatogenesis in the adult wistar male rats

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M R Sailani

2007-01-01

Full Text Available Objective: The present study was undertaken to evaluate the effects of alcohol extracts of Ruta graveolens and Cannabis sativa that were used traditionally in medieval Persian medicine as male contraceptive drugs, on spermatogenesis in the adult male rats. Materials and Methods: Ethanol extracts of these plants were obtained by the maceration method. The male rats were injected intraperitionaly with C. sativa and R. graveolens 5% ethanol extracts at dose of 20 mg/day for 20 consecutive days, respectively. Twenty-four hours after the last treatment, testicular function was assessed by epididymal sperm count. Result: The statistical results showed that the ethanol extracts of these plants reduced the number of sperms significantly ( P =0.00 in the treatment groups in comparison to the control group. The results also showed that the group, treated by extract of R. graveolens reduced spermatogenesis more than the group treated by extracts of C. sativa . Conclusion: The present study demonstrated the spermatogenesis reducing properties of the ethanol extracts of R. graveolens and C. sativa in the adult male wistar rats but more studies are necessary to reveal the mechanism of action that is involved in spermatogenesis.

Adolescent social instability stress increases aggression in a food competition task in adult male Long-Evans rats.

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Cumming, Mark J; Thompson, Madison A; McCormick, Cheryl M

2014-11-01

Adolescent social instability stress (SS; daily 1 hr isolation + new cage partners postnatal days 30-45; thereafter with original cage partner, also in the SS condition) and control (CTL) rats competed for access to a preferred food in five sessions against their cage partner. In the first session, SS pairs displayed more aggression (face whacks, p = .02; rear attacks, p = .03), were less likely to relinquish access to the food voluntarily (p = .03), spent more time at the feeder than CTL pairs (p = .06), but did not differ in latency to access the feeder (p = .41). Pairs were considered in dominant-submissive relationships (DSR) if one rat spent significantly more time at the feeder than the other; 8 of 12 SS and 8 of 12 CTL pairs displayed DSRs (remaining: no-DSR). Aggression increased from the 1st to 5th session (p food reward. These results add to evidence that SS in adolescence modifies the adult social repertoire of rats and highlight the importance of adolescent social experiences for adult behavior. © 2014 Wiley Periodicals, Inc.

Endogenous stem cell proliferation induced by intravenous hedgehog agonist administration after contusion in the adult rat spinal cord.

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Bambakidis, Nicholas C; Horn, Eric M; Nakaji, Peter; Theodore, Nicholas; Bless, Elizabeth; Dellovade, Tammy; Ma, Chiyuan; Wang, Xukui; Preul, Mark C; Coons, Stephen W; Spetzler, Robert F; Sonntag, Volker K H

2009-02-01

Sonic hedgehog (Shh) is a glycoprotein molecule that upregulates the transcription factor Gli1. The Shh protein plays a critical role in the proliferation of endogenous neural precursor cells when directly injected into the spinal cord after a spinal cord injury in adult rodents. Small-molecule agonists of the hedgehog (Hh) pathway were used in an attempt to reproduce these findings through intravenous administration. The expression of Gli1 was measured in rat spinal cord after the intravenous administration of an Hh agonist. Ten adult rats received a moderate contusion and were treated with either an Hh agonist (10 mg/kg, intravenously) or vehicle (5 rodents per group) 1 hour and 4 days after injury. The rats were killed 5 days postinjury. Tissue samples were immediately placed in fixative. Samples were immunohistochemically stained for neural precursor cells, and these cells were counted. Systemic dosing with an Hh agonist significantly upregulated Gli1 expression in the spinal cord (p < 0.005). After spinal contusion, animals treated with the Hh agonist had significantly more nestin-positive neural precursor cells around the rim of the lesion cavity than in vehicle-treated controls (means +/- SDs, 46.9 +/- 12.9 vs 20.9 +/- 8.3 cells/hpf, respectively, p < 0.005). There was no significant difference in the area of white matter injury between the groups. An intravenous Hh agonist at doses that upregulate spinal cord Gli1 transcription also increases the population of neural precursor cells after spinal cord injury in adult rats. These data support previous findings based on injections of Shh protein directly into the spinal cord.

Transient gestational and neonatal hypothyroidism-induced specific changes in androgen receptor expression in skeletal and cardiac muscles of adult rat.

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Annapoorna, K; Anbalagan, J; Neelamohan, R; Vengatesh, G; Stanley, J; Amudha, G; Aruldhas, M M

2013-03-01

The present study aims to identify the association between androgen status and metabolic activity in skeletal and cardiac muscles of adult rats with transient gestational/neonatal-onset hypothyroidism. Pregnant and lactating rats were made hypothyroid by exposing to 0.05% methimazole in drinking water; gestational exposure was from embryonic day 9-14 (group II) or 21 (group III), lactational exposure was from postnatal day 1-14 (group IV) or 29 (group V). Serum was collected for hormone assay. Androgen receptor status, Glu-4 expression, and enzyme activities were assessed in the skeletal and cardiac muscles. Serum testosterone and estradiol levels decreased in adult rats of groups II and III, whereas testosterone remained normal but estradiol increased in group IV and V, when compared to coeval control. Androgen receptor ligand binding activity increased in both muscle phenotypes with a consistent increase in the expression level of its mRNA and protein expressions except in the forelimb of adult rats with transient hypothyroidism (group II-V). Glut-4 expression remained normal in skeletal and cardiac muscle of experimental rats. Specific activity of hexokinase and lactate dehydrogenase increased in both muscle phenotypes whereas, creatine kinase activity increased in skeletal muscles alone. It is concluded that transient gestational/lactational exposure to methimazole results in hypothyroidism during prepuberal life whereas it increases AR status and glycolytic activity in skeletal and cardiac muscles even at adulthood. Thus, the present study suggests that euthyroid status during prenatal and early postnatal life is essential to have optimal AR status and metabolic activity at adulthood. © Georg Thieme Verlag KG Stuttgart · New York.

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

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Andreas A Ioannides

2013-08-01

Full Text Available Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1 and motor (M1 cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45 to 70 Hz activity at latencies of 20 to 50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occured in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

Unimodal primary sensory cortices are directly connected by long-range horizontal projections in the rat sensory cortex

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Jimmy eStehberg

2014-09-01

Full Text Available Research based on functional imaging and neuronal recordings in the barrel cortex subdivision of primary somatosensory cortex (SI of the adult rat has revealed novel aspects of structure-function relationships in this cortex. Specifically, it has demonstrated that single whisker stimulation evokes subthreshold neuronal activity that spreads symmetrically within gray matter from the appropriate barrel area, crosses cytoarchitectural borders of SI and reaches deeply into other unimodal primary cortices such as primary auditory (AI and primary visual (VI. It was further demonstrated that this spread is supported by a spatially matching underlying diffuse network of border-crossing, long-range projections that could also reach deeply into AI and VI. Here we seek to determine whether such a network of border-crossing, long-range projections is unique to barrel cortex or characterizes also other primary, unimodal sensory cortices and therefore could directly connect them. Using anterograde (BDA and retrograde (CTb tract-tracing techniques, we demonstrate that such diffuse horizontal networks directly and mutually connect VI, AI and SI. These findings suggest that diffuse, border-crossing axonal projections connecting directly primary cortices are an important organizational motif common to all major primary sensory cortices in the rat. Potential implications of these findings for topics including cortical structure-function relationships, multisensory integration, functional imaging and cortical parcellation are discussed.

Atypical visual and somatosensory adaptation in schizophrenia-spectrum disorders

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Andrade, G N; Butler, J S; Peters, G A; Molholm, S; Foxe, J J

2016-01-01

Neurophysiological investigations in patients with schizophrenia consistently show early sensory processing deficits in the visual system. Importantly, comparable sensory deficits have also been established in healthy first-degree biological relatives of patients with schizophrenia and in first-episode drug-naive patients. The clear implication is that these measures are endophenotypic, related to the underlying genetic liability for schizophrenia. However, there is significant overlap between patient response distributions and those of healthy individuals without affected first-degree relatives. Here we sought to develop more sensitive measures of sensory dysfunction in this population, with an eye to establishing endophenotypic markers with better predictive capabilities. We used a sensory adaptation paradigm in which electrophysiological responses to basic visual and somatosensory stimuli presented at different rates (ranging from 250 to 2550 ms interstimulus intervals, in blocked presentations) were compared. Our main hypothesis was that adaptation would be substantially diminished in schizophrenia, and that this would be especially prevalent in the visual system. High-density event-related potential recordings showed amplitude reductions in sensory adaptation in patients with schizophrenia (N=15 Experiment 1, N=12 Experiment 2) compared with age-matched healthy controls (N=15 Experiment 1, N=12 Experiment 2), and this was seen for both sensory modalities. At the individual participant level, reduced adaptation was more robust for visual compared with somatosensory stimulation. These results point to significant impairments in short-term sensory plasticity across sensory modalities in schizophrenia. These simple-to-execute measures may prove valuable as candidate endophenotypes and will bear follow-up in future work. PMID:27163205

Effect of Electromagnetic Radiation Exposure on Histology and DNA Content of the Brain Cortex and Hypothalamus of Young and Adult Male Albino Rats

International Nuclear Information System (INIS)

Othman, A.I.; Othman, A.I.

2012-01-01

Concerns have been raised regarding the potential adverse effects of exposure to electromagnetic radiation (EMR) arising from mobile phone. The present study investigates the effect of the daily exposure of adult and young rats to EMR for 1 hour (at a frequency of 900 MHz, a power density of 0.02 mW/cm 2 and an average specific absorption rate of 1.165 W/kg) on the DNA content and tissue architecture of the cortex and hypothalamus of the rat brain. Both young and adult rats were sacrificed at two intervals, after 4 months of daily EMR exposure and after 1 month of stopping the exposure. The present results showed a significant increase in the DNA intensity of young and adult rats in both areas after 4 months of daily EMR exposure. However, decreased DNA content around the normal level was observed after one month of stopping the exposure. Light microscopic examination of irradiated rats revealed edema, vacuolation, necrosis and proliferated glial cells. Stopping EMR exposure showed mild amelioration in the structural damage of the cerebral cortex of young animals, however, most drastic changes still persisted in the other animals. In conclusion, these data may confirm the neurotoxic risks arising from the extensive use of mobile phones that may alter the brain histology and impair its function

Histological changes in kidneys of adult rats treated with Monosodium glutamate: A light microscopic study

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Singh BR, Ujwal Gajbe, Anil Kumar Reddy, Vandana Kumbhare

2015-01-01

Full Text Available Introduction: Monosodium Glutamate (MSG, which is chemically known as AJI-NO-MOTO also familiar as MSG in routine life. MSG is always considered to be a controversial food additive used in the world. It is a natural excitatory neurotransmitter, helps in transmitting the fast synaptic signals in one third of CNS. Liver and kidney play a crucial role in metabolism as well as elimination of MSG from the body. Present study is to detect structural changes in adult rat kidney tissue treated with MSG; observations are done with a light microscope. Materials & Methods: The study was conducted in the department of Anatomy, J.N.M.C, Sawangi (M Wardha. Thirty (30 adult Wistar rats (2-3 months old weighing about (200 ± 20g were used in the current study, animals were divided into three groups (Group – A, B, C. Group A: Control, Group B: 3 mg /gm body weight, Group C: 6 mg /gm body weight, MSG were administered orally daily for 45 days along with the regular diet. Observations & Results: The Mean values of animals weight at the end of experiment (46th day respectively were 251.2 ± 13, 244.4 ± 19.9 and 320 ± 31.1. Early degenerative changes like, Glomerular shrinkage (GSr, loss of brush border in proximal convoluted tubules and Cloudy degeneration was observed in sections of kidney treated with 3 mg/gm body weight of MSG. Animals treated with 6 mg/gm body weight of MSG showed rare changes like interstitial chronic inflammatory infiltrate with vacuolation in some of the glomeruli, and much glomerular shrinkage invaginated by fatty lobules. Conclusion: The effects of MSG on kidney tissues of adult rats revealed that the revelatory changes are directly proportional to the doses of MSG.

Testosterone potentiates the hypoxic ventilatory response of adult male rats subjected to neonatal stress.

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Fournier, Sébastien; Gulemetova, Roumiana; Joseph, Vincent; Kinkead, Richard

2014-05-01

Neonatal stress disrupts development of homeostatic systems. During adulthood, male rats subjected to neonatal maternal separation (NMS) are hypertensive and show a larger hypoxic ventilatory response (HVR), with greater respiratory instability during sleep. Neonatal stress also affects sex hormone secretion; hypoxia increases circulating testosterone of NMS (but not control) male rats. Given that these effects of NMS are not observed in females, we tested the hypothesis that testosterone elevation is necessary for the stress-related increase of the HVR in adult male rats. Pups subjected to NMS were placed in an incubator for 3 h per day from postnatal day 3 to 12. Control pups remained undisturbed. Rats were reared until adulthood, and the HVR was measured by plethysmography (fractional inspired O2 = 0.12, for 20 min). We used gonadectomy to evaluate the effects of reducing testosterone on the HVR. Gonadectomy had no effect on the HVR of control animals but reduced that of NMS animals below control levels. Immunohistochemistry was used to quantify androgen receptors in brainstem areas involved in the HVR. Androgen receptor expression was generally greater in NMS rats than in control rats; the most significant increase was noted in the caudal region of the nucleus tractus solitarii. We conclude that the abnormal regulation of testosterone is important in stress-related augmentation of the HVR. The greater number of androgen receptors within the brainstem may explain why NMS rats are more sensitive to testosterone withdrawal. Based on the similarities of the cardiorespiratory phenotype of NMS rats and patients suffering from sleep-disordered breathing, these results provide new insight into its pathophysiology, especially sex-based differences in its prevalence. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

Alterations in monoamines level in discrete brain regions and other peripheral tissues in young and adult male rats during experimental hyperthyroidism.

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Hassan, Wafaa A; Rahman, Taghride Abdel; Aly, Mona S; Shahat, Asmaa S

2013-08-01

The present study was conducted to investigate the effect of experimentally-induced hyperthyroidism on dopamine (DA), norepinephrine (NE) and serotonin (5-HT) levels in different brain regions as well as in blood plasma, cardiac muscle and adrenal gland of young and adult male albino rats (60 rats of each age). Hyperthyroidism was induced by daily s.c. injection of L-thyroxine (L-T4, 500 μg/kg body wt.) for 21 consecutive days. Induction of hyperthyroidism caused a significant elevation in DA and 5-HT levels in most of the tissues studied of both young and adult animals after 7, 14, and 21 days. NE content significantly decreased after 21 days in most of the brain regions examined and after 14 and 21 days in blood plasma of young rats following hyperthyroidism. In adult rats, NE content decreased after 14 and 21 days in cardiac muscle and after 21 days only in adrenal gland. It may be suggested that the changes in monoamines level induced by hyperthyroidism may be due to disturbance in the synthesis, turnover and release of these amines through the neurons impairment or may attributed to an alteration pattern of their synthesis and/or degradative enzymes or changes in the sensitivity of their receptors. Copyright © 2013 ISDN. Published by Elsevier Ltd. All rights reserved.

The third-stimulus temporal discrimination threshold: focusing on the temporal processing of sensory input within primary somatosensory cortex.

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Leodori, Giorgio; Formica, Alessandra; Zhu, Xiaoying; Conte, Antonella; Belvisi, Daniele; Cruccu, Giorgio; Hallett, Mark; Berardelli, Alfredo

2017-10-01

The somatosensory temporal discrimination threshold (STDT) has been used in recent years to investigate time processing of sensory information, but little is known about the physiological correlates of somatosensory temporal discrimination. The objective of this study was to investigate whether the time interval required to discriminate between two stimuli varies according to the number of stimuli in the task. We used the third-stimulus temporal discrimination threshold (ThirdDT), defined as the shortest time interval at which an individual distinguishes a third stimulus following a pair of stimuli delivered at the STDT. The STDT and ThirdDT were assessed in 31 healthy subjects. In a subgroup of 10 subjects, we evaluated the effects of the stimuli intensity on the ThirdDT. In a subgroup of 16 subjects, we evaluated the effects of S1 continuous theta-burst stimulation (S1-cTBS) on the STDT and ThirdDT. Results show that ThirdDT is shorter than STDT. We found a positive correlation between STDT and ThirdDT values. As long as the stimulus intensity was within the perceivable and painless range, it did not affect ThirdDT values. S1-cTBS significantly affected both STDT and ThirdDT, although the latter was affected to a greater extent and for a longer period of time. We conclude that the interval needed to discriminate between time-separated tactile stimuli is related to the number of stimuli used in the task. STDT and ThirdDT are encoded in S1, probably by a shared tactile temporal encoding mechanism whose performance rapidly changes during the perception process. ThirdDT is a new method to measure somatosensory temporal discrimination. NEW & NOTEWORTHY To investigate whether the time interval required to discriminate between stimuli varies according to changes in the stimulation pattern, we used the third-stimulus temporal discrimination threshold (ThirdDT). We found that the somatosensory temporal discrimination acuity varies according to the number of stimuli in the

Prefrontal cortex and somatosensory cortex in tactile crossmodal association: an independent component analysis of ERP recordings.

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Yixuan Ku

2007-08-01

Full Text Available Our previous studies on scalp-recorded event-related potentials (ERPs showed that somatosensory N140 evoked by a tactile vibration in working memory tasks was enhanced when human subjects expected a coming visual stimulus that had been paired with the tactile stimulus. The results suggested that such enhancement represented the cortical activities involved in tactile-visual crossmodal association. In the present study, we further hypothesized that the enhancement represented the neural activities in somatosensory and frontal cortices in the crossmodal association. By applying independent component analysis (ICA to the ERP data, we found independent components (ICs located in the medial prefrontal cortex (around the anterior cingulate cortex, ACC and the primary somatosensory cortex (SI. The activity represented by the IC in SI cortex showed enhancement in expectation of the visual stimulus. Such differential activity thus suggested the participation of SI cortex in the task-related crossmodal association. Further, the coherence analysis and the Granger causality spectral analysis of the ICs showed that SI cortex appeared to cooperate with ACC in attention and perception of the tactile stimulus in crossmodal association. The results of our study support with new evidence an important idea in cortical neurophysiology: higher cognitive operations develop from the modality-specific sensory cortices (in the present study, SI cortex that are involved in sensation and perception of various stimuli.

Cortical somatosensory reorganization in children with spastic cerebral palsy: a multimodal neuroimaging study

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CHRISTOS ePAPADELIS

2014-09-01

Full Text Available Although cerebral palsy (CP is among the most common causes of physical disability in early childhood, we know little about the functional and structural changes of this disorder in the developing brain. Here, we investigated with three different neuroimaging modalities (magnetoencephalography (MEG, diffusion tension imaging (DTI, and resting state fMRI whether spastic CP is associated with functional and anatomical abnormalities in the sensorimotor network. Ten children participated in the study: four with diplegic CP (DCP, three with hemiplegic CP (HCP, and three typically-developing (TD children. Somatosensory evoked fields (SEFs were recorded in response to pneumatic stimuli applied to digits D1, D3, and D5 of both hands. Several parameters of water diffusion were calculated from DTI between the thalamus and the precentral and postcentral gyri in both hemispheres. The sensorimotor resting state networks (RSNs were examined by using an independent component analysis method. Tactile stimulation of the fingers elicited the first prominent cortical response at ~50 ms, in all except one child, localized over the primary somatosensory cortex (S1. In five CP children, abnormal somatotopic organization was observed in the affected (or more affected hemisphere. Euclidean distances were markedly different between the two hemispheres in the HCP children, and between DCP and TD children for both hemispheres. DTI analysis revealed decreased fractional anisotropy and increased apparent diffusion coefficient for the thalamocortical pathways in the more affected compared to less affected hemisphere in CP children. Rs-fMRI results indicated absent and/or abnormal sensorimotor RSNs for children with HCP and DCP consistent with the severity and location of their lesions. Our findings suggest an abnormal somatosensory processing mechanism in the sensorimotor network of children with CP possibly as a result of diminished thalamocortical projections.

Direct and crossed effects of somatosensory stimulation on neuronal excitability and motor performance in humans

NARCIS (Netherlands)

Veldman, M. P.; Maffiuletti, N. A.; Hallett, M.; Zijdewind, I.; Hortobagyi, T.

2014-01-01

This analytic review reports how prolonged periods of somatosensory electric stimulation (SES) with repetitive transcutaneous nerve stimulation can have 'direct' and 'crossed' effects on brain activation, corticospinal excitability, and motor performance. A review of 26 studies involving 315 healthy

Moderate perinatal thyroid hormone insufficiency alters visual system function in adult rats.

Science.gov (United States)

Boyes, William K; Degn, Laura; George, Barbara Jane; Gilbert, Mary E

2018-04-21

Thyroid hormone (TH) is critical for many aspects of neurodevelopment and can be disrupted by a variety of environmental contaminants. Sensory systems, including audition and vision are vulnerable to TH insufficiencies, but little data are available on visual system development at less than severe levels of TH deprivation. The goal of the current experiments was to explore dose-response relations between graded levels of TH insufficiency during development and the visual function of adult offspring. Pregnant Long Evans rats received 0 or 3 ppm (Experiment 1), or 0, 1, 2, or 3 ppm (Experiment 2) of propylthiouracil (PTU), an inhibitor of thyroid hormone synthesis, in drinking water from gestation day (GD) 6 to postnatal day (PN) 21. Treatment with PTU caused dose-related reductions of serum T4, with recovery on termination of exposure, and euthyroidism by the time of visual function testing. Tests of retinal (electroretinograms; ERGs) and visual cortex (visual evoked potentials; VEPs) function were assessed in adult offspring. Dark-adapted ERG a-waves, reflecting rod photoreceptors, were increased in amplitude by PTU. Light-adapted green flicker ERGs, reflecting M-cone photoreceptors, were reduced by PTU exposure. UV-flicker ERGs, reflecting S-cones, were not altered. Pattern-elicited VEPs were significantly reduced by 2 and 3 ppm PTU across a range of stimulus contrast values. The slope of VEP amplitude-log contrast functions was reduced by PTU, suggesting impaired visual contrast gain. Visual contrast gain primarily reflects function of visual cortex, and is responsible for adjusting sensitivity of perceptual mechanisms in response to changing visual scenes. The results indicate that moderate levels of pre-and post-natal TH insufficiency led to alterations in visual function of adult rats, including both retinal and visual cortex sites of dysfunction. Copyright © 2018. Published by Elsevier B.V.

MOBIUS-STRIP-LIKE COLUMNAR FUNCTIONAL CONNECTIONS ARE REVEALED IN SOMATO-SENSORY RECEPTIVE FIELD CENTROIDS.

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James Joseph Wright

2014-10-01

Full Text Available Receptive fields of neurons in the forelimb region of areas 3b and 1 of primary somatosensory cortex, in cats and monkeys, were mapped using extracellular recordings obtained sequentially from nearly radial penetrations. Locations of the field centroids indicated the presence of a functional system, in which cortical homotypic representations of the limb surfaces are entwined in three-dimensional Mobius-strip-like patterns of synaptic connections. Boundaries of somatosensory receptive field in nested groups irregularly overlie the centroid order, and are interpreted as arising from the superposition of learned connections upon the embryonic order. Since the theory of embryonic synaptic self-organisation used to model these results was devised and earlier used to explain findings in primary visual cortex, the present findings suggest the theory may be of general application throughout cortex, and may reveal a modular functional synaptic system, which, only in some parts of the cortex, and in some species, is manifest as anatomical ordering into columns.

The response of young and adult rats to the riboflavin supplementation

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Camille Feitoza França

2010-08-01

Full Text Available The aim of this article was to study the response of young and adult rats on the supplementation of diet with riboflavin. Twenty-four young and adult normotensives (Wistar male rats, subdivided into two groups: treated (10mg riboflavin/Kg of body weight and control (receiving vehicle were daily evaluated for physical and behavioural aspects. Systolic blood pressure was determined twice a week and liver toxicity was investigated it the end of treatment. Data were evaluated using one-way ANOVA and pO processo do envelhecimento e alguns transtornos, incluindo hipertensão, foram estreitamente associados ao estresse oxidativo. Em relação à riboflavina (vitamina B2, existe uma possibilidade de que suas propriedades antioxidantes podem contribuir para controlar esse evento. Assim, esse estudo utilizou vinte e quatro ratos machos jovens e velhos normotensos (Wistar, sendo subdivididos em dois grupos: tratado (riboflavina 10 mg / kg de peso corporal e o controle (recebendo veículo. Foram avaliados diariamente aspectos físicos e comportamentais. A pressão arterial sistólica foi determinada duas vezes por semana e a toxicidade hepática foi investigada no final do tratamento. Os dados foram avaliados usando ANOVA one-way e p <0,05. A suplementação não alterou os aspectos de saúde geral dos ratos tratados, no entanto, a suplementação provocou uma significativa (p <0,05 redução da pressão arterial sistólica.

Maternal periodontal disease in rats decreases insulin sensitivity and insulin signaling in adult offspring.

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Shirakashi, Daisy J; Leal, Rosana P; Colombo, Natalia H; Chiba, Fernando Y; Garbin, Cléa A S; Jardim, Elerson G; Antoniali, Cristina; Sumida, Doris H

2013-03-01

Periodontal disease during pregnancy has been recognized as one of the causes of preterm and low-birth-weight (PLBW) babies. Several studies have demonstrated that PLBW babies are prone to developing insulin resistance as adults. Although there is controversy over the association between periodontal disease and PLBW, the phenomenon known as programming can translate any stimulus or aggression experienced during intrauterine growth into physiologic and metabolic alterations in adulthood. The purpose of the present study is to investigate whether the offspring of rats with periodontal disease develop insulin resistance in adulthood. Ten female Wistar rats were divided into periodontal disease (PED) and control (CN) groups. All rats were mated at 7 days after induction of periodontal disease. Male offspring were divided into two groups: 1) periodontal disease offspring (PEDO; n = 24); and 2) control offspring (CNO; n = 24). Offspring body weight was measured from birth until 75 days. When the offspring reached 75 days old, the following parameters were measured: 1) plasma concentrations of glucose, insulin, fructosamine, lipase, amylase, and tumor necrosis factor-α (TNF-α); 2) insulin sensitivity (IS); and 3) insulin signal transduction (IST) in insulin-sensitive tissues. Low birth weight was not detected in the PEDO group. However, plasma concentrations of glucose, insulin, fructosamine, lipase, amylase, and TNF-α were increased and IS and IST were reduced (P PEDO group compared with the CNO group. Maternal periodontal disease may induce insulin resistance and reduce IST in adult offspring, but such alterations are not attributable to low birth weight.

Effects of caffeine on cortical epileptic afterdischarges in adult rats are modulated by postnatal treatment

Czech Academy of Sciences Publication Activity Database

Tchekalarova, Jana; Kubová, Hana; Mareš, Pavel

2013-01-01

Roč. 113, č. 4 (2013), s. 493-500 ISSN 0300-9009 R&D Projects: GA MZd(CZ) NR9184; GA MŠk(CZ) LH11015 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : caffeine * perinatal administration * cortical epileptic afterdischarges * adult rats Subject RIV: FH - Neurology Impact factor: 0.598, year: 2013

Stretch induced endothelin-1 secretion by adult rat astrocytes involves calcium influx via stretch-activated ion channels (SACs)

International Nuclear Information System (INIS)

Ostrow, Lyle W.; Suchyna, Thomas M.; Sachs, Frederick

2011-01-01

Highlights: → Endothelin-1 expression by adult rat astrocytes correlates with cell proliferation. → Stretch-induced ET-1 is inhibited by GsMtx-4, a specific inhibitor of Ca 2+ permeant SACs. → The less specific SAC inhibitor streptomycin also inhibits ET-1 secretion. → Stretch-induced ET-1 production depends on a calcium influx. → SAC pharmacology may provide a new class of therapeutic agents for CNS pathology. -- Abstract: The expression of endothelins (ETs) and ET-receptors is often upregulated in brain pathology. ET-1, a potent vasoconstrictor, also inhibits the expression of astrocyte glutamate transporters and is mitogenic for astrocytes, glioma cells, neurons, and brain capillary endothelia. We have previously shown that mechanical stress stimulates ET-1 production by adult rat astrocytes. We now show in adult astrocytes that ET-1 production is driven by calcium influx through stretch-activated ion channels (SACs) and the ET-1 production correlates with cell proliferation. Mechanical stimulation using biaxial stretch ( 2+ threshold. This coupling of mechanical stress to the astrocyte endothelin system through SACs has treatment implications, since all pathology deforms the surrounding parenchyma.

9-Hydroxyprostaglandin dehydrogenase activity in the adult rat kidney. Regional distribution and sub-fractionation.

Science.gov (United States)

Asciak, C P; Domazet, Z

1975-02-20

1. Catabolism of prostaglandin F2alpha in the adult rat kidney takes place by the following sequence of enzymatic steps: (1) 15-hydroxyprostaglandin dehydrogenase; (2) prostaglandin delta13-reductase; and (3) 9-hydroxyprostaglandin dehydrogenase. 2. 9-Hydroxyprostaglandin dehydrogenase activity was highest in the cortex with lesser amounts in the medulla and negligible activity detected in the papilla. A similar distribution was observed for 15-hydroxyprostaglandin dehydrogenase and prostaglandin delta13-reductase. 3. Most of the 9-hydroxyprostaglandin dehydrogenase activity in the homogenate was found in the high-speed supernatant as also observed for 15-hydroxyprostaglandin dehydrogenase and prostaglandin delta13-reductase. 4. These observations indicate that the rat kidney contains an abundance of prostaglandin-catabolising enzymes which favour formation of metabolites of the E-type.

Psychotherapy With Somatosensory Stimulation for Endometriosis-Associated Pain: A Randomized Controlled Trial.

Science.gov (United States)

Meissner, Karin; Schweizer-Arau, Annemarie; Limmer, Anna; Preibisch, Christine; Popovici, Roxana M; Lange, Isabel; de Oriol, Barbara; Beissner, Florian

2016-11-01

To evaluate whether psychotherapy with somatosensory stimulation is effective for the treatment of pain and quality of life in patients with endometriosis-related pain. Patients with a history of endometriosis and chronic pelvic pain were randomized to either psychotherapy with somatosensory stimulation (ie, different techniques of acupuncture point stimulation) or wait-list control for 3 months, after which all patients were treated. The primary outcome was brain connectivity assessed by functional magnetic resonance imaging. Prespecified secondary outcomes included pain on 11-point numeric rating scales (maximal and average global pain, pelvic pain, dyschezia, and dyspareunia) and physical and mental quality of life. A sample size of 30 per group was planned to compare outcomes in the treatment group and the wait-list control group. From March 2010 through March 2012, 67 women (mean age 35.6 years) were randomly allocated to intervention (n=35) or wait-list control (n=32). In comparison with wait-list controls, treated patients showed improvements after 3 months in maximal global pain (mean group difference -2.1, 95% confidence interval [CI] -3.4 to -0.8; P=.002), average global pain (-2.5, 95% CI -3.5 to -1.4; P<.001), pelvic pain (-1.4, 95% CI -2.7 to -0.1; P=.036), dyschezia (-3.5, 95% CI -5.8 to -1.3; P=.003), physical quality of life (3.8, 95% CI 0.5-7.1, P=.026), and mental quality of life (5.9, 95% CI 0.6-11.3; P=.031); dyspareunia improved nonsignificantly (-1.8, 95% CI -4.4 to 0.7; P=.150). Improvements in the intervention group remained stable at 6 and 24 months, and control patients showed comparable symptom relief after delayed intervention. Psychotherapy with somatosensory stimulation reduced global pain, pelvic pain, and dyschezia and improved quality of life in patients with endometriosis. After 6 and 24 months, when all patients were treated, both groups showed stable improvements. ClinicalTrials.gov, https://clinicaltrials.gov, NCT01321840.

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...

Cytoarchitecture and cortical connections of the posterior cingulate and adjacent somatosensory fields in the rhesus monkey.

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Morecraft, R J; Cipolloni, P B; Stilwell-Morecraft, K S; Gedney, M T; Pandya, D N

2004-01-26

The cytoarchitecture and connections of the caudal cingulate and medial somatosensory areas were investigated in the rhesus monkey. There is a stepwise laminar differentiation starting from retrosplenial area 30 towards the isocortical regions of the medial parietal cortex. This includes a gradational emphasis on supragranular laminar organization and general reduction of the infragranular neurons as one proceeds from area 30 toward the medial parietal regions, including areas 3, 1, 2, 5, 31, and the supplementary sensory area (SSA). This trend includes a progressive increase in layer IV neurons. Area 23c in the lower bank and transitional somatosensory area (TSA) in the upper bank of the cingulate sulcus appear as nodal points. From area 23c and TSA the architectonic progression can be traced in three directions: one culminates in areas 3a and 3b (core line), the second in areas 1, 2, and 5 (belt line), and the third in areas 31 and SSA (root line). These architectonic gradients are reflected in the connections of these regions. Thus, cingulate areas (30, 23a, and 23b) are connected with area 23c and TSA on the one hand and have widespread connections with parieto-temporal, frontal, and parahippocampal (limbic) regions on the other. Area 23c has connections with areas 30, 23a and b, and TSA as well as with medial somatosensory areas 3, 1, 2, 5, and SSA. Area 23c also has connections with parietotemporal, frontal, and limbic areas similar to areas 30, 23a, and 23b. Area TSA, like area 23c, has connections with areas 3, 1, 2, 5, and SSA. However, it has only limited connections with the parietotemporal and frontal regions and none with the parahippocampal gyrus. Medial area 3 is mainly connected to medial and dorsal sensory areas 3, 1, 2, 5, and SSA and to areas 4 and 6 as well as to supplementary (M2 or area 6m), rostral cingulate (M3 or areas 24c and d), and caudal cingulate (M4 or areas 23c and d) motor cortices. Thus, in parallel with the architectonic gradient

Prolonged hypothyroidism severely reduces ovarian follicular reserve in adult rats.

Science.gov (United States)

Meng, Li; Rijntjes, Eddy; Swarts, Hans J M; Keijer, Jaap; Teerds, Katja J

2017-03-16

There is substantial evidence both in humans and in animals that a prolonged reduction in plasma thyroid hormone concentration leads to reproductive problems, including disturbed folliculogenesis, impaired ovulation and fertilization rates, miscarriage and pregnancy complications. The objective of the present study is to examine the consequences of chronic hypothyroidism, induced in adulthood, for the size of the ovarian follicle pool. In order to investigate this, adult female rats were provided either a control or an iodide deficient diet in combination with perchlorate supplementation to inhibit iodide uptake by the thyroid. Sixteen weeks later animals were sacrificed. Blood was collected for hormone analyses and ovaries were evaluated histologically. At the time of sacrifice, plasma thyroid-stimulating hormone concentrations were 20- to 40-fold increased, thyroxine concentrations were negligible while tri-iothyronin concentrations were decreased by 40% in the hypothyroid group, confirming that the animals were hypothyroid. Primordial, primary and preantral follicle numbers were significantly lower in the hypothyroid ovaries compared to the euthyroid controls, while a downward trend in antral follicle and corpora lutea numbers was observed. Surprisingly the percentage of atretic follicles was not significantly different between the two groups, suggesting that the reduced preantral and antral follicle numbers were presumably not the consequence of increased degeneration of these follicle types in the hypothyroid group. Plasma anti-Müllerian hormone (AMH) levels showed a significant correlation with the growing follicle population represented by the total ovarian number of primary, preantral and antral follicles, suggesting that also under hypothyroid conditions AMH can serve as a surrogate marker to assess the growing ovarian follicle population. The induction of a chronic hypothyroid condition in adult female rats negatively affects the ovarian follicular

Avoiding escalation from play to aggression in adult male rats: The role of ultrasonic calls.

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Burke, Candace J; Kisko, Theresa M; Pellis, Sergio M; Euston, David R

2017-11-01

Play fighting is most commonly associated with juvenile animals, but in some species, including rats, it can continue into adulthood. Post-pubertal engagement in play fighting is often rougher and has an increased chance of escalation to aggression, making the use of play signals to regulate the encounter more critical. During play, both juvenile and adult rats emit many 50-kHz calls and some of these may function as play facilitating signals. In the present study, unfamiliar adult male rats were introduced in a neutral enclosure and their social interactions were recorded. While all pairs escalated their playful encounters to become rougher, only the pairs in which one member was devocalized escalated to serious biting. A Monte Carlo shuffling technique was used for the analysis of the correlations between the overt playful and aggressive actions performed and the types and frequencies of various 50-kHz calls that were emitted. The analysis revealed that lower frequency (20-30kHz) calls with a flat component maybe particularly critical for de-escalating encounters and so allowing play to continue. Moreover, coordinating calls reciprocally, with either the same call mimicked in close, temporal association or with complementary calls emitted by participants as they engage in complementary actions (e.g., attacking the nape, being attacked on the nape), appeared to be ways with which calls could be potentially used to avoid escalation to aggression and so sustain playful interactions. Copyright © 2017 Elsevier B.V. All rights reserved.

Anti-correlated cortical networks of intrinsic connectivity in the rat brain.

Science.gov (United States)

Schwarz, Adam J; Gass, Natalia; Sartorius, Alexander; Risterucci, Celine; Spedding, Michael; Schenker, Esther; Meyer-Lindenberg, Andreas; Weber-Fahr, Wolfgang

2013-01-01

In humans, resting-state blood oxygen level-dependent (BOLD) signals in the default mode network (DMN) are temporally anti-correlated with those from a lateral cortical network involving the frontal eye fields, secondary somatosensory and posterior insular cortices. Here, we demonstrate the existence of an analogous lateral cortical network in the rat brain, extending laterally from anterior secondary sensorimotor regions to the insular cortex and exhibiting low-frequency BOLD fluctuations that are temporally anti-correlated with a midline "DMN-like" network comprising posterior/anterior cingulate and prefrontal cortices. The primary nexus for this anti-correlation relationship was the anterior secondary motor cortex, close to regions that have been identified with frontal eye fields in the rat brain. The anti-correlation relationship was corroborated after global signal removal, underscoring this finding as a robust property of the functional connectivity signature in the rat brain. These anti-correlated networks demonstrate strong anatomical homology to networks identified in human and monkey connectivity studies, extend the known preserved functional connectivity relationships between rodent and primates, and support the use of resting-state functional magnetic resonance imaging as a translational imaging method between rat models and humans.

Cognitive deficits in adult rats by lead intoxication are related with regional specific inhibition of cNOS.

Science.gov (United States)

García-Arenas, Guadalupe; Ramírez-Amaya, Victor; Balderas, Israela; Sandoval, Jimena; Escobar, Martha L; Ríos, Camilo; Bermúdez-Rattoni, Federico

2004-02-04

It is well known that lead can affect several cognitive abilities in developing animals. In this work, we investigate the effects of different sub-chronic lead doses (0, 65, 125, 250 and 500 ppm of lead acetate in their drinking water for 14 days) in the performance of male adult rats in a water maze, cue maze and inhibitory avoidance tasks. We found that the acquisition of these tasks was not affected by lead, however, the highest dosage of lead (500 ppm) impaired memory consolidation in spatial and inhibitory avoidance tasks, but not in cue maze task while the 250 ppm dose only affected retrieval of spatial memory. Additionally, hippocampal long-term potentiation (LTP) induction in the perforant path after exposing adult rats to different doses of lead was studied. LTP induction was affected in a dose-dependent manner, and treatments of 250 and 500 ppm completely blocked LTP. We investigated the effects of lead intoxication on the activity of constitutive nitric oxide synthase (cNOS) in different brain regions of adult animals. The activity of cNOS was significantly inhibited in the hippocampus and cerebellum but not in the frontal cortex and brain stem, although lead had accumulated in all brain regions. These results suggest that lead intoxication can impair memory in adult animals and this impairment might be related with region-specific effects on cNOS activity.

Tris-(2,3-Dibromopropyl Isocyanurate, a New Emerging Pollutant, Impairs Cognition and Provokes Depression-Like Behaviors in Adult Rats.

Directory of Open Access Journals (Sweden)

Liang Ye

Full Text Available Tris-(2,3-dibromopropyl isocyanurate (TDBP-TAZTO, an emerging brominated flame retardant, possesses the characteristics of candidate persistent organic pollutants and has displayed toxicity to fish and rodents. TDBP-TAZTO can pass through the blood brain barrier and accumulate in brain. However, the neurotoxicity of TDBP-TAZTO has not yet studied in rodents. We hypothesize that TDBP-TAZTO could induce the neurotoxicity in rat hippocampal neurons. The male adult rats were exposed to TDBP-TAZTO of 5 and 50 mg/kg by gavage, daily for 6 months. TDBP-TAZTO resulted in cognitive impairment and depression-like behaviors, which may be related with TDBP-TAZTO-induced hypothalamic-pituitary-adrenal axis hyperactivation, upregulation of inflammatory and oxidative stress markers, overexpression of pro-apoptotic proteins, downexpression of neurogenesis-related proteins in hippocampus, and hippocampal neurons damage in DG, CA1 and CA3 areas. Our findings suggested that TDBP-TAZTO induces significant hippocampal neurotoxicity, which provokes cognitive impairment and depression-like behaviors in adult rats. Therefore, this research will contribute to evaluate the neurotoxic effects of TDBP-TAZTO in human.

Testis evaluation of adult Wistar rats after neonatal treatment with fluoxetine - doi: 10.4025/actascibiolsci.v35i1.10946

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Bruno Mendes Tenorio

2012-12-01

Full Text Available In current assay the serotoninergic system in newly-born Wistar rats underwent pharmacological modification by fluoxetine, a selective serotonin reuptake inhibitor (SSRI, to investigate its repercussion on testicular parameters in adult animals. Thirty animals were distributed according to treatment: control animals (n = 6, animals treated with 1 mg kg-1 (n = 6, 5 mg kg-1 (n = 6, 10 mg kg-1 (n = 6 and 20 mg kg-1 (n = 6 of fluoxetine (IP. When 150 days old, the animals were anesthetized and perfused intra-cardiacally with fixative solution. Testes were routinely processed for inclusion in plastic resin (methacrylate glycol. Further, 4 µm-thick histological sections were stained with toluidine blue/sodium borate 1% and analyzed histometrically. Pharmacological intervention on the serotoninergic system during the postnatal period of the testes development in Wistar rats with fluoxetine chlorohydrate reduced parameters, such as testicular weight, testis liquid weight and seminiferous tubules diameter. However, testicular parameters, such as daily sperm production (DSP, spermatogenesis efficiency (DSP/g/testis and cell population in stage VII of adult animals, were not influenced by fluoxetine chlorohydrate usage during neonatal period. Results show that administration of fluoxetine during 21 days after birth may induce adverse changes in the spermatogenesis of adult rats.  

Early life stress elicits visceral hyperalgesia and functional reorganization of pain circuits in adult rats

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D.P. Holschneider

2016-06-01

Full Text Available Early life stress (ELS is a risk factor for developing functional gastrointestinal disorders, and has been proposed to be related to a central amplification of sensory input and resultant visceral hyperalgesia. We sought to characterize ELS-related changes in functional brain responses during acute noxious visceral stimulation. Neonatal rats (males/females were exposed to limited bedding (ELS or standard bedding (controls on postnatal days 2–9. Age 10–11 weeks, animals were implanted with venous cannulas and transmitters for abdominal electromyography (EMG. Cerebral blood flow (rCBF was mapped during colorectal distension (CRD using [14C]-iodoantipyrine autoradiography, and analyzed in three-dimensionally reconstructed brains by statistical parametric mapping and functional connectivity. EMG responses to CRD were increased after ELS, with no evidence of a sex difference. ELS rats compared to controls showed a greater significant positive correlation of EMG with amygdalar rCBF. Factorial analysis revealed a significant main effect of ‘ELS’ on functional activation of nodes within the pain pathway (somatosensory, insular, cingulate and prefrontal cortices, locus coeruleus/lateral parabrachial n. [LC/LPB], periaqueductal gray, sensory thalamus, as well as in the amygdala, hippocampus and hypothalamus. In addition, ELS resulted in an increase in the number of significant functional connections (i.e. degree centrality between regions within the pain circuit, including the amygdala, LC/LPB, insula, anterior ventral cingulate, posterior cingulate (retrosplenium, and stria terminalis, with decreases noted in the sensory thalamus and the hippocampus. Sex differences in rCBF were less broadly expressed, with significant differences noted at the level of the cortex, amygdala, dorsal hippocampus, raphe, sensory thalamus, and caudate-putamen. ELS showed a sexually dimorphic effect (‘Sex x ELS’ interaction at the LC/LPB complex, globus pallidus

Short-Term Fructose Feeding Induces Inflammation and Oxidative Stress in the Hippocampus of Young and Adult Rats.

Science.gov (United States)

Cigliano, Luisa; Spagnuolo, Maria Stefania; Crescenzo, Raffaella; Cancelliere, Rosa; Iannotta, Lucia; Mazzoli, Arianna; Liverini, Giovanna; Iossa, Susanna

2018-04-01

The drastic increase in the consumption of fructose encouraged the research to focus on its effects on brain physio-pathology. Although young and adults differ largely by their metabolic and physiological profiles, most of the previous studies investigated brain disturbances induced by long-term fructose feeding in adults. Therefore, we investigated whether a short-term consumption of fructose (2 weeks) produces early increase in specific markers of inflammation and oxidative stress in the hippocampus of young and adult rats. After the high-fructose diet, plasma lipopolysaccharide and tumour necrosis factor (TNF)-alpha were found significantly increased in parallel with hippocampus inflammation, evidenced by a significant rise in TNF-alpha and glial fibrillar acidic protein concentrations in both the young and adult groups. The fructose-induced inflammatory condition was associated with brain oxidative stress, as increased levels of lipid peroxidation and nitro-tyrosine were detected in the hippocampus. The degree of activation of the protein kinase B, extracellular signal-regulated kinase 1/2, and insulin receptor substrate 1 pathways found in the hippocampus after fructose feeding indicates that the detrimental effects of the fructose-rich diet might largely depend on age. Mitochondrial function in the hippocampus, together with peroxisome proliferator-activated receptor gamma coactivator 1-alpha content, was found significantly decreased in fructose-treated adult rats. In vitro studies with BV-2 microglial cells confirmed that fructose treatment induces TNF-alpha production as well as oxidative stress. In conclusion, these results suggest that unbalanced diet, rich in fructose, may be highly deleterious in young people as in adults and must be strongly discouraged for the prevention of diet-associated neuroinflammation and neurological diseases.

Intrauterine Growth Restriction Programs the Hypothalamus of Adult Male Rats: Integrated Analysis of Proteomic and Metabolomic Data.

Science.gov (United States)

Pedroso, Amanda P; Souza, Adriana P; Dornellas, Ana P S; Oyama, Lila M; Nascimento, Cláudia M O; Santos, Gianni M S; Rosa, José C; Bertolla, Ricardo P; Klawitter, Jelena; Christians, Uwe; Tashima, Alexandre K; Ribeiro, Eliane B

2017-04-07

Programming of hypothalamic functions regulating energy homeostasis may play a role in intrauterine growth restriction (IUGR)-induced adulthood obesity. The present study investigated the effects of IUGR on the hypothalamus proteome and metabolome of adult rats submitted to 50% protein-energy restriction throughout pregnancy. Proteomic and metabolomic analyzes were performed by data independent acquisition mass spectrometry and multiple reaction monitoring, respectively. At age 4 months, the restricted rats showed elevated adiposity, increased leptin and signs of insulin resistance. 1356 proteins were identified and 348 quantified while 127 metabolites were quantified. The restricted hypothalamus showed down-regulation of 36 proteins and 5 metabolites and up-regulation of 21 proteins and 9 metabolites. Integrated pathway analysis of the proteomics and metabolomics data indicated impairment of hypothalamic glucose metabolism, increased flux through the hexosamine pathway, deregulation of TCA cycle and the respiratory chain, and alterations in glutathione metabolism. The data suggest IUGR modulation of energy metabolism and redox homeostasis in the hypothalamus of male adult rats. The present results indicated deleterious consequences of IUGR on hypothalamic pathways involved in pivotal physiological functions. These results provide guidance for future mechanistic studies assessing the role of intrauterine malnutrition in the development of metabolic diseases later in life.

In vivo autoradiographic demonstration of β-adrenergic binding sites in adult rat type II alveolar epithelial cells

International Nuclear Information System (INIS)

Smith, D.M.; Sidhu, M.K.

1984-01-01

Adult male rats were injected intravenously with the muscarinic binding probe 3 H-Quinuclidinyl benzilate (QNB) or the β-adrenergic probe 3 H-dihydroalprenolol (DHA). Other rats were pre-treated with an intraperitoneal injection of a 500-fold excess of L-isoproterenol prior to the DHA. Light microscopic autoradiography of 0.5 μm sections of lung from the QNB group demonstrated very little labelling even after 6 months of exposure. In constrast, trachealis smooth muscle from these animals contained substantial labelling. Autoradiographs of lung from rats injected with DHA demonstrated labelling which was well localized over alveolar septa and concentrated over the cytoplasm of type II cells. Quantitative analysis of labelling in the DHA groups indicated a significant reduction of labelling in animals treated with L-isoproterenol prior to DHA, in both the alveolar parenchyma in general and over type II cells. The results of this study provide morphologic evidence for the uptake and specific binding of β-adrenergic antagonists by the adult lung in vivo, while failing to demonstrate similar binding of a muscarinic probe. In addition, the results demonstrate specific β-adrenergic receptors on type II cells in vivo and substantiate the view of a direct effect of β-adrenergic agonists on alveolar type II cells

Somatosensory discrimination deficits following pediatric cerebral malaria.

Science.gov (United States)

Dugbartey, A T; Spellacy, F J; Dugbartey, M T

1998-09-01

Pathologic studies of central nervous system damage in human falciparum malaria indicate primary localization in the cerebral white matter. We report a sensory-perceptual investigation of 20 Ghanaian children with a recent history of cerebral malaria who were age-, gender-, and education-matched with 20 healthy control subjects. Somatosensory examinations failed to show any evidence of hemianesthesia, pseudohemianesthesia, or extinction to double simultaneous tactile stimulation. While unilateral upper limb testing revealed intact unimanual tactile roughness discrimination, bimanual tactile discrimination, however, was significantly impaired in the cerebral malaria group. A strong negative correlation (r = -0.72) between coma duration and the bimanual tactile roughness discrimination test was also found. An inefficiency in the integrity of callosal fibers appear to account for our findings, although alternative subcortical mechanisms known to be involved in information transfer across the cerebral hemispheres may be compromised as well.

Magnetic resonance imaging of the normal and chronically injured adult rat spinal cord in vivo

International Nuclear Information System (INIS)

Guizar-Sahagun, G.; Rivera, F.; Babinski, E.; Berlanga, E.; Madrazo, M.; Franco-Bourland, R.; Grijalva, I.; Gonzalez, J.; Contreras, B.; Madrazo, I.

1994-01-01

We assessed the capacity of MRI to show and characterise the spinal cord (SC) in vivo in normal and chronically injured adult rats. In the chronically injured animals the SC was studied by MRI and histological examination. MRI was performed at 1.5 T, using gradient-echo and spin-echo (SE) sequences, the latter with and without gadolinium-DTPA (Gd-DTPA). Several positions were tried for good alignment and to diminish interference by respiratory movements. Images of the SC were obtained in sagittal, coronal, and axial planes. Normal SC was observed as a continuous intensity in both sequences, although contrast resolution was better using SE; it was not possible to differentiate the grey and white matter. Low signal was seen in the damaged area in chronically injured rats, which corresponded to cysts, trabeculae, mononuclear infiltrate, and fibroglial wall on histological examination. Gd-DTPA failed to enhance the SC in normal or chronically injured rats. It did, however, cause enhancement of the lesion after acute SC injury. (orig.)

Differentiation in boron distribution in adult male and female rats' normal brain: A BNCT approach

International Nuclear Information System (INIS)

Goodarzi, Samereh; Pazirandeh, Ali; Jameie, Seyed Behnamedin; Baghban Khojasteh, Nasrin

2012-01-01

Boron distribution in adult male and female rats' normal brain after boron carrier injection (0.005 g Boric Acid+0.005 g Borax+10 ml distilled water, pH: 7.4) was studied in this research. Coronal sections of control and trial animal tissue samples were irradiated with thermal neutrons. Using alpha autoradiography, significant differences in boron concentration were seen in forebrain, midbrain and hindbrain sections of male and female animal groups with the highest value, four hours after boron compound injection. - Highlights: ► Boron distribution in male and female rats' normal brain was studied in this research. ► Coronal sections of animal tissue samples were irradiated with thermal neutrons. ► Alpha and Lithium tracks were counted using alpha autoradiography. ► Different boron concentration was seen in brain sections of male and female rats. ► The highest boron concentration was seen in 4 h after boron compound injection.

Magnetic resonance imaging of the normal and chronically injured adult rat spinal cord in vivo

Energy Technology Data Exchange (ETDEWEB)

Guizar-Sahagun, G [Centro de Investigacion del Proyecto Camina, Mexico City (Mexico) Dept. of Clinical Research in Neurology and Neurosurgery, Hospital de Especialidades, Centro Medico Nacional Siglo XXI, Inst. Mexicano del Seguro Social, Mexico City (Mexico); Rivera, F [Centro de Investigacion del Proyecto Camina, Mexico City (Mexico); Babinski, E [Centro de Investigacion del Proyecto Camina, Mexico City (Mexico); Berlanga, E [Dept. of Magnetic Resonance Imaging, Hospital Angeles del Pedregal, Mexico City (Mexico); Madrazo, M [Dept. of Magnetic Resonance Imaging, Hospital Angeles del Pedregal, Mexico City (Mexico); Franco-Bourland, R [Centro de Investigacion del Proyecto Camina, Mexico City (Mexico) Dept. of Biochemistry, Inst. Nacional de la Nutricion, Mexico City (Mexico); Grijalva, I [Centro de Investigacion del Proyecto Camina, Mexico City (Mexico) Dept. of Clinical Research in Neurology and Neurosurgery, Hospital de Especialidades, Centro Medico Nacional Siglo

1994-08-01

We assessed the capacity of MRI to show and characterise the spinal cord (SC) in vivo in normal and chronically injured adult rats. In the chronically injured animals the SC was studied by MRI and histological examination. MRI was performed at 1.5 T, using gradient-echo and spin-echo (SE) sequences, the latter with and without gadolinium-DTPA (Gd-DTPA). Several positions were tried for good alignment and to diminish interference by respiratory movements. Images of the SC were obtained in sagittal, coronal, and axial planes. Normal SC was observed as a continuous intensity in both sequences, although contrast resolution was better using SE; it was not possible to differentiate the grey and white matter. Low signal was seen in the damaged area in chronically injured rats, which corresponded to cysts, trabeculae, mononuclear infiltrate, and fibroglial wall on histological examination. Gd-DTPA failed to enhance the SC in normal or chronically injured rats. It did, however, cause enhancement of the lesion after acute SC injury. (orig.)

The protective effect of omega-3 oil against the hepatotoxicity of cadmium chloride in adult and weanling rats

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Ismail, Treefa F.; Aziz, Falah M.

2017-09-01

The purpose of the present study was to investigate the protective role of omega-3 oil against the toxic effect of cadmium as cadmium chloride (CdCl2) on the liver of male, dams and weanling rats from the histological, ultrastructural and immunohistochemical points of view. Thirty adult male and thirty adult female rats (dams) were used in the present work, divided randomly into five groups, six rats for each group and ten weanling male rats were chosen from each dam group. First group was considered as control group and given only standard diet and drinking water, second group was given (40 mg/ L) of CdCl2 in drinking water. The third group was given (60 mg/ L) of CdCl2 in drinking water. The fourth group was given (40 mg/L) of CdCl2 in drinking water plus omega-3 oil (4 gm/ kg diet) and the fifth group was given (60 mg/L) of CdCl2 in drinking water plus omega-3 oil (4 gm/ kg diet). All the above groups were left for 30 days for males and 42 days for the females) i.e. at the 21th day of the weanling rats birth). Both doses of CdCl2 have caused a lot of histological and ultrastructural alterations in the liver including high degeneration of hepatocytes. Electron microscope images showed thickening of mitochondrial membrane, variation in the size and shape of the mitochondria of the above cells and deposition of Cd particles in the lining of blood sinusoids. The hepatocytes of the weanling rats showed more ultrastructural changes especially the accumulation of lipid droplets. The immunohistochemical images of the mother liver showed a positive P53 reaction in the cells of the liver of CdCl2 treated rats especially those around the portal area. These reactions disappeared in the omega-3 plus CdCl2 groups. The present results suggested a protective role of omega-3 against the cadmium induced hepatotoxicity.

Tibial nerve somatosensory evoked potentials in dogs with degenerative lumbosacral stenosis.

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Meij, Björn P; Suwankong, Niyada; van den Brom, Walter E; Venker-van Haagen, Anjop J; Hazewinkel, Herman A W

2006-02-01

To determine somatosensory evoked potentials (SEPs) in dogs with degenerative lumbosacral stenosis (DLS) and in healthy dogs. Clinical and experimental study. Dogs with DLS (n = 21) and 11 clinically normal dogs, age, and weight matched. Under anesthesia, the tibial nerve was stimulated at the caudolateral aspect of the stifle, and lumbar SEP (LSEP) were recorded percutaneously from S1 to T13 at each interspinous space. Cortical SEP (CSEP) were recorded from the scalp. LSEP were identified as the N1-P1 (latency 3-6 ms) and N2-P2 (latency 7-13 ms) wave complexes in the recordings of dogs with DLS and control dogs. Latency of N1-P1 increased and that of N2-P2 decreased as the active recording electrode was moved cranially from S1 to T13. Compared with controls, latencies were significantly delayed in DLS dogs: .8 ms for N1-P1 and 1.7 ms for the N2-P2 complex. CSEP were not different between groups. Surface needle recording of tibial nerve SEP can be used to monitor somatosensory nerve function of pelvic limbs in dogs. In dogs with DLS, the latency of LSEP, but not of CSEP, is prolonged compared with normal dogs. In dogs with lumbosacral pain from DLS, the cauda equina compression is sufficient to affect LSEP at the lumbar level.

Action of selective serotonin reuptake inhibitor on aggressive behavior in adult rat submitted to the neonatal malnutrition

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Medeiros Jairza Maria Barreto

2001-01-01

Full Text Available The effect of the malnutrition during suckling on the aggressiveness was investigated in adult rats treated or not with citalopram, a selective serotonin reuptake inhibitor (SSRI. The animals were divided into two groups according to the diet used: nourished group-- the rats received the control diet with 23% protein during the life; and malnourished group-- the rats had its mothers submitted to diet with 7.8% protein during suckling. At 120 days of age, each group was sub-divided according to the treatment: acute -- consisting a single i.p. injection of saline solution or 20-mg/Kg citalopram; chronic -- consisting the single injections (1 per day during 14 days of saline or 20 mg/Kg citalopram. The acute or chronic treatment with SSRI reduces aggressive response in nourished rats, but not in malnourished ones. Thus, the malnutrition during the critical period of brain development seems to induce durable alterations in the function of the serotoninergic neurotransmission

Effects of chronic treatment with fluvoxamine and paroxetine during adolescence on serotonin-related behavior in adult male rats.

NARCIS (Netherlands)

Jong, T.R. de; Snaphaan, L.J.A.E.; Pattij, T.; Veening, J.G.; Waldinger, M.D.; Cools, A.R.; Olivier, B.

2006-01-01

Selective Serotonin Reuptake Inhibitors (SSRIs) are designed to treat adults, but are increasingly prescribed for adolescents. SSRIs might cause permanent changes in serotonin-related behavior in adolescents, since their serotonergic system is still developing. Male Wistar rats were treated with

Synaptic protein changes after a chronic period of sensorimotor perturbation in adult rats: a potential role of phosphorylation/O-GlcNAcylation interplay.

Science.gov (United States)

Fourneau, Julie; Canu, Marie-Hélène; Cieniewski-Bernard, Caroline; Bastide, Bruno; Dupont, Erwan

2018-05-28

In human, a chronic sensorimotor perturbation (SMP) through prolonged body immobilization alters motor task performance through a combination of peripheral and central factors. Studies performed on a rat model of SMP have shown biomolecular changes and a reorganization of sensorimotor cortex through events such as morphological modifications of dendritic spines (number, length, functionality). However, underlying mechanisms are still unclear. It is well known that phosphorylation regulates a wide field of synaptic activity leading to neuroplasticity. Another post-translational modification that interplays with phosphorylation is O-GlcNAcylation. This atypical glycosylation, reversible and dynamic, is involved in essential cellular and physiological processes such as synaptic activity, neuronal morphogenesis, learning and memory. We examined potential roles of phosphorylation/O-GlcNAcylation interplay in synaptic plasticity within rat sensorimotor cortex after a SMP period. For this purpose, sensorimotor cortex synaptosomes were separated by sucrose gradient, in order to isolate a subcellular compartment enriched in proteins involved in synaptic functions. A period of SMP induced plastic changes at the pre- and postsynaptic levels, characterized by a reduction of phosphorylation (synapsin1, AMPAR GluA2) and expression (synaptophysin, PSD-95, AMPAR GluA2) of synaptic proteins, as well as a decrease in MAPK/ERK42 activation. Expression levels of OGT/OGA enzymes was unchanged but we observed a specific reduction of synapsin1 O-GlcNAcylation in sensorimotor cortex synaptosomes. The synergistic regulation of synapsin1 phosphorylation/O-GlcNAcylation could affect presynaptic neurotransmitter release. Associated with other pre- and postsynaptic changes, synaptic efficacy could be impaired in somatosensory cortex of SMP rat. Thus, synapsin1 O-GlcNAcylation/phosphorylation interplay also appears to be involved in this synaptic plasticity by finely regulating neural activity

Fluoxetine Dose and Administration Method Differentially Affect Hippocampal Plasticity in Adult Female Rats

Science.gov (United States)

Pawluski, Jodi L.; van Donkelaar, Eva; Abrams, Zipporah; Steinbusch, Harry W. M.; Charlier, Thierry D.

2014-01-01

Selective serotonin reuptake inhibitor medications are one of the most common treatments for mood disorders. In humans, these medications are taken orally, usually once per day. Unfortunately, administration of antidepressant medications in rodent models is often through injection, oral gavage, or minipump implant, all relatively stressful procedures. The aim of the present study was to investigate how administration of the commonly used SSRI, fluoxetine, via a wafer cookie, compares to fluoxetine administration using an osmotic minipump, with regards to serum drug levels and hippocampal plasticity. For this experiment, adult female Sprague-Dawley rats were divided over the two administration methods: (1) cookie and (2) osmotic minipump and three fluoxetine treatment doses: 0, 5, or 10 mg/kg/day. Results show that a fluoxetine dose of 5 mg/kg/day, but not 10 mg/kg/day, results in comparable serum levels of fluoxetine and its active metabolite norfluoxetine between the two administration methods. Furthermore, minipump administration of fluoxetine resulted in higher levels of cell proliferation in the granule cell layer (GCL) at a 5 mg dose compared to a 10 mg dose. Synaptophysin expression in the GCL, but not CA3, was significantly lower after fluoxetine treatment, regardless of administration method. These data suggest that the administration method and dose of fluoxetine can differentially affect hippocampal plasticity in the adult female rat. PMID:24757568

Fluoxetine Dose and Administration Method Differentially Affect Hippocampal Plasticity in Adult Female Rats

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Jodi L. Pawluski

2014-01-01

Full Text Available Selective serotonin reuptake inhibitor medications are one of the most common treatments for mood disorders. In humans, these medications are taken orally, usually once per day. Unfortunately, administration of antidepressant medications in rodent models is often through injection, oral gavage, or minipump implant, all relatively stressful procedures. The aim of the present study was to investigate how administration of the commonly used SSRI, fluoxetine, via a wafer cookie, compares to fluoxetine administration using an osmotic minipump, with regards to serum drug levels and hippocampal plasticity. For this experiment, adult female Sprague-Dawley rats were divided over the two administration methods: (1 cookie and (2 osmotic minipump and three fluoxetine treatment doses: 0, 5, or 10 mg/kg/day. Results show that a fluoxetine dose of 5 mg/kg/day, but not 10 mg/kg/day, results in comparable serum levels of fluoxetine and its active metabolite norfluoxetine between the two administration methods. Furthermore, minipump administration of fluoxetine resulted in higher levels of cell proliferation in the granule cell layer (GCL at a 5 mg dose compared to a 10 mg dose. Synaptophysin expression in the GCL, but not CA3, was significantly lower after fluoxetine treatment, regardless of administration method. These data suggest that the administration method and dose of fluoxetine can differentially affect hippocampal plasticity in the adult female rat.

Cutaneous and periodontal inputs to the cerebellum of the naked mole-rat (Heterocephalus glaber

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Diana K Sarko

2013-11-01

Full Text Available The naked mole-rat (Heterocephalus glaber is a small fossorial rodent with specialized dentition that is reflected by the large cortical area dedicated to representation of the prominent incisors. Due to naked mole-rats’ behavioral reliance on the incisors for digging and for manipulating objects, as well as their ability to move the lower incisors independently, we hypothesized that expanded somatosensory representations of the incisors would be present within the cerebellum in order to accommodate a greater degree of proprioceptive, cutaneous, and periodontal input. Multiunit electrophysiological recordings targeting the ansiform lobule were used to investigate tactile inputs from receptive fields on the entire body with a focus on the incisors. Similar to other rodents, a fractured somatotopy appeared to be present with discrete representations of the same receptive fields repeated within each folium of the cerebellum. These findings confirm the presence of somatosensory inputs to a large area of the naked mole-rat cerebellum with particularly extensive representations of the lower incisors and mystacial vibrissae. We speculate that these extensive inputs facilitate processing of tactile cues as part of a sensorimotor integration network that optimizes how sensory stimuli are acquired through active exploration and in turn adjusts motor outputs (such as independent movement of the lower incisors. These results highlight the diverse sensory specializations and corresponding brain organizational schemes that have evolved in different mammals to facilitate exploration of and interaction with their environment.

Prolongation of GFP-expressed skin graft after intrathymic injection of GFP positive splenocytes in adult rat

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Hakamata, Yoji; Igarashi, Yuka; Murakami, Takashi; Kobayashi, Eiji

2006-02-01

GFP is a fluorescent product of the jellyfish Aequorea victoria and has been used for a variety of biological experiments as a reporter molecule. While GFP possesses advantages for the non-invasive imaging of viable cells, GFP-positive cells are still considered potential xeno-antigens. It is difficult to observe the precise fate of transplanted cells/organs in recipients without immunological control. The aim of this study was to determine whether intrathymic injection of GFP to recipients and the depletion of peripheral lymphocytes could lead to donor-specific unresponsiveness to GFP-expressed cell. LEW rats were administered intraperitoneally with 0.2 ml of anti-rat lymphocyte serum (ALS) 1 day prior to intrathymic injection of donor splenocytes or adeno-GFP vector. Donor cells and vector were non-invasively inoculated into the thymus under high frequency ultrasound imaging using an echo-guide. All animals subsequently received a 7 days GFP-expressed skin graft from the same genetic background GFP LEW transgenic rat. Skin graft survival was greater in rats injected with donor splenocytes (23.6+/-9.1) compared with adeno-GFP (13.0+/-3.7) or untreated control rats (9.5+/-1.0). Intrathymic injection of donor antigen into adult rats can induce donor-specific unresponsiveness. Donor cells can be observed for a long-term in recipients with normal immunity using this strategy.

Moderate and severe perinatal asphyxia induces differential effects on cocaine sensitization in adult rats.

Science.gov (United States)

Galeano, Pablo; Romero, Juan Ignacio; Luque-Rojas, María Jesús; Suárez, Juan; Holubiec, Mariana Inés; Bisagno, Verónica; Santín, Luis Javier; De Fonseca, Fernando Rodríguez; Capani, Francisco; Blanco, Eduardo

2013-09-01

Perinatal asphyxia (PA) increases the likelihood of suffering from dopamine-related disorders, such as ADHD and schizophrenia. Since dopaminergic transmission plays a major role in cocaine sensitization, the purpose of this study was to determine whether PA could be associated with altered behavioral sensitization to cocaine. To this end, adult rats born vaginally (CTL), by caesarean section (C+), or by C+ with 15 min (PA15, moderate PA) or 19 min (PA19, severe PA) of global anoxia were repeatedly administered with cocaine (i.p., 15 mg/kg) and then challenged with cocaine (i.p., 15 mg/kg) after a 5-day withdrawal period. In addition, c-Fos, FosB/ΔFosB, DAT, and TH expression were assessed in dorsal (CPu) and ventral (NAcc) striatum. Results indicated that PA15 rats exhibited an increased locomotor sensitization to cocaine, while PA19 rats displayed an abnormal acquisition of locomotor sensitization and did not express a sensitized response to cocaine. c-Fos expression in NAcc, but not in CPu, was associated with these alterations in cocaine sensitization. FosB/ΔFosB expression was increased in all groups and regions after repeated cocaine administration, although it reached lower expression levels in PA19 rats. In CTL, C+, and PA15, but not in PA19 rats, the expression of TH in NAcc was reduced in groups repeatedly treated with cocaine, independently of the challenge test. Furthermore, this reduction was more pronounced in PA15 rats. DAT expression remained unaltered in all groups and regions studied. These results suggest that moderate PA may increase the vulnerability to drug abuse and in particular to cocaine addiction. Copyright © 2013 Wiley Periodicals, Inc.

Lentiviral gene transfer into the dorsal root ganglion of adult rats

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Park Frank

2011-08-01

Full Text Available Abstract Background Lentivector-mediated gene delivery into the dorsal root ganglion (DRG is a promising method for exploring pain pathophysiology and for genetic treatment of chronic neuropathic pain. In this study, a series of modified lentivector particles with different cellular promoters, envelope glycoproteins, and viral accessory proteins were generated to evaluate the requirements for efficient transduction into neuronal cells in vitro and adult rat DRG in vivo. Results In vitro, lentivectors expressing enhanced green fluorescent protein (EGFP under control of the human elongation factor 1α (EF1α promoter and pseudotyped with the conventional vesicular stomatitis virus G protein (VSV-G envelope exhibited the best performance in the transfer of EGFP into an immortalized DRG sensory neuron cell line at low multiplicities of infection (MOIs, and into primary cultured DRG neurons at higher MOIs. In vivo, injection of either first or second-generation EF1α-EGFP lentivectors directly into adult rat DRGs led to transduction rates of 19 ± 9% and 20 ± 8% EGFP-positive DRG neurons, respectively, detected at 4 weeks post injection. Transduced cells included a full range of neuronal phenotypes, including myelinated neurons as well as both non-peptidergic and peptidergic nociceptive unmyelinated neurons. Conclusion VSV-G pseudotyped lentivectors containing the human elongation factor 1α (EF1α-EGFP expression cassette demonstrated relatively efficient transduction to sensory neurons following direct injection into the DRG. These results clearly show the potential of lentivectors as a viable system for delivering target genes into DRGs to explore basic mechanisms of neuropathic pain, with the potential for future clinical use in treating chronic pain.

Presurgical motor, somatosensory and language fMRI: Technical feasibility and limitations in 491 patients over 13 years

International Nuclear Information System (INIS)

Tyndall, Anthony J.; Reinhardt, Julia; Stippich, Christoph; Tronnier, Volker; Mariani, Luigi

2017-01-01

To analyse the long-term feasibility and limitations of presurgical fMRI in a cohort of tumour and epilepsy patients with different MR-scanners at 1.5 and 3.0 T. Four hundred and ninety-one consecutive patients undergoing presurgical fMRI between 2000 and 2012 on five different MR-scanners using established paradigms and semi-automated data processing were included. Success rates of task performance and BOLD-activation were determined for motor and somatosensory somatotopic mapping and language localisation. Procedural success, failures and imaging artifacts were analysed. MR-field strengths were compared. Two thousand three hundred fifteen of 2348 (98.6 %) attempted paradigms (1033 motor, 1220 speech, 95 somatosensory) were successfully performed. 100 paradigms (4.3 %) were repetition runs. 23 speech, 6 motor and 2 sensory paradigms failed for non-compliance and technical issues. Most language paradigm failures were noted in overt sentence generation. Average significant BOLD-activation was higher for motor than language paradigms (95.8 vs. 81.6 %). Most language paradigms showed significantly higher activation rates at 3 T compared to 1.5 T, whereas no significant difference was found for motor paradigms. fMRI proved very robust for the presurgical localisation of the different motor and somatosensory body representations, as well as Broca's and Wernicke's language areas across different MR-scanners at 1.5 and 3.0 T over 13 years. (orig.)

Presurgical motor, somatosensory and language fMRI: Technical feasibility and limitations in 491 patients over 13 years

Energy Technology Data Exchange (ETDEWEB)

Tyndall, Anthony J.; Reinhardt, Julia; Stippich, Christoph [University Hospital Basel, Division of Diagnostic and Interventional Neuroradiology, Basel (Switzerland); Tronnier, Volker [University Hospital Schleswig-Holstein, Luebeck Campus, Department of Neurosurgery, Luebeck (Germany); Mariani, Luigi [University Hospitals Basel, Department of Neurosurgery, Basel (Switzerland)

2017-01-15

To analyse the long-term feasibility and limitations of presurgical fMRI in a cohort of tumour and epilepsy patients with different MR-scanners at 1.5 and 3.0 T. Four hundred and ninety-one consecutive patients undergoing presurgical fMRI between 2000 and 2012 on five different MR-scanners using established paradigms and semi-automated data processing were included. Success rates of task performance and BOLD-activation were determined for motor and somatosensory somatotopic mapping and language localisation. Procedural success, failures and imaging artifacts were analysed. MR-field strengths were compared. Two thousand three hundred fifteen of 2348 (98.6 %) attempted paradigms (1033 motor, 1220 speech, 95 somatosensory) were successfully performed. 100 paradigms (4.3 %) were repetition runs. 23 speech, 6 motor and 2 sensory paradigms failed for non-compliance and technical issues. Most language paradigm failures were noted in overt sentence generation. Average significant BOLD-activation was higher for motor than language paradigms (95.8 vs. 81.6 %). Most language paradigms showed significantly higher activation rates at 3 T compared to 1.5 T, whereas no significant difference was found for motor paradigms. fMRI proved very robust for the presurgical localisation of the different motor and somatosensory body representations, as well as Broca's and Wernicke's language areas across different MR-scanners at 1.5 and 3.0 T over 13 years. (orig.)

Chronic prenatal caffeine exposure impairs novel object recognition and radial arm maze behaviors in adult rats.

Science.gov (United States)

Soellner, Deborah E; Grandys, Theresa; Nuñez, Joseph L

2009-12-14

In this report, we demonstrate that chronic prenatal exposure to a moderate dose of caffeine disrupts novel object recognition and radial arm maze behaviors in adult male and female rats. Pregnant dams were administered either tap water or 75 mg/L caffeinated tap water throughout gestation. Oral self-administration in the drinking water led to an approximate maternal intake of 10mg/kg/day, equivalent to 2-3 cups of coffee/day in humans based on a metabolic body weight conversion. In adulthood, the offspring underwent testing on novel object recognition, radial arm maze, and Morris water maze tasks. Prenatal caffeine exposure was found to impair 24-h memory retention in the novel object recognition task and impair both working and reference memory in the radial arm maze. However, prenatal caffeine exposure did not alter Morris water maze performance in either a simple water maze procedure or in an advanced water maze procedure that included reversal and working memory paradigms. These findings demonstrate that chronic oral intake of caffeine throughout gestation can alter adult cognitive behaviors in rats.

Cocaine enhances resistance to extinction of responding for brain-stimulation reward in adult prenatally stressed rats.

Science.gov (United States)

Gao, Shuibo; Suenaga, Toshiko; Oki, Yutaka; Yukie, Masao; Nakahara, Daiichiro

2011-10-01

The present experiment assessed whether prenatal stress (PS) can alter the ability of acute and chronic cocaine administration to increase and decrease the rewarding effectiveness of the medial forebrain bundle (MFB) using intracranial self-stimulation (ICSS), and also whether PS can affect the extinction of the MFB stimulation response. Adult male offspring of female rats that received PS or no PS (nPS) were implanted with MFB stimulating electrodes, and were then tested in ICSS paradigms. In both nPS and PS offspring, acute cocaine injection decreased ICSS thresholds dose-dependently. However, the threshold-lowering effects at any dose were not significantly different between groups. There was also no group-difference in the threshold-elevating effects of chronic cocaine administration. Nevertheless, chronically drug-administered PS rats exhibited a resistance to the extinguishing of the response for brain-stimulation reward when acutely treated with cocaine, as compared to extinction without cocaine treatment. The results suggest that PS may weaken the ability for response inhibition under cocaine loading in male adult offspring. Copyright © 2011 Elsevier B.V. All rights reserved.

Neonatal tobacco smoke reduces thermogenesis capacity in brown adipose tissue in adult rats

OpenAIRE

Peixoto, T.C.; Moura, E.G.; Oliveira, E.; Younes-Rapozo, V.; Soares, P.N.; Rodrigues, V.S.T.; Santos, T.R.; Peixoto-Silva, N.; Carvalho, J.C.; Calvino, C.; Conceição, E.P.S.; Guarda, D.S.; Claudio-Neto, S.; Manhães, A.C.; Lisboa, P.C.

2018-01-01

Maternal smoking is a risk factor for progeny obesity. We have previously shown, in a rat model of neonatal tobacco smoke exposure, a mild increase in food intake and a considerable increase in visceral adiposity in the adult offspring. Males also had secondary hyperthyroidism, while females had only higher T4. Since brown adipose tissue (BAT) hypofunction is related to obesity, here we tested the hypothesis that higher levels of thyroid hormones are not functional in BAT, suggesting a lower ...

Immediate effects of somatosensory stimulation on hand function in patients with poststroke hemiparesis: a randomized cross-over trial.

Science.gov (United States)

Sim, Sun-Mi; Oh, Duck-Won; Chon, Seung-chul

2015-12-01

This study aimed to determine the immediate effects of somatosensory stimulation on hand function in patients with poststroke hemiparesis. Eleven patients with poststroke hemiparesis participated in this study. Four types (no stimulation, vibration, and light and rough touches) of somatosensory stimulation were performed randomly for 4 days applying only one type of somatosensory stimulation each day. The box and block test (BBT), the Jebsen-Taylor hand function test (JTHFT), hand grip strength (HGS), and movement distance and peak velocity of the wrist joint during a forward-reaching task were measured. The BBT and JTHFT scores for no stimulation [BBT: median (interquartile range), 0.00 (-1.00 to 1.00) and JTHFT: 2.57 (-0.47 to 4.92)] were significantly different from those for vibration [BBT: 3.00 (2.00-5.00) and JTHFT: -16.02 (-23.06 to -4.31)], light touch [BBT: 3.00 (1.00-4.00) and JTHFT: -5.00 (-21.20 to -0.94)], and rough touch [BBT: 2.00 (1.00-4.00) and JTHFT: -6.19 (-18.22 to -3.70)]. The JTHFT score was significantly higher for vibration than that for rough touch (Phemiparesis, with more favorable effects observed in vibration stimulation.

Pheromones enhance somatosensory processing in newt brains through a vasotocin-dependent mechanism.

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Thompson, R R; Dickinson, P S; Rose, J D; Dakin, K A; Civiello, G M; Segerdahl, A; Bartlett, R

2008-07-22

We tested whether the sex pheromones that stimulate courtship clasping in male roughskin newts do so, at least in part, by amplifying the somatosensory signals that directly trigger the motor pattern associated with clasping and, if so, whether that amplification is dependent on endogenous vasotocin (VT). Female olfactory stimuli increased the number of action potentials recorded in the medulla of males in response to tactile stimulation of the cloaca, which triggers the clasp motor reflex, as well as to tactile stimulation of the snout and hindlimb. That enhancement was blocked by exposing the medulla to a V1a receptor antagonist before pheromone exposure. However, the antagonist did not affect medullary responses to tactile stimuli in the absence of pheromone exposure, suggesting that pheromones amplify somatosensory signals by inducing endogenous VT release. The ability of VT to couple sensory systems together in response to social stimulation could allow this peptide to induce variable behavioural outcomes, depending on the immediate context of the social interaction and thus on the nature of the associated stimuli that are amplified. If widespread in vertebrates, this mechanism could account for some of the behavioural variability associated with this and related peptides both within and across species.

Brain activation during dual-task processing is associated with cardiorespiratory fitness and performance in older adults

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Chelsea N Wong

2015-08-01

Full Text Available Higher cardiorespiratory fitness is associated with better cognitive performance and enhanced brain activation. Yet, the extent to which cardiorespiratory fitness-related brain activation is associated with better cognitive performance is not well understood. In this cross-sectional study, we examined whether the association between cardiorespiratory fitness and executive function was mediated by greater prefrontal cortex activation in healthy older adults. Brain activation was measured during dual-task performance with functional magnetic resonance imaging in a sample of 128 healthy older adults (59-80 years. Higher cardiorespiratory fitness was associated with greater activation during dual-task processing in several brain areas including the anterior cingulate and supplementary motor cortex (ACC/SMA, thalamus and basal ganglia, right motor/somatosensory cortex and middle frontal gyrus, and left somatosensory cortex, controlling for age, sex, education, and gray matter volume. Of these regions, greater ACC/SMA activation mediated the association between cardiorespiratory fitness and dual-task performance. We provide novel evidence that cardiorespiratory fitness may support cognitive performance by facilitating brain activation in a core region critical for executive function.

Galanin-like peptide stimulates feeding and sexual behavior via dopaminergic fibers within the medial preoptic area of adult male rats.

Science.gov (United States)

Taylor, A; Madison, F N; Fraley, G S

2009-03-01

Galanin-like peptide (GALP) is located in the arcuate nucleus (Arc) of the hypothalamus and is known to regulate both food intake and sexual behaviors in adult male rats. We have previously demonstrated that ICV GALP administration elicits a significant fos response within the medial preoptic area (mPOA). GALP is known to stimulate both food intake and male-typical sex behavior, presumably by direct actions within the mPOA. Recent data from our and other labs have led us to suspect that GALP effects on sex behaviors are due to activation of incertohypothalamic dopaminergic neurons that terminate within the mPOA. To test the hypothesis that GALP activates mPOA dopaminergic systems, we utilized an immunolesion technique to eliminate dopaminergic fiber input to the mPOA via a dopamine transporter-specific toxin (DATSAP, n=8) and compared to control injections (SAP, n=8). All animals were sexually experienced adult male Long-Evans rats. DATSAP-treated male rats showed a significant (psexual behaviors compared to SAP controls. We found that elimination of dopaminergic fibers within the mPOA significantly (psexual behavior under normal mating paradigms. Injections of GALP (5.0 nmol) significantly increased (psexual behaviors in male rats by stimulating dopaminergic neurons that terminate within the mPOA.

Electrical somatosensory stimulation followed by motor training of the paretic upper limb in acute stroke

DEFF Research Database (Denmark)

Ghaziani, Emma; Couppé, Christian; Henkel, Cecilie

2017-01-01

functioning is most pronounced during the first 4 weeks post stroke, there are few studies investigating the effect of rehabilitation during this critical time window. The purpose of this trial is to determine the effect of electrical somatosensory stimulation (ESS) initiated in the acute stroke phase...

Salicylate-induced changes in auditory thresholds of adolescent and adult rats.

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Brennan, J F; Brown, C A; Jastreboff, P J

1996-01-01

Shifts in auditory intensity thresholds after salicylate administration were examined in postweanling and adult pigmented rats at frequencies ranging from 1 to 35 kHz. A total of 132 subjects from both age levels were tested under two-way active avoidance or one-way active avoidance paradigms. Estimated thresholds were inferred from behavioral responses to presentations of descending and ascending series of intensities for each test frequency value. Reliable threshold estimates were found under both avoidance conditioning methods, and compared to controls, subjects at both age levels showed threshold shifts at selective higher frequency values after salicylate injection, and the extent of shifts was related to salicylate dose level.

Exercise training reinstates cortico-cortical sensorimotor functional connectivity following striatal lesioning: Development and application of a subregional-level analytic toolbox for perfusion autoradiographs of the rat brain

Science.gov (United States)

Peng, Yu-Hao; Heintz, Ryan; Wang, Zhuo; Guo, Yumei; Myers, Kalisa; Scremin, Oscar; Maarek, Jean-Michel; Holschneider, Daniel

2014-12-01

Current rodent connectome projects are revealing brain structural connectivity with unprecedented resolution and completeness. How subregional structural connectivity relates to subregional functional interactions is an emerging research topic. We describe a method for standardized, mesoscopic-level data sampling from autoradiographic coronal sections of the rat brain, and for correlation-based analysis and intuitive display of cortico-cortical functional connectivity (FC) on a flattened cortical map. A graphic user interface “Cx-2D” allows for the display of significant correlations of individual regions-of-interest, as well as graph theoretical metrics across the cortex. Cx-2D was tested on an autoradiographic data set of cerebral blood flow (CBF) of rats that had undergone bilateral striatal lesions, followed by 4 weeks of aerobic exercise training or no exercise. Effects of lesioning and exercise on cortico-cortical FC were examined during a locomotor challenge in this rat model of Parkinsonism. Subregional FC analysis revealed a rich functional reorganization of the brain in response to lesioning and exercise that was not apparent in a standard analysis focused on CBF of isolated brain regions. Lesioned rats showed diminished degree centrality of lateral primary motor cortex, as well as neighboring somatosensory cortex--changes that were substantially reversed in lesioned rats following exercise training. Seed analysis revealed that exercise increased positive correlations in motor and somatosensory cortex, with little effect in non-sensorimotor regions such as visual, auditory, and piriform cortex. The current analysis revealed that exercise partially reinstated sensorimotor FC lost following dopaminergic deafferentation. Cx-2D allows for standardized data sampling from images of brain slices, as well as analysis and display of cortico-cortical FC in the rat cerebral cortex with potential applications in a variety of autoradiographic and histologic

Experimentally induced hyperthyroidism influences oxidant and antioxidant status and impairs male gonadal functions in adult rats.

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Asker, M E; Hassan, W A; El-Kashlan, A M

2015-08-01

The objective of the present experiment was to study the effect of hyperthyroidism on male gonadal functions and oxidant/antioxidant biomarkers in testis of adult rats. Induction of hyperthyroidism by L-thyroxine (L-T4, 300 μg kg(-1) body weight) treatment once daily for 3 or 8 weeks caused a decrease in body weight gain as well as in absolute genital sex organs weight. The epididymal sperm counts and their motility were significantly decreased in a time-dependent manner following L-T4 treatment. Significant decline in serum levels of luteinising hormone, follicle stimulating hormone and testosterone along with significant increase in serum estradiol level was observed in hyperthyroid rats compared with euthyroid ones. Significant increase in malondialdehyde and nitric oxide concentration associated with significant decrease in superoxide dismutase and catalase activity was also noticed following hyperthyroidism induction. Both reduced glutathione content and glutathione peroxidase activity were increased in hyperthyroid rats compared with control rats. Marked histopathological alterations were observed in testicular section of hyperthyroid rats. These results provide evidence that hypermetabolic state induced by excess level of thyroid hormones may be a causative factor for the impairment of testicular physiology as a consequence of oxidative stress. © 2014 Blackwell Verlag GmbH.

RNA synthesis in primary cultures of adult rat hepatocytes

International Nuclear Information System (INIS)

Fugassa, E.; Gallo, G.; Voci, A.; Cordone, A.

1983-01-01

The ability of hepatocyte monolayers to synthesize RNA was investigated by measuring [3H]orotic acid incorporation into RNA and the total nuclear RNA polymerase activity as a function of the time in culture. The results demonstrate that primary cultures of hepatocytes maintained in a chemically defined serum- and hormone-free medium are able to synthesize RNA actively. This ability increases within the first 2 d of culture, despite the concomitant decrease in [3H]orotic acid uptake, and decreases only after 3 d. Factors such as serum, insulin, and dexamethasone, known to improve maintenance of functional hepatocytes, markedly stimulate the uptake of labeled precursor without apparently affecting the rate of RNA synthesis by cultured cells. It is suggested that the culture of adult rat hepatocytes provides a useful experimental model for the studies of hormonal regulation of transcription in liver

The effects of sildenafil ciltrate on the lateral geniculate body of adult Wistar rats (Rattus norvegicus- A histological study

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Andrew Osayame Eweka

2010-07-01

Full Text Available The histological effect of oral administration of sildenafil citrate (Viagra, commonly used as an aphrodisiac and for the treatment of erectile dysfunction on one of the visual relay centres namely the lateral geniculate body (LGB of adult Wistar rat was carefully studied. The rats of both sexes (n=24, average weight of 202g were randomly assigned into three treatment (n=18 and control (n=6 groups. The rats in the treatment groups ‘A’, ‘B’ and ‘C’ received respectively, 0.25mg/kg, 0.70mg/kg and 1.43mg/kg body weight of sildenafil citrate base dissolved in distilled water daily for 30 days, through orogastric feeding tube, while that of the control group D, received equal volume of distilled water daily during the period of the experiment. The rats were fed with growers’ mash obtained from Edo Feeds and Flour Mill Ltd, Ewu, Edo State, Nigeria and were given water liberally. The rats were sacrificed on day thirty-one of the experiment. The lateral geniculate body (LGB was carefully dissected out and quickly fixed in 10% formal saline for histological studies. The histological findings after H&E method indicated that the treated section of the lateral geniculate body (LGB showed some varying degree of reduced cellular population based on its sparse distribution, degenerative changes, cellular hypertrophy, and intercellular vacuolations appearing in the stroma. Varying dosage and long administration of sildenafil citrate may have some deleterious effects on the neurons of the intracranial visual relay centre and this may probably have some adverse effects on visual sensibilities by its deleterious effects on the cells of the lateral geniculate body (LGB of adult Wistar rats. It is therefore recommended that further studies aimed at corroborating these observations be carried out.

Ontogenic changes in selenite metabolism in rats

International Nuclear Information System (INIS)

Ostadalova, I.; Babicky, A.; Kopoldova, J.

1982-01-01

Radioselenium concentration and excretion was studied after administration of 75 Se-labelled selenite to male rats during ontogeny. The concentration of radioselenium in individual organs decreases with increasing age. The largest differences between young and adults were in the quantity and quality of excreted substances. During 2 h after the administration of 20 μmol selenite/kg young rats excreted 2.4% of the dose, essentially in the urine only, whilst adults excreted a total of 11%, distributed equally in breath and urine. The part excreted as methylated metabolites was 0.1% of the administered dose in young and 6.3% in adult rats. These results support the hypothesis that the differences in the sensitivity to the toxic action of selenite between young and adult rats can be due to ontogenic differences in selenium metabolism. (orig.)

Asymmetric Functional Connectivity of the Contra- and Ipsilateral Secondary Somatosensory Cortex during Tactile Object Recognition

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Yinghua Yu

2018-01-01

Full Text Available In the somatosensory system, it is well known that the bilateral secondary somatosensory cortex (SII receives projections from the unilateral primary somatosensory cortex (SI, and the SII, in turn, sends feedback projections to SI. Most neuroimaging studies have clearly shown bilateral SII activation using only unilateral stimulation for both anatomical and functional connectivity across SII subregions. However, no study has unveiled differences in the functional connectivity of the contra- and ipsilateral SII network that relates to frontoparietal areas during tactile object recognition. Therefore, we used event-related functional magnetic resonance imaging (fMRI and a delayed match-to-sample (DMS task to investigate the contributions of bilateral SII during tactile object recognition. In the fMRI experiment, 14 healthy subjects were presented with tactile angle stimuli on their right index finger and asked to encode three sample stimuli during the encoding phase and one test stimulus during the recognition phase. Then, the subjects indicated whether the angle of test stimulus was presented during the encoding phase. The results showed that contralateral (left SII activity was greater than ipsilateral (right SII activity during the encoding phase, but there was no difference during the recognition phase. A subsequent psycho-physiological interaction (PPI analysis revealed distinct connectivity from the contra- and ipsilateral SII to other regions. The left SII functionally connected to the left SI and right primary and premotor cortex, while the right SII functionally connected to the left posterior parietal cortex (PPC. Our findings suggest that in situations involving unilateral tactile object recognition, contra- and ipsilateral SII will induce an asymmetrical functional connectivity to other brain areas, which may occur by the hand contralateral effect of SII.

INCREASES IN ANXIETY-LIKE BEHAVIOR INDUCED BY ACUTE STRESS ARE REVERSED BY ETHANOL IN ADOLESCENT BUT NOT ADULT RATS

OpenAIRE

Varlinskaya, Elena I.; Spear, Linda P.

2011-01-01

Repeated exposure to stressors has been found to increase anxiety-like behavior in laboratory rodents, with the social anxiety induced by repeated restraint being extremely sensitive to anxiolytic effects of ethanol in both adolescent and adult rats. No studies, however, have compared social anxiogenic effects of acute stress or the capacity of ethanol to reverse this anxiety in adolescent and adult animals. Therefore, the present study was designed to investigate whether adolescent [postnata...

Effect of Simultaneous Use of Ritalin with Grape Seed Extract on Passive Avoidance Learning in Adult Male Rats

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Tooba Karimizadeh Moneh

2016-10-01

Full Text Available Background & objectives: Ritalin is one of the drugs used in the treatment of attention-deficit/hyperactivity disorder (ADHD. This study aimed to investigate the comparative effect of Ritalin with grape seed extract on passive avoidance learning in adult male rats. Methods: In this experimental study, 40 adult male Wistar rats divided randomly into 5 groups of 8 rats including control, sham and three experimental groups. The control group received no treatment. The sham group received 1 ml of distilled water per day. At the same time the experimental groups received 100 mg/kg grape seed extract, 1 mg/kg Ritalin or 100 mg/kg grape seed extract together with 1 mg/kg of Ritalin by gavage for 28 days. For measuring the amount of avoidance learning, Shuttle box was used. Data analyzed by ANOVA and consistent Tukey's tests using SPSS-18 software and p>0.05 considered as significant. Results: The results showed that Ritalin decreases the passive avoidance learning, while the grape seed extract alone or together with Ritalin increases passive avoidance learning. Conclusion:  The outcome of this research shows that taking Ritalin leads to decreasing passive avoidance learning. However, the simultaneous taking Ritalin with grape seed extract inhibits the Ritalin effect and increasing the learning.

Structural reorganization of the early visual cortex following Braille training in sighted adults.

Science.gov (United States)

Bola, Łukasz; Siuda-Krzywicka, Katarzyna; Paplińska, Małgorzata; Sumera, Ewa; Zimmermann, Maria; Jednoróg, Katarzyna; Marchewka, Artur; Szwed, Marcin

2017-12-12

Training can induce cross-modal plasticity in the human cortex. A well-known example of this phenomenon is the recruitment of visual areas for tactile and auditory processing. It remains unclear to what extent such plasticity is associated with changes in anatomy. Here we enrolled 29 sighted adults into a nine-month tactile Braille-reading training, and used voxel-based morphometry and diffusion tensor imaging to describe the resulting anatomical changes. In addition, we collected resting-state fMRI data to relate these changes to functional connectivity between visual and somatosensory-motor cortices. Following Braille-training, we observed substantial grey and white matter reorganization in the anterior part of early visual cortex (peripheral visual field). Moreover, relative to its posterior, foveal part, the peripheral representation of early visual cortex had stronger functional connections to somatosensory and motor cortices even before the onset of training. Previous studies show that the early visual cortex can be functionally recruited for tactile discrimination, including recognition of Braille characters. Our results demonstrate that reorganization in this region induced by tactile training can also be anatomical. This change most likely reflects a strengthening of existing connectivity between the peripheral visual cortex and somatosensory cortices, which suggests a putative mechanism for cross-modal recruitment of visual areas.

Motor and somatosensory conversion disorder: a functional unawareness syndrome?

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Perez, David L; Barsky, Arthur J; Daffner, Kirk; Silbersweig, David A

2012-01-01

Although conversion disorder is closely connected to the origins of neurology and psychiatry, it remains poorly understood. In this article, the authors discuss neural and clinical parallels between lesional unawareness disorders and unilateral motor and somatosensory conversion disorder, emphasizing functional neuroimaging/disease correlates. Authors suggest that a functional-unawareness neurobiological framework, mediated by right hemisphere-lateralized, large-scale brain network dysfunction, may play a significant role in the neurobiology of conversion disorder. The perigenual anterior cingulate and the posterior parietal cortices are detailed as important in disease pathophysiology. Further investigations will refine the functional-unawareness concept, clarify the role of affective circuits, and delineate the process through which functional neurologic symptoms emerge.

Assessment of the neuroprotective effects of Lavandula angustifolia extract on the contusive model of spinal cord injury in Wistar rats

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Gholamreza eKaka

2016-02-01

Full Text Available IntroductionSpinal cord injury (SCI involves a primary trauma and secondary cellular processes that can lead to severe damage to the nervous system, resulting in long-term spinal deficits. At the cellular level, SCI causes astrogliosis, of which glial fibrillary acidic protein (GFAP is a major index. ObjectiveThe aim of this study was to investigate the neuroprotective effects of Lavandula angustifolia (Lav on the repair of spinal cord injuries in Wistar rats.Materials and MethodsForty-five female rats were randomly divided into six groups of seven rats each: the intact, sham, control (SCI, Lav 100, Lav 200, and Lav 400 groups. Every week after SCI onset, all animals were evaluated for behavior outcomes by the Basso, Beattie, and Bresnahan (BBB score. H&E staining was performed to examine the lesions post-injury. GFAP expression was assessed for astrogliosis. Somatosensory evoked potential (SEP testing was performed to detect the recovery of neural conduction.Results BBB scores were significantly increased and delayed responses on sensory tests were significantly decreased in the Lav 200 and Lav 400 groups compared to the control group. The greatest decrease of GFAP was evident in the Lav 200 and Lav 400 groups. EMG results showed significant improvement in the hindlimbs in the Lav 200 and Lav 400 groups compared to the control group. Cavity areas significantly decreased and the number of ventral motor neurons significantly increased in the Lav 200 and Lav 400 groups.ConclusionLav at doses of 200 mg/kg and 400 mg/kg can promote structural and functional recovery after SCI. The neuroprotective effects of L. angustifolia can lead to improvement in the contusive model of spinal cord injury in Wistar rats.Keywords Spinal cord injury (SCI; Lavandula angustifolia; neuroprotection; Basso, Beattie, and Bresnahan (BBB; glial fibrillary acidic protein (GFAP; somatosensory evoked potential (SEP

BOLD responses in somatosensory cortices better reflect heat sensation than pain.

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Moulton, Eric A; Pendse, Gautam; Becerra, Lino R; Borsook, David

2012-04-25

The discovery of cortical networks that participate in pain processing has led to the common generalization that blood oxygen level-dependent (BOLD) responses in these areas indicate the processing of pain. Physical stimuli have fundamental properties that elicit sensations distinguishable from pain, such as heat. We hypothesized that pain intensity coding may reflect the intensity coding of heat sensation during the presentation of thermal stimuli during fMRI. Six 3T fMRI heat scans were collected for 16 healthy subjects, corresponding to perceptual levels of "low innocuous heat," "moderate innocuous heat," "high innocuous heat," "low painful heat," "moderate painful heat," and "high painful heat" delivered by a contact thermode to the face. Subjects rated pain and heat intensity separately after each scan. A general linear model analysis detected different patterns of brain activation for the different phases of the biphasic response to heat. During high painful heat, the early phase was associated with significant anterior insula and anterior cingulate cortex activation. Persistent responses were detected in the right dorsolateral prefrontal cortex and inferior parietal lobule. Only the late phase showed significant correlations with perceptual ratings. Significant heat intensity correlated activation was identified in contralateral primary and secondary somatosensory cortices, motor cortex, and superior temporal lobe. These areas were significantly more related to heat ratings than pain. These results indicate that heat intensity is encoded by the somatosensory cortices, and that pain evaluation may either arise from multimodal evaluative processes, or is a distributed process.

From acute to persistent low back pain: a longitudinal investigation of somatosensory changes using quantitative sensory testing—an exploratory study

Science.gov (United States)

Marcuzzi, Anna; Wrigley, Paul J.; Dean, Catherine M.; Graham, Petra L.; Hush, Julia M.

2018-01-01

Abstract Introduction: Chronic low back pain (LBP) is commonly associated with generalised pain hypersensitivity. It is suggested that such somatosensory alterations are important determinants for the transition to persistent pain from an acute episode of LBP. Although cross-sectional research investigating somatosensory function in the acute stage is developing, no longitudinal studies designed to evaluate temporal changes have been published. Objectives: This exploratory study aimed to investigate the temporal development of somatosensory changes from the acute stage of LBP to up to 4 months from onset. Methods: Twenty-five people with acute LBP (pain-free controls were prospectively assessed at baseline using quantitative sensory testing with the assessor blinded to group allocation, and again at 2 and 4 months. Psychological variables were concurrently assessed. People with acute LBP were classified based on their average pain severity over the previous week at 4 months as recovered (≤1/10 numeric rating scale) or persistent (≥2/10 numeric rating scale) LBP. Results: In the persistent LBP group, (1) there was a significant decrease in pressure pain threshold between 2 and 4 months (P pain threshold was significantly different from the recovered LBP group (P pain-free control reference value. Pain-related psychological variables were significantly higher in those with persistent LBP compared with the recovered LBP group at all time points (P pain sensitivity occurring in the subacute stage warrant further longitudinal evaluation to better understand the role of somatosensory changes in the development of persistent LBP. Pain-related cognitions at baseline distinguished persistent from the recovered LBP groups, emphasizing the importance of concurrent evaluation of psychological contributors in acute LBP. PMID:29756087

Cardiac oxidative stress following maternal separation stress was mitigated following adolescent voluntary exercise in adult male rat.