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Sample records for soleus h-reflex gain

  1. Changes in soleus H-reflex during walking in middle-aged, healthy subjects

    DEFF Research Database (Denmark)

    Raffalt, Peter C; Alkjær, Tine; Simonsen, Erik B

    2015-01-01

    INTRODUCTION: To assess the effect of aging on stretch reflex modulation during walking, soleus H-reflexes obtained in 15 middle-aged (mean age 56.4±6.9 years) and 15 young (mean age 23.7±3.9 years) subjects were compared. METHODS: The H-reflex amplitude, muscle activity (EMG) of the soleus...... and tibialis anterior muscles, and EMG/H-reflex gain were measured during 4-km/h treadmill walking. RESULTS: The normalized H-reflex amplitude was lower in the swing phase for the middle-aged group, and there was no difference in muscle activity. EMG/H-reflex gain did not differ between groups. CONCLUSIONS: H......-reflex amplitude during walking was affected by aging, and changes during the swing phase could be seen in the middle-aged subjects. Subdividing the 2 age groups into groups of facilitated or suppressed swing-phase H-reflex revealed that the H-reflex amplitude modulation pattern in the group with facilitated swing...

  2. Soleus H reflex extinction in controls and spastic patients: ordered occlusion or diffuse inhibition?

    NARCIS (Netherlands)

    Hilgevoord, A. A.; Bour, L. J.; Koelman, J. H.; Ongerboer de Visser, B. W.

    1995-01-01

    Extinction of the soleus H reflex at higher stimulus intensities is commonly attributed to retrograde conduction of action potentials in motor axons. This study was designed to gain further insight into the mechanisms underlying the extinction. The decrease of the H reflex was quantified in a group

  3. Soleus and lateral gastrocnemius H-reflexes during standing with unstable footwear.

    Science.gov (United States)

    Friesenbichler, Bernd; Lepers, Romuald; Maffiuletti, Nicola A

    2015-05-01

    Unstable footwear has been shown to increase lower extremity muscle activity, but the reflex response to perturbations induced by this intervention is unknown. Twenty healthy subjects stood in stable and unstable footwear conditions (presented randomly) while H-reflex amplitude and background muscle activity were measured in the soleus and lateral gastrocnemius (LG) muscles. Wearing unstable footwear resulted in larger H-reflexes (normalized to the maximal M-wave) for the LG (+12%; P = 0.025), but not for the soleus (+4%; P > 0.05). Background activity of both muscles was significantly higher in the unstable condition. The H-reflex facilitation observed with unstable footwear was unexpected, as challenging postural conditions usually result in reflex depression. Increased muscle activity, decreased presynaptic inhibition, and/or more forward postural position may have (over-)compensated the expected reflex depression. Differences between LG and soleus H-reflex modulation may be due to diverging motor unit recruitment thresholds. © 2015 Wiley Periodicals, Inc.

  4. Soleus muscle H-reflex monitoring in endoscopic surgery under general anesthesia percutaneous interlaminar approach.

    Science.gov (United States)

    Wang, Huixue; Gao, Yingji; Ji, Lixin; Bai, Wanshan

    2018-05-01

    The clinical value of soleus muscle H-reflex monitoring in general anesthesia percutaneous interlaminar approach was investigated. A total of 80 cases with unilateral L5-S1 disc herniation between January 2015 and October 2016 were randomly divided into control group (without soleus muscle H-reflex monitoring, n=40) and observation group (with soleus muscle H-reflex monitoring, n=40). Results showed that the operation time of the observation group was shorter than that of the control group (Ph after operation, the amplitude of H-reflex in diseased side soleus muscle was significantly lower than that in healthy side (Ph postoperatively, the latency of H-reflex in diseased side soleus muscle was shorter than that of healthy side (PH-reflex latency in soleus muscle were significantly lower (PH-reflex monitoring can effectively reduce the damage to the nerve roots under percutaneous endoscopic intervertebral endoscopic surgery under general anesthesia, improve the accuracy of surgery, reduce the complications, shorten the operation time and reduce the surgical bleeding, which is more beneficial to patients smooth recovery.

  5. Operant conditioning of the soleus H-reflex does not induce long-term changes in the gastrocnemius H-reflexes and does not disturb normal locomotion in humans.

    Science.gov (United States)

    Makihara, Yukiko; Segal, Richard L; Wolpaw, Jonathan R; Thompson, Aiko K

    2014-09-15

    In normal animals, operant conditioning of the spinal stretch reflex or the H-reflex has lesser effects on synergist muscle reflexes. In rats and people with incomplete spinal cord injury (SCI), soleus H-reflex operant conditioning can improve locomotion. We studied in normal humans the impact of soleus H-reflex down-conditioning on medial (MG) and lateral gastrocnemius (LG) H-reflexes and on locomotion. Subjects completed 6 baseline and 30 conditioning sessions. During conditioning trials, the subject was encouraged to decrease soleus H-reflex size with the aid of visual feedback. Every sixth session, MG and LG H-reflexes were measured. Locomotion was assessed before and after conditioning. In successfully conditioned subjects, the soleus H-reflex decreased 27.2%. This was the sum of within-session (task dependent) adaptation (13.2%) and across-session (long term) change (14%). The MG H-reflex decreased 14.5%, due mainly to task-dependent adaptation (13.4%). The LG H-reflex showed no task-dependent adaptation or long-term change. No consistent changes were detected across subjects in locomotor H-reflexes, EMG activity, joint angles, or step symmetry. Thus, in normal humans, soleus H-reflex down-conditioning does not induce long-term changes in MG/LG H-reflexes and does not change locomotion. In these subjects, task-dependent adaptation of the soleus H-reflex is greater than it is in people with SCI, whereas long-term change is less. This difference from results in people with SCI is consistent with the fact that long-term change is beneficial in people with SCI, since it improves locomotion. In contrast, in normal subjects, long-term change is not beneficial and may necessitate compensatory plasticity to preserve satisfactory locomotion. Copyright © 2014 the American Physiological Society.

  6. Soleus H-reflex tests in causalgia-dystonia compared with dystonia and mimicked dystonic posture

    NARCIS (Netherlands)

    Koelman, J. H.; Hilgevoord, A. A.; Bour, L. J.; Speelman, J. D.; Ongerboer de Visser, B. W.

    1999-01-01

    Dystonia in the causalgia-dystonia syndrome is characterized by a fixed dystonic posture. To identify involvement of central pathophysiologic mechanisms, we analyzed soleus H-reflex tests in five patients with causalgia-dystonia. Soleus H-reflex test results in these patients differed from those in

  7. Test-retest reliability of the soleus H-reflex excitability measured during human walking

    DEFF Research Database (Denmark)

    Simonsen, Erik B; Dyhre-Poulsen, Poul

    2010-01-01

    The purpose of the study was to investigate with what accuracy the soleus H-reflex modulation and excitability could be measured during human walking on two occasions separated by days. The maximal M-wave (Mmax) was measured at rest in the standing position. During treadmill walking every stimulus...... elicited an M-wave of 25+/-10% of Mmax in the soleus muscle and a supra-maximal stimulus elicited a maximal M-wave 60ms after the first stimulus. Both Mmax during rest and during walking were later used for normalization. When normalized to resting Mmax, the peak reflex amplitude during walking was 5...

  8. Post-activation depression of soleus stretch reflexes in healthy and spastic humans

    DEFF Research Database (Denmark)

    Grey, Michael James; Klinge, Klaus; Crone, Clarissa

    2007-01-01

    Reduced depression of transmitter release from Ia afferents following previous activation (post-activation depression) has been suggested to be involved in the pathophysiology of spasticity. However, the effect of this mechanism on the myotatic reflex and its possible contribution to increased...... reflex excitability in spastic participants has not been tested. To investigate these effects, we examined post-activation depression in Soleus H-reflex responses and in mechanically evoked Soleus stretch reflex responses. Stretch reflex responses were evoked with consecutive dorsiflexion perturbations...... of the soleus stretch reflex and H-reflex decreased as the interval between the stimulus/perturbation was decreased. Similarly, the stretch-evoked torque decreased. In the spastic participants, the post-activation depression of both reflexes and the stretch-evoked torque was significantly smaller than...

  9. Short-term locomotor adaptation to a robotic ankle exoskeleton does not alter soleus Hoffmann reflex amplitude.

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    Kao, Pei-Chun; Lewis, Cara L; Ferris, Daniel P

    2010-07-26

    To improve design of robotic lower limb exoskeletons for gait rehabilitation, it is critical to identify neural mechanisms that govern locomotor adaptation to robotic assistance. Previously, we demonstrated soleus muscle recruitment decreased by approximately 35% when walking with a pneumatically-powered ankle exoskeleton providing plantar flexor torque under soleus proportional myoelectric control. Since a substantial portion of soleus activation during walking results from the stretch reflex, increased reflex inhibition is one potential mechanism for reducing soleus recruitment when walking with exoskeleton assistance. This is clinically relevant because many neurologically impaired populations have hyperactive stretch reflexes and training to reduce the reflexes could lead to substantial improvements in their motor ability. The purpose of this study was to quantify soleus Hoffmann (H-) reflex responses during powered versus unpowered walking. We tested soleus H-reflex responses in neurologically intact subjects (n=8) that had trained walking with the soleus controlled robotic ankle exoskeleton. Soleus H-reflex was tested at the mid and late stance while subjects walked with the exoskeleton on the treadmill at 1.25 m/s, first without power (first unpowered), then with power (powered), and finally without power again (second unpowered). We also collected joint kinematics and electromyography. When the robotic plantar flexor torque was provided, subjects walked with lower soleus electromyographic (EMG) activation (27-48%) and had concomitant reductions in H-reflex amplitude (12-24%) compared to the first unpowered condition. The H-reflex amplitude in proportion to the background soleus EMG during powered walking was not significantly different from the two unpowered conditions. These findings suggest that the nervous system does not inhibit the soleus H-reflex in response to short-term adaption to exoskeleton assistance. Future studies should determine if the

  10. Proximally evoked soleus H-reflex to S1 nerve root stimulation in sensory neuronopathies (ganglionopathies).

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    Zhu, Dong-Qing; Zhu, Yu; Qiao, Kai; Zheng, Chao-Jun; Bradley, Scott; Weber, Robert; Chen, Xiang-Jun

    2013-11-01

    Sensory neuronopathy (SNN) mimics distal sensory axonopathy. The conventional H-reflex elicited by tibial nerve stimulation (tibial H-reflex) is usually abnormal in both conditions. We evaluated the proximally evoked soleus H-reflex in response to S1 nerve root stimulation (S1 foramen H-reflex) in SNN. Eleven patients with SNN and 6 with distal sensory axonopathy were studied. Tibial and S1 foramen H-reflexes were performed bilaterally in each patient. Tibial and S1 foramen H-reflexes were absent bilaterally in all patients with SNN. In the patients with distal sensory axonopathy, tibial H-reflexes were absent in 4 and demonstrated prolonged latencies in 2, but S1 foramen H-reflexes were normal. Characteristic absence of the H-reflex after both proximal and distal stimulation reflects primary loss of dorsal root ganglion (DRG) neurons and the distinct non-length-dependent impairment of sensory nerve fibers in SNN. Copyright © 2013 Wiley Periodicals, Inc.

  11. Influence of stimulus intensity on the soleus H-reflex amplitude and modulation during locomotion

    DEFF Research Database (Denmark)

    Simonsen, Erik B; Alkjær, Tine; Raffalt, Peter C

    2013-01-01

    -reflex methodology itself. Accordingly, the purpose of the present study was to study the effect on the soleus H-reflex during walking and running using stimulus intensities normally considered too high (up to 45% Mmax). Using M-waves of 25-45% Mmax as opposed to 5-25% Mmax showed a significant suppression...... of the peak H-reflex during the stance phase of walking, while no changes were observed during running. No differences were observed regarding modulation pattern. So a possible use of too high stimulus intensity cannot explain the differences mentioned. The surprising result in running may be explained...

  12. Cumulative vibratory indices and the H/M ratio of the soleus H-reflex: a quantitative study in control and spastic subjects

    NARCIS (Netherlands)

    Ongerboer de Visser, B. W.; Bour, L. J.; Koelman, J. H.; Speelman, J. D.

    1989-01-01

    Suppression of the soleus (Sol) H-reflex recruitment curve by Achilles tendon vibration and the ratio of maximum Sol H-reflex (Hmax) to maximum M-response (H/M ratio) have been studied by means of computer processing on the basis of peak-to-peak (P-P) and area values in 46 controls and in 16 spastic

  13. Soleus stretch reflex during cycling

    DEFF Research Database (Denmark)

    Grey, Michael James; Pierce, C. W.; Milner, T. E.

    2001-01-01

    The modulation and strength of the human soleus short latency stretch reflex was investigated by mechanically perturbing the ankle during an unconstrained pedaling task. Eight subjects pedaled at 60 rpm against a preload of 10 Nm. A torque pulse was applied to the crank at various positions durin...

  14. Acute effects of high-frequency microfocal vibratory stimulation on the H reflex of the soleus muscle. A double-blind study in healthy subjects.

    Science.gov (United States)

    Alfonsi, Enrico; Paone, Paolo; Tassorelli, Cristina; De Icco, Roberto; Moglia, Arrigo; Alvisi, Elena; Marchetta, Lucky; Fresia, Mauro; Montini, Alessandra; Calabrese, Marzia; Versiglia, Vittorio; Sandrini, Giorgio

    2015-01-01

    This study in healthy subjects examined the effects of a system delivering focal microvibrations at high frequency (Equistasi®) on tonic vibration stimulus (TVS)-induced inhibition of the soleus muscle H reflex. Highfrequency microvibrations significantly increased the inhibitory effect of TVS on the H reflex for up to three minutes. Moreover, Equistasi® also significantly reduced alpha-motoneuron excitability, as indicated by the changes in the ratio between the maximumamplitude H reflex (Hmax reflex) and the maximumamplitude muscle response (Mmax response); this effect was due to reduction of the amplitude of the H reflex because the amplitude of muscle response remained unchanged. The present findings indicate that Equistasi® has a modulatory effect on proprioceptive reflex circuits. Therefore, Equistasi® might interfere with some mechanisms involved in both physiological and pathophysiological control of movement and of posture.

  15. D1 and D2 Inhibitions of the Soleus H-Reflex Are Differentially Modulated during Plantarflexion Force and Position Tasks.

    Directory of Open Access Journals (Sweden)

    Fernando Henrique Magalhães

    Full Text Available Presynaptic inhibition (PSI has been shown to modulate several neuronal pathways of functional relevance by selectively gating the connections between sensory inputs and spinal motoneurons, thereby regulating the contribution of the stretch reflex circuitry to the ongoing motor activity. In this study, we investigated whether a differential regulation of Ia afferent inflow by PSI may be associated with the performance of two types of plantarflexion sensoriomotor tasks. The subjects (in a seated position controlled either: 1 the force level exerted by the foot against a rigid restraint (force task, FT; or 2 the angular position of the ankle when sustaining inertial loads (position task, PT that required the same level of muscle activation observed in FT. Subjects were instructed to maintain their force/position at target levels set at ~10% of maximum isometric voluntary contraction for FT and 90° for PT, while visual feedback of the corresponding force/position signals were provided. Unconditioned H-reflexes (i.e. control reflexes and H-reflexes conditioned by electrical pulses applied to the common peroneal nerve with conditioning-to-test intervals of 21 ms and 100 ms (corresponding to D1 and D2 inhibitions, respectively were evoked in a random fashion. A significant main effect for the type of the motor task (FT vs PT (p = 0.005, η2p = 0.603 indicated that PTs were undertaken with lower levels of Ia PSI converging onto the soleus motoneuron pool. Additionally, a significant interaction between the type of inhibition (D1 vs D2 and the type of motor task (FT vs PT (p = 0.038, η2p = 0.395 indicated that D1 inhibition was associated with a significant reduction in PSI levels from TF to TP (p = 0.001, η2p = 0.731, whereas no significant difference between the tasks was observed for D2 inhibition (p = 0.078, η2p = 0.305. These results suggest that D1 and D2 inhibitions of the soleus H-reflex are differentially modulated during the performance of

  16. Group II muscle afferents probably contribute to the medium latency soleus stretch reflex during walking in humans

    DEFF Research Database (Denmark)

    Grey, Michael James; Ladouceur, Michel; Andersen, Jacob B.

    2001-01-01

    1. The objective of this study was to determine which afferents contribute to the medium latency response of the soleus stretch reflex resulting from an unexpected perturbation during human walking. 2. Fourteen healthy subjects walked on a treadmill at approximately 3.5 km h(-1) with the left ankle...... = 0.007), whereas the short latency component was unchanged (P = 0.653). 7. An ankle block with lidocaine hydrochloride was performed to suppress the cutaneous afferents of the foot and ankle. Neither the short (P = 0.453) nor medium (P = 0.310) latency reflexes were changed. 8. Our results support...

  17. Human H-reflexes are smaller in difficult beam walking than in normal treadmill walking.

    Science.gov (United States)

    Llewellyn, M; Yang, J F; Prochazka, A

    1990-01-01

    Hoffman (H) reflexes were elicited from the soleus (SOL) muscle while subjects walked on a treadmill and on a narrow beam (3.5 cm wide, raised 34 cm from the floor). The speed of walking on the treadmill was selected for each subject to match the background activation level of their SOL muscle during beam walking. The normal reciprocal activation pattern of the tibialis anterior and SOL muscles in treadmill walking was replaced by a pattern dominated by co-contraction on the beam. In addition, the step cycle duration was more variable and the time spent in the swing phase was reduced on the beam. The H-reflexes were highly modulated in both tasks, the amplitude being high in the stance phase and low in the swing phase. The H-reflex amplitude was on average 40% lower during beam walking than treadmill walking. The relationship between the H-reflex amplitude and the SOL EMG level was quantified by a regression line relating the two variables. The slope of this line was on average 41% lower in beam walking than treadmill walking. The lower H-reflex gain observed in this study and the high level of fusimotor drive observed in cats performing similar tasks suggest that the two mechanisms which control the excitability of this reflex pathway (i.e. fusimotor action and control of transmission at the muscle spindle to moto-neuron synapse) may be controlled independently.

  18. Time Course of the Soleus M Response and H Reflex after Lidocaine Tibial Nerve Block in the Rat

    Directory of Open Access Journals (Sweden)

    Kévin Buffenoir

    2013-01-01

    Full Text Available Aims. In spastic subjects, lidocaine is often used to induce a block predictive of the result provided by subsequent surgery. Lidocaine has been demonstrated to inhibit the Hoffmann (H reflex to a greater extent than the direct motor (M response induced by electrical stimulation, but the timecourse of these responses has not been investigated. Methods. An animal (rat model of the effects of lidocaine on M and H responses was therefore developed to assess this time course. M and H responses were recorded in 18 adult rats before and after application of lidocaine to the sciatic nerve. Results. Two to five minutes after lidocaine injection, M responses were markedly reduced (mean reduction of 44% and H reflexes were completely abolished. Changes were observed more rapidly for the H reflex. The effects of lidocaine then persisted for 100 minutes. The effect of lidocaine was therefore more prolonged on the H reflex than on the M response. Conclusion. This study confirms that lidocaine blocks not only alpha motoneurons but also Ia afferent fibres responsible for the H reflex. The authors describe, for the first time, the detailed time course of the effect of lidocaine on direct or reflex activation of motoneurons in the rat.

  19. H-reflexes reduce fatigue of evoked contractions after spinal cord injury.

    Science.gov (United States)

    Bergquist, Austin J; Wiest, Matheus J; Okuma, Yoshino; Collins, David F

    2014-08-01

    Neuromuscular electrical stimulation (NMES) over a muscle belly (mNMES) generates contractions predominantly through M-waves, while NMES over a nerve trunk (nNMES) can generate contractions through H-reflexes in people who are neurologically intact. We tested whether the differences between mNMES and nNMES are present in people with chronic motor-complete spinal cord injury and, if so, whether they influence contraction fatigue. Plantar-flexion torque and soleus electromyography were recorded from 8 participants. Fatigue protocols were delivered using mNMES and nNMES on separate days. nNMES generated contractions that fatigued less than mNMES. Torque decreased the least when nNMES generated contractions, at least partly through H-reflexes (n = 4 participants; 39% decrease), and torque decreased the most when contractions were generated through M-waves, regardless of NMES site (nNMES 71% decrease, n = 4; mNMES, 73% decrease, n = 8). nNMES generates contractions that fatigue less than mNMES, but only when H-reflexes contribute to the evoked contractions. Copyright © 2013 Wiley Periodicals, Inc.

  20. Soleus H-reflex excitability during pedaling post-stroke

    DEFF Research Database (Denmark)

    Schindler-Ivens, Sheila; Brown, David A.; Lewis, Gwyn N.

    2008-01-01

    A major contributor to impaired locomotion post-stroke is abnormal phasing of paretic muscle activity, but the mechanisms remain unclear. Previous studies have shown that, in the paretic limb of people post-stroke, Group Ia reflexes are abnormally elevated and fail to decrease in amplitude during...

  1. Effects of tripolar TENS on slow and fast motoneurons: a preliminary study using H-reflex recovery curve method.

    Science.gov (United States)

    Simorgh, L; Torkaman, G; Firoozabadi, S M

    2008-01-01

    This study aimed at examining the effect of tripolar TENS of vertebral column on the activity of slow and fast motoneurons on 10 healthy non-athlete women aged 22.7 +/- 2.21 yrs. H-reflex recovery curve of soleus (slow) and gastrocnemius (fast) muscles were recorded before and after applying tripolar TENS. For recording of this curve, rectangular paired stimuli were applied on tibial nerve (with 40-520 ISI, frequency of 0.2 Hz and pulse width of 600 micros). Our findings showed that maximum H-reflex recovery in gastrocnemius muscle appeared in the shorter ISI, while in soleus muscle, it appeared in the longer ISI and its amplitude slightly decreased after applying tripolar TENS. It is suggested that tripolar TENS excites not only the skin but also Ia and Ib afferents in the dorsal column. A Synaptic interaction of these afferents in spinal cord causes the inhibition of type I MNs and facilitation of type II MNs. This effect can be used in muscle tone modulation.

  2. Restoring walking after spinal cord injury: operant conditioning of spinal reflexes can help.

    Science.gov (United States)

    Thompson, Aiko K; Wolpaw, Jonathan R

    2015-04-01

    People with incomplete spinal cord injury (SCI) frequently suffer motor disabilities due to spasticity and poor muscle control, even after conventional therapy. Abnormal spinal reflex activity often contributes to these problems. Operant conditioning of spinal reflexes, which can target plasticity to specific reflex pathways, can enhance recovery. In rats in which a right lateral column lesion had weakened right stance and produced an asymmetrical gait, up-conditioning of the right soleus H-reflex, which increased muscle spindle afferent excitation of soleus, strengthened right stance and eliminated the asymmetry. In people with hyperreflexia due to incomplete SCI, down-conditioning of the soleus H-reflex improved walking speed and symmetry. Furthermore, modulation of electromyographic activity during walking improved bilaterally, indicating that a protocol that targets plasticity to a specific pathway can trigger widespread plasticity that improves recovery far beyond that attributable to the change in the targeted pathway. These improvements were apparent to people in their daily lives. They reported walking faster and farther, and noted less spasticity and better balance. Operant conditioning protocols could be developed to modify other spinal reflexes or corticospinal connections; and could be combined with other therapies to enhance recovery in people with SCI or other neuromuscular disorders. © The Author(s) 2014.

  3. Increase in H-reflex gain following 1 week of immobilization

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye; Sørensen, Mie; Nielsen, Jens Bo

    It is well established that motor experience induces structural and functional plasticity within the central nervous system. It is less well investigated whether reduced motor activity in relation to immobilization is also associated with plastic neuronal changes. The present experiment examined ...... removal all measurements had returned to preimmobilization levels. These results show that immobilization of only one week duration is associated with reversible adaptive changes in the gain of the central part of the monosynaptic stretch reflex....

  4. The effect of operant-conditioning balance training on the down-regulation of spinal H-reflexes in a spastic patient.

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    Hoseini, Najmeh; Koceja, David M; Riley, Zachary A

    2011-10-24

    Spasticity in chronic hemiparetic stroke patients has primarily been treated pharmacologically. However, there is increasing evidence that physical rehabilitation can help manage hyper-excitability of reflexes (hyperreflexia), which is a primary contributor to spasticity. In the present study, one chronic hemiparetic stroke patient operantly conditioned the soleus H-reflex while training on a balance board for two weeks. The results showed a minimal decrease in the Hmax-Mmax ratio for both the affected and unaffected limb, indicating that the H-reflex was not significantly altered with training. Alternatively, paired-reflex depression (PRD), a measure of history-dependent changes in reflex excitability, could be conditioned. This was evident by the rightward shift and decreased slope of reflex excitability in the affected limb. The non-affected limb decreased as well, although the non-affected limb was very sensitive to PRD initially, whereas the affected limb was not. Based on these results, it was concluded that PRD is a better index of hyperreflexia, and this measurement could be more informative of synapse function than simple H-reflexes. This study presents a novel and non-pharmacological means of managing spasticity that warrants further investigation with the potential of being translated to the clinic. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  5. Facilitation of Hoffmann reflexes of ankle muscles in prone but not standing positions by focal ankle-joint cooling.

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    Kim, Kyung-Min; Ingersoll, Christopher D; Hertel, Jay

    2015-05-01

    Focal ankle-joint cooling (FAJC) has been shown to increase Hoffmann (H) reflex amplitudes of select leg muscles while subjects lie prone, but it is unknown whether the neurophysiological cooling effects persist in standing. To assess the effects of FAJC on H-reflexes of the soleus and fibularis longus during 3 body positions (prone, bipedal, and unipedal stances) in individuals with and without chronic ankle instability (CAI). Crossover. Laboratory. 15 young adults with CAI (9 male, 6 female) and 15 healthy controls. All subjects received both FAJC and sham treatments on separate days in a randomized order. FAJC was accomplished by applying a 1.5-L plastic bag filled with crushed ice to the ankle for 20 min. Sham treatment involved room-temperature candy corn. Maximum amplitudes of H-reflexes and motor (M) waves were recorded while subjects lay prone and then stood in quiet bipedal and unipedal stances before and immediately after each treatment. Primary outcome measures were H(max):M(max) ratios for the soleus and fibularis longus. Three-factor (group × treatment condition × time) repeated-measures ANOVAs and Fisher LSD tests were performed for statistical analyses. Significant interactions of treatment condition by time for prone H(max):M(max) ratios were found in the soleus (P = .001) and fibularis longus (P = .003). In both muscles, prone H(max):M(max) ratios moderately increased after FAJC but not after sham treatment. The CAI and healthy groups responded similarly to FAJC. In contrast, there were no significant interactions or main effects in the bipedal and unipedal stances in either muscle (P > .05). FAJC moderately increased H-reflex amplitudes of the soleus and fibularis longus while subjects were prone but not during bipedal or unipedal standing. These results were not different between groups with and without CAI.

  6. Load rather than length sensitive feedback contributes to soleus muscle activity during human treadmill walking

    DEFF Research Database (Denmark)

    af Klint, Richard; Mazzaro, Nazarena; Nielsen, Jens Bo

    2010-01-01

    Walking requires a constant adaptation of locomotor output from sensory afferent feedback mechanisms to ensure efficient and stable gait. We investigated the nature of the sensory afferent feedback contribution to the soleus motoneuronal drive and to the corrective stretch reflex by manipulating...... on the soleus stretch reflex was measured by presenting dorsiflexion perturbations ( approximately 5 degrees, 360-400 degrees/s) in mid and late stances. Short (SLRs) and medium latency reflexes (MLRs) were quantified in a 15 ms analysis window. The MLR decreased with decreased loading (P = 0.......045), but no significant difference was observed for the SLR (P = 0.13). Similarly, the effect of the BWS was measured on the unload response, i.e., the depression in soleus activity following a plantar-flexion perturbation ( approximately 5.6 degrees, 203-247 degrees/s), quantified over a 50 ms analysis window...

  7. Effects of postural changes of the upper limb on reflex transmission in the lower limb. Cervicolumbar reflex interactions in man.

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    Delwaide, P J; Figiel, C; Richelle, C

    1977-06-01

    The influence of passive changes in upper limb position on the excitability of three myotatic arc reflexes (soleus, quadriceps, and biceps femoris) of the lower limb has been explored on 42 volunteers. The results indicate that the excitability of the three myotatic arcs can be influenced at a distance by postural modifications of the upper limb. When the ipsilateral upper limb is forwards or the contralateral backwards, a facilitation of both soleus and quadriceps tendon reflexes is observed while the biceps femoris reflexes are reduced. This pattern of facilitation and inhibition is reversed when the ipsilateral upper limb is backwards or the contralateral forwards. The facilitations as well as inhibitions of proximal myotatic arc reflexes are quantitatively more marked than that of the soleus reflex. Facilitation and inhibition are not linearly related to the angle of the arm with the trunk. Effects begin at a considerable angle, become maximal at 45 degrees, and progressively disappear for greater values. It is suggested that the distinct pattern of facilitation and inhibition which is exerted in reciprocal fashion on extensor and flexor motor nuclei might depend on the long propriospinal neurones connecting cervical and lumbar enlargements.

  8. [H reflex in patients with spastic quadriplegia].

    Science.gov (United States)

    Miyama, Sahoko; Arimoto, Kiyoshi; Kimiya, Satoshi

    2009-01-01

    Hoffmann reflex (H reflex) is an electrically elicited spinal monosynaptic reflex. H reflex was examined in 18 patients with spastic quadriplegia who had perinatal or postnatal problems. H reflex was elicitable in 11 patients for the abductor pollicis brevis (61.1%), 10 for the abductor digiti minimi (55.6%) and 16 for the abductor hallucis (88.9%). Because the abductor pollicis brevis and the abductor digiti minimi do not exhibit H reflex in normal subjects, it was suggested that the excitability of alpha motor neurons innervating these muscles was increased. H reflex was not detected for the extensor digitorum brevis in any patients, indicating the difference in the excitability among alpha motor neurons. In some patients, H reflex did not disappear under supramaximal stimuli. We conclude that the mechanism of evolution of H reflex in patients with spastic quadriplegia is different from that in normal subjects.

  9. Effects of patterned peripheral nerve stimulation on soleus spinal motor neuron excitability

    DEFF Research Database (Denmark)

    Jimenez, Samuel; Mordillo-Mateos, Laura; Dileone, Michele

    2018-01-01

    obtained was discarded, since non-patterned 15 Hz stimulation at 110% HT led to pain scores similar to those induced by EcTBS at 110% HT, but was not able to induce any modulation of the H reflex amplitude. Together, the results provide first time evidence that peripheral continuous TBS induces a short......Spinal plasticity is thought to contribute to sensorimotor recovery of limb function in several neurological disorders and can be experimentally induced in animals and humans using different stimulation protocols. In healthy individuals, electrical continuous Theta Burst Stimulation (TBS....... In 26 healthy subjects, we examined the effects of electrical TBS given to the tibial nerve in the popliteal fossa on the excitability of lumbar spinal motoneurons as measured by H-reflex amplitude of the soleus muscle evoked by tibial nerve stimulation. Continuous TBS was given at 110% of H...

  10. A task dependent change in the medium latency component of the soleus stretch reflex

    DEFF Research Database (Denmark)

    Grey, Michael James; Larsen, Birgit; Sinkjær, Thomas

    2002-01-01

    In comparison to the H-reflex, the task dependency of the human stretch reflex during locomotive and postural tasks has not received a great deal of attention in the literature. The few studies on reflex task dependency that have been performed to date have concentrated on either the group Ia...

  11. Changes in H-Reflex Recruitment After Trans-Spinal Direct Current Stimulation With Multiple Electrode Configurations

    Directory of Open Access Journals (Sweden)

    Alexander Kuck

    2018-03-01

    Full Text Available Trans-spinal direct current stimulation (tsDCS is an electro-modulatory tool with possible application in the rehabilitation of spinal cord injury. TsDCS generates a small electric field, aiming to induce lasting, functional neuromodulation in the targeted neuronal networks. Earlier studies have shown significant modulatory effects after application of lumbar tsDCS. However, for clinical application, a better understanding of application specific factors is required. Our goal was to investigate the effect of different electrode configurations using lumbar spinal tsDCS on spinal excitability. We applied tsDCS (2.5 mA, 15 min in 10 healthy subjects with three different electrode configurations: (1 Anode and cathode placed over vertebra T11, and the posterior left shoulder respectively (LSC-S (one polarity, and (2 Both electrodes placed in equal distance (ED (7 cm above and below vertebra T11, investigated for two polarities (ED-Anodal/Cathodal. The soleus H-Reflex is measured before, during and after tsDCS in either electrode configuration or a sham condition. To account for genetic predispositions in response to direct current stimulation, subject BDNF genotype was assessed. Stimulation in configuration ED-Cathodal induced an amplitude reduction of the H-reflex, 30 min after tsDCS with respect to baseline, whereas none of the other configurations led to significant post intervention effects. BDNF genotype did not correlate with post intervention effects. Furthermore, we failed to replicate effects shown by a previous study, which highlights the need for a better understanding of methodological and subject specific influences on tsDCS outcome. The H-reflex depression after tsDCS (Config. ED-Cathodal provides new insights and may foster our understanding of the working mechanism of tsDCS.

  12. Spatial facilitation of reciprocal inhibition and crossed inhibitory responses to soleus motoneurons during walking

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas; Geertsen, Svend Sparre; Nielsen, Jens Bo

    2016-01-01

    In humans, short-latency crossed spinal inhibitory reflexes are elicited in the contralateral soleus (cSOL) muscle following stimulation of the ipsilateral posterior tibial nerve (iPTN). To date, the spinal interneurons mediating the cSOL inhibition are unknown. This study investigated whether...

  13. Modulation of the Fibularis Longus Hoffmann Reflex and Postural Instability Associated With Chronic Ankle Instability

    Science.gov (United States)

    Kim, Kyung-Min; Hart, Joseph M.; Saliba, Susan A.; Hertel, Jay

    2016-01-01

    Context: Individuals with chronic ankle instability (CAI) present with decreased modulation of the Hoffmann reflex (H-reflex) from a simple to a more challenging task. The neural alteration is associated with impaired postural control, but the relationship has not been investigated in individuals with CAI. Objective: To determine differences in H-reflex modulation and postural control between individuals with or without CAI and to identify if they are correlated in individuals with CAI. Design: Descriptive laboratory study. Setting: Laboratory. Patients or Other Participants: A total of 15 volunteers with CAI (9 males, 6 females; age = 22.6 ± 5.8 years, height = 174.7 ± 8.1 cm, mass = 74.9 ± 12.8 kg) and 15 healthy sex-matched volunteers serving as controls (9 males, 6 females; age = 23.8 ± 5.8 years, height = 171.9 ± 9.9 cm, mass = 68.9 ± 15.5 kg) participated. Intervention(s): Maximum H-reflex (Hmax) and motor wave (Mmax) from the soleus and fibularis longus were recorded while participants lay prone and then stood in unipedal stance. We assessed postural tasks of unipedal stance with participants' eyes closed for 10 seconds using a forceplate. Main Outcome Measure(s): We normalized Hmax to Mmax to obtain Hmax : Mmax ratios for the 2 positions. For each muscle, H-reflex modulation was quantified using the percentage change scores in Hmax : Mmax ratios calculated from prone position to unipedal stance. Center-of-pressure data were used to compute 4 time-to-boundary variables. Separate independent-samples t tests were performed to determine group differences. Pearson product moment correlation coefficients were calculated between the modulation and balance measures in the CAI group. Results: The CAI group presented less H-reflex modulation in the soleus (t26 = −3.77, P = .001) and fibularis longus (t25 = −2.59, P = .02). The mean of the time-to-boundary minima in the anteroposterior direction was lower in the CAI group (t28 = −2.06, P = .048

  14. No evidence hip joint angle modulates intrinsically produced stretch reflex in human hopping.

    Science.gov (United States)

    Gibson, W; Campbell, A; Allison, G

    2013-09-01

    Motor output in activities such as walking and hopping is suggested to be mediated neurally by purported stretch reflex augmentation of muscle output. Reflex EMG activity during these tasks has been frequently investigated in the soleus muscle; with alterations in reflex amplitude being associated with changes in hip joint angle/phase of the gait cycle. Previous work has focussed on reflex activity induced by an artificial perturbation or by induction of H-reflexes. As such, it is currently unknown if stretch reflex activity induced intrinsically (as part of the task) is modulated by changes in hip joint angle. This study investigated whether hip joint angle modulated reflex EMG 'burst' activity during a hopping task performed on a custom-built partially reclined sleigh. Ten subjects participated; EMG and kinematic data (VICON motor capture system) was collected for each hop cycle. Participants completed 5 sets of 30s of self-paced hopping in (1) hip neutral and (2) hip 60° flexion conditions. There was no difference in EMG 'burst' activity or in sagittal plane kinematics (knee/ankle) in the hopping task between the two conditions. The results indicate that during a functional task such as hopping, changes in hip angle do not alter the stretch reflex-like activity associated with landing. Copyright © 2013 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2015-04-01

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

  16. Interindividual differences in H reflex modulation during normal walking

    DEFF Research Database (Denmark)

    Simonsen, Erik B; Dyhre-Poulsen, Poul; Alkjaer, T

    2002-01-01

    was greater for the S group. The hip joint moment was similar for the groups. The EMG activity in the vastus lateralis and anterior tibial muscles was greater prior to heel strike for the S group. These data indicate that human walking exhibits at least two different motor patterns as evaluated by gating...... of afferent input to the spinal cord, by EMG activity and by walking mechanics. Increasing H reflex excitability during the swing phase appears to protect the subject against unexpected perturbations around heel strike by a facilitated stretch reflex in the triceps surae muscle. Alternatively, in subjects...... with a suppressed H reflex in the swing phase the knee joint extensors seem to form the primary protection around heel strike....

  17. Elevated interstitial fluid volume in rat soleus muscles by hindlimb unweighting

    DEFF Research Database (Denmark)

    Kandarian, S C; Boushel, Robert Christopher; Schulte, Lars

    1991-01-01

    ) by tail suspension. Soleus muscles were studied after 28 days and compared with those from five age-matched control (C) rats. Interstitial fluid volume ([3H]inulin space) and maximum tetanic tension (Po) were measured in vitro at 25 degrees C. Soleus muscles atrophied 58% because of unweighting (C = 147...

  18. β-adrenergic ([3H] CGP-12177) receptors are elevated in slices of soleus muscle from CHF 147 dystrophic hamsters

    International Nuclear Information System (INIS)

    Watson-Wright, W.M.; Wilkinson, M.

    1987-01-01

    The authors utilized a muscle slice technique to compare the ontogeny of cell surface β-adrenergic receptor binding in soleus and extensor digitorum longus (EDL) muscles of male Golden Syrian (GS) and Canadian Hybrid Farms 147 (CHF 147) dystrophic hamsters. Binding of the β-adrenergic antagonist, [ 3 H] CGP-12177 (CGP), to GS muscle slices was reversible, saturable, stereospecific and of high affinity. Bmax was higher in the soleus (2.57+/-.12 fmol/mg wet wt) than in the EDL (1.61+/-.17 fmol/mg wet wt) of adult animals while affinities were similar (0.35+/-.06 and 0.24+/-.04 nM respectively). No differences in binding characteristics were seen in EDL of GS compared to CHF 147 animals. In soleus slices from GS hamsters, Bmax was highest at 16 days of age (5.72+/-0.26 fmol/mg), decreased between 16 and 29 days and remained constant until 300 days (2.51+/-0.52 fmol/mg). In dystrophic soleus slices, Bmax was also higher at 16 days than at any other age but receptor number decreased gradually, remaining higher than in GS until 90 days of age (p<0.05). The failure of β-adrenergic receptor number to decrease at a normal rate may be implicated in the pathogenesis of hamster polymyopathy. 21 references, 5 figures, 1 table

  19. Effect of joint mobilization on the H Reflex amplitude in people with spasticity

    OpenAIRE

    Pérez Parra, Julio Ernesto; Henao Lema, Claudia Patricia

    2011-01-01

    Objective: To determine the effect of ankle joint mobilization on the H reflex amplitude of thesoleus muscle in people with spasticity. Materials and methods: A quasi-experimental study withcrossover design and simple masking was conducted in 24 randomized subjects to initiate thecontrol or experimental group. Traction and rhythmic oscillation were applied for five minutesto the ankle joint. H wave amplitude changes of Hoffmann reflex (electrical equivalent of themonosynaptic spinal reflex) w...

  20. Locomotor training improves premotoneuronal control after chronic spinal cord injury.

    Science.gov (United States)

    Knikou, Maria; Mummidisetty, Chaithanya K

    2014-06-01

    Spinal inhibition is significantly reduced after spinal cord injury (SCI) in humans. In this work, we examined if locomotor training can improve spinal inhibition exerted at a presynaptic level. Sixteen people with chronic SCI received an average of 45 training sessions, 5 days/wk, 1 h/day. The soleus H-reflex depression in response to low-frequency stimulation, presynaptic inhibition of soleus Ia afferent terminals following stimulation of the common peroneal nerve, and bilateral EMG recovery patterns were assessed before and after locomotor training. The soleus H reflexes evoked at 1.0, 0.33, 0.20, 0.14, and 0.11 Hz were normalized to the H reflex evoked at 0.09 Hz. Conditioned H reflexes were normalized to the associated unconditioned H reflex evoked with subjects seated, while during stepping both H reflexes were normalized to the maximal M wave evoked after the test H reflex at each bin of the step cycle. Locomotor training potentiated homosynaptic depression in all participants regardless the type of the SCI. Presynaptic facilitation of soleus Ia afferents remained unaltered in motor complete SCI patients. In motor incomplete SCIs, locomotor training either reduced presynaptic facilitation or replaced presynaptic facilitation with presynaptic inhibition at rest. During stepping, presynaptic inhibition was modulated in a phase-dependent manner. Locomotor training changed the amplitude of locomotor EMG excitability, promoted intralimb and interlimb coordination, and altered cocontraction between knee and ankle antagonistic muscles differently in the more impaired leg compared with the less impaired leg. The results provide strong evidence that locomotor training improves premotoneuronal control after SCI in humans at rest and during walking. Copyright © 2014 the American Physiological Society.

  1. Do changes in spinal reflex excitability elicited by transcranial magnetic stimulation differ based on the site of cerebellar stimulation?

    Science.gov (United States)

    Matsugi, Akiyoshi

    2018-05-06

    The present study aimed to investigate whether spinal reflex excitability is influenced by the site of cerebellar transcranial magnetic stimulation (C-TMS). Fourteen healthy volunteers (mean age: 24.6 ± 6.6 years [11 men]) participated. Participants lay on a bed in the prone position, with both ankle joints fixed to prevent unwanted movement. Right tibial nerve stimulation was provided to elicit the H-reflex in the right soleus muscle. Conditioning transcranial magnetic stimulation (TMS) was delivered at one of the following sites 110 ms prior to tibial stimulation: right, central, or left cerebellum; midline parietal (Pz) region; or sham stimulation. A total of 10 test trials were included for each condition, in random order. The unconditioned and conditioned H-reflexes were measured during random inter-test trials, and the cerebellar spinal facilitation (CSpF) ratios for each site were calculated (the ratio of conditioned to unconditioned H-reflexes). CSpF ratios were compared among TMS sites. CSpF ratios were significantly higher at cerebellar sites than at the Pz site or during sham stimulation. However, there was no significant difference in CSpF ratio among cerebellar sites. TMS conditioning over any part of the cerebellum facilitated the excitability of the spinal motoneuron pool. Facilitation of the H-reflex due to C-TMS may involve the effects of the bilateral descending tract of the spinal cord on the spinal motoneuron pool. Alternatively, direct brainstem stimulation may have activated portions of the bilateral descending tract of the spinal cord.

  2. A High-Gain Reflex-Based Bidirectional DC Charger with Efficient Energy Recycling for Low-Voltage Battery Charging-Discharging Power Control

    Directory of Open Access Journals (Sweden)

    Ching-Ming Lai

    2018-03-01

    Full Text Available This study proposes a high-gain reflex-charging-based bidirectional DC charger (RC-BDC to enhance the battery charging efficiency of light electric vehicles (LEV in a DC-microgrid. The proposed charger topology consists of an unregulated level converter (ULC and a two-phase interleaved buck-boost charge-pump converter (IBCPC, which together provide low ripple and high voltage conversion ratio. As the high-gain RC-BDC charges, the LEV’s battery with reflex charging currents, high battery charging efficiency, and prolonged battery life cycles are achieved. This is possible due to the recovering of negative pulse energy of reflex charging currents to reduce charge dissipations within LEV’s batteries. Derivations of the operating principles of the high-gain RC-BDC, analyses of its topology, and the closed-loop control designs were presented. Simulations and experiments were implemented with battery voltage of 48 V and DC-bus voltage of 400 V for a 500 W prototype. The results verify the feasibility of the proposed concept and were compared with the typical constant-current/constant-voltage (CC/CV charger. The comparison shows that the proposed high gain RC-BDC improves battery charging speed and reduces the battery thermal deterioration effect by about 12.7% and 25%, respectively.

  3. Different corticospinal control between discrete and rhythmic movement of the ankle.

    Science.gov (United States)

    Goto, Yumeno; Jono, Yasutomo; Hatanaka, Ryota; Nomura, Yoshifumi; Tani, Keisuke; Chujo, Yuta; Hiraoka, Koichi

    2014-01-01

    We investigated differences in corticospinal and spinal control between discrete and rhythmic ankle movements. Motor evoked potentials (MEPs) in the tibialis anterior and soleus muscles and soleus H-reflex were elicited in the middle of the plantar flexion phase during discrete ankle movement or in the initial or later cycles of rhythmic ankle movement. The H-reflex was evoked at an intensity eliciting a small M-wave and MEPs were elicited at an intensity of 1.2 times the motor threshold of the soleus MEPs. Only trials in which background EMG level, ankle angle, and ankle velocity were similar among the movement conditions were included for data analysis. In addition, only trials with a similar M-wave were included for data analysis in the experiment evoking H-reflexes. Results showed that H reflex and MEP amplitudes in the soleus muscle during discrete movement were not significantly different from those during rhythmic movement. MEP amplitude in the tibialis anterior muscle during the later cycles of rhythmic movement was significantly larger than that during the initial cycle of the rhythmic movement or during discrete movement. Higher corticospinal excitability in the tibialis anterior muscle during the later cycles of rhythmic movement may reflect changes in corticospinal control from the initial cycle to the later cycles of rhythmic movement.

  4. Decreased contribution from afferent feedback to the soleus muscle during walking in patients with spastic stroke

    DEFF Research Database (Denmark)

    Mazzaro, Nazarena; Nielsen, Jørgen Feldbæk; Grey, Michael James

    2007-01-01

    We investigated the contribution of afferent feedback to the soleus (SOL) muscle activity during the stance phase of walking in patients with spastic stroke. A total of 24 patients with hemiparetic spastic stroke and age-matched healthy volunteers participated in the study. A robotic actuator...... by the Ashworth score. These results indicate that although the stretch reflex response is facilitated during spastic gait, the contribution of afferent feedback to the ongoing locomotor SOL activity is depressed in patients with spastic stroke....

  5. Different corticospinal control between discrete and rhythmic movement of the ankle

    OpenAIRE

    Goto, Yumeno; Jono, Yasutomo; Hatanaka, Ryota; Nomura, Yoshifumi; Tani, Keisuke; Chujo, Yuta; Hiraoka, Koichi

    2014-01-01

    We investigated differences in corticospinal and spinal control between discrete and rhythmic ankle movements. Motor evoked potentials (MEPs) in the tibialis anterior and soleus muscles and soleus H-reflex were elicited in the middle of the plantar flexion phase during discrete ankle movement or in the initial or later cycles of rhythmic ankle movement. The H-reflex was evoked at an intensity eliciting a small M-wave and MEPs were elicited at an intensity of 1.2 times the motor threshold of t...

  6. Electroacupuncture improves gait locomotion, H-reflex and ventral root potentials of spinal compression injured rats.

    Science.gov (United States)

    Escobar-Corona, Carlos; Torres-Castillo, Sergio; Rodríguez-Torres, Erika Elizabeth; Segura-Alegría, Bertha; Jiménez-Estrada, Ismael; Quiroz-González, Salvador

    2017-05-01

    This study explored the effect of electroacupuncture stimulation (EA) on alterations in the Hoffman reflex (H-reflex) response and gait locomotion provoked by spinal cord injury (SCI) in the rat. A compression lesion of the spinal cord was evoked by insufflating a Fogarty balloon located in the epidural space at the T8-9 spinal level of adult Wistar male rats (200-250 gr; n=60). In different groups of SCI rats, EA (frequencies: 2, 50 and 100Hz) was applied simultaneously to Huantiao (GB30), Yinmen (BL37), Jizhong (GV6) and Zhiyang (GV9) acupoints from the third post-injury day until the experimental session. At 1, 2, 3 and 4 post-injury weeks, the BBB scores of the SCI group of rats treated with EA at 50Hz showed a gradual but greater enhancement of locomotor activity than the other groups of rats. Unrestrained gait kinematic analysis of SCI rats treated with EA-50Hz stimulation showed a significant improvement in stride duration, length and speed (p<0.05), whereas a discrete recovery of gait locomotion was observed in the other groups of animals. After four post-injury weeks, the H-reflex amplitude and H-reflex/M wave amplitude ratio obtained in SCI rats had a noticeable enhancement (217%) compared to sham rats (n=10). Meanwhile, SCI rats treated with EA at 50Hz manifested a decreased facilitation of the H-reflex amplitude and H/M amplitude ratio (154%) and a reduced frequency-dependent amplitude depression of the H-reflex (66%). In addition, 50 Hz-EA treatment induced a recovery of the presynaptic depression of the Gs-VRP evoked by PBSt conditioning stimulation in the SCI rat (63.2±8.1%; n=9). In concordance with the latter, it could be suggested that 50 Hz-EA stimulation reduced the hyper-excitability of motoneurons and provokes a partial improvement of the locomotive performance and H reflex responses by a possible recovery of presynaptic mechanisms in the spinal cord of experimentally injured rats. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Vestibulo-ocular reflex gain values in the suppression head impulse test of healthy subjects.

    Science.gov (United States)

    Rey-Martinez, Jorge; Thomas-Arrizabalaga, Izaskun; Espinosa-Sanchez, Juan Manuel; Batuecas-Caletrio, Angel; Trinidad-Ruiz, Gabriel; Matiño-Soler, Eusebi; Perez-Fernandez, Nicolas

    2018-02-15

    To assess whether there are differences in vestibulo-ocular reflex (VOR) gain for suppression head impulse (SHIMP) and head impulse (HIMP) video head impulse test paradigms, and if so, what are their causes. Prospective multicenter observational double-blind nonrandomized clinical study was performed by collecting 80 healthy subjects from four reference hospitals. SHIMP data was postprocessed to eliminate impulses in which early SHIMP saccades were detected. Differences between HIMP and SHIMP VOR gain values were statistically evaluated. Head impulse maximum velocity, gender, age, direction of impulse, and hospital center were considered as possible influential factors. A small significant statistical difference between HIMP and SHIMP VOR gain values was found on repeated measures analysis of variance (-0.05 ± 0.006, P gain values and did not find influence between gain values differences and maximum head impulse velocity. Both HIMP and SHIMP VOR gain values were significant lower (-0.09, P gain values not adequately explained by known gain modification factors. The persistence of this slight but significant difference indicates that there are more factors causing lower SHIMP VOR gain values. This difference must to be considered in further studies as well as in the clinical SHIMP testing protocols. We hypothesized that VOR phasic response inhibition could be the underlying cause of this difference. IIb. Laryngoscope, 2018. © 2018 The American Laryngological, Rhinological and Otological Society, Inc.

  8. F response and H reflex analysis of physiological unity of gravity and antigravity muscles in man.

    Science.gov (United States)

    García, H A; Fisher, M A

    1977-01-01

    Observational differences between reflex (H reflex) and antidromic (F response) activation of segmental motoneurons by a peripheral electrical stimulus are described. In contrast to H reflexes, the percentage of F responses found after a series of stimuli is directly related to the pick-up field of the recording electrode consistent with this response being due to the variable activation of a small fraction of the available motoneuron pool. Despite the differing physiological mechanisms, both F responses and H reflexes can be used to demonstrate similar relative "central excitatory states" for antigravity muscles (i.e. extensors in the lower extremity and flexors in the upper extremity) and their antagonist gravity muscles. H reflexes were elicited not only in their usual location in certain antigravity muscles but also in unusual locations by length/tension changes in agonist and antagonist groups as well as by passive stretch. The data argue for the physiological unity of similarly acting gravity and antigravity muscles as well as supporting a meaningful role of group II afferents in normal segmental motoneuron pool excitability.

  9. Three-O-methylglucose transport in soleus muscle of bacteremic rats

    International Nuclear Information System (INIS)

    Westfall, M.V.; Sayeed, M.M.

    1987-01-01

    Basal and insulin-stimulated soleus muscle 3-O-[ 14 C]merhylglucose ([ 14 C]-3-O-MG) transport was studied in vitro and in vivo during bacteremia in rats. Fasted rats were injected with Escherichia coli to produce bacteremia (B), and controls (C) received saline. In vitro studies using soleus muscles were carried out 8 of 12 hr after bacterial injection, and transport was measured using the rate coefficient (λ = min/sup /minus/1/). Although insulin-stimulated [ 14 C]-3-O-MG transport was decreased in 12-h bacteremic rat muscles the basal [ 14 C]-3-O-MG transport was rate coefficient was elevated. For in vivo studies, [ 14 C]-3-O-MG with or without insulin was injected into rats 10-40 min prior to removing soleus muscles at 12 h postbacterial or postsaline injection. Transport was measured as the ratio of [ 14 C]-3-O-MG/sub intracell//[ 14 C]-3-O-MG/sub extracell/. Basal ratios were not different and muscles from both control and bacteremic rats responded comparably to insulin with increased [ 14 C]-3-O-MG transport during the initial 30 min. At 35-40 min postinsulin injection there was a further stimulation of [ 14 C]-3-O-MG transport in control but not in 12-h bacteremic rat muscles. The changes in [ 14 C]-3-O-MG transport observed in vitro and in vivo after 12 h of bacteremia may be due to circulating mediators and/or changes in membrane function

  10. H-reflex amplitude depression as a marker of presynaptic inhibition in Painful Diabetic Neuropathy (PDN.

    Directory of Open Access Journals (Sweden)

    Ahmad Asmedi

    2016-02-01

    Full Text Available ABSTRACT Painful Diabetic Neuropathy (PDN is a common complication of diabetes mellitus (DM. Disruption in presynaptic inhibition in dorsal horn of the spinal cord has been proposed as one of the pathomechanism of PDN. Previous research showed that presynaptic inhibition can be detected by H-reflex examination. The aim of this study was to know whether the reduction of presynaptic inhibition in spinal dorsal horn of PDN patients really exist, and detectable by H-reflex examination. It was cohort prospective involving 141 (58 men, 83 women patients with DM and impaired glucose tolerance (IGT between the ages of 40 and 61 years from several health facilities in Yogyakarta. All patients underwent clinical, laboratory and electrodiagnostic examination. Demographic, clinical and electrodiagnostic data were collected and analyzed. By survival analysis there were 25 new cases of PDN (12.12% cumulative incidence. Using survival Kaplan Meier analysis, the significant hazard ratio for PDN were 12.81 for median motor nerve amplitude, 5.74 for median nerve distal latency, 3.71 for median sensory nerve amplitude, 6.33 for median sensory latency, 3.4 for tibial nerve amplitude, 3.48 for tibial nerve distal latency, 2.29 for sural nerve amplitude, 4.47 for sural nerve latency, 3.99 for H-reflex latency, 5.88 for H-reflex amplitude, and 17.83 for Diabetic Neuropathy (DN status. Using hazard proportional cox analysis, only H amplitude and DN status (DNS score were significantly correlated with PDN (p= 0.026; hazard ratio = 15.450; CI 95%= 1.39 – 171.62 for H amplitude and p= 0.030; hazard ratio = 10.766; CI 95%=1.26 – 92.09 for DN status. This study showed that depression of H-reflex amplitude was correlated with the occurrence of PDN. This result proves that there was presynaptic inhibition process in PDN that manifests as low H-reflex amplitude.

  11. Gain modulation of the middle latency cutaneous reflex in patients with chronic joint instability after ankle sprain.

    Science.gov (United States)

    Futatsubashi, Genki; Sasada, Shusaku; Tazoe, Toshiki; Komiyama, Tomoyoshi

    2013-07-01

    To investigate the neural alteration of reflex pathways arising from cutaneous afferents in patients with chronic ankle instability. Cutaneous reflexes were elicited by applying non-noxious electrical stimulation to the sural nerve of subjects with chronic ankle instability (n=17) and control subjects (n=17) while sitting. Electromyographic (EMG) signals were recorded from each ankle and thigh muscle. The middle latency response (MLR; latency: 70-120 ms) component was analyzed. In the peroneus longus (PL) and vastus lateralis (VL) muscles, linear regression analyses between the magnitude of the inhibitory MLR and background EMG activity showed that, compared to the uninjured side and the control subjects, the gain of the suppressive MLR was increased in the injured side. This was also confirmed by the pooled data for both groups. The degree of MLR alteration was significantly correlated to that of chronic ankle instability in the PL. The excitability of middle latency cutaneous reflexes in the PL and VL is modulated in subjects with chronic ankle instability. Cutaneous reflexes may be potential tools to investigate the pathological state of the neural system that controls the lower limbs in subjects with chronic ankle instability. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  12. Isoform-Specific Na,K-ATPase Alterations Precede Disuse-Induced Atrophy of Rat Soleus Muscle

    Directory of Open Access Journals (Sweden)

    Violetta V. Kravtsova

    2015-01-01

    Full Text Available This study examines the isoform-specific effects of short-term hindlimb suspension (HS on the Na,K-ATPase in rat soleus muscle. Rats were exposed to 24–72 h of HS and we analyzed the consequences on soleus muscle mass and contractile parameters; excitability and the resting membrane potential (RMP of muscle fibers; the electrogenic activity, protein, and mRNA content of the α1 and α2 Na,K-ATPase; the functional activity and plasma membrane localization of the α2 Na,K-ATPase. Our results indicate that 24–72 h of HS specifically decreases the electrogenic activity of the Na,K-ATPase α2 isozyme and the RMP of soleus muscle fibers. This decrease occurs prior to muscle atrophy or any change in contractile parameters. The α2 mRNA and protein content increased after 24 h of HS and returned to initial levels at 72 h; however, even the increased content was not able to restore α2 enzyme activity in the disused soleus muscle. There was no change in the membrane localization of α2 Na,K-ATPase. The α1 Na,K-ATPase electrogenic activity, protein and mRNA content did not change. Our findings suggest that skeletal muscle use is absolutely required for α2 Na,K-ATPase transport activity and provide the first evidence that Na,K-ATPase alterations precede HS-induced muscle atrophy.

  13. Muscle disuse caused by botulinum toxin injection leads to increased central gain of the stretch reflex in the rat

    DEFF Research Database (Denmark)

    Pingel, Jessica; Hultborn, Hans; Naslund-Koch, Lui

    2017-01-01

    Botulinum toxin (Btx) is used in children with cerebral palsy and other neurological patients to diminish spasticity and reduce the risk of development of contractures. Here, we investigated changes in the central gain of the stretch reflex circuitry in response to botulinum toxin injection...

  14. Eccentric exercise training as a countermeasure to non-weight-bearing soleus muscle atrophy

    Science.gov (United States)

    Kirby, Christopher R.; Ryan, Mirelle J.; Booth, Frank W.

    1992-01-01

    This investigation tested whether eccentric resistance training could prevent soleus muscle atrophy during non-weight bearing. Adult female rats were randomly assigned to either weight bearing +/- intramuscular electrodes or non-weight bearing +/- intramuscular electrodes groups. Electrically stimulated maximal eccentric contractions were performed on anesthetized animals at 48-h intervals during the 10-day experiment. Non-weight bearing significantly reduced soleus muscle wet weight (28-31 percent) and noncollagenous protein content (30-31 percent) compared with controls. Eccentric exercise training during non-weight bearing attenuated but did not prevent the loss of soleus muscle wet weight and noncollagenous protein by 77 and 44 percent, respectively. The potential of eccentric exercise training as an effective and highly efficient counter-measure to non-weight-bearing atrophy is demonstrated in the 44 percent attenuation of soleus muscle noncollagenous protein loss by eccentric exercise during only 0.035 percent of the total non-weight-bearing time period.

  15. Suprasegmental neurophysiological monitoring with H reflex and TcMEP in spinal surgery. Transient loss due to hypotension. A case report

    Directory of Open Access Journals (Sweden)

    Ángel Saponaro-González

    Full Text Available Objective: H-reflex is a well known neurophysiological test used to evaluate sensory afferent and motor efferent impulses of S1 root. Despite its simplicity and feasibility, it is not used very often in the operating room. Methods: We report the case of a 16-year-old male patient who undergoes a surgical correction for a severe paralytic scoliosis (160°. On account of previous deficits, intraoperative neurophysiological monitoring was achieved through TcMEP and H-reflex. Results: Intraoperative neurophysiological monitoring (IONM showed a transient and simultaneous loss of bilateral TcMEP and H-reflex, coinciding with an abrupt hypotension during pedicle screw placement. After having dismissed mechanical injury and after increasing blood pressure, TcMEP and H-reflex were equivalent to those at baseline. Conclusions: The H-reflex is a classic neurophysiological test not used very frequently in the operating room. It is a feasible and reliable technique that can be helpful during spine surgery IONM, especially in patients with preexisting neurological deficits. Although simultaneous TcMEP and H-reflex monitoring has been previously described, to our knowledge, this is the first recorded case of a decline in both associated with abrupt hypotension. Keywords: Intraoperative neurophysiological monitoring, TcMEP, H-reflex, Scoliosis, Hypotension

  16. Locomotor adaptation to a soleus EMG-controlled antagonistic exoskeleton.

    Science.gov (United States)

    Gordon, Keith E; Kinnaird, Catherine R; Ferris, Daniel P

    2013-04-01

    Locomotor adaptation in humans is not well understood. To provide insight into the neural reorganization that occurs following a significant disruption to one's learned neuromuscular map relating a given motor command to its resulting muscular action, we tied the mechanical action of a robotic exoskeleton to the electromyography (EMG) profile of the soleus muscle during walking. The powered exoskeleton produced an ankle dorsiflexion torque proportional to soleus muscle recruitment thus limiting the soleus' plantar flexion torque capability. We hypothesized that neurologically intact subjects would alter muscle activation patterns in response to the antagonistic exoskeleton by decreasing soleus recruitment. Subjects practiced walking with the exoskeleton for two 30-min sessions. The initial response to the perturbation was to "fight" the resistive exoskeleton by increasing soleus activation. By the end of training, subjects had significantly reduced soleus recruitment resulting in a gait pattern with almost no ankle push-off. In addition, there was a trend for subjects to reduce gastrocnemius recruitment in proportion to the soleus even though only the soleus EMG was used to control the exoskeleton. The results from this study demonstrate the ability of the nervous system to recalibrate locomotor output in response to substantial changes in the mechanical output of the soleus muscle and associated sensory feedback. This study provides further evidence that the human locomotor system of intact individuals is highly flexible and able to adapt to achieve effective locomotion in response to a broad range of neuromuscular perturbations.

  17. Locomotor adaptation to a soleus EMG-controlled antagonistic exoskeleton

    Science.gov (United States)

    Kinnaird, Catherine R.; Ferris, Daniel P.

    2013-01-01

    Locomotor adaptation in humans is not well understood. To provide insight into the neural reorganization that occurs following a significant disruption to one's learned neuromuscular map relating a given motor command to its resulting muscular action, we tied the mechanical action of a robotic exoskeleton to the electromyography (EMG) profile of the soleus muscle during walking. The powered exoskeleton produced an ankle dorsiflexion torque proportional to soleus muscle recruitment thus limiting the soleus' plantar flexion torque capability. We hypothesized that neurologically intact subjects would alter muscle activation patterns in response to the antagonistic exoskeleton by decreasing soleus recruitment. Subjects practiced walking with the exoskeleton for two 30-min sessions. The initial response to the perturbation was to “fight” the resistive exoskeleton by increasing soleus activation. By the end of training, subjects had significantly reduced soleus recruitment resulting in a gait pattern with almost no ankle push-off. In addition, there was a trend for subjects to reduce gastrocnemius recruitment in proportion to the soleus even though only the soleus EMG was used to control the exoskeleton. The results from this study demonstrate the ability of the nervous system to recalibrate locomotor output in response to substantial changes in the mechanical output of the soleus muscle and associated sensory feedback. This study provides further evidence that the human locomotor system of intact individuals is highly flexible and able to adapt to achieve effective locomotion in response to a broad range of neuromuscular perturbations. PMID:23307949

  18. Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling

    Directory of Open Access Journals (Sweden)

    Gregory E. P. Pearcey

    2017-12-01

    Full Text Available Spinal cord excitability, as assessed by modulation of Hoffmann (H- reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation (CONTROL + STIM, sprints with sensory stimulation (SPRINT + STIM and sprints without stimulation (SPRINT. Seven participants also performed a fourth session (CONTROL, which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM, participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM, participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output

  19. Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling.

    Science.gov (United States)

    Pearcey, Gregory E P; Noble, Steven A; Munro, Bridget; Zehr, E Paul

    2017-01-01

    Spinal cord excitability, as assessed by modulation of Hoffmann (H-) reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation ( CONTROL + STIM ), sprints with sensory stimulation ( SPRINT + STIM ) and sprints without stimulation ( SPRINT ). Seven participants also performed a fourth session ( CONTROL ), which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM , participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM , participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output, compared

  20. The effects of a single session of spinal manipulation on strength and cortical drive in athletes

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lykke; Niazi, Imran Khan; Holt, Kelly

    2018-01-01

    PURPOSE: The primary purpose of this study was to investigate whether a single session of spinal manipulation (SM) increases strength and cortical drive in the lower limb (soleus muscle) of elite Taekwondo athletes. METHODS: Soleus-evoked V-waves, H-reflex and maximum voluntary contraction (MVC) ...

  1. Simultaneous characterizations of reflex and nonreflex dynamic and static changes in spastic hemiparesis

    Science.gov (United States)

    Chung, Sun G.; Ren, Yupeng; Liu, Lin; Roth, Elliot J.; Rymer, W. Zev

    2013-01-01

    This study characterizes tonic and phasic stretch reflex and stiffness and viscosity changes associated with spastic hemiparesis. Perturbations were applied to the ankle of 27 hemiparetic and 36 healthy subjects under relaxed or active contracting conditions. A nonlinear delay differential equation model characterized phasic and tonic stretch reflex gains, elastic stiffness, and viscous damping. Tendon reflex was characterized with reflex gain and threshold. Reflexively, tonic reflex gain was increased in spastic ankles at rest (P hemiparesis may help to evaluate and treat them more effectively. PMID:23636726

  2. The Cerebellum in Maintenance of a Motor Skill: A Hierarchy of Brain and Spinal Cord Plasticity Underlies H-Reflex Conditioning

    Science.gov (United States)

    Wolpaw, Jonathan R.; Chen, Xiang Yang

    2006-01-01

    Operant conditioning of the H-reflex, the electrical analog of the spinal stretch reflex, is a simple model of skill acquisition and involves plasticity in the spinal cord. Previous work showed that the cerebellum is essential for down-conditioning the H-reflex. This study asks whether the cerebellum is also essential for maintaining…

  3. Linear time delay methods and stability analyses of the human spine. Effects of neuromuscular reflex response.

    Science.gov (United States)

    Franklin, Timothy C; Granata, Kevin P; Madigan, Michael L; Hendricks, Scott L

    2008-08-01

    Linear stability methods were applied to a biomechanical model of the human musculoskeletal spine to investigate effects of reflex gain and reflex delay on stability. Equations of motion represented a dynamic 18 degrees-of-freedom rigid-body model with time-delayed reflexes. Optimal muscle activation levels were identified by minimizing metabolic power with the constraints of equilibrium and stability with zero reflex time delay. Muscle activation levels and associated muscle forces were used to find the delay margin, i.e., the maximum reflex delay for which the system was stable. Results demonstrated that stiffness due to antagonistic co-contraction necessary for stability declined with increased proportional reflex gain. Reflex delay limited the maximum acceptable proportional reflex gain, i.e., long reflex delay required smaller maximum reflex gain to avoid instability. As differential reflex gain increased, there was a small increase in acceptable reflex delay. However, differential reflex gain with values near intrinsic damping caused the delay margin to approach zero. Forward-dynamic simulations of the fully nonlinear time-delayed system verified the linear results. The linear methods accurately found the delay margin below which the nonlinear system was asymptotically stable. These methods may aid future investigations in the role of reflexes in musculoskeletal stability.

  4. Presynaptic control of group Ia afferents in relation to acquisition of a visuo-motor skill in healthy humans

    DEFF Research Database (Denmark)

    Perez, Monica A.; Lungholt, Bjarke K.S.; Nielsen, Jens Bo

    2005-01-01

    Sensory information continuously converges on the spinal cord during a variety of motor behaviours. Here, we examined presynaptic control of group Ia afferents in relation to acquisition of a novel motor skill. We tested whether repetition of two motor tasks with different degrees of difficulty......, a novel visuo-motor task involving the ankle muscles, and a control task involving simple voluntary ankle movements, would induce changes in the size of the soleus H-reflex. The slope of the H-reflex recruitment curve and the H-max/M-max ratio were depressed after repetition of the visuo-motor skill task...... of the monosynaptic Ia facilitation of the soleus H-reflex evoked by femoral nerve stimulation. The D1 inhibition was increased and the femoral nerve facilitation was decreased following the visuo-motor skill task, suggesting an increase in presynaptic inhibition of Ia afferents. No changes were observed...

  5. The pulse duration of electrical stimulation influences H-reflexes but not corticospinal excitability for tibialis anterior.

    Science.gov (United States)

    Hindle, Alyssa R; Lou, Jenny W H; Collins, David F

    2014-10-01

    The afferent volley generated by neuromuscular electrical stimulation (NMES) influences corticospinal (CS) excitability and frequent NMES sessions can strengthen CS pathways, resulting in long-term improvements in function. This afferent volley can be altered by manipulating NMES parameters. Presently, we manipulated one such parameter, pulse duration, during NMES over the common peroneal nerve and assessed the influence on H-reflexes and CS excitability. We hypothesized that compared with shorter pulse durations, longer pulses would (i) shift the H-reflex recruitment curve to the left, relative to the M-wave curve; and (ii) increase CS excitability more. Using 3 pulse durations (50, 200, 1000 μs), M-wave and H-reflex recruitment curves were collected and, in separate experiments, CS excitability was assessed by comparing motor evoked potentials elicited before and after 30 min of NMES. Despite finding a leftward shift in the H-reflex recruitment curve when using the 1000 μs pulse duration, consistent with a larger afferent volley for a given efferent volley, the increases in CS excitability were not influenced by pulse duration. Hence, although manipulating pulse duration can alter the relative recruitment of afferents and efferents in the common peroneal nerve, under the present experimental conditions it is ineffective for maximizing CS excitability for rehabilitation.

  6. Soleus muscle injury: sensitivity of ultrasound patterns

    Energy Technology Data Exchange (ETDEWEB)

    Balius, Ramon [Sport Catalan Council, Generalitat de Catalunya, Barcelona (Spain); Clinica CMI Diagonal, Barcelona (Spain); Rodas, Gil [F.C. Barcelona Medical Services, Barcelona (Spain); Pedret, Carles [Clinica CMI Diagonal, Barcelona (Spain); Clinica Mapfre de Medicina del Tenis, Sports Medicine and Imaging Department, Barcelona (Spain); Centre de Diagnostic per Imatge de Tarragona, Tarragona (Spain); Capdevila, Lluis [Universitat Autonoma de Barcelona, Laboratory of Sport Psychology, Barcelona (Spain); Alomar, Xavier [Clinica Creu Blanca, Barcelona (Spain); Bong, David A. [Instituto Poal de Reumatologia, Barcelona (Spain)

    2014-06-15

    To assess the sensitivity of ultrasound in detecting soleus muscle lesions diagnosed on magnetic resonance imaging (MRI) and to characterize their location, ultrasound pattern, and evolution. Ultrasound and MRI studies were performed between May 2009 and February 2013 on all patients who presented to the Medical Services Clinic of the Catalan Sport Council with the initial onset of sharp pain in the calf compatible with injury of the soleus muscle. An inter-observer ultrasound reliability study was also performed. A total of 55 cases of soleus injury were studied prospectively (22 with right leg involvement, 33 left) by ultrasound and MRI, which was utilized as the ''gold standard.'' In MRI studies, 24 cases (43.7 %) had myofascial injuries that were localized in the posterior aponeurosis (PMF) in 15 cases (27.3 %) and in the anterior aponeurosis (AMF) in 9 (16.4 %). Thirty-one cases (56.3 %) were musculotendinous injuries, with 9 cases (16.4 %) in the medial aponeurosis (MMT), 11 cases (20 %) in the lateral aponeurosis (LMT), and 11 cases (20 %) in the central tendon (CMT). In comparison to MRI, ultrasound was able to detect injury to the soleus in 27.2 % of cases. No injuries were detected by ultrasound alone. Posterior myofascial injuries were more likely to be detected by ultrasound than anterior myofascial injuries or all types of musculotendinous injuries. Ultrasound patterns for each type of injury were described. Ultrasound is not a sensitive technique for detecting and assessing soleus traumatic tears compared with MRI, although the sensitivity is enhanced by a thorough anatomically based ultrasound examination. Timing of the ultrasound examination may be of importance. Each type of soleus injury appears to have a characteristic ultrasound pattern based on a defect of connective expansions, the existence of small myofascial filiform collections, and the rarefaction of the fibrillar area. (orig.)

  7. Soleus muscle injury: sensitivity of ultrasound patterns.

    Science.gov (United States)

    Balius, Ramon; Rodas, Gil; Pedret, Carles; Capdevila, Lluís; Alomar, Xavier; Bong, David A

    2014-06-01

    To assess the sensitivity of ultrasound in detecting soleus muscle lesions diagnosed on magnetic resonance imaging (MRI) and to characterize their location, ultrasound pattern, and evolution. Ultrasound and MRI studies were performed between May 2009 and February 2013 on all patients who presented to the Medical Services Clinic of the Catalan Sport Council with the initial onset of sharp pain in the calf compatible with injury of the soleus muscle. An inter-observer ultrasound reliability study was also performed. A total of 55 cases of soleus injury were studied prospectively (22 with right leg involvement, 33 left) by ultrasound and MRI, which was utilized as the "gold standard." In MRI studies, 24 cases (43.7%) had myofascial injuries that were localized in the posterior aponeurosis (PMF) in 15 cases (27.3%) and in the anterior aponeurosis (AMF) in 9 (16.4%). Thirty-one cases (56.3%) were musculotendinous injuries, with 9 cases (16.4%) in the medial aponeurosis (MMT), 11 cases (20%) in the lateral aponeurosis (LMT), and 11 cases (20%) in the central tendon (CMT). In comparison to MRI, ultrasound was able to detect injury to the soleus in 27.2% of cases. No injuries were detected by ultrasound alone. Posterior myofascial injuries were more likely to be detected by ultrasound than anterior myofascial injuries or all types of musculotendinous injuries. Ultrasound patterns for each type of injury were described. Ultrasound is not a sensitive technique for detecting and assessing soleus traumatic tears compared with MRI, although the sensitivity is enhanced by a thorough anatomically based ultrasound examination. Timing of the ultrasound examination may be of importance. Each type of soleus injury appears to have a characteristic ultrasound pattern based on a defect of connective expansions, the existence of small myofascial filiform collections, and the rarefaction of the fibrillar area.

  8. Soleus muscle injury: sensitivity of ultrasound patterns

    International Nuclear Information System (INIS)

    Balius, Ramon; Rodas, Gil; Pedret, Carles; Capdevila, Lluis; Alomar, Xavier; Bong, David A.

    2014-01-01

    To assess the sensitivity of ultrasound in detecting soleus muscle lesions diagnosed on magnetic resonance imaging (MRI) and to characterize their location, ultrasound pattern, and evolution. Ultrasound and MRI studies were performed between May 2009 and February 2013 on all patients who presented to the Medical Services Clinic of the Catalan Sport Council with the initial onset of sharp pain in the calf compatible with injury of the soleus muscle. An inter-observer ultrasound reliability study was also performed. A total of 55 cases of soleus injury were studied prospectively (22 with right leg involvement, 33 left) by ultrasound and MRI, which was utilized as the ''gold standard.'' In MRI studies, 24 cases (43.7 %) had myofascial injuries that were localized in the posterior aponeurosis (PMF) in 15 cases (27.3 %) and in the anterior aponeurosis (AMF) in 9 (16.4 %). Thirty-one cases (56.3 %) were musculotendinous injuries, with 9 cases (16.4 %) in the medial aponeurosis (MMT), 11 cases (20 %) in the lateral aponeurosis (LMT), and 11 cases (20 %) in the central tendon (CMT). In comparison to MRI, ultrasound was able to detect injury to the soleus in 27.2 % of cases. No injuries were detected by ultrasound alone. Posterior myofascial injuries were more likely to be detected by ultrasound than anterior myofascial injuries or all types of musculotendinous injuries. Ultrasound patterns for each type of injury were described. Ultrasound is not a sensitive technique for detecting and assessing soleus traumatic tears compared with MRI, although the sensitivity is enhanced by a thorough anatomically based ultrasound examination. Timing of the ultrasound examination may be of importance. Each type of soleus injury appears to have a characteristic ultrasound pattern based on a defect of connective expansions, the existence of small myofascial filiform collections, and the rarefaction of the fibrillar area. (orig.)

  9. Contribution of pH, diprotonated phosphate and potassium for the reflex increase in blood pressure during handgrip

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Madsen, P; Nielsen, H B

    1998-01-01

    The relative importance of pH, diprotonated phosphate (H2PO4-) and potassium (K+) for the reflex increase in mean arterial pressure (MAP) during exercise was evaluated in seven subjects during rhythmic handgrip at 15 and 30% maximal voluntary contraction (MVC), followed by post-exercise muscle...... to the exercise levels. Analysis of each variable as a predictor of blood pressure indicated that only the intracellular pH and diprotonated phosphate were linked to the reflex elevation of blood pressure during handgrip....

  10. Increased response to insulin of glucose metabolism in the 6-day unloaded rat soleus muscle

    Science.gov (United States)

    Henriksen, Erik J.; Tischler, Marc E.; Johnson, David G.

    1986-01-01

    Hind leg muscles of female rats were unloaded by tail cast suspension for 6 days. In the fresh-frozen unloaded soleus, the significantly greater concentration of glycogen correlated with a lower activity ratio of glycogen phosphorylase (p less than 0.02). The activity ratio of glycogen synthase also was lower (p less than 0.001), possibly due to the higher concentration of glycogen. In isolated unloaded soleus, insulin (0.1 milliunit/ml) increased the oxidation of D(U-C-14) glucose, release of lactate and pyruvate, incorporation of D-(U-C-14) glucose into glycogen, and the concentration of glucose 6-phosphate more (p less than 0.05) than in the weight-bearing soleus. At physiological doses of insulin, the percent of maximal uptake of 2-deoxy-D-(1,2-H-3) glucose/muscle also was greater in the unloaded soleus. Unloading of the soleus increased, by 50 percent the concentration of insuling receptors, due to no decrease in total receptor number during muscle atrophy. This increase may account for the greater response of glucose metabolism to insulin in this muscle. The extensor digitorum longus, which generally shows little response to unloading, displayed no differential response of glucose metabolism to insulin.

  11. Plastic changes in spinal synaptic transmission following botulinum toxin A in patients with post-stroke spasticity.

    Science.gov (United States)

    Kerzoncuf, Marjorie; Bensoussan, Laurent; Delarque, Alain; Durand, Jacques; Viton, Jean-Michel; Rossi-Durand, Christiane

    2015-11-01

    The therapeutic effects of intramuscular injections of botulinum toxin-type A on spasticity can largely be explained by its blocking action at the neuromuscular junction. Botulinum toxin-type A is also thought to have a central action on the functional organization of the central nervous system. This study assessed the action of botulinum toxin-type A on spinal motor networks by investigating post-activation depression of the soleus H-reflex in post-stroke patients. Post-activation depression, a presynaptic mechanism controlling the synaptic efficacy of Ia-motoneuron transmission, is involved in the pathophysiology of spasticity. Eight patients with chronic hemiplegia post-stroke presenting with lower limb spasticity and requiring botulinum toxin-type A injection in the ankle extensor muscle. Post-activation depression of soleus H-reflex assessed as frequency-related depression of H-reflex was investigated before and 3, 6 and 12 weeks after botulinum toxin-type A injections in the triceps surae. Post-activation depression was quantified as the ratio between H-reflex amplitude at 0.5 and 0.1 Hz. Post-activation depression of soleus H-reflex, which is reduced on the paretic leg, was affected 3 weeks after botulinum toxin-type A injection. Depending on the residual motor capacity of the post-stroke patients, post-activation depression was either restored in patients with preserved voluntary motor control or further reduced in patients with no residual voluntary control. Botulinum toxin treatment induces synaptic plasticity at the Ia-motoneuron synapse in post-stroke paretic patients, which suggests that the effectiveness of botulinum toxin-type A in post-stroke rehabilitation might be partly due to its central effects.

  12. Hypothyroidism in the rat results in decreased soleus motoneurone soma size

    NARCIS (Netherlands)

    Bakels, R; Nijenhuis, Albertine; Mast, L; Kernell, D

    1998-01-01

    Adult female rats were thyroidectomized. After an average of 17 weeks, horseradish peroxidase (HRP) was injected into the right side soleus muscle. Two days later, left side soleus muscle properties were recorded and muscles and spinal cord were removed for further histological measurements. Soleus

  13. Etnography and Reflexivity

    Directory of Open Access Journals (Sweden)

    Mario Cardano

    2014-01-01

    Full Text Available This essay deals with a relevant and controversial topic – objectivity in ethnographic research. More specifically, I would like to examine how reflexive procedures, more precisely “reflexive account”, can increase the robustness of results gained through an ethnographic research. The essay is organized in five parts. I will start by giving a preliminary definition of the two key concepts which are at the center of the analysis – objectivity and reflexivity. I will then give a brief description of the epistemological framework in which the proposed conceptions of objectivity and reflexivity are located. Thirdly, I move on to consider the epistemic status of ethnographic research, and will emphasize that ethnographies are not just “theory-laden”, as many writers have stated, but also “praxis” or “procedure laden”. In other words, I will stress that it is not only theories which are inevitably embedded in research, influencing how observations can be made; much the same can also be said of the concrete research practices which contribute to determine the experience of the ethnographer and its representation in a text. Fourthly, I will discuss why it is useful to employ reflexive practices, and then immediately afterwards will illustrate the ways in which reflexive descriptions can contribute to greater objectivity of ethnographic accounts. In conclusion, I will discuss a number of objections which have been raised against this use of reflexivity.

  14. Decrease of Horizontal Canal Vestibulo-Oculomotor Reflex Gain in the Elderly with Dysequilibrium without Lifetime Vertigo.

    Science.gov (United States)

    Teggi, Roberto; Trimarchi, Matteo; Gatti, Omar; Fornasari, Francesco; Bussi, Mario

    2017-01-01

    Unsteadiness in the elderly is a frequent complaint and a strong predictor of falls and psychological distress. Although there is a general consensus that it is a multifactorial condition, recent studies have focused on the role of aging of the vestibular system as a possible cofactor. The aim of our work was to assess horizontal canal function in the elderly. We evaluated the gain of horizontal vestibulo-ocular reflex (VOR) with a video head impulse test on a sample of 58 subjects aged >70 years without lifetime episodes of vertigo and correlated the value with different clinical conditions (hypertension, diabetes, prior cardiovascular and vascular disorders of the central nervous system, and falls). The mean value of the gain was 0.86 ± 0.12, and people aged between 70 and 80 years presented higher values (0.90 ± 0.1) compared to those >80 years (0.81 ± 0.13; p = 0.025). Previous vascular disorders of the central nervous system were a predictor of decreased VOR gain (p = 0.0003). A nonparametric analysis demonstrated that sex, age, and VOR gain (p ˂ 0.0001) were predictive of falls. Our data support the hypothesis of a decrease of VOR gain in the elderly. The decrease of canal function may therefore play a role in the risk of falls in the elderly. © 2017 S. Karger AG, Basel.

  15. Does spinal excitability scale to the difficulty of the dual-task?

    Science.gov (United States)

    Day, Devon M; Boivin, Mario T; Adkin, Allan L; Tokuno, Craig D

    2017-08-01

    This study examined whether spinal excitability, as measured by the soleus Hoffmann reflex (H-reflex), is scaled to the difficulty level of the dual-task being performed. Twenty-two participants completed a combination of three balance task and three secondary cognitive (visuo-motor) task difficulty levels for a total of nine dual-task conditions. An additional eight participants were tested while performing the same three balance task difficulty levels on its own (i.e., single-tasking). The balance task required participants to maintain their balance on a fixed or rotating stabilometer while the visuo-motor task required participants to respond to moving targets presented on a monitor. Throughout each single- and dual-task trial, H-reflexes were elicited from the soleus. Although dual-task performance, as quantified by visuo-motor task accuracy as well as the root mean square of the stabilometer position and velocity, decreased by 10-34% with increasing dual-task difficulty (p dual-task conditions (p = 0.483-0.758). This contrasts to when participants performed the balance task as a single-task, where the H-reflex amplitude decreased by ~25% from the easy to the hard balance task difficulty level (p = 0.037). In contrast to the commonly reported finding of a reduced soleus H-reflex amplitude when individuals perform a less posturally stable task by itself, the results indicate that spinal excitability is not modulated as a function of dual-task difficulty. It is possible that when an individual's attentional resource capacity is exceeded during dual-tasking, they become ineffective in regulating spinal excitability for balance control.

  16. Baseline muscle mass is a poor predictor of functional overload-induced gain in the mouse model

    Directory of Open Access Journals (Sweden)

    Audrius Kilikevicius

    2016-11-01

    Full Text Available Genetic background contributes substantially to individual variability in muscle mass. Muscle hypertrophy in response to resistance training can also vary extensively. However, it is less clear if muscle mass at baseline is predictive of the hypertrophic response.The aim of this study was to examine the effect of genetic background on variability in muscle mass at baseline and in the adaptive response of the mouse fast- and slow-twitch muscles to overload. Males of eight laboratory mouse strains: C57BL/6J (B6, n=17, BALB/cByJ (n=7, DBA/2J (D2, n=12, B6.A-(rs3676616-D10Utsw1/Kjn (B6.A, n=9, C57BL/6J-Chr10A/J/NaJ (B6.A10, n=8, BEH+/+ (n=11, BEH (n=12 and DUHi (n=12, were studied. Compensatory growth of soleus and plantaris muscles was triggered by a 4-week overload induced by synergist unilateral ablation. Muscle weight in the control leg (baseline varied from 5.2±07 mg soleus and 11.4±1.3 mg plantaris in D2 mice to 18.0±1.7 mg soleus in DUHi and 43.7±2.6 mg plantaris in BEH (p<0.001 for both muscles. In addition, soleus in the B6.A10 strain was ~40% larger (p<0.001 compared to the B6. Functional overload increased muscle weight, however, the extent of gain was strain-dependent for both soleus (p<0.01 and plantaris (p<0.02 even after accounting for the baseline differences. For the soleus muscle, the BEH strain emerged as the least responsive, with a 1.3-fold increase, compared to a 1.7-fold gain in the most responsive D2 strain, and there was no difference in the gain between the B6.A10 and B6 strains. The BEH strain appeared the least responsive in the gain of plantaris as well, 1.3-fold, compared to ~1.5-fold gain in the remaining strains. We conclude that variation in muscle mass at baseline is not a reliable predictor of that in the overload-induced gain. This suggests that a different set of genes influence variability in muscle mass acquired in the process of normal development, growth and maintenance, and in the process of adaptive

  17. Vergence increases the gain of the human angular vestibulo-ocular reflex during peripheral hyposensitivity elicited by cold thermal irrigation.

    Science.gov (United States)

    Tamás, László T; Lundberg, Yunxia W; Büki, Béla

    2018-01-01

    When viewing a far target, the gain of the horizontal vestibulo-ocular reflex (VOR) is around 1.0, but when viewing a near target there is an increased response. It has been shown that while this convergence-mediated modulation is unaffected by canal plugging and clinically practical transmastoid galvanic stimulation, it is eliminated by a partial peripheral gentamicin lesion. The aim of this study was to determine if convergence increases the gain during peripheral hyposensitivity elicited by cold thermal irrigation. The high frequency VOR gain was measured using video head impulse testing immediately after the cold caloric stimulus in 9 healthy human subjects with the lateral semicircular canals oriented approximately earth-vertical. Before caloric irrigation, near viewing (15 cm) increased the average VOR gain by 28% (from 1 to 1.28). Cold (24°C) water irrigation of the right ear decreased the gain to 0.66 (far viewing) and 0.82 (near viewing) (22% difference). Although vergence also increased the gain for impulses to the left to the same degree before caloric stimulus, the caloric irrigation itself (applied to the right ear) did not influence the gain for contralateral impulses. In our experiments vergence increased the gain of the human angular VOR during peripheral hyposensitivity elicited by cold thermal irrigation. These results suggest that cold irrigation does not abolish the function of the nonlinear/phasic vestibular afferent pathway.

  18. Lower Amplitude of the Hoffmann Reflex in Women With Patellofemoral Pain: Thinking Beyond Proximal, Local, and Distal Factors.

    Science.gov (United States)

    de Oliveira Silva, Danilo; Magalhães, Fernando Henrique; Faria, Nathálie Clara; Pazzinatto, Marcella Ferraz; Ferrari, Deisi; Pappas, Evangelos; de Azevedo, Fábio Mícolis

    2016-07-01

    To investigate whether vastus medialis (VM) Hoffmann reflexes (H-reflexes) differ on the basis of the presence or absence of patellofemoral pain (PFP) and to assess the capability of VM H-reflex measurements in accurately discriminating between women with and without PFP. Cross-sectional study. Laboratory of biomechanics and motor control. Women (N=30) aged 18 to 35 years were recruited, consisting of 2 groups: women with PFP (n=15) and asymptomatic controls (n=15). Not applicable. Maximum evoked responses were obtained by electrical stimulation applied to the femoral nerve, and peak-to-peak amplitudes of maximal Hoffmann reflex (Hmax) and maximal motor wave (Mmax) ratios were calculated. Independent samples t tests were performed to identify differences between groups, and a receiver operating characteristic curve was constructed to assess the discriminatory capability of VM H-reflex measurements. VM Hmax/Mmax ratios were significantly lower in participants with PFP than in pain-free participants (P=.007). In addition, the VM Hmax/Mmax ratios presented large and balanced discriminatory capability values (sensitivity, 73%; specificity, 67%). This study is the first to show that VM H-reflexes are lower in women with PFP than in asymptomatic controls. Therefore, increasing the excitation of the spinal cord in PFP participants may be essential to maintaining the gains acquired during the rehabilitation programs. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  19. beta-adrenergic effects on carbohydrate metabolism in the unweighted rat soleus muscle

    Science.gov (United States)

    Kirby, Christopher R.; Tischler, Marc E.

    1990-01-01

    The effect of unweighting on the response of the soleus-muscle carbohydrate metabolism to a beta-adrenergic agonist (isoproterenol) was investigated in rats that were subjected to three days of tail-cast suspension. It was found that isoproterenol promoted glycogen degradation in soleus from suspended rats to a higher degree than in weighted soleus from control rats, and had no effect in unweighted digitorum longus. However, isoproterenol did not have a greater inhibitory effect on the net uptake of tritium-labeled 2-deoxy-glucose by the unweighted soleus and that isoproterenol inhibited hexose phosphorylation less in the unweighted than in the control muscle.

  20. Impaired translocation of GLUT4 results in insulin resistance of atrophic soleus muscle.

    Science.gov (United States)

    Xu, Peng-Tao; Song, Zhen; Zhang, Wen-Cheng; Jiao, Bo; Yu, Zhi-Bin

    2015-01-01

    Whether or not the atrophic skeletal muscle induces insulin resistance and its mechanisms are not resolved now. The antigravity soleus muscle showed a progressive atrophy in 1-week, 2-week, and 4-week tail-suspended rats. Hyperinsulinemic-euglycemic clamp showed that the steady-state glucose infusion rate was lower in 4-week tail-suspended rats than that in the control rats. The glucose uptake rates under insulin- or contraction-stimulation were significantly decreased in 4-week unloaded soleus muscle. The key protein expressions of IRS-1, PI3K, and Akt on the insulin-dependent pathway and of AMPK, ERK, and p38 on the insulin-independent pathway were unchanged in unloaded soleus muscle. The unchanged phosphorylation of Akt and p38 suggested that the activity of two signal pathways was not altered in unloaded soleus muscle. The AS160 and GLUT4 expression on the common downstream pathway also was not changed in unloaded soleus muscle. But the GLUT4 translocation to sarcolemma was inhibited during insulin stimulation in unloaded soleus muscle. The above results suggest that hindlimb unloading in tail-suspended rat induces atrophy in antigravity soleus muscle. The impaired GLUT4 translocation to sarcolemma under insulin stimulation may mediate insulin resistance in unloaded soleus muscle and further affect the insulin sensitivity of whole body in tail-suspended rats.

  1. Impaired Translocation of GLUT4 Results in Insulin Resistance of Atrophic Soleus Muscle

    Directory of Open Access Journals (Sweden)

    Peng-Tao Xu

    2015-01-01

    Full Text Available Whether or not the atrophic skeletal muscle induces insulin resistance and its mechanisms are not resolved now. The antigravity soleus muscle showed a progressive atrophy in 1-week, 2-week, and 4-week tail-suspended rats. Hyperinsulinemic-euglycemic clamp showed that the steady-state glucose infusion rate was lower in 4-week tail-suspended rats than that in the control rats. The glucose uptake rates under insulin- or contraction-stimulation were significantly decreased in 4-week unloaded soleus muscle. The key protein expressions of IRS-1, PI3K, and Akt on the insulin-dependent pathway and of AMPK, ERK, and p38 on the insulin-independent pathway were unchanged in unloaded soleus muscle. The unchanged phosphorylation of Akt and p38 suggested that the activity of two signal pathways was not altered in unloaded soleus muscle. The AS160 and GLUT4 expression on the common downstream pathway also was not changed in unloaded soleus muscle. But the GLUT4 translocation to sarcolemma was inhibited during insulin stimulation in unloaded soleus muscle. The above results suggest that hindlimb unloading in tail-suspended rat induces atrophy in antigravity soleus muscle. The impaired GLUT4 translocation to sarcolemma under insulin stimulation may mediate insulin resistance in unloaded soleus muscle and further affect the insulin sensitivity of whole body in tail-suspended rats.

  2. Plasticity of the human otolith-ocular reflex

    Science.gov (United States)

    Wall, C. 3rd; Smith, T. R.; Furman, J. M.

    1992-01-01

    The eye movement response to earth vertical axis rotation in the dark, a semicircular canal stimulus, can be altered by prior exposure to combined visual-vestibular stimuli. Such plasticity of the vestibulo-ocular reflex has not been described for earth horizontal axis rotation, a dynamic otolith stimulus. Twenty normal human subjects underwent one of two types of adaptation paradigms designed either to attenuate or enhance the gain of the semicircular canal-ocular reflex prior to undergoing otolith-ocular reflex testing with horizontal axis rotation. The adaptation paradigm paired a 0.2 Hz sinusoidal rotation about a vertical axis with a 0.2 Hz optokinetic stripe pattern that was deliberately mismatched in peak velocity. Pre- and post-adaptation horizontal axis rotations were at 60 degrees/s in the dark and produced a modulation in the slow component velocity of nystagmus having a frequency of 0.17 Hz due to putative stimulation of the otolith organs. Results showed that the magnitude of this modulation component response was altered in a manner similar to the alteration in semicircular canal-ocular responses. These results suggest that physiologic alteration of the vestibulo-ocular reflex using deliberately mismatched visual and semicircular canal stimuli induces changes in both canal-ocular and otolith-ocular responses. We postulate, therefore, that central nervous system pathways responsible for controlling the gains of canal-ocular and otolith-ocular reflexes are shared.

  3. Lectins binding during alloxan-induced diabetes in rat soleus muscle

    African Journals Online (AJOL)

    Membrane structural changes of soleus muscle of alloxan-diabetic rats were detected with a panel of six biotinylated lectins. Samples of muscles were obtained from normal and diabetic rats. The biotinylated lectins in staining were detected by avidin-peroxidase complex. Lectin stainning of soleus muscle cryostat sections ...

  4. Gait variability and motor control in people with knee osteoarthritis

    DEFF Research Database (Denmark)

    Alkjaer, Tine; Raffalt, Peter C; Dalsgaard, Helle

    2015-01-01

    fluctuation analysis. The motor control was assessed by the soleus (SO) Hoffmann (H)-reflex modulation and muscle co-activation during walking. The results showed no statistically significant mean group differences in any of the gait variability measures or muscle co-activation levels. The SO H...

  5. Reflexives and reflexive constructions in Afrikaans

    African Journals Online (AJOL)

    Kate H

    2. Reflexives. Afrikaans items belonging to the traditional lexical category of reflexives (or reflexive ... reflexive and non-reflexive pronouns are syntactically derived from the same lexical root pronoun √PRON. The ...... 32 The matrix verbs in (33) and (34) both concern a future activity of an entity: belowe (“promise”) in the (a).

  6. The soleus syndrome. A cause of medial tibial stress (shin splints).

    Science.gov (United States)

    Michael, R H; Holder, L E

    1985-01-01

    Radionuclide bone scans have demonstrated linear uptake along the posterior medial border of the tibia in patients with shin splints. This area was investigated by anatomical dissection (14 human cadavers), electromyographic (EMG) and muscle stimulation studies (10 patients), and open biopsy (1 patient). Histologically, the increased metabolic activity manifested on the radionuclide scan is due to a periostitis with new bone formation. The soleus muscle and its investing fascia are anatomically and biomechanically implicated in the production of these stress changes, particularly when the heel is in the pronated position. The soleus muscle and fascia form a tough "soleus bridge" over the deep compartment which is thought to be important in patients requiring surgical decompression.

  7. Effect of salbutamol on innervated and denervated rat soleus muscle

    Directory of Open Access Journals (Sweden)

    ?oic-Vranic T.

    2005-01-01

    Full Text Available The objective of the present investigation was to perform a 14-day time-course study of treatment with salbutamol, a ß2 adrenoceptor agonist, on rat soleus muscle in order to assess fiber type selectivity in the hypertrophic response and fiber type composition. Male Wistar rats were divided into four groups: control (N = 10, treated with salbutamol (N = 30, denervated (N = 30, and treated with salbutamol after denervation (N = 30. Salbutamol was injected intraperitoneally in the rats of the 2nd and 4th groups at a concentration of 0.3 mg/kg twice a day for 2 weeks. The muscles were denervated using the crush method with pean. The animals were sacrificed 3, 6, 9, 12, and 14 days after treatment. Frozen cross-sections of soleus muscle were stained for myosin ATPase, pH 9.4. Cross-sectional area and percent of muscle fibers were analyzed morphometrically by computerized image analysis. Treatment with salbutamol induced hypertrophy of all fiber types and a higher percentage of type II fibers (21% in the healthy rat soleus muscle. Denervation caused marked atrophy of all fibers and conversion from type I to type II muscle fibers. Denervated muscles treated with salbutamol showed a significantly larger cross-sectional area of type I muscle fibers, 28.2% compared to the denervated untreated muscle. Moreover, the number of type I fibers was increased. These results indicate that administration of salbutamol is able to induce changes in cross-sectional area and fiber type distribution in the early phase of treatment. Since denervation-induced atrophy and conversion from type I to type II fibers were improved by salbutamol treatment we propose that salbutamol, like other ß2 adrenoceptor agonists, may have a therapeutic potential in improving the condition of skeletal muscle after denervation.

  8. Maintained changes in motoneuronal excitability by short‐lasting synaptic inputs in the decerebrate cat

    DEFF Research Database (Denmark)

    Crone, C.; Hultborn, H.; Kiehn, O.

    1988-01-01

    1. During investigation of the tonic stretch reflex in the unanaesthetized decerebrate cat we observed that a short train of impulses in Ia afferents from the soleus muscle (or its synergists) may cause a prolonged activity in the soleus muscle as judged by EMG and tension recordings. This excita......1. During investigation of the tonic stretch reflex in the unanaesthetized decerebrate cat we observed that a short train of impulses in Ia afferents from the soleus muscle (or its synergists) may cause a prolonged activity in the soleus muscle as judged by EMG and tension recordings...

  9. Contribution of the maculo-ocular reflex to gaze stability in the rabbit.

    Science.gov (United States)

    Pettorossi, V E; Errico, P; Santarelli, R M

    1991-01-01

    The contribution of the maculo-ocular reflex to gaze stability was studied in 10 pigmented rabbits by rolling the animals at various angles of sagittal inclination of the rotation and/or longitudinal animal axes. At low frequencies (0.005-0.01 Hz) of sinusoidal stimulation the vestibulo-ocular reflex (VOR) was due to macular activation, while at intermediate and high frequencies it was mainly due to ampullar activation. The following results were obtained: 1) maculo-ocular reflex gain decreased as a function of the cosine of the angle between the rotation axis and the earth's horizontal plane. No change in gain was observed when longitudinal animal axis alone was inclined. 2) At 0 degrees of rotation axis and with the animal's longitudinal axis inclination also set at 0 degrees, the maculo-ocular reflex was oriented about 20 degrees forward and upward with respect to the earth's vertical axis. This orientation remained constant with sagittal inclinations of the rotation and/or longitudinal animal axes ranging from approximately 5 degrees upward to 30 degrees downward. When the longitudinal animal axis was inclined beyond these limits, the eye trajectory tended to follow the axis inclination. In the upside down position, the maculo-ocular reflex was anticompensatory, oblique and fixed with respect to orbital coordinates. 3) Ampullo-ocular reflex gain did not change with inclinations of the rotation and/or longitudinal animal axes. The ocular responses were consistently oriented to the stimulus plane. At intermediate frequencies the eye movement trajectory was elliptic because of directional differences between the ampullo- and maculo-ocular reflexes.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Balanced Diet-Fed Fat-1 Transgenic Mice Exhibit Lower Hindlimb Suspension-Induced Soleus Muscle Atrophy

    Directory of Open Access Journals (Sweden)

    Gabriel Nasri Marzuca-Nassr

    2017-10-01

    Full Text Available The consequences of two-week hindlimb suspension (HS on skeletal muscle atrophy were investigated in balanced diet-fed Fat-1 transgenic and C57BL/6 wild-type mice. Body composition and gastrocnemius fatty acid composition were measured. Skeletal muscle force, cross-sectional area (CSA, and signaling pathways associated with protein synthesis (protein kinase B, Akt; ribosomal protein S6, S6, eukaryotic translation initiation factor 4E-binding protein 1, 4EBP1; glycogen synthase kinase3-beta, GSK3-beta; and extracellular-signal-regulated kinases 1/2, ERK 1/2 and protein degradation (atrophy gene-1/muscle atrophy F-box, atrogin-1/MAFbx and muscle RING finger 1, MuRF1 were evaluated in the soleus muscle. HS decreased soleus muscle wet and dry weights (by 43% and 26%, respectively, muscle isotonic and tetanic force (by 29% and 18%, respectively, CSA of the soleus muscle (by 36%, and soleus muscle fibers (by 45%. Fat-1 transgenic mice had a decrease in the ω-6/ω-3 polyunsaturated fatty acids (PUFAs ratio as compared with C57BL/6 wild-type mice (56%, p < 0.001. Fat-1 mice had lower soleus muscle dry mass loss (by 10% and preserved absolute isotonic force (by 17% and CSA of the soleus muscle (by 28% after HS as compared with C57BL/6 wild-type mice. p-GSK3B/GSK3B ratio was increased (by 70% and MuRF-1 content decreased (by 50% in the soleus muscle of Fat-1 mice after HS. Balanced diet-fed Fat-1 mice are able to preserve in part the soleus muscle mass, absolute isotonic force and CSA of the soleus muscle in a disuse condition.

  11. A reflexive perspective in problem solving

    OpenAIRE

    Chio, José Angel; Álvarez, Aida; López, Margarita

    2013-01-01

    The objective of this paper is to favour the methodological process of reflexive analysis in problem solving in the general teaching methods that concentrates in strengthening the dimensional analysis, to gain a greater preparation of the students for the solution of mathematical problems.

  12. Time-varying auditory gain control in response to double-pulse stimuli in harbour porpoises is not mediated by a stapedial reflex

    Directory of Open Access Journals (Sweden)

    Asger Emil Munch Schrøder

    2017-04-01

    Full Text Available Echolocating animals reduce their output level and hearing sensitivity with decreasing echo delays, presumably to stabilize the perceived echo intensity during target approaches. In bats, this variation in hearing sensitivity is formed by a call-induced stapedial reflex that tapers off over time after the call. Here, we test the hypothesis that a similar mechanism exists in toothed whales by subjecting a trained harbour porpoise to a series of double sound pulses varying in delay and frequency, while measuring the magnitudes of the evoked auditory brainstem responses (ABRs. We find that the recovery of the ABR to the second pulse is frequency dependent, and that a stapedial reflex therefore cannot account for the reduced hearing sensitivity at short pulse delays. We propose that toothed whale auditory time-varying gain control during echolocation is not enabled by the middle ear as in bats, but rather by frequency-dependent mechanisms such as forward masking and perhaps higher-order control of efferent feedback to the outer hair cells.

  13. Group Ia afferents likely contribute to short-latency interlimb reflexes in the human biceps femoris muscle

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas; Kamavuako, Ernest Nlandu; Geertsen, Svend Sparre

    2017-01-01

    amplitudes (4 vs. 8°) at the same 150°/s velocity (p’s > 0.08). Conclusion: Because fast conducting group Ia muscle spindle afferents are sensitive to changes in muscle stretch velocity, while group II spindle afferents are sensitive to changes in amplitude (Grey et al., JPhysiol., 2001; Matthews, Trends...... Neurosci., 1991), group Ia velocity sensitive muscle spindle afferents likely contribute to the short-latency crossed spinal reflexes in the cBF muscle following iKnee joint rotations. This supports the findings for the short-latency crossed responses in the human soleus muscle (Stubbs & Mrachacz...... neurons in humans, with primary contributions from group Ia muscle spindle afferents....

  14. Time course of the response of carbohydrate metabolism to unloading of the soleus

    Science.gov (United States)

    Henriksen, Erik J.; Tischler, Marc E.

    1988-01-01

    The time course of the response of carbohydrate metabolism to unloading was studied in the soleus muscle of rats subjected to tail-cast suspension. In the fresh soleus, 12 hours of unloading led to higher concentrations of glycogen and lower activity ratios of both glycogen synthase and glycogen phosphorylase. These changes were still evident on day three. Thereafter, the increased glycogen concentration apparently diminished the activity ratio of glycogen synthase, leading to a subsequent fall in the total glycogen content after day one. After 24 hours of unloading, when no significant atrophy was detectable, there was no differential response to insulin for in vitro glucose metabolism. On day three, the soleus atrophied significantly and displayed a greater sensitivity to insulin for most of these parameters compared to the weight-bearing control muscle. However, insulin sensitivity for glycogen synthesis was unchanged. These results showed that the increased sensitivity to insulin of the unloaded soleus is associated with the degree of muscle atrophy, likely due to an increased insulin binding capacity relative to muscle mass. This study also showed that insulin regulation of glucose uptake and of glycogen synthesis is affected differentially in the unloaded soleus muscle.

  15. Glycogen supercompensation in rat soleus muscle during recovery from nonweight bearing

    Science.gov (United States)

    Henriksen, Erik J.; Kirby, Christopher R.; Tischler, Marc E.

    1989-01-01

    Events leading to the normalization of the glycogen metabolism in the soleus muscle of rat, altered by 72-h three days of hind-limb suspension, were investigated during the 72-h recovery period when the animals were allowed to bear weight on all four limbs. Relative importance of the factors affecting glycogen metabolism in skeletal muscle during the recovery period was also examined. Glycogen concentration was found to decrease within 15 min and up to 2 h of recovery, while muscle glucose 6-phosphate, and the fractional activities of glycogen phosphorylase and glycogen synthase increased. From 2 to 4 h, when the glycogen synthase activity remained elevated and the phosphorylase activity declined, glycogen concentration increased, until it reached maximum values at about 24 h, after which it started to decrease, reaching control values by 72 h. At 12 and 24 h, the inverse relationship between glycogen concentration and the synthase activity ratio was lost, indicating that the reloading transiently uncoupled glycogen control of this enzyme.

  16. Immobilization induces changes in presynaptic control of group Ia afferents in healthy humans

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye; Nielsen, Jens Bo

    2008-01-01

    immobilized the left foot and ankle joint for 2 weeks in 12 able-bodied subjects. Disynaptic reciprocal inhibition of soleus (SOL) motoneurones and presynaptic control of SOL group Ia afferents was measured before and after the immobilization as well as following 2 weeks of recovery. Following immobilization...... maximal voluntary plantar- and dorsiflexion torque (MVC) was significantly reduced and the maximal SOL H-reflex amplitude increased with no changes in Mmax. Decreased presynaptic inhibition of the Ia afferents likely contributed to the increase of the H-reflex size, since we observed a significant...... decrease in the long-latency depression of the SOL H-reflex evoked by peroneal nerve stimulation (D2 inhibition) and an increase in the size of the monosynaptic Ia facilitation of the SOL H-reflex evoked by femoral nerve stimulation. These two measures provide independent evidence of changes in presynaptic...

  17. Adaptation to sensory-motor reflex perturbations is blind to the source of errors.

    Science.gov (United States)

    Hudson, Todd E; Landy, Michael S

    2012-01-06

    In the study of visual-motor control, perhaps the most familiar findings involve adaptation to externally imposed movement errors. Theories of visual-motor adaptation based on optimal information processing suppose that the nervous system identifies the sources of errors to effect the most efficient adaptive response. We report two experiments using a novel perturbation based on stimulating a visually induced reflex in the reaching arm. Unlike adaptation to an external force, our method induces a perturbing reflex within the motor system itself, i.e., perturbing forces are self-generated. This novel method allows a test of the theory that error source information is used to generate an optimal adaptive response. If the self-generated source of the visually induced reflex perturbation is identified, the optimal response will be via reflex gain control. If the source is not identified, a compensatory force should be generated to counteract the reflex. Gain control is the optimal response to reflex perturbation, both because energy cost and movement errors are minimized. Energy is conserved because neither reflex-induced nor compensatory forces are generated. Precision is maximized because endpoint variance is proportional to force production. We find evidence against source-identified adaptation in both experiments, suggesting that sensory-motor information processing is not always optimal.

  18. Gait variability and motor control in people with knee osteoarthritis.

    Science.gov (United States)

    Alkjaer, Tine; Raffalt, Peter C; Dalsgaard, Helle; Simonsen, Erik B; Petersen, Nicolas C; Bliddal, Henning; Henriksen, Marius

    2015-10-01

    Knee osteoarthritis (OA) is a common disease that impairs walking ability and function. We compared the temporal gait variability and motor control in people with knee OA with healthy controls. The purpose was to test the hypothesis that the temporal gait variability would reflect a more stereotypic pattern in people with knee OA compared with healthy age-matched subjects. To assess the gait variability the temporal structure of the ankle and knee joint kinematics was quantified by the largest Lyapunov exponent and the stride time fluctuations were quantified by sample entropy and detrended fluctuation analysis. The motor control was assessed by the soleus (SO) Hoffmann (H)-reflex modulation and muscle co-activation during walking. The results showed no statistically significant mean group differences in any of the gait variability measures or muscle co-activation levels. The SO H-reflex amplitude was significantly higher in the knee OA group around heel strike when compared with the controls. The mean group difference in the H-reflex in the initial part of the stance phase (control-knee OA) was -6.6% Mmax (95% CI: -10.4 to -2.7, p=0.041). The present OA group reported relatively small impact of their disease. These results suggest that the OA group in general sustained a normal gait pattern with natural variability but with suggestions of facilitated SO H-reflex in the swing to stance phase transition. We speculate that the difference in SO H-reflex modulation reflects that the OA group increased the excitability of the soleus stretch reflex as a preparatory mechanism to avoid sudden collapse of the knee joint which is not uncommon in knee OA. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Three-dimensional architecture of the whole human soleus muscle in vivo

    Science.gov (United States)

    Finni, Taija; D’Souza, Arkiev; Eguchi, Junya; Clarke, Elizabeth C.; Herbert, Robert D.

    2018-01-01

    Background Most data on the architecture of the human soleus muscle have been obtained from cadaveric dissection or two-dimensional ultrasound imaging. We present the first comprehensive, quantitative study on the three-dimensional anatomy of the human soleus muscle in vivo using diffusion tensor imaging (DTI) techniques. Methods We report three-dimensional fascicle lengths, pennation angles, fascicle curvatures, physiological cross-sectional areas and volumes in four compartments of the soleus at ankle joint angles of 69 ± 12° (plantarflexion, short muscle length; average ± SD across subjects) and 108 ± 7° (dorsiflexion, long muscle length) of six healthy young adults. Microdissection and three-dimensional digitisation on two cadaveric muscles corroborated the compartmentalised structure of the soleus, and confirmed the validity of DTI-based muscle fascicle reconstructions. Results The posterior compartments of the soleus comprised 80 ± 5% of the total muscle volume (356 ± 58 cm3). At the short muscle length, the average fascicle length, pennation angle and curvature was 37 ± 8 mm, 31 ± 3° and 17 ± 4 /m, respectively. We did not find differences in fascicle lengths between compartments. However, pennation angles were on average 12° larger (p < 0.01) in the posterior compartments than in the anterior compartments. For every centimetre that the muscle-tendon unit lengthened, fascicle lengths increased by 3.7 ± 0.8 mm, pennation angles decreased by −3.2 ± 0.9° and curvatures decreased by −2.7 ± 0.8 /m. Fascicles in the posterior compartments rotated almost twice as much as in the anterior compartments during passive lengthening. Discussion The homogeneity in fascicle lengths and inhomogeneity in pennation angles of the soleus may indicate a functionally different role for the anterior and posterior compartments. The data and techniques presented here demonstrate how DTI can be used to obtain detailed, quantitative measurements of the

  20. Muscle weakness and lack of reflex gain adaptation predominate during post-stroke posture control of the wrist

    Directory of Open Access Journals (Sweden)

    van der Helm Frans CT

    2009-07-01

    Full Text Available Abstract Background Instead of hyper-reflexia as sole paradigm, post-stroke movement disorders are currently considered the result of a complex interplay between neuronal and muscular properties, modified by level of activity. We used a closed loop system identification technique to quantify individual contributors to wrist joint stiffness during an active posture task. Methods Continuous random torque perturbations applied to the wrist joint by a haptic manipulator had to be resisted maximally. Reflex provoking conditions were applied i.e. additional viscous loads and reduced perturbation signal bandwidth. Linear system identification and neuromuscular modeling were used to separate joint stiffness into the intrinsic resistance of the muscles including co-contraction and the reflex mediated contribution. Results Compared to an age and sex matched control group, patients showed an overall 50% drop in intrinsic elasticity while their reflexive contribution did not respond to provoking conditions. Patients showed an increased mechanical stability compared to control subjects. Conclusion Post stroke, we found active posture tasking to be dominated by: 1 muscle weakness and 2 lack of reflex adaptation. This adds to existing doubts on reflex blocking therapy as the sole paradigm to improve active task performance and draws attention to muscle strength and power recovery and the role of the inability to modulate reflexes in post stroke movement disorders.

  1. Balanced Diet-Fed Fat-1 Transgenic Mice Exhibit Lower Hindlimb Suspension-Induced Soleus Muscle Atrophy.

    Science.gov (United States)

    Marzuca-Nassr, Gabriel Nasri; Murata, Gilson Masahiro; Martins, Amanda Roque; Vitzel, Kaio Fernando; Crisma, Amanda Rabello; Torres, Rosângela Pavan; Mancini-Filho, Jorge; Kang, Jing Xuan; Curi, Rui

    2017-10-06

    The consequences of two-week hindlimb suspension (HS) on skeletal muscle atrophy were investigated in balanced diet-fed Fat-1 transgenic and C57BL/6 wild-type mice. Body composition and gastrocnemius fatty acid composition were measured. Skeletal muscle force, cross-sectional area (CSA), and signaling pathways associated with protein synthesis (protein kinase B, Akt; ribosomal protein S6, S6, eukaryotic translation initiation factor 4E-binding protein 1, 4EBP1; glycogen synthase kinase3-beta, GSK3-beta; and extracellular-signal-regulated kinases 1/2, ERK 1/2) and protein degradation (atrophy gene-1/muscle atrophy F-box, atrogin-1/MAFbx and muscle RING finger 1, MuRF1) were evaluated in the soleus muscle. HS decreased soleus muscle wet and dry weights (by 43% and 26%, respectively), muscle isotonic and tetanic force (by 29% and 18%, respectively), CSA of the soleus muscle (by 36%), and soleus muscle fibers (by 45%). Fat-1 transgenic mice had a decrease in the ω-6/ω-3 polyunsaturated fatty acids (PUFAs) ratio as compared with C57BL/6 wild-type mice (56%, p Balanced diet-fed Fat-1 mice are able to preserve in part the soleus muscle mass, absolute isotonic force and CSA of the soleus muscle in a disuse condition.

  2. Possible mechanism for changes in glycogen metabolism in unloaded soleus muscle

    Science.gov (United States)

    Henriksen, E. J.; Tischler, M. E.

    1985-01-01

    Carbohydrate metabolism has been shown to be affected in a number of ways by different models of hypokinesia. In vivo glycogen levels in the soleus muscle are known to be increased by short-term denervation and harness suspension. In addition, exposure to 7 days of hypogravity also caused a dramatic increase in glycogen concentration in this muscle. The biochemical alterations caused by unloading that may bring about these increases in glycogen storage in the soleus were sought.

  3. Effects of short term water immersion on peripheral reflex excitability in hemiplegic and healthy individuals: A preliminary study.

    Science.gov (United States)

    Cronin, N J; Valtonen, A M; Waller, B; Pöyhönen, T; Avela, J

    2016-03-01

    Reflex excitability is increased in hemiplegic patients compared to healthy controls. One challenge of stroke rehabilitation is to decrease the effects of hyperreflexia, which may be possible with water immersion. Methods/Aims: The present study examined the effects of acute water immersion on electrically-evoked Hmax:Mmax ratios (a measure of reflex excitability) in 7 hyperreflexive hemiplegic patients and 7 age-matched healthy people. Hmax:Mmax ratios were measured from soleus on dry land (L1), immediately after (W1) and 5 minutes after immersion (W5), and again after five minutes on land (L5). Water immersion led to an acute increase in Hmax:Mmax ratio in both groups. However, after returning to dry land, there was a non-significant decrease in the Hmax:Mmax ratio of 8% in the hemiplegic group and 10% in healthy controls compared to pre-immersion values. A short period of water immersion can decrease peripheral reflex excitability after returning to dry land in both healthy controls and post-stroke patients, although longer immersion periods may be required for sustainable effects. Water immersion may offer promise as a low-risk, non-invasive and non-pharmaceutical method of decreasing hyperreflexivity, and could thus support aquatic rehabilitation following stroke.

  4. Feedforward neural control of toe walking in humans.

    Science.gov (United States)

    Lorentzen, Jakob; Willerslev-Olsen, Maria; Hüche Larsen, Helle; Svane, Christian; Forman, Christian; Frisk, Rasmus; Farmer, Simon Francis; Kersting, Uwe; Nielsen, Jens Bo

    2018-03-23

    Activation of ankle muscles at ground contact during toe walking is unaltered when sensory feedback is blocked or the ground is suddenly dropped. Responses in the soleus muscle to transcranial magnetic stimulation, but not peripheral nerve stimulation, are facilitated at ground contact during toe walking. We argue that toe walking is supported by feedforward control at ground contact. Toe walking requires careful control of the ankle muscles in order to absorb the impact of ground contact and maintain a stable position of the joint. The present study aimed to clarify the peripheral and central neural mechanisms involved. Fifteen healthy adults walked on a treadmill (3.0 km h -1 ). Tibialis anterior (TA) and soleus (Sol) EMG, knee and ankle joint angles, and gastrocnemius-soleus muscle fascicle lengths were recorded. Peripheral and central contributions to the EMG activity were assessed by afferent blockade, H-reflex testing, transcranial magnetic brain stimulation (TMS) and sudden unloading of the planter flexor muscle-tendon complex. Sol EMG activity started prior to ground contact and remained high throughout stance. TA EMG activity, which is normally seen around ground contact during heel strike walking, was absent. Although stretch of the Achilles tendon-muscle complex was observed after ground contact, this was not associated with lengthening of the ankle plantar flexor muscle fascicles. Sol EMG around ground contact was not affected by ischaemic blockade of large-diameter sensory afferents, or the sudden removal of ground support shortly after toe contact. Soleus motor-evoked potentials elicited by TMS were facilitated immediately after ground contact, whereas Sol H-reflexes were not. These findings indicate that at the crucial time of ankle stabilization following ground contact, toe walking is governed by centrally mediated motor drive rather than sensory driven reflex mechanisms. These findings have implications for our understanding of the control of

  5. Catalase-positive microperoxisomes in rat soleus and extensor digitorum longus muscle fiber types

    Science.gov (United States)

    Riley, Danny A.; Bain, James L. W.; Ellis, Stanley

    1988-01-01

    The size, distribution, and content of catalase-reactive microperoxisomes were investigated cytochemically in three types of muscle fibers from the soleus and the extensor digitorum longus (EDL) of male rats. Muscle fibers were classified on the basis of the mitochondrial content and distribution, the Z-band widths, and the size and shape of myofibrils as the slow-twitch oxidative (SO), the fast-twitch oxidative glycolytic (FOG), and the fast-twitch glycolytic (FG) fibers. It was found that both the EDL and soleus SO fibers possessed the largest microperoxisomes. A comparison of microperoxisome number per muscle fiber area or the microperoxisome area per fiber area revealed following ranking, starting from the largest number and the area-ratio values: soleus SO, EDL SO, EDL FOG, and EDL FG.

  6. 75 FR 33990 - Built-in Gains and Losses Under Section 382(h)

    Science.gov (United States)

    2010-06-16

    ... Gains and Losses Under Section 382(h) AGENCY: Internal Revenue Service (IRS), Treasury. ACTION: Final... section 382(h). DATES: Effective Date: These regulations are effective on June 11, 2010. Applicability...) regarding the treatment of prepaid income under the built-in gain provisions of section 382(h) were...

  7. Isoform-specific changes in the Na,K-ATPase of rat soleus muscle during acute hindlinb suspension

    Science.gov (United States)

    Krivoi, Igor; Heiny, Judith; Bouzinova, Elena; Matchkov, Vladimir; Kravtsova, Violetta; Petrov, Aleksey; Zefirov, Andrey; Vasiliev, Alexander

    The largest pool of Na,K-ATPase (NKA) in a vertebrate's body is contained in the skeletal muscles where the alpha1 and alpha2 isoforms of NKA alpha subunit are expressed. The NKA is critically important for excitability, electrogenesis and contractility of skeletal muscle. Skeletal muscle use strongly regulates the content of NKA, and increased muscle activity differently regulates the alpha1 and alpha2 isoforms. However, whether skeletal muscle disuse affects NKA content and activity has not been investigated. This study examines for the first time the consequences of acute hindlinb suspension (HS) on the alpha1 and alpha2 NKA isozymes in rat soleus muscle. We subjected rats to HS for 6-12 hours and analyzed its effect on the resting membrane potential (RMP) in different sarcolemma regions of m.soleus fibers; the electrogenic transport activity, protein content and mRNA expression of the alpha1 and alpha2 NKA; the extracellular level of acetylcholine, and the plasma membrane localization of the alpha2 isozyme using confocal microscopy with cytochemistry. Our results show that 6 h HS specifically decreases the electrogenic activity of the NKA alpha2 isozyme and depolarizes m.soleus fibers. These effects are irreversible in the extrajunctional membrane region up to 12 h HS. The decreased alpha2 NKA activity is due to a decrease in enzyme activity rather than by altered protein content, mRNA expression, or localization in the sarcolemma. In addition, HS does not alter the alpha2 NKA electrogenic transport due to decreased extracellular acetylcholine level. However, adaptive mechanism(s) operate at the junctional membrane to restore alpha2 NKA electrogenic activities and the RMP after 12 h of HS. This mechanism operates specifically at the synaptic membrane region, presumably via increase in both alpha2 isozyme mRNA expression and protein content. This basic information on a protein as vital as the NKA is expected to advance our understanding of the cellular and

  8. Neuromuscular function during drop jumps in young and elderly males.

    Science.gov (United States)

    Piirainen, Jarmo M; Linnamo, Vesa; Sippola, Niina; Avela, Janne

    2012-12-01

    The Hoffman reflex (H-reflex), indicating alpha-motoneuron pool activity, has been shown to be task - and in resting conditions - age dependent. How aging affects H-reflex activity during explosive movements is not clear at present. The purpose of this study was to examine the effects of aging on H-reflexes during drop jumps, and its possible role in drop jump performance. Ten young (26.8 ± 2.7 years) and twenty elderly (64.2 ± 2.7 years) subjects participated in the study. Maximal drop jump performance and soleus H-reflex response (H/M jump) 20 ms after ground contact were measured in a sledge ergometer. Maximal H-reflex, maximal M-wave, Hmax/Mmax-ratio and H-reflex excitability curves were measured during standing rest. Although in young the H-reflex response (Hmax/Mmax) was 6.5% higher during relaxed standing and 19.7% higher during drop jumps (H jump/M jump) than in the elderly group, these differences were not statistically significant. In drop jumps, the elderly subjects had lower jumping height (30.4%, p push-off force (18.0%, p push-off time (31.0% p push-off force (r = 0.833, p push-off time (r = -0.857, p < 0.01) in young but not in the elderly. Correlations between H-reflex response and jumping parameters in young may indicate different jumping and activation strategies in drop jumps. However, it does not fully explain age related differences in jumping performance, since age related differences in H-reflex activity were non-significant. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Effect of altered thyroid state on the in situ mechanical properties of adult cat soleus

    Science.gov (United States)

    Roy, R. R.; Zhong, H.; Hodgson, J. A.; Grossman, E. J.; Edgerton, V. R.

    2003-01-01

    To determine the responsiveness of cat hindlimb muscles to thyroid manipulation, adult female cats were made hypothyroid (thyroidectomy plus tapazole treatment), hyperthyroid (synthroid pellets), or maintained euthyroid. After 4 months, the hypothyroid soleus had slower time-to-peak (TPT, 80%) and half-relaxation (HRT) times, whereas the hyperthyroid soleus had faster TPT (20%) and HRT than euthyroid cats. The tension at low stimulation frequencies (5-15 Hz) was higher in hypothyroid and lower in hyperthyroid cats compared to euthyroid cats. Muscle weight, maximum twitch and tetanic (Po) tensions, and maximum rates of shortening (Vmax) were similar across groups. The soleus of hypothyroid cats was more fatigable than normal. The myosin heavy chain (MHC) composition, based on gel electrophoresis, was unaffected by thyroid hormone manipulation. Based on the reaction of monoclonal antibodies for specific MHCs, some fast fibers in the hypothyroid cats coexpressed developmental MHC. These data indicate that 4 months of an altered thyroid state result in changes in the isometric twitch speed properties of the cat soleus, but not the tension-related or isotonic properties. Further, a chronic decrease in thyroid hormone had a greater impact than a chronic increase in thyroid hormone on the mechanical properties of the adult cat soleus. Copyright 2003 S. Karger AG, Basel.

  10. Local vibration inhibits H-reflex but does not compromise manual dexterity and does not increase tremor.

    Science.gov (United States)

    Budini, Francesco; Laudani, Luca; Bernardini, Sergio; Macaluso, Andrea

    2017-10-01

    The present work aimed at investigating the effects of local vibration on upper limb postural and kinetic tremor, on manual dexterity and on spinal reflex excitability. Previous studies have demonstrated a decrease in spinal reflex excitability and in force fluctuations in the lower limb but an increase in force fluctuation in the upper limbs. As hand steadiness is of vital importance in many daily-based tasks, and local vibration may also be applied in movement disorders, we decided to further explore this phenomenon. Ten healthy volunteers (26±3years) were tested for H reflex, postural and kinetic tremor and manual dexterity through a Purdue test. EMG was recorded from flexor carpi radialis (FCR) and extensor digitorum communis (EDC). Measurements were repeated at baseline, after a control period during which no vibration was delivered and after vibration. Intervention consisted in holding for two minutes a vibrating handle (frequency 75Hz, displacement∼7mm), control consisted in holding for two minutes the same handle powered off. Reflex excitability decreased after vibration whilst postural tremor and manual dexterity were not affected. Peak kinetic tremor frequency increased from baseline to control measurements (P=0.002). Co-activation EDC/FCR increased from control to vibration (P=0.021). These results show that two minutes local vibration lead to a decrease in spinal excitability, did not compromise manual dexterity and did not increase tremor; however, in contrast with expectations, tremor did not decrease. It is suggested that vibration activated several mechanisms with opposite effects, which resulted in a neutral outcome on postural and kinetic tremor. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. The horizontal and vertical cervico-ocular reflexes of the rabbit.

    Science.gov (United States)

    Barmack, N H; Nastos, M A; Pettorossi, V E

    1981-11-16

    Horizontal and vertical cervico-ocular reflexes of the rabbit (HCOR, VCOR) were evoked by sinusoidal oscillation of the body about the vertical and longitudinal axes while the head was fixed. These reflexes were studied over a frequency range of 0.005-0.800 Hz and at stimulus amplitudes of +/- 10 degrees. When the body of the rabbit was rotated horizontally clockwise around the fixed head, clockwise conjugate eye movements were evoked. When the body was rotated about the longitudinal axis onto the right side, the right eye rotated down and the left eye rotated up. The mean gain of the HCOR (eye velocity/body velocity) rose from 0.21 and 0.005 Hz to 0.27 at 0.020 Hz and then declined to 0.06 at 0.3Hz. The gain of the VCOR was less than the gain of the HCOR by a factor of 2-3. The HCOR was measured separately and in combination with the horizontal vestibulo-ocular reflex (HVOR). These reflexes combine linearly. The relative movements of the first 3 cervical vertebrae during stimulation of the HCOR and VCOR were measured. For the HCOR, the largest angular displacement (74%) occurs between C1 and C2. For the VCOR, the largest relative angular displacement (45%) occurs between C2 and C3. Step horizontal clockwise rotation of the head and body (HVOR) evoked low velocity counterclockwise eye movements followed by fast clockwise (resetting) eye movements. Step horizontal clockwise rotation of the body about the fixed head (HCOR) evoked low velocity clockwise eye movements which were followed by fast clockwise eye movements. Step horizontal clockwise rotation of the head about the fixed body (HCOR + HVOR) evoked low velocity counterclockwise eye movements which were not interrupted by fast clockwise eye movements. These data provide further evidence for a linear combination of independent HCOR and HVOR signals.

  12. Effect of one stretch a week applied to the immobilized soleus muscle on rat muscle fiber morphology

    Directory of Open Access Journals (Sweden)

    Gomes A.R.S.

    2004-01-01

    Full Text Available We determined the effect of stretching applied once a week to the soleus muscle immobilized in the shortened position on muscle fiber morphology. Twenty-six male Wistar rats weighing 269 ± 26 g were divided into three groups. Group I, the left soleus was immobilized in the shortened position for 3 weeks; group II, the soleus was immobilized in the shortened position and stretched once a week for 3 weeks; group III, the soleus was submitted only to stretching once a week for 3 weeks. The medial part of the soleus muscle was frozen for histology and muscle fiber area evaluation and the lateral part was used for the determination of number and length of serial sarcomeres. Soleus muscle submitted only to immobilization showed a reduction in weight (44 ± 6%, P = 0.002, in serial sarcomere number (23 ± 15% and in cross-sectional area of the fibers (37 ± 31%, P < 0.001 compared to the contralateral muscles. The muscle that was immobilized and stretched showed less muscle fiber atrophy than the muscles only immobilized (P < 0.05. Surprisingly, in the muscles submitted only to stretching, fiber area was decreased compared to the contralateral muscle (2548 ± 659 vs 2961 ± 806 µm², respectively, P < 0.05. In conclusion, stretching applied once a week for 40 min to the soleus muscle immobilized in the shortened position was not sufficient to prevent the reduction of muscle weight and of serial sarcomere number, but provided significant protection against muscle fiber atrophy. In contrast, stretching normal muscles once a week caused a reduction in muscle fiber area.

  13. Decreased rate of protein synthesis, caspase-3 activity, and ubiquitin-proteasome proteolysis in soleus muscles from growing rats fed a low-protein, high-carbohydrate diet.

    Science.gov (United States)

    Batistela, Emanuele; Pereira, Mayara Peron; Siqueira, Juliany Torres; Paula-Gomes, Silvia; Zanon, Neusa Maria; Oliveira, Eduardo Brandt; Navegantes, Luiz Carlos Carvalho; Kettelhut, Isis C; Andrade, Claudia Marlise Balbinotti; Kawashita, Nair Honda; Baviera, Amanda Martins

    2014-06-01

    The aim of this study was to investigate the changes in the rates of both protein synthesis and breakdown, and the activation of intracellular effectors that control these processes in soleus muscles from growing rats fed a low-protein, high-carbohydrate (LPHC) diet for 15 days. The mass and the protein content, as well as the rate of protein synthesis, were decreased in the soleus from LPHC-fed rats. The availability of amino acids was diminished, since the levels of various essential amino acids were decreased in the plasma of LPHC-fed rats. Overall rate of proteolysis was also decreased, explained by reductions in the mRNA levels of atrogin-1 and MuRF-1, ubiquitin conjugates, proteasome activity, and in the activity of caspase-3. Soleus muscles from LPHC-fed rats showed increased insulin sensitivity, with increased levels of insulin receptor and phosphorylation levels of AKT, which probably explains the inhibition of both the caspase-3 activity and the ubiquitin-proteasome system. The fall of muscle proteolysis seems to represent an adaptive response that contributes to spare proteins in a condition of diminished availability of dietary amino acids. Furthermore, the decreased rate of protein synthesis may be the driving factor to the lower muscle mass gain in growing rats fed the LPHC diet.

  14. Avaliação da inibição recíproca em humanos durante contrações isométricas dos músculos tibial anterior e sóleo Assessment of reciprocal inhibition in humans during isometric contractions of the tibialis anterior and soleus muscles

    Directory of Open Access Journals (Sweden)

    José Eduardo Pompeu

    2009-09-01

    Full Text Available Os objetivos do presente trabalho foram: (1 desenvolver um método para estimar o grau de inibição recíproca (IR entre músculos antagonistas em humanos (sóleo e tibial anterior e (2 comparar os níveis de IR no repouso, na dorsiflexão (DF e na flexão plantar (FP. Participaram nove sujeitos saudáveis com idade entre 20 e 30 anos, quatro homens e cinco mulheres. Os sujeitos permaneceram sentados numa cadeira com o pé direito apoiado e fixo num pedal acoplado a um torquímetro; as medições foram feitas no repouso e durante contração isométrica dos músculos dorsiflexores e flexores plantares do tornozelo. A onda H do músculo sóleo foi captada por eletrodos de superfície. O reflexo H (RH "teste" do músculo sóleo foi medido aplicando-se um estímulo na fossa poplítea (nervo tibial. O reflexo H "condicionado" foi obtido pelo pareamento de dois estímulos: o primeiro aplicado sobre a cabeça da fíbula e o segundo, na fossa poplítea, após 1 a 3 ms.. As amplitudes pico-a-pico dos RH teste e condicionado foram utilizadas para o cálculo da IR. Os valores de IR foram: 16,41%±8,68 no repouso; 21,94%±5,39 na DF e 3,12%±11,84 na FP. Foi constatada menor inibição recíproca na FP quando comparada às demais condições (pThe purposes of the present study were (1 to develop a method to estimate the level of reciprocal inhibition (RI between antagonist (soleus and anterior tibial muscles in humans, and (2 to compare RI levels during rest, dorsiflexion (DF and plantar flexion (PF. Nine healthy subjects (four men, five women aged between 20 and 30 years were assessed. Each subject remained seated with his/her right foot strapped to a rigid foot plate coupled to a torquemeter; measurements were taken at rest and during isometric contraction of the ankle dorsiflexor and plantar flexor muscles. The soleus muscle H-wave was captured by surface electrodes. A "test" H- reflex was elicited by a stimulus (electrical pulse to the popliteal fossa

  15. Short-term plasticity in a monosynaptic reflex pathway to forearm muscles after continuous robot-assisted passive stepping

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Nakajima

    2016-07-01

    Full Text Available Both active and passive rhythmic limb movements reduce the amplitude of spinal cord Hoffmann (H- reflexes in muscles of moving and distant limbs. This could have clinical utility in remote modulation of the pathologically hyperactive reflexes found in spasticity after stroke or spinal cord injury. However, such clinical translation is currently hampered by a lack of critical information regarding the minimum or effective duration of passive movement needed for modulating spinal cord excitability. We therefore investigated the H-reflex modulation in the flexor carpi radialis (FCR muscle during and after various durations (5, 10, 15, and 30 min of passive stepping in 11 neurologically normal subjects. Passive stepping was performed by a robotic gait trainer system (Lokomat® while a single pulse of electrical stimulation to the median nerve elicited H-reflexes in the FCR. The amplitude of the FCR H-reflex was significantly suppressed during passive stepping. Although 30 minutes of passive stepping was sufficient to elicit a persistent H-reflex suppression that lasted up to 15 minutes, 5 minutes of passive stepping was not. The duration of H-reflex suppression correlated with that of the stepping. These findings suggest that the accumulation of stepping-related afferent feedback from the leg plays a role in generating short-term interlimb plasticity in the circuitry of the FCR H-reflex.

  16. Understanding inhibitory mechanisms of lumbar spinal manipulation using H-reflex and F-wave responses: a methodological approach.

    Science.gov (United States)

    Dishman, J Donald; Weber, Kenneth A; Corbin, Roger L; Burke, Jeanmarie R

    2012-09-30

    The purpose of this research was to characterize unique neurophysiologic events following a high velocity, low amplitude (HVLA) spinal manipulation (SM) procedure. Descriptive time series analysis techniques of time plots, outlier detection and autocorrelation functions were applied to time series of tibial nerve H-reflexes that were evoked at 10-s intervals from 100 s before the event until 100 s after three distinct events L5-S1 HVLA SM, or a L5-S1 joint pre-loading procedure, or the control condition. Sixty-six subjects were randomly assigned to three procedures, i.e., 22 time series per group. If the detection of outliers and correlograms revealed a pattern of non-randomness that was only time-locked to a single, specific event in the normalized time series, then an experimental effect would be inferred beyond the inherent variability of H-reflex responses. Tibial nerve F-wave responses were included to determine if any new information about central nervous function following a HVLA SM procedure could be ascertained. Time series analyses of H(max)/M(max) ratios, pre-post L5-S1 HVLA SM, substantiated the hypothesis that the specific aspects of the manipulative thrust lead to a greater attenuation of the H(max)/M(max) ratio as compared to the non-specific aspects related to the postural perturbation and joint pre-loading. The attenuation of the H(max)/M(max) ratio following the HVLA SM procedure was reliable and may hold promise as a translational tool to measure the consistency and accuracy of protocol implementation involving SM in clinical trials research. F-wave responses were not sensitive to mechanical perturbations of the lumbar spine. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Heat shock transcription factor 1-deficiency attenuates overloading-associated hypertrophy of mouse soleus muscle.

    Science.gov (United States)

    Koya, Tomoyuki; Nishizawa, Sono; Ohno, Yoshitaka; Goto, Ayumi; Ikuta, Akihiro; Suzuki, Miho; Ohira, Tomotaka; Egawa, Tatsuro; Nakai, Akira; Sugiura, Takao; Ohira, Yoshinobu; Yoshioka, Toshitada; Beppu, Moroe; Goto, Katsumasa

    2013-01-01

    Hypertrophic stimuli, such as mechanical stress and overloading, induce stress response, which is mediated by heat shock transcription factor 1 (HSF1), and up-regulate heat shock proteins (HSPs) in mammalian skeletal muscles. Therefore, HSF1-associated stress response may play a key role in loading-associated skeletal muscle hypertrophy. The purpose of this study was to investigate the effects of HSF1-deficiency on skeletal muscle hypertrophy caused by overloading. Functional overloading on the left soleus was performed by cutting the distal tendons of gastrocnemius and plantaris muscles for 4 weeks. The right muscle served as the control. Soleus muscles from both hindlimbs were dissected 2 and 4 weeks after the operation. Hypertrophy of soleus muscle in HSF1-null mice was partially inhibited, compared with that in wild-type (C57BL/6J) mice. Absence of HSF1 partially attenuated the increase of muscle wet weight and fiber cross-sectional area of overloaded soleus muscle. Population of Pax7-positive muscle satellite cells in HSF1-null mice was significantly less than that in wild-type mice following 2 weeks of overloading (pmuscle hypertrophy might be attributed to the greater and prolonged enhancement of IL-6 expression. HSF1 and/or HSF1-mediated stress response may, in part, play a key role in loading-induced skeletal muscle hypertrophy.

  18. Refixation saccades with normal gain values

    DEFF Research Database (Denmark)

    Korsager, Leise Elisabeth Hviid; Faber, Christian Emil; Schmidt, Jesper Hvass

    2017-01-01

    -ocular reflex. However, this partial deficit is in conflict with the current way of interpreting vHIT results in which the vestibular function is classified as either normal or pathological based only on the gain value. Refixation saccades, which are evident signs of vestibulopathy, are not considered...

  19. Monosynaptic Stretch Reflex Fails to Explain the Initial Postural Response to Sudden Lateral Perturbations

    Directory of Open Access Journals (Sweden)

    Andreas Mühlbeier

    2017-06-01

    Full Text Available Postural reflexes are essential for locomotion and postural stability, and may play an important role in the etiology of chronic back pain. It has recently been theoretically predicted, and with the help of unilateral perturbations of the trunk experimentally confirmed that the sensorimotor control must lower the reflex amplitude for increasing reflex delays to maintain spinal stability. The underlying neuromuscular mechanism for the compensation of postural perturbations, however, is not yet fully understood. In this study, we applied unilateral and bilateral sudden external perturbations to the trunk of healthy subjects and measured the muscular activity and the movement onset of the trunk. We found that the onset of the trunk muscle activity is prior to, or coincident with, the onset of the trunk movement. Additionally, the results of our experiments imply that the muscular response mechanism integrates distant sensory information from both sides of the body. These findings rule out a simple monosynaptic stretch reflex in favor of a more complex polysynaptic postural reflex mechanism to compensate postural perturbations. Moreover, the previously predicted negative correlation between reflex delay and reflex gain was also confirmed for bilateral perturbations.

  20. Being reflexive in qualitative grounded theory: discussion and application of a model of reflexivity.

    Science.gov (United States)

    Engward, Hilary; Davis, Geraldine

    2015-07-01

    A discussion of the meaning of reflexivity in research with the presentation of examples of how a model of reflexivity was used in a grounded theory research project. Reflexivity requires the researcher to make transparent the decisions they make in the research process and is therefore important in developing quality in nursing research. The importance of being reflexive is highlighted in the literature in relation to nursing research, however, practical guidance as to how to go about doing research reflexively is not always clearly articulated. This is a discussion paper. The concept of reflexivity in research is explored using the Alvesson and Skoldberg model of reflexivity and practical examples of how a researcher developed reflexivity in a grounded theory project are presented. Nurse researchers are encouraged to explore and apply the concept of reflexivity in their research practices to develop transparency in the research process and to increase robustness in their research. The Alvesson and Skoldberg model is of value in applying reflexivity in qualitative nursing research, particularly in grounded theory research. Being reflexive requires the researcher to be completely open about decisions that are made in the research process. The Alvesson and Skolberg model of reflexivity is a useful model that can enhance reflexivity in the research process. It can be a useful practical tool to develop reflexivity in grounded theory research. © 2015 John Wiley & Sons Ltd.

  1. Gene Expression Profiling in Slow-Type Calf Soleus Muscle of 30 Days Space-Flown Mice.

    Directory of Open Access Journals (Sweden)

    Guido Gambara

    Full Text Available Microgravity exposure as well as chronic disuse are two main causes of skeletal muscle atrophy in animals and humans. The antigravity calf soleus is a reference postural muscle to investigate the mechanism of disuse-induced maladaptation and plasticity of human and rodent (rats or mice skeletal musculature. Here, we report microgravity-induced global gene expression changes in space-flown mouse skeletal muscle and the identification of yet unknown disuse susceptible transcripts found in soleus (a mainly slow phenotype but not in extensor digitorum longus (a mainly fast phenotype dorsiflexor as functional counterpart to soleus. Adult C57Bl/N6 male mice (n = 5 flew aboard a biosatellite for 30 days on orbit (BION-M1 mission, 2013, a sex and age-matched cohort were housed in standard vivarium cages (n = 5, or in a replicate flight habitat as ground control (n = 5. Next to disuse atrophy signs (reduced size and myofiber phenotype I to II type shift as much as 680 differentially expressed genes were found in the space-flown soleus, and only 72 in extensor digitorum longus (only 24 genes in common compared to ground controls. Altered expression of gene transcripts matched key biological processes (contractile machinery, calcium homeostasis, muscle development, cell metabolism, inflammatory and oxidative stress response. Some transcripts (Fzd9, Casq2, Kcnma1, Ppara, Myf6 were further validated by quantitative real-time PCR (qRT-PCR. Besides previous reports on other leg muscle types we put forth for the first time a complete set of microgravity susceptible gene transcripts in soleus of mice as promising new biomarkers or targets for optimization of physical countermeasures and rehabilitation protocols to overcome disuse atrophy conditions in different clinical settings, rehabilitation and spaceflight.

  2. Automatic gain control of neural coupling during cooperative hand movements.

    Science.gov (United States)

    Thomas, F A; Dietz, V; Schrafl-Altermatt, M

    2018-04-13

    Cooperative hand movements (e.g. opening a bottle) are controlled by a task-specific neural coupling, reflected in EMG reflex responses contralateral to the stimulation site. In this study the contralateral reflex responses in forearm extensor muscles to ipsilateral ulnar nerve stimulation was analyzed at various resistance and velocities of cooperative hand movements. The size of contralateral reflex responses was closely related to the level of forearm muscle activation required to accomplish the various cooperative hand movement tasks. This indicates an automatic gain control of neural coupling that allows a rapid matching of corrective forces exerted at both sides of an object with the goal 'two hands one action'.

  3. Postfatigue potentiation of the paralyzed soleus muscle: evidence for adaptation with long-term electrical stimulation training

    OpenAIRE

    Shields, Richard K.; Dudley-Javoroski, Shauna; Littmann, Andrew E.

    2006-01-01

    Understanding the torque output behavior of paralyzed muscle has important implications for the use of functional neuromuscular electrical stimulation systems. Postfatigue potentiation is an augmentation of peak muscle torque during repetitive activation after a fatigue protocol. The purposes of this study were 1) to quantify postfatigue potentiation in the acutely and chronically paralyzed soleus and 2) to determine the effect of long-term soleus electrical stimulation training on the potent...

  4. Influence of different degrees of bilateral emulated contractures at the triceps surae on gait kinematics: The difference between gastrocnemius and soleus.

    Science.gov (United States)

    Attias, M; Bonnefoy-Mazure, A; De Coulon, G; Cheze, L; Armand, S

    2017-10-01

    Ankle plantarflexion contracture results from a permanent shortening of the muscle-tendon complex. It often leads to gait alterations. The objective of this study was to compare the kinematic adaptations of different degrees of contractures and between isolated bilateral gastrocnemius and soleus emulated contractures using an exoskeleton. Eight combinations of contractures were emulated bilaterally on 10 asymptomatic participants using an exoskeleton that was able to emulate different degrees of contracture of gastrocnemius (biarticular muscle) and soleus (monoarticular muscle), corresponding at 0°, 10°, 20°, and 30° ankle plantarflexion contracture (knee-flexed and knee-extended). Range of motion was limited by ropes attached for soleus on heel and below the knee and for gastrocnemius on heel and above the knee. A gait analysis session was performed to evaluate the effect of these different emulated contractures on the Gait Profile Score, walking speed and gait kinematics. Gastrocnemius and soleus contractures influence gait kinematics, with an increase of the Gait Profile Score. Significant differences were found in the kinematics of the ankles, knees and hips. Contractures of soleus cause a more important decrease in the range of motion at the ankle than the same degree of gastrocnemius contractures. Gastrocnemius contractures cause greater knee flexion (during the stance phase) and hip flexion (during all the gait cycle) than the same level of soleus contractures. These results can support the interpretation of the Clinical Gait Analysis data by providing a better understanding of the effect of isolate contracture of soleus and gastrocnemius on gait kinematics. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Modulation of high-frequency vestibuloocular reflex during visual tracking in humans

    Science.gov (United States)

    Das, V. E.; Leigh, R. J.; Thomas, C. W.; Averbuch-Heller, L.; Zivotofsky, A. Z.; Discenna, A. O.; Dell'Osso, L. F.

    1995-01-01

    1. Humans may visually track a moving object either when they are stationary or in motion. To investigate visual-vestibular interaction during both conditions, we compared horizontal smooth pursuit (SP) and active combined eye-head tracking (CEHT) of a target moving sinusoidally at 0.4 Hz in four normal subjects while the subjects were either stationary or vibrated in yaw at 2.8 Hz. We also measured the visually enhanced vestibuloocular reflex (VVOR) during vibration in yaw at 2.8 Hz over a peak head velocity range of 5-40 degrees/s. 2. We found that the gain of the VVOR at 2.8 Hz increased in all four subjects as peak head velocity increased (P modulation in vestibuloocular reflex gain occurred with increasing peak head velocity during a control condition when subjects were rotated in darkness. 3. During both horizontal SP and CEHT, tracking gains were similar, and the mean slip speed of the target's image on the retina was held below 5.5 degrees/s whether subjects were stationary or being vibrated at 2.8 Hz. During both horizontal SP and CEHT of target motion at 0.4 Hz, while subjects were vibrated in yaw, VVOR gain for the 2.8-Hz head rotations was similar to or higher than that achieved during fixation of a stationary target. This is in contrast to the decrease of VVOR gain that is reported while stationary subjects perform CEHT.(ABSTRACT TRUNCATED AT 250 WORDS).

  6. Utilization of photoconductive gain in a-Si:H devices for radiation detection

    International Nuclear Information System (INIS)

    Lee, H.K.; Drewery, J.S.; Hong, W.S.; Jing, T.; Kaplan, S.N.; Perez-Mendez, V.

    1995-05-01

    The photoconductive gain mechanism in a-Si:H was investigated in connection with applications to radiation detection. Various device types such as p-i-n, n-i-n and n-i-p-i-n structures were fabricated and tested. Photoconductive gain was measured in two time scales: one for short pulses of visible light ( 2 . Various gain results are discussed in terms of the device structure, applied bias and dark current

  7. Cold exposure increases slow-type myosin heavy chain 1 (MyHC1) composition of soleus muscle in rats.

    Science.gov (United States)

    Mizunoya, Wataru; Iwamoto, Yohei; Sato, Yusuke; Tatsumi, Ryuichi; Ikeuchi, Yoshihide

    2014-03-01

    The aim of this study was to examine the effects of cold exposure on rat skeletal muscle fiber type, according to myosin heavy chain (MyHC) isoform and metabolism-related factors. Male Wistar rats (7 weeks old) were housed individually at 4 ± 2°C as a cold-exposed group or at room temperature (22 ± 2°C) as a control group for 4 weeks. We found that cold exposure significantly increased the slow-type MyHC1 content in the soleus muscle (a typical slow-type fiber), while the intermediate-type MyHC2A content was significantly decreased. In contrast to soleus, MyHC composition of extensor digitorum longus (EDL, a typical fast-type fiber) and gastrocnemius (a mix of slow-type and fast-type fibers) muscle did not change from cold exposure. Cold exposure increased mRNA expression of mitochondrial uncoupling protein 3 (UCP3) in both the soleus and EDL. Cold exposure also increased mRNA expression of myoglobin, peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1α) and forkhead box O1 (FOXO1) in the soleus. Upregulation of UCP3 and PGC1α proteins were observed with Western blotting in the gastrocnemius. Thus, cold exposure increased metabolism-related factors in all muscle types that were tested, but MyHC isoforms changed only in the soleus. © 2013 Japanese Society of Animal Science.

  8. Movement Behavior of High-Heeled Walking

    DEFF Research Database (Denmark)

    Alkjær, Tine; Raffalt, Peter Christian; Petersen, Nicolas Caesar

    2012-01-01

    The human locomotor system is flexible and enables humans to move without falling even under less than optimal conditions. Walking with high-heeled shoes constitutes an unstable condition and here we ask how the nervous system controls the ankle joint in this situation? We investigated the movement...... behavior of high-heeled and barefooted walking in eleven female subjects. The movement variability was quantified by calculation of approximate entropy (ApEn) in the ankle joint angle and the standard deviation (SD) of the stride time intervals. Electromyography (EMG) of the soleus (SO) and tibialis...... anterior (TA) muscles and the soleus Hoffmann (H-) reflex were measured at 4.0 km/h on a motor driven treadmill to reveal the underlying motor strategies in each walking condition. The ApEn of the ankle joint angle was significantly higher (p...

  9. Facilitation of soleus but not tibialis anterior motor evoked potentials before onset of antagonist contraction

    DEFF Research Database (Denmark)

    Geertsen, Svend Sparre; Zuur, Abraham Theodore; Nielsen, Jens Bo

    2008-01-01

    Objective: It is well documented that corticospinal projections to motoneurons of one muscle inhibit antagonist motoneurons through collaterals to reciprocally organized spinal inhibitory interneurons. During and just prior to dorsiflexion of the ankle, soleus motoneurons are thus inhibited...... the MEP is evoked. Methods: Seated subjects (n=11) were instructed to react to an auditory cue by contracting either the tibialis anterior (TA) or soleus muscle of the left ankle to 30% of their maximal dorsiflexion voluntary contraction (MVC) or plantar flexion MVC, respectively. Focal TMS at 1.2 x motor...

  10. Acute rhabdomyolysis of the soleus muscle induced by a lightning strike: magnetic resonance and scintigraphic findings

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Naofumi; Inaoka, Tsutomu; Shuke, Noriyuki; Takahashi, Koji; Aburano, Tamio [Asahikawa Medical College, Department of Radiology, Asahikawa (Japan); Chisato, Naoyuki; Go, Kazutomo [Asahikawa Medical College, Department of Emergency Medicine, Asahikawa (Japan); Nochi, Hitoshi [Asahikawa Medical College, Department of Orthopaedic Surgery, Asahikawa (Japan)

    2007-07-15

    Among natural disasters, a lightning strike is a rare but potentially life-threatening phenomenon. If victims survive a cardiac arrest due to instantaneous passage of an exceptionally high voltage electric charge through the whole body, they may be afflicted with various complications such as muscle necrosis resulting in acute renal failure. In this article, we report a case of a 54-year-old man with acute rhabdomyolysis of the left soleus muscle associated with a lightning strike. T2-weighted and short-tau inversion recovery MR images showed a high signal intensity in the left soleus muscle. A whole-body bone scintigram showed abnormal uptakes in the left soleus muscle and the dorsal aspect of the left foot. MR and scintigraphic evaluations were very useful in depicting the site and extent of muscle damage. Since the patient showed a surprisingly high level of serum creatine kinase, the added information was very valuable for determining the patient's management. (orig.)

  11. Acute rhabdomyolysis of the soleus muscle induced by a lightning strike: magnetic resonance and scintigraphic findings

    International Nuclear Information System (INIS)

    Watanabe, Naofumi; Inaoka, Tsutomu; Shuke, Noriyuki; Takahashi, Koji; Aburano, Tamio; Chisato, Naoyuki; Go, Kazutomo; Nochi, Hitoshi

    2007-01-01

    Among natural disasters, a lightning strike is a rare but potentially life-threatening phenomenon. If victims survive a cardiac arrest due to instantaneous passage of an exceptionally high voltage electric charge through the whole body, they may be afflicted with various complications such as muscle necrosis resulting in acute renal failure. In this article, we report a case of a 54-year-old man with acute rhabdomyolysis of the left soleus muscle associated with a lightning strike. T2-weighted and short-tau inversion recovery MR images showed a high signal intensity in the left soleus muscle. A whole-body bone scintigram showed abnormal uptakes in the left soleus muscle and the dorsal aspect of the left foot. MR and scintigraphic evaluations were very useful in depicting the site and extent of muscle damage. Since the patient showed a surprisingly high level of serum creatine kinase, the added information was very valuable for determining the patient's management. (orig.)

  12. Strain differences in baroceptor reflex in adult Wistar Kyoto rats

    Directory of Open Access Journals (Sweden)

    Vitor E. Valenti

    2010-01-01

    Full Text Available OBJECTIVES: A subset of normotensive Sprague-Dawley rats show lower baroreflex sensitivity; however, no previous study investigated whether there are differences in baroreflex sensitivity within this subset. Our study compared baroreflex sensitivity among conscious rats of this specific subtype. METHODS: Male Wistar Kyoto (WKY rats (16 weeks old were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure (MAP and heart rate (HR. Baroreflex gain was calculated as the ratio between change in HR and MAP variation (ΔHR/ΔMAP in response to a depressor dose of sodium nitroprusside (SNP, 50 µg/kg, i.v. and a pressor dose of phenylephrine (PE, 8 µg/kg, i.v.. Rats were divided into four groups: 1 low bradycardic baroreflex (LB, baroreflex gain (BG between -1 and -2 bpm/mmHg tested with PE; 2 high bradycardic baroreflex (HB, BG < -2 bpm/mmHg tested with PE; 3 low tachycardic baroreflex (LT, BG between -1 and -2 bpm/mmHg tested with SNP and; 4 high tachycardic baroreflex (HT, BG < -2 bpm/mmHg tested with SNP. Significant differences were considered for p < 0.05. RESULTS: Approximately 37% of the rats showed a reduced bradycardic peak, bradycardic reflex and decreased bradycardic gain of baroreflex while roughly 23% had a decreased basal HR, tachycardic peak, tachycardic reflex and reduced sympathetic baroreflex gain. No significant alterations were noted with regard to basal MAP. CONCLUSION: There is variability regarding baroreflex sensitivity among WKY rats from the same laboratory.

  13. Automated data reduction workflows for astronomy. The ESO Reflex environment

    Science.gov (United States)

    Freudling, W.; Romaniello, M.; Bramich, D. M.; Ballester, P.; Forchi, V.; García-Dabló, C. E.; Moehler, S.; Neeser, M. J.

    2013-11-01

    Context. Data from complex modern astronomical instruments often consist of a large number of different science and calibration files, and their reduction requires a variety of software tools. The execution chain of the tools represents a complex workflow that needs to be tuned and supervised, often by individual researchers that are not necessarily experts for any specific instrument. Aims: The efficiency of data reduction can be improved by using automatic workflows to organise data and execute a sequence of data reduction steps. To realize such efficiency gains, we designed a system that allows intuitive representation, execution and modification of the data reduction workflow, and has facilities for inspection and interaction with the data. Methods: The European Southern Observatory (ESO) has developed Reflex, an environment to automate data reduction workflows. Reflex is implemented as a package of customized components for the Kepler workflow engine. Kepler provides the graphical user interface to create an executable flowchart-like representation of the data reduction process. Key features of Reflex are a rule-based data organiser, infrastructure to re-use results, thorough book-keeping, data progeny tracking, interactive user interfaces, and a novel concept to exploit information created during data organisation for the workflow execution. Results: Automated workflows can greatly increase the efficiency of astronomical data reduction. In Reflex, workflows can be run non-interactively as a first step. Subsequent optimization can then be carried out while transparently re-using all unchanged intermediate products. We found that such workflows enable the reduction of complex data by non-expert users and minimizes mistakes due to book-keeping errors. Conclusions: Reflex includes novel concepts to increase the efficiency of astronomical data processing. While Reflex is a specific implementation of astronomical scientific workflows within the Kepler workflow

  14. 75 FR 44138 - Build-In Gains and Losses Under Section 382(h); Correction

    Science.gov (United States)

    2010-07-28

    ... DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Part 1 [TD 9487] RIN 1545-BG03 Build-In Gains and Losses Under Section 382(h); Correction AGENCY: Internal Revenue Service (IRS), Treasury... providing guidance regarding the treatment of prepaid income under the built-in gain provisions of section...

  15. Transient photoconductive gain in a-Si:H devices and its applications in radiation detection

    International Nuclear Information System (INIS)

    Lee, H.K.; Suh, T.S.; Choe, B.Y.; Shinn, K.S.; Perez-Mendez, V.

    1997-01-01

    Using the transient behavior of the photoconductive-gain mechanism, a signal gain in radiation detection with a-Si:H devices may be possible. The photoconductive gain mechanism in two types of hydrogenated amorphous silicon devices, p-i-n and n-i-n configurations, was investigated in connection with applications to radiation detection. Photoconductive gain was measured in two time scales: one for short pulses of visible light ( 2 . Various gain results are discussed in terms of the device structure, applied bias and dark-current density. (orig.)

  16. Reflexivity in qualitative research

    DEFF Research Database (Denmark)

    Evans, Adam Brian; Nistrup, Anne; Henderson, Hannah

    2018-01-01

    There has been something of a “reflexive shift” in sociological research. Sociological researchers are increasingly encouraged to be “present” within their work, and to recognize their own role in structuring the entire research process. One way to achieve this is through engagement in reflexive...... practice, that is, to reflect on our own values, beliefs, and biographies. It can be difficult to know exactly how a researcher should engage in these practices, however. Here, we discuss our reflexive practice in two case studies, both which utilized the same figurational theoretical framework...... Kingdom. Reflexive practice in both studies was affected by researcher biographies and by study design. In Study 1, both researchers were reasonably detached from the study context, the theoretical framework was in place from the very beginning, and reflexive practice was embedded in the study design...

  17. The effect of betahistine, a histamine H1 receptor agonist/H3 antagonist, on olanzapine-induced weight gain in first-episode schizophrenia patients.

    Science.gov (United States)

    Poyurovsky, Michael; Pashinian, Artashes; Levi, Aya; Weizman, Ronit; Weizman, Abraham

    2005-03-01

    Histamine antagonism has been implicated in antipsychotic drug-induced weight gain. Betahistine, a histamine enhancer with H1 agonistic/H3 antagonistic properties (48 mg t.i.d.), was coadministered with olanzapine (10 mg/day) in three first-episode schizophrenia patients for 6 weeks. Body weight was measured at baseline and weekly thereafter. Clinical rating scales were completed at baseline and at week 6. All participants gained weight (mean weight gain 3.1+/-0.9 kg) and a similar pattern of weight gain was observed: an increase during the first 2 weeks and no additional weight gain (two patients) or minor weight loss (one patient) from weeks 3 to 6. None gained 7% of baseline weight, which is the cut-off for clinically significant weight gain. Betahistine was safe and well tolerated and did not interfere with the antipsychotic effect of olanzapine. Our findings justify a placebo-controlled evaluation of the putative weight-attenuating effect of betahistine in olanzapine-induced weight gain.

  18. Deficiency of heat shock transcription factor 1 suppresses heat stress-associated increase in slow soleus muscle mass of mice.

    Science.gov (United States)

    Ohno, Y; Egawa, T; Yokoyama, S; Nakai, A; Sugiura, T; Ohira, Y; Yoshioka, T; Goto, K

    2015-12-01

    Effects of heat shock transcription factor 1 (HSF1) deficiency on heat stress-associated increase in slow soleus muscle mass of mice were investigated. Both HSF1-null and wild-type mice were randomly assigned to control and heat-stressed groups. Mice in heat-stressed group were exposed to heat stress (41 °C for 60 min) in an incubator without anaesthesia. Significant increase in wet and dry weights, and protein content of soleus muscle in wild-type mice was observed seven days after the application of the heat stress. However, heat stress had no impact on soleus muscle mass in HSF1-null mice. Neither type of mice exhibited much effect of heat stress on HSF mRNA expression (HSF1, HSF2 and HSF4). On the other hand, heat stress upregulated heat shock proteins (HSPs) at the mRNA (HSP72) and protein (HSP72 and HSP110) levels in wild-type mice, but not in HSF1-null mice. The population of Pax7-positive nuclei relative to total myonuclei of soleus muscle in wild-type mice was significantly increased by heat stress, but not in HSF1-null mice. Furthermore, the absence of HSF1 gene suppressed heat stress-associated phosphorylation of Akt and p70 S6 kinase (p-p70S6K) in soleus muscle. Heat stress-associated increase in skeletal muscle mass may be induced by HSF1 and/or HSF1-mediated stress response that activates muscle satellite cells and Akt/p70S6K signalling pathway. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  19. Alleviation of Motor Impairments in Patients with Cerebral Palsy: Acute Effects of Whole-body Vibration on Stretch Reflex Response, Voluntary Muscle Activation and Mobility

    Directory of Open Access Journals (Sweden)

    Anne Krause

    2017-08-01

    Full Text Available IntroductionIndividuals suffering from cerebral palsy (CP often have involuntary, reflex-evoked muscle activity resulting in spastic hyperreflexia. Whole-body vibration (WBV has been demonstrated to reduce reflex activity in healthy subjects, but evidence in CP patients is still limited. Therefore, this study aimed to establish the acute neuromuscular and kinematic effects of WBV in subjects with spastic CP.Methods44 children with spastic CP were tested on neuromuscular activation and kinematics before and immediately after a 1-min bout of WBV (16–25 Hz, 1.5–3 mm. Assessment included (1 recordings of stretch reflex (SR activity of the triceps surae, (2 electromyography (EMG measurements of maximal voluntary muscle activation of lower limb muscles, and (3 neuromuscular activation during active range of motion (aROM. We recorded EMG of m. soleus (SOL, m. gastrocnemius medialis (GM, m. tibialis anterior, m. vastus medialis, m. rectus femoris, and m. biceps femoris. Angular excursion was recorded by goniometry of the ankle and knee joint.ResultsAfter WBV, (1 SOL SRs were decreased (p < 0.01 while (2 maximal voluntary activation (p < 0.05 and (3 angular excursion in the knee joint (p < 0.01 were significantly increased. No changes could be observed for GM SR amplitudes or ankle joint excursion. Neuromuscular coordination expressed by greater agonist–antagonist ratios during aROM was significantly enhanced (p < 0.05.DiscussionThe findings point toward acute neuromuscular and kinematic effects following one bout of WBV. Protocols demonstrate that pathological reflex responses are reduced (spinal level, while the execution of voluntary movement (supraspinal level is improved in regards to kinematic and neuromuscular control. This facilitation of muscle and joint control is probably due to a reduction of spasticity-associated spinal excitability in favor of giving access for greater supraspinal input during voluntary motor

  20. Transcranial Direct Current Stimulation (tDCS) Enhances the Excitability of Trigemino-Facial Reflex Circuits.

    Science.gov (United States)

    Cabib, Christopher; Cipullo, Federica; Morales, Merche; Valls-Solé, Josep

    2016-01-01

    Transcranial direct current stimulation (tDCS) causes a tiny burning sensation through activation of local cutaneous trigeminal afferents. Trigeminal sensory inputs from tDCS may generate excitability changes in the trigemino-facial reflex circuits. Sixteen healthy volunteers were submitted to 20 minutes tDCS sessions with two types of electrode-montage conditions: 1. Real vs Sham 'bi-hemispheric' tDCS (cathode/anode: C4/C3), for blinded assessment of effects, and 2. 'uni-hemispheric' tDCS (cathode/anode: Fp3/C3), for assessment of laterality of the effects. Supraorbital nerve stimuli were used to obtain blink reflexes before, during (10 minutes from onset) and after (30 minutes from onset) the tDCS session. Outcome measures were R2 habituation (R2H) to repeated stimuli, the blink reflex excitability recovery (BRER) to paired stimuli and the blink reflex inhibition by a prepulse (BRIP). Real but not sham bi-hemispheric tDCS caused a significant decrease of R2H and leftward shift of BRER curve (p tDCS on BRER and BRIP were larger on ipsilateral than on contralateral blink reflexes (p tDCS enhances the excitability of trigemino-facial reflex circuits. The finding of larger ipsilateral than contralateral effects suggests that sensitization through cutaneous trigeminal afferents adds on other possible mechanisms such as activation of cortico-nuclear or cortico-reticular connections. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. [Reflex seizures, cinema and television].

    Science.gov (United States)

    Olivares-Romero, Jesús

    2015-12-16

    In movies and television series are few references to seizures or reflex epilepsy even though in real life are an important subgroup of total epileptic syndromes. It has performed a search on the topic, identified 25 films in which they appear reflex seizures. Most seizures observed are tonic-clonic and visual stimuli are the most numerous, corresponding all with flashing lights. The emotions are the main stimuli in higher level processes. In most cases it is not possible to know if a character suffers a reflex epilepsy or suffer reflex seizures in the context of another epileptic syndrome. The main conclusion is that, in the movies, the reflex seizures are merely a visual reinforcing and anecdotal element without significant influence on the plot.

  2. Arakeri’s Reflex: an Alternative Pathway for Dento-Cardiac Reflex Mediated Syncope

    Directory of Open Access Journals (Sweden)

    Veena Arali

    2010-03-01

    Full Text Available Introduction: Dentocardiac reflex, a variant of trigeminocardiac reflex elicited specifically during tooth extraction procedures in den-tal/maxillofacial surgery and is believed to cause syncope with an afferent link mediated by posterior superior alveolar nerve. Another variant of trigeminocardiac reflex which is also of interest to the oral and maxillofacial surgeon is oculocardiac reflex which can be triggered by direct or indirect manipulation of eye globe or muscles around it.The hypothesis: Excessive or injudicious pressure or manipulations around the maxillary first molars during extraction procedure are as-sociated with maximum incidence of bradycardia and hypotension than around incisor/ canine/ third molars. This is because; the pressure on eye globe and ophthalmic rectus muscle is maximum during extraction of first molar than incisor/canine and third molars. This observation led us to postulate an alternative pathway for dentocardiac reflex mediated syncope which may possibly justify the maxillary first molar region as a prone factor for the trigger. Evaluation of the hypothesis: Present hypothesis may not confer the specific factor responsible for switch in autonomic response in syncope origin during the tooth extraction procedure, but may provide a clue to where we should be looking.

  3. Acute Gastrocnemius-Soleus Complex Injuries in National Football League Athletes

    OpenAIRE

    Werner, Brian C.; Belkin, Nicole S.; Kennelly, Steve; Weiss, Leigh; Barnes, Ronnie P.; Potter, Hollis G.; Warren, Russell F.; Rodeo, Scott A.

    2017-01-01

    Background: Lower extremity muscle injuries are common in professional football. Although less common than hamstring or quadriceps injuries in National Football League (NFL) athletes, calf injuries occur with relative frequency and have not previously been studied. Purpose: To evaluate gastrocnemius-soleus complex muscle injuries over the past 13 years from a single NFL team to determine the incidence of such injuries, their imaging characteristics, and return to play after such injuries and ...

  4. Are skeletal muscles independent actuators? Force transmission from soleus muscle in the cat

    NARCIS (Netherlands)

    Maas, H.; Sandercock, T.G.

    2008-01-01

    It is unclear if skeletal muscles act mechanically as independent actuators. The purpose of the present study was to investigate force transmission from soleus (SO) muscle for physiological lengths as well as relative positions in the intact cat hindlimb. We hypothesized that force transmission from

  5. Effect of e-Cigarette Use on Cough Reflex Sensitivity.

    Science.gov (United States)

    Dicpinigaitis, Peter V; Lee Chang, Alfredo; Dicpinigaitis, Alis J; Negassa, Abdissa

    2016-01-01

    E-cigarettes (e-cigs) have attained widespread popularity, yet knowledge of their physiologic effects remains minimal. The aim of this study was to evaluate the effect of a single exposure to e-cig vapor on cough reflex sensitivity. Thirty healthy nonsmokers underwent cough reflex sensitivity measurement using capsaicin cough challenge at baseline, 15 min, and 24 h after e-cig exposure (30 puffs 30 s apart). The end point of cough challenge is the concentration of capsaicin inducing five or more coughs (C5). The number of coughs induced by each e-cig inhalation was counted. A subgroup of subjects (n = 8) subsequently underwent an identical protocol with a non-nicotine-containing e-cig. Cough reflex sensitivity was significantly inhibited (C5 increased) 15 min after e-cig use (?0.29; 95% CI, ?0.43 to ?0.15; P < .0001); 24 h later, C5 returned to baseline (0.24; 95% CI, 0.10-0.38; P = .0002 vs post-15-min value). A subgroup of eight subjects demonstrating the largest degree of cough reflex inhibition had no suppression after exposure to a non-nicotine-containing e-cig (P = .0078 for comparison of ?C5 after nicotine vs non-nicotine device). Furthermore, more coughing was induced by the nicotine-containing vs non-nicotine-containing device (P = .0156). A single session of e-cig use, approximating nicotine exposure of one tobacco cigarette, induces significant inhibition of cough reflex sensitivity. Exploratory analysis of a subgroup of subjects suggests that nicotine is responsible for this observation. Our data, consistent with previous studies of nicotine effect, suggest a dual action of nicotine: an immediate, peripheral protussive effect and a delayed central antitussive effect. ClinicalTrials.gov; No.: NCT02203162; URL: www.clinicaltrials.gov. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  6. Influenza preparedness and the bureaucratic reflex: anticipating and generating the 2009 H1N1 event.

    Science.gov (United States)

    Barker, Kezia

    2012-07-01

    This paper draws together work on the event to problematise the generative implications of anticipatory governance in the management of emerging infectious disease. Through concerns for preparedness, the need to anticipate outbreaks of disease has taken on a new urgency. With the identification of the H1N1 virus circulating amongst human populations in 2009, public health measures and security practices at regional, national and international levels were rapidly put into play. However, as the ensuing event demonstrated, the social, political and economic disruptions of emerging infectious diseases can be matched by those of anticipatory actions. I argue that the event-making potential of surveillance practices and the pre-determined arrangements of influenza preparedness planning, when triggered by the H1N1 virus, caused an event acceleration through the hyper-sensitised global health security architecture. In the UK, this led to a bureaucratic reflex, a security response event that overtook the present actualities of the disease. This raises questions about the production of forms of insecurity by the security apparatus itself. Copyright © 2012. Published by Elsevier Ltd.

  7. Vestibulo-ocular reflexes in rabbits: reduction by intravenous injection of diazepam.

    Science.gov (United States)

    Barmack, N H; Pettorossi, V E

    1980-11-01

    We have studied the influence of intravenously administered diazepam on the horizontal (HVOR) and vertical (VVOR) vestibulo-ocular reflexes of the rabbit. The HVOR and VVOR were evoked by sinusoidal oscillation of rabbits on a rate table (0.01 to 0.8 Hz, +/- 10 degrees), and eye movements were measured with an infrared light-projection technique. The gains of the HVOR and VVOR (evoked eye velocity/head velocity) were reduced by diazepam injections of 5 microgram/kg. The dose required to produce a 50% reduction in HVOR gain was 500 microgram/kg. The time required to reduce the HVOR gain to 50% of its maximal reduction at dose of 400 microgram/kg (0.4 Hz +/- 10 degrees) was 60 s. These data suggest that diazepam might be effective as an anti-motion-sickness agent.

  8. Case report 376: Accessory (anomalous) soleus muscle

    International Nuclear Information System (INIS)

    Apple, J.S.; Khoury, M.B.; Martinez, S.; Nunley, J.A.

    1986-01-01

    In summary, a case has been presented of a 24-year-old woman who developed pain in the left lower extremity while jogging. Physical examination showed a soft, palpable mass medial and anterior to the Achilles tendon in the left lower extremity. Although a lipoma was suspected, plain films and CT studies indicated clearly that the mass was not of fatty density. In fact, the density of the mass was equivalent to adjacent muscles. The mass itself was lying in the soft tissues of the left ankle tissue. An open biopsy showed a normal muscle which represented an accessory soleus muscle - a muscle known to be anomalous on accoasion and reported as being symptomatic or asymptomatic in different individuals. (orig./SHA)

  9. On Reflexive Data Models

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, S.

    2000-08-20

    An information system is reflexive if it stores a description of its current structure in the body of stored information and is acting on the base of this information. A data model is reflexive, if its language is meta-closed and can be used to build such a system. The need for reflexive data models in new areas of information technology applications is argued. An attempt to express basic notions related to information systems is made in the case when the system supports and uses meta-closed representation of the data.

  10. Some remarks on Romanian reflexive verbs derived by the prefix "în"

    Directory of Open Access Journals (Sweden)

    Veronica Tomescu

    2008-01-01

    Full Text Available The paper discusses a small group of Romanian reflexive verbs, denominals derived by means of the prefix în, as well as a group of transitive verbs which are reflexivized. Their behaviour will be briefly considered. A search on the Internet has also been made alongside the dictionary study in order to gain an insight into the frequency of use of certain forms.

  11. Dynamic clinical measurements of voluntary vaginal contractions and autonomic vaginal reflexes.

    Science.gov (United States)

    Broens, Paul M A; Spoelstra, Symen K; Weijmar Schultz, Willibrord C M

    2014-12-01

    The vaginal canal is an active and responsive canal. It has pressure variations along its length and shows reflex activity. At present, the prevailing idea is that the vaginal canal does not have a sphincter mechanism. It is hypothesized that an active vaginal muscular mechanism exists and might be involved in the pathophysiology of genito-pelvic pain/penetration disorder. The aim of this study was to detect the presence of a canalicular vaginal "sphincter mechanism" by measuring intravaginal pressure at different levels of the vaginal canal during voluntary pelvic floor contractions and during induced reflexive contractions. Sixteen nulliparous women, without sexual dysfunction and pelvic floor trauma, were included in the study. High-resolution solid-state circumferential catheters were used to measure intravaginal pressures and vaginal contractions at different levels in the vaginal canal. Voluntary intravaginal pressure measurements were performed in the left lateral recumbent position only, while reflexive intravaginal pressure measurements during slow inflation of a vaginal balloon were performed in the left lateral recumbent position and in the sitting position. Intravaginal pressures and vaginal contractions were the main outcome measures. In addition, a general demographic and medical history questionnaire was administered to gain insight into the characteristics of the study population. Fifteen out of the sixteen women had deep and superficial vaginal high-pressure zones. In one woman, no superficial high-pressure zone was found. The basal and maximum pressures, as well as the duration of the autonomic reflexive contractions significantly exceeded the pressures and the duration of the voluntary contractions. There were no significant differences between the reflexive measurements obtained in the left lateral recumbent and the sitting position. The two high-pressure zones found in this study, as a result of voluntary contractions and, even more pronounced

  12. Effect of hindlimb unweighting on single soleus fiber maximal shortening velocity and ATPase activity

    Science.gov (United States)

    Mcdonald, K. S.; Fitts, R. H.

    1993-01-01

    The effect of hindlimb unweighting (HU) for 1 to 3 wks on the shortening velocity of a soleus fiber, its ATPase content, and the relative contents of the slow and fast myosin was investigated by measuring fiber force, V(0), ATPase activity, and myosin content in SDS protein profiles of a single rat soleus fiber suspended between a motor arm and a transducer. It was found that HU induces a progressive increase in fiber V(0) that is likely caused, at least in part, by an increase in the fiber's myofibrillar ATPase activity. The HU-induced increases in V(0) and ATPase were associated with the presence of a greater percentage of fast type IIa fibers. However, a large population of fibers after 1, 2, and 3 wks of HU showed increases in V(0) and ATPase but displayed the same myosin protein profile on SDS gels as control fibers.

  13. Hypertrophy Stimulation at the Onset of Type I Diabetes Maintains the Soleus but Not the EDL Muscle Mass in Wistar Rats

    Science.gov (United States)

    Fortes, Marco A. S.; Scervino, Maria V. M.; Marzuca-Nassr, Gabriel N.; Vitzel, Kaio F.; da Justa Pinheiro, Carlos H.; Curi, Rui

    2017-01-01

    Diabetes mellitus induces a reduction in skeletal muscle mass and strength. Strength training is prescribed as part of treatment since it improves glycemic control and promotes increase of skeletal muscle mass. The mechanisms involved in overload-induced muscle hypertrophy elicited at the establishment of the type I diabetic state was investigated in Wistar rats. The purpose was to examine whether the overload-induced hypertrophy can counteract the hypotrophy associated to the diabetic state. The experiments were performed in oxidative (soleus) or glycolytic (EDL) muscles. PI3K/Akt/mTOR protein synthesis pathway was evaluated 7 days after overload-induced hypertrophy of soleus and of EDL muscles. The mRNA expression of genes associated with different signaling pathways that control muscle hypertrophy was also evaluated: mechanotransduction (FAK), Wnt/β-catenin, myostatin, and follistatin. The soleus and EDL muscles when submitted to overload had similar hypertrophic responses in control and diabetic animals. The increase of absolute and specific twitch and tetanic forces had the same magnitude as muscle hypertrophic response. Hypertrophy of the EDL muscle from diabetic animals mostly involved mechanical loading-stimulated PI3K/Akt/mTOR pathway besides the reduced activation of AMP-activated protein kinase (AMPK) and decrease of myostatin expression. Hypertrophy was more pronounced in the soleus muscle of diabetic animals due to a more potent activation of rpS6 and increased mRNA expression of insulin-like growth factor-1 (IGF-1), mechano-growth factor (MGF) and follistatin, and decrease of myostatin, MuRF-1 and atrogin-1 contents. The signaling changes enabled the soleus muscle mass and force of the diabetic rats to reach the values of the control group. PMID:29123487

  14. Neurodevelopmental Reflex Testing in Neonatal Rat Pups.

    Science.gov (United States)

    Nguyen, Antoinette T; Armstrong, Edward A; Yager, Jerome Y

    2017-04-24

    Neurodevelopmental reflex testing is commonly used in clinical practice to assess the maturation of the nervous system. Neurodevelopmental reflexes are also referred to as primitive reflexes. They are sensitive and consistent with later outcomes. Abnormal reflexes are described as an absence, persistence, reappearance, or latency of reflexes, which are predictive indices of infants that are at high risk for neurodevelopmental disorders. Animal models of neurodevelopmental disabilities, such as cerebral palsy, often display aberrant developmental reflexes, as would be observed in human infants. The techniques described assess a variety of neurodevelopmental reflexes in neonatal rats. Neurodevelopmental reflex testing offers the investigator a testing method that is not otherwise available in such young animals. The methodology presented here aims to assist investigators in examining developmental milestones in neonatal rats as a method of detecting early-onset brain injury and/or determining the effectiveness of therapeutic interventions. The methodology presented here aims to provide a general guideline for investigators.

  15. Cervico-ocular Reflex Is Increased in People With Nonspecific Neck Pain.

    Science.gov (United States)

    de Vries, Jurryt; Ischebeck, Britta K; Voogt, Lennard P; Janssen, Malou; Frens, Maarten A; Kleinrensink, Gert-Jan; van der Geest, Jos N

    2016-08-01

    Neck pain is a widespread complaint. People experiencing neck pain often present an altered timing in contraction of cervical muscles. This altered afferent information elicits the cervico-ocular reflex (COR), which stabilizes the eye in response to trunk-to-head movements. The vestibulo-ocular reflex (VOR) elicited by the vestibulum is thought to be unaffected by afferent information from the cervical spine. The aim of the study was to measure the COR and VOR in people with nonspecific neck pain. This study utilized a cross-sectional design in accordance with the STROBE statement. An infrared eye-tracking device was used to record the COR and the VOR while the participant was sitting on a rotating chair in darkness. Eye velocity was calculated by taking the derivative of the horizontal eye position. Parametric statistics were performed. The mean COR gain in the control group (n=30) was 0.26 (SD=0.15) compared with 0.38 (SD=0.16) in the nonspecific neck pain group (n=37). Analyses of covariance were performed to analyze differences in COR and VOR gains, with age and sex as covariates. Analyses of covariance showed a significantly increased COR in participants with neck pain. The VOR between the control group, with a mean VOR of 0.67 (SD=0.17), and the nonspecific neck pain group, with a mean VOR of 0.66 (SD=0.22), was not significantly different. Measuring eye movements while the participant is sitting on a rotating chair in complete darkness is technically complicated. This study suggests that people with nonspecific neck pain have an increased COR. The COR is an objective, nonvoluntary eye reflex and an unaltered VOR. This study shows that an increased COR is not restricted to patients with traumatic neck pain. © 2016 American Physical Therapy Association.

  16. Reflex and Non-Reflex Torque Responses to Stretch of the Human Knee Extensors

    National Research Council Canada - National Science Library

    Mrachacz-Kersting, N

    2001-01-01

    .... The quadriceps muscles were stretched at various background torques, produced either voluntarily or electrically and thus the purely reflex-mediated torque could be calculated. The contribution of the reflex mediated stiffness initially low, increased with increasing background torques for the range of torques investigated.

  17. Somatic modulation of spinal reflex bladder activity mediated by nociceptive bladder afferent nerve fibers in cats.

    Science.gov (United States)

    Xiao, Zhiying; Rogers, Marc J; Shen, Bing; Wang, Jicheng; Schwen, Zeyad; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2014-09-15

    The goal of the present study was to determine if supraspinal pathways are necessary for inhibition of bladder reflex activity induced by activation of somatic afferents in the pudendal or tibial nerve. Cats anesthetized with α-chloralose were studied after acute spinal cord transection at the thoracic T9/T10 level. Dilute (0.25%) acetic acid was used to irritate the bladder, activate nociceptive afferent C-fibers, and trigger spinal reflex bladder contractions (amplitude: 19.3 ± 2.9 cmH2O). Hexamethonium (a ganglionic blocker, intravenously) significantly (P reflex bladder contractions to 8.5 ± 1.9 cmH2O. Injection of lidocaine (2%, 1-2 ml) into the sacral spinal cord or transection of the sacral spinal roots and spinal cord further reduced the contraction amplitude to 4.2 ± 1.3 cmH2O. Pudendal nerve stimulation (PNS) at frequencies of 0.5-5 Hz and 40 Hz but not at 10-20 Hz inhibited reflex bladder contractions, whereas tibial nerve stimulation (TNS) failed to inhibit bladder contractions at all tested frequencies (0.5-40 Hz). These results indicate that PNS inhibition of nociceptive afferent C-fiber-mediated spinal reflex bladder contractions can occur at the spinal level in the absence of supraspinal pathways, but TNS inhibition requires supraspinal pathways. In addition, this study shows, for the first time, that after acute spinal cord transection reflex bladder contractions can be triggered by activating nociceptive bladder afferent C-fibers using acetic acid irritation. Understanding the sites of action for PNS or TNS inhibition is important for the clinical application of pudendal or tibial neuromodulation to treat bladder dysfunctions. Copyright © 2014 the American Physiological Society.

  18. Sensor-Motor Maps for Describing Linear Reflex Composition in Hopping

    Directory of Open Access Journals (Sweden)

    Christian Schumacher

    2017-11-01

    Full Text Available In human and animal motor control several sensory organs contribute to a network of sensory pathways modulating the motion depending on the task and the phase of execution to generate daily motor tasks such as locomotion. To better understand the individual and joint contribution of reflex pathways in locomotor tasks, we developed a neuromuscular model that describes hopping movements. In this model, we consider the influence of proprioceptive length (LFB, velocity (VFB and force feedback (FFB pathways of a leg extensor muscle on hopping stability, performance and efficiency (metabolic effort. Therefore, we explore the space describing the blending of the monosynaptic reflex pathway gains. We call this reflex parameter space a sensor-motor map. The sensor-motor maps are used to visualize the functional contribution of sensory pathways in multisensory integration. We further evaluate the robustness of these sensor-motor maps to changes in tendon elasticity, body mass, segment length and ground compliance. The model predicted that different reflex pathway compositions selectively optimize specific hopping characteristics (e.g., performance and efficiency. Both FFB and LFB were pathways that enable hopping. FFB resulted in the largest hopping heights, LFB enhanced hopping efficiency and VFB had the ability to disable hopping. For the tested case, the topology of the sensor-motor maps as well as the location of functionally optimal compositions were invariant to changes in system designs (tendon elasticity, body mass, segment length or environmental parameters (ground compliance. Our results indicate that different feedback pathway compositions may serve different functional roles. The topology of the sensor-motor map was predicted to be robust against changes in the mechanical system design indicating that the reflex system can use different morphological designs, which does not apply for most robotic systems (for which the control often follows a

  19. Sensor-Motor Maps for Describing Linear Reflex Composition in Hopping.

    Science.gov (United States)

    Schumacher, Christian; Seyfarth, André

    2017-01-01

    In human and animal motor control several sensory organs contribute to a network of sensory pathways modulating the motion depending on the task and the phase of execution to generate daily motor tasks such as locomotion. To better understand the individual and joint contribution of reflex pathways in locomotor tasks, we developed a neuromuscular model that describes hopping movements. In this model, we consider the influence of proprioceptive length (LFB), velocity (VFB) and force feedback (FFB) pathways of a leg extensor muscle on hopping stability, performance and efficiency (metabolic effort). Therefore, we explore the space describing the blending of the monosynaptic reflex pathway gains. We call this reflex parameter space a sensor-motor map . The sensor-motor maps are used to visualize the functional contribution of sensory pathways in multisensory integration. We further evaluate the robustness of these sensor-motor maps to changes in tendon elasticity, body mass, segment length and ground compliance. The model predicted that different reflex pathway compositions selectively optimize specific hopping characteristics (e.g., performance and efficiency). Both FFB and LFB were pathways that enable hopping. FFB resulted in the largest hopping heights, LFB enhanced hopping efficiency and VFB had the ability to disable hopping. For the tested case, the topology of the sensor-motor maps as well as the location of functionally optimal compositions were invariant to changes in system designs (tendon elasticity, body mass, segment length) or environmental parameters (ground compliance). Our results indicate that different feedback pathway compositions may serve different functional roles. The topology of the sensor-motor map was predicted to be robust against changes in the mechanical system design indicating that the reflex system can use different morphological designs, which does not apply for most robotic systems (for which the control often follows a specific

  20. Role of the brain stem in tibial inhibition of the micturition reflex in cats.

    Science.gov (United States)

    Ferroni, Matthew C; Slater, Rick C; Shen, Bing; Xiao, Zhiying; Wang, Jicheng; Lee, Andy; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2015-08-01

    This study examined the role of the brain stem in inhibition of bladder reflexes induced by tibial nerve stimulation (TNS) in α-chloralose-anesthetized decerebrate cats. Repeated cystometrograms (CMGs) were performed by infusing saline or 0.25% acetic acid (AA) to elicit normal or overactive bladder reflexes, respectively. TNS (5 or 30 Hz) at three times the threshold (3T) intensity for inducing toe movement was applied for 30 min between CMGs to induce post-TNS inhibition or applied during the CMGs to induce acute TNS inhibition. Inhibition was evident as an increase in bladder capacity without a change in amplitude of bladder contractions. TNS applied for 30 min between saline CMGs elicited prolonged (>2 h) poststimulation inhibition that significantly (P reflexes but are not involved in inhibition of normal bladder reflexes. Copyright © 2015 the American Physiological Society.

  1. Astaxanthin Supplementation Delays Physical Exhaustion and Prevents Redox Imbalances in Plasma and Soleus Muscles of Wistar Rats

    Directory of Open Access Journals (Sweden)

    Tatiana G. Polotow

    2014-12-01

    Full Text Available Astaxanthin (ASTA is a pinkish-orange carotenoid commonly found in marine organisms, especially salmon. ASTA is a powerful antioxidant and suggested to provide benefits for human health, including the inhibition of LDL oxidation, UV-photoprotection, and prophylaxis of bacterial stomach ulcers. Exercise is associated to overproduction of free radicals in muscles and plasma, with pivotal participation of iron ions and glutathione (GSH. Thus, ASTA was studied here as an auxiliary supplement to improve antioxidant defenses in soleus muscles and plasma against oxidative damage induced by exhaustive exercise. Long-term 1 mg ASTA/kg body weight (BW supplementation in Wistar rats (for 45 days significantly delayed time to exhaustion by 29% in a swimming test. ASTA supplementation increased scavenging/iron-chelating capacities (TEAC/FRAP and limited exercise-induced iron overload and its related pro-oxidant effects in plasma of exercising animals. On the other hand, ASTA induced significant mitochondrial Mn-dependent superoxide dismutase and cytosolic glutathione peroxidase antioxidant responses in soleus muscles that, in turn, increased GSH content during exercise, limited oxidative stress, and delayed exhaustion. We also provided significant discussion about a putative “mitochondrial-targeted” action of ASTA based on previous publications and on the positive results found in the highly mitochondrial populated (oxidative-type soleus muscles here.

  2. Hypertrophy Stimulation at the Onset of Type I Diabetes Maintains the Soleus but Not the EDL Muscle Mass in Wistar Rats

    Directory of Open Access Journals (Sweden)

    Marco A. S. Fortes

    2017-10-01

    Full Text Available Diabetes mellitus induces a reduction in skeletal muscle mass and strength. Strength training is prescribed as part of treatment since it improves glycemic control and promotes increase of skeletal muscle mass. The mechanisms involved in overload-induced muscle hypertrophy elicited at the establishment of the type I diabetic state was investigated in Wistar rats. The purpose was to examine whether the overload-induced hypertrophy can counteract the hypotrophy associated to the diabetic state. The experiments were performed in oxidative (soleus or glycolytic (EDL muscles. PI3K/Akt/mTOR protein synthesis pathway was evaluated 7 days after overload-induced hypertrophy of soleus and of EDL muscles. The mRNA expression of genes associated with different signaling pathways that control muscle hypertrophy was also evaluated: mechanotransduction (FAK, Wnt/β-catenin, myostatin, and follistatin. The soleus and EDL muscles when submitted to overload had similar hypertrophic responses in control and diabetic animals. The increase of absolute and specific twitch and tetanic forces had the same magnitude as muscle hypertrophic response. Hypertrophy of the EDL muscle from diabetic animals mostly involved mechanical loading-stimulated PI3K/Akt/mTOR pathway besides the reduced activation of AMP-activated protein kinase (AMPK and decrease of myostatin expression. Hypertrophy was more pronounced in the soleus muscle of diabetic animals due to a more potent activation of rpS6 and increased mRNA expression of insulin-like growth factor-1 (IGF-1, mechano-growth factor (MGF and follistatin, and decrease of myostatin, MuRF-1 and atrogin-1 contents. The signaling changes enabled the soleus muscle mass and force of the diabetic rats to reach the values of the control group.

  3. Charitable giving and reflexive individuals: How personal reflexivity mediates between structure and agency.

    Science.gov (United States)

    Sanghera, Balihar

    2017-03-01

    This article examines how individuals are reflexive beings who interpret the world in relation to things that matter to them, and how charitable acts are evaluated and embedded in their lives with different degrees of meaning and importance. Rather than framing the discussion of charitable practices in terms of an altruism/egoism binary or imputing motivations and values to social structures, the article explains how reflexivity is an important and neglected dimension of social practices, and how it interacts with sympathy, sentiments and discourses to shape giving. The study also shows that there are different modes of reflexivity, which have varied effects on charity and volunteering.

  4. [Early diagnosis and prognosis evaluation of Bell palsy with blink reflex ].

    Science.gov (United States)

    Xie, Dan-dan; Li, Xiao-song; Liu, Yuan-yuan

    2014-11-01

    To determine the value of blink reflex in early diagnosis and prognosis evaluation of Bell palsy. Blink reflex and facial nerve conduction were examined in 58 patients with Bell palsy within one week after symptom onset. The patients without response of R1 , R2 and R2 ' waves were classified as complete efferent retardarce (Group A, 30 cases), and those with response of R1 , R2 and R2 ' waves were classified as incomplete efferent anomalies (Group B, 28 cases). The clinical outcomes after three months of systemic therapy were evaluated using the House-Blackmann (H-B) scale. Efferent anomalies of blink reflex occurred in ail of the 58 patients. Abnormal results of facial nerve conduction appeared in 23 (39. 7%) patients. The three months therapy was effective in 93% patients in Group B and 70% patients in Group A (PBell palsy.

  5. [Laryngeal adduction reflex].

    Science.gov (United States)

    Ptok, M; Bonenberger, S; Miller, S; Kühn, D; Jungheim, M

    2014-07-01

    Laryngeal Adductor Reflex Background: A rapid closure of the vocal folds is necessary, whenever foreign materials or food particles penetrate into the larynx. Otherwise a passage of these particles into the trachea or the lower respiratory tract would be imminent. An aspiration could mechanically block the respiratory tract and cause severe dyspnoea or cause aspiration pneumonia. For this systematic review a selective literature research in PubMed and Scopus using the keywords "laryngeal adductor reflex" and "vocal fold closure" has been carried out. Apart from the oesophago-glottal and pharyngo-glottal closure reflexes, the laryngeal adductor reflex (LAR) has been investigated in particular. The LAR qualifies as a reflectory laryngeal adductor mechanism and involves early, presumably di- or oligosynaptic ipsilateral LAR1 as well as late polysynaptic ipsi- and contralateral LAR2 components. In clinical routine diagnostic settings of dysphagia, LAR is only assessed qualitatively and usually triggered by air pulses or tactile stimulation. Dysphagiologists often find that not only the laryngeal sensibility in general is impaired, but especially the protective laryngeal adduction mechanism, which results in a higher risk of aspiration. Thus, it appears mandatory to test the LAR not only qualitatively but also quantitatively. Unfortunately a valid and reliable method that can be employed in clinical practice has not yet been put forward. © Georg Thieme Verlag KG Stuttgart · New York.

  6. Afferent-mediated modulation of the soleus muscle activity during the stance phase of human walking

    DEFF Research Database (Denmark)

    Nazarena, Mazzaro; Grey, Michael James; do Nascimento, Omar Feix

    2006-01-01

    The aim of this study was to investigate the contribution of proprioceptive feedback to the amplitude modulation of the soleus muscle activity during human walking. We have previously shown that slow-velocity, small-amplitude ankle dorsiflexion enhancements and reductions applied during the stance...

  7. Neuromuscular function and fatigue resistance of the plantar flexors following short-term cycling endurance training

    Directory of Open Access Journals (Sweden)

    Martin eBehrens

    2015-05-01

    Full Text Available Previously published studies on the effect of short-term endurance training on the neuromuscular function of the plantar flexors have shown that the H-reflex elicited at rest and during weak voluntary contractions was increased following the training regime. However, these studies did not test H-reflex modulation during isometric maximum voluntary contraction (iMVC and did not incorporate a control group in their study design to compare the results of the endurance training group to individuals without the endurance training stimulus. Therefore, this randomized controlled study was directed to investigate the neuromuscular function of the plantar flexors at rest and during iMVC before and after eight weeks of cycling endurance training. Twenty-two young adults were randomly assigned to an intervention group and a control group. During neuromuscular testing, rate of torque development, isometric maximum voluntary torque and muscle activation were measured. Triceps surae muscle activation and tibialis anterior muscle co-activation were assessed by normalized root mean square of the EMG signal during the initial phase of contraction (0-100, 100-200 ms and isometric maximum voluntary contraction of the plantar flexors. Furthermore, evoked spinal reflex responses of the soleus muscle (H-reflex evoked at rest and during iMVC, V-wave, peak twitch torques induced by electrical stimulation of the posterior tibial nerve at rest and fatigue resistance were evaluated. The results indicate that the endurance training did not lead to a significant change in any variable of interest. Data of the present study conflict with the outcome of previously published studies that have found an increase in H-reflex excitability after endurance training. However, these studies had not included a control group in their study design as was the case here. It is concluded that short-term cycling endurance training does not necessarily enhance H-reflex responses and fatigue

  8. Three-Dimensional Muscle Architecture and Comprehensive Dynamic Properties of Rabbit Gastrocnemius, Plantaris and Soleus: Input for Simulation Studies.

    Science.gov (United States)

    Siebert, Tobias; Leichsenring, Kay; Rode, Christian; Wick, Carolin; Stutzig, Norman; Schubert, Harald; Blickhan, Reinhard; Böl, Markus

    2015-01-01

    The vastly increasing number of neuro-muscular simulation studies (with increasing numbers of muscles used per simulation) is in sharp contrast to a narrow database of necessary muscle parameters. Simulation results depend heavily on rough parameter estimates often obtained by scaling of one muscle parameter set. However, in vivo muscles differ in their individual properties and architecture. Here we provide a comprehensive dataset of dynamic (n = 6 per muscle) and geometric (three-dimensional architecture, n = 3 per muscle) muscle properties of the rabbit calf muscles gastrocnemius, plantaris, and soleus. For completeness we provide the dynamic muscle properties for further important shank muscles (flexor digitorum longus, extensor digitorum longus, and tibialis anterior; n = 1 per muscle). Maximum shortening velocity (normalized to optimal fiber length) of the gastrocnemius is about twice that of soleus, while plantaris showed an intermediate value. The force-velocity relation is similar for gastrocnemius and plantaris but is much more bent for the soleus. Although the muscles vary greatly in their three-dimensional architecture their mean pennation angle and normalized force-length relationships are almost similar. Forces of the muscles were enhanced in the isometric phase following stretching and were depressed following shortening compared to the corresponding isometric forces. While the enhancement was independent of the ramp velocity, the depression was inversely related to the ramp velocity. The lowest effect strength for soleus supports the idea that these effects adapt to muscle function. The careful acquisition of typical dynamical parameters (e.g. force-length and force-velocity relations, force elongation relations of passive components), enhancement and depression effects, and 3D muscle architecture of calf muscles provides valuable comprehensive datasets for e.g. simulations with neuro-muscular models, development of more realistic muscle models, or

  9. Three-Dimensional Muscle Architecture and Comprehensive Dynamic Properties of Rabbit Gastrocnemius, Plantaris and Soleus: Input for Simulation Studies.

    Directory of Open Access Journals (Sweden)

    Tobias Siebert

    Full Text Available The vastly increasing number of neuro-muscular simulation studies (with increasing numbers of muscles used per simulation is in sharp contrast to a narrow database of necessary muscle parameters. Simulation results depend heavily on rough parameter estimates often obtained by scaling of one muscle parameter set. However, in vivo muscles differ in their individual properties and architecture. Here we provide a comprehensive dataset of dynamic (n = 6 per muscle and geometric (three-dimensional architecture, n = 3 per muscle muscle properties of the rabbit calf muscles gastrocnemius, plantaris, and soleus. For completeness we provide the dynamic muscle properties for further important shank muscles (flexor digitorum longus, extensor digitorum longus, and tibialis anterior; n = 1 per muscle. Maximum shortening velocity (normalized to optimal fiber length of the gastrocnemius is about twice that of soleus, while plantaris showed an intermediate value. The force-velocity relation is similar for gastrocnemius and plantaris but is much more bent for the soleus. Although the muscles vary greatly in their three-dimensional architecture their mean pennation angle and normalized force-length relationships are almost similar. Forces of the muscles were enhanced in the isometric phase following stretching and were depressed following shortening compared to the corresponding isometric forces. While the enhancement was independent of the ramp velocity, the depression was inversely related to the ramp velocity. The lowest effect strength for soleus supports the idea that these effects adapt to muscle function. The careful acquisition of typical dynamical parameters (e.g. force-length and force-velocity relations, force elongation relations of passive components, enhancement and depression effects, and 3D muscle architecture of calf muscles provides valuable comprehensive datasets for e.g. simulations with neuro-muscular models, development of more realistic

  10. Effect of chronic and acute cigarette smoking on the pharyngo-upper oesophageal sphincter contractile reflex and reflexive pharyngeal swallow

    OpenAIRE

    Dua, K; Bardan, E; Ren, J; Sui, Z; Shaker, R

    1998-01-01

    Background—Cigarette smoking is known to affect adversely the defence mechanisms against gastro-oesophageal reflux. The effect of smoking on the supraoesophageal reflexes that prevent aspiration of gastric contents has not been previously studied. 
Aims—To elucidate the effect of cigarette smoking on two of the supraoesophageal reflexes: the pharyngo-upper oesophageal sphincter (UOS) contractile reflex; and the reflexive pharyngeal swallow. 
Methods—Ten chronic smokers and 10 non-...

  11. Two weeks of metformin treatment induces AMPK dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle

    DEFF Research Database (Denmark)

    Kristensen, Jonas Møller; Treebak, Jonas Thue; Schjerling, Peter

    2014-01-01

    signaling. Methods: Oral doses of metformin or saline treatment were given muscle-specific kinase α2 dead AMPK mice (KD) and wild type (WT) littermates either once or chronically for 2 weeks. Soleus and Extensor Digitorum Longus (EDL) muscles were used for measurements of glucose transport and Western blot......Background: Metformin-induced activation of AMPK has been associated with enhanced glucose uptake in skeletal muscle but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent upon AMPK...... analyzes. Results: Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (45%, P...

  12. A novel reflex cough testing device.

    Science.gov (United States)

    Fujiwara, Kazunori; Kawamoto, Katsuyuki; Shimizu, Yoko; Fukuhara, Takahiro; Koyama, Satoshi; Kataoka, Hideyuki; Kitano, Hiroya; Takeuchi, Hiromi

    2017-01-18

    The reflex cough test is useful for detecting silent aspiration, a risk factor for aspiration pneumonia. However, assessing the risk of aspiration pneumonia requires measuring not only the cough reflex but also cough strength. Currently, no reflex cough testing device is available that can directly measure reflex cough strength. We therefore developed a new testing device that can easily and simultaneously measure cough strength and the time until the cough reflex, and verified whether screening with this new instrument is feasible for evaluating the risk of aspiration pneumonia. This device consists of a special pipe with a double lumen, a nebulizer, and an electronic spirometer. We used a solution of prescription-grade L-tartaric acid to initiate the cough reflex. The solution was inhaled through a mouthpiece as a microaerosol produced by an ultrasonic nebulizer. The peak cough flow (PCF) of the induced cough was measured with the spirometer. The 70 patients who participated in this study comprised 49 patients without a history of pneumonia (group A), 21 patients with a history of pneumonia (group B), and 10 healthy volunteers (control group). With the novel device, PCF and time until cough reflex could be measured without adverse effects. The PCF values were 118.3 ± 64.0 L/min, 47.7 ± 38.5 L/min, and 254.9 ± 83.8 L/min in group A, group B, and the control group, respectively. The PCF of group B was significantly lower than that of group A and the control group (p reflex was 4.2 ± 5.9 s, 7.0 ± 7.0 s, and 1 s in group A, group B, and the control group, respectively. This duration was significantly longer for groups A and B than for the control group (A: p reflex and the strength of involuntary coughs for assessment of patients at risk of aspiration pneumonia.

  13. Oedema and fatty degeneration of the soleus and gastrocnemius muscles on MR images in patients with achilles tendon abnormalities

    International Nuclear Information System (INIS)

    Hoffmann, Adrienne; Mamisch, Nadja; Buck, Florian M.; Pfirrmann, Christian W.A.; Zanetti, Marco; Espinosa, Norman

    2011-01-01

    The purpose of this study was to evaluate the frequency of oedema and fatty degeneration of the soleus and gastrocnemius muscles in patients with Achilles tendon abnormalities. Forty-five consecutive patients (mean 51 years; range 14-84 years) with achillodynia were examined with magnetic resonance (MR) images of the calf. The frequency of oedema and fatty degeneration in the soleus and gastrocnemius muscles was determined in patients with normal tendons, tendinopathy and in patients with a partial tear or a complete tear of the Achilles tendon. Oedema was encountered in 35% (7/20) of the patients with tendinopathy (n = 20; range 13-81 years), and in 47% (9/19) of the patients with partial tears or complete tears (n = 19; 28-78 years). Fatty degeneration was encountered in 10% (2/20) of the patients with tendinopathy, and in 32% (6/19) of the patients with tears. The prevalence of fatty degeneration was significantly more common in patients with a partial or complete tear compared with the patients with a normal Achilles tendon (p = 0.032 and p = 0.021, respectively). Oedema and fatty degeneration of the soleus and gastrocnemius muscles are common in patients with Achilles tendon abnormalities. (orig.)

  14. Effect of fatigue on hamstring reflex responses and posterior-anterior tibial translation in men and women.

    Directory of Open Access Journals (Sweden)

    Martin Behrens

    Full Text Available Anterior cruciate ligament (ACL rupture ranks among the most common injuries in sports. The incidence of ACL injuries is considerably higher in females than in males and the underlying mechanisms are still under debate. Furthermore, it has been suggested that muscle fatigue can be a risk factor for ACL injuries. We investigated gender differences in hamstring reflex responses and posterior-anterior tibial translation (TT before and after fatiguing exercise. We assessed the isolated movement of the tibia relative to the femur in the sagittal plane as a consequence of mechanically induced TT in standing subjects. The muscle activity of the hamstrings was evaluated. Furthermore, isometric maximum voluntary torque (iMVT and rate of torque development (RTD of the hamstrings (H and quadriceps (Q were measured and the MVT H/Q as well as the RTD H/Q ratios were calculated. After fatigue, reflex onset latencies were enhanced in women. A reduction of reflex responses associated with an increased TT was observed in females. Men showed no differences in these parameters. Correlation analysis revealed no significant associations between parameters for TT and MVT H/Q as well as RTD H/Q. The results of the present study revealed that the fatigue protocol used in this study altered the latency and magnitude of reflex responses of the hamstrings as well as TT in women. These changes were not found in men. Based on our results, it is conceivable that the fatigue-induced decrease in neuromuscular function with a corresponding increase in TT probably contributes to the higher incidence of ACL injuries in women.

  15. The effects of patterned electrical stimulation combined with voluntary contraction on spinal reciprocal inhibition in healthy individuals

    DEFF Research Database (Denmark)

    Takahashi, Yoko; Fujiwara, Toshiyuki; Yamaguchi, Tomofumi

    2017-01-01

    The aim of this study was to examine the effects of voluntary contraction (VC) on the modulation of reciprocal inhibition induced by patterned electrical stimulation (PES) in healthy individuals. Twelve healthy volunteers participated in this study. PES was applied to the common peroneal nerve...... a soleus H-reflex conditioning-test paradigm at the time points of before, immediately after, 10 min after, 20 min after, and 30 min after the tasks. PES+VC increased the amount of reciprocal inhibition, with after-effects lasting up to 20 min. PES alone increased reciprocal inhibition and maintained...

  16. Effect of 48-h food deprivation on the expressions of myosin heavy-chain isoforms and fiber type-related factors in rats.

    Science.gov (United States)

    Mizunoya, Wataru; Sawano, Shoko; Iwamoto, Yohei; Sato, Yusuke; Tatsumi, Ryuichi; Ikeuchi, Yoshihide

    2013-01-01

    The primary aim of this study was to examine the effects of 48-h food deprivation on rat skeletal muscle fiber type, according to myosin heavy-chain (MyHC) isoform composition and some metabolism-related factors in both slow-type dominant and fast-type dominant muscle tissues. Male Wistar rats (7 wk old) were treated with 48-h food deprivation or ad libitum feeding as control. After the treatment, the soleus muscle (slow-type dominant) and the extensor digitorum longus (EDL, fast-type dominant) were excised. We found that 48-h food deprivation did not affect MyHC composition in either the soleus or EDL, compared with fed rats by electrophoretic separation of MyHC isoforms. However, 48-h food deprivation significantly increased the mRNA expression of fast-type MyHC2B in the EDL muscle. Moreover, food deprivation increased fatty acid metabolism, as shown by elevated levels of related serum energy substrates and mRNA expression of mitochondrial uncoupling protein (UCP) 3 and lipoprotein lipase (LPL) in both the soleus and EDL. UCP3 and LPL are generally expressed at higher levels in slow-type fibers. Furthermore, we found that food deprivation significantly decreased the protein amounts of PGC1α and phosphorylated FOXO1, which are known as skeletal muscle fiber type regulators. In conclusion, 48-h food deprivation increased mRNA expression of fast-type MyHC isoform and oxidative metabolism-related factors in EDL, whereas MyHC composition at the protein level did not change in either the soleus or EDL.

  17. Lack of on-going adaptations in the soleus muscle activity during walking in patients affected by large-fiber neuropathy

    DEFF Research Database (Denmark)

    Nazarena, Mazzaro; Grey, Michael James; Sinkjær, Thomas

    2005-01-01

    The aim of this study was to investigate the contribution of feedback from large-diameter sensory fibers to the adaptation of soleus muscle activity after small ankle trajectory modifications during human walking. Small-amplitude and slow-velocity ankle dorsiflexion enhancements and reductions were...... applied during the stance phase of the gait cycle to mimic the normal variability of the ankle trajectory during walking. Patients with demyelination of large sensory fibers (Charcot-Marie-Tooth type 1A and antibodies to myelin-associated glycoprotein neuropathy) and age-matched controls participated...... duration (P ankle dorsiflexion was, respectively, enhanced or reduced. In the patients, the soleus EMG increased during the dorsiflexion...

  18. "On Becoming a Critically Reflexive Practitioner" Redux: What Does It Mean to "Be" Reflexive?

    Science.gov (United States)

    Cunliffe, Ann L.

    2016-01-01

    In this commentary, Cunliffe states that is convinced that reflexivity offers a way of foregrounding our moral and ethical responsibility for people and for the world around us. To "BE" reflexive was defined as embracing "subjective understandings of reality as a basis for thinking more critically about the impact of our…

  19. The past, present, and future of health development campaigns: reflexivity and the critical-cultural approach.

    Science.gov (United States)

    Dutta, Mohan Jyoti; de Souza, Rebecca

    2008-07-01

    In contemporary society, health issues have gained increasing urgency in both political and academic spheres. Looking back at the failure of the modernist development initiatives, there is the need to realize that we live in a time of increasing sociopolitical complexity. The present moment is perhaps best understood in terms of a complex tension and linkage between the past and present, global and local, modern and postmodern. The critical-cultural approach to health campaigns is an approach that, through the reflexive interrogation of modernist assumptions underlying health communication campaigns, attempts to foreground the tensions inherent in the practice of health campaigns. This essay discusses the manner in which the critical-cultural approach interrogates modernist assumptions and provides an alternative paradigm for approaching the theory and practice of health campaigns by suggesting the necessity for reflexivity. Specifically, we discuss how the perspective interrogates the role of the media in development, the significance of culture, the locus of health responsibility, the impact of structural conditions, and the politics of knowledge, providing examples of campaigns that illustrate this reflexivity.

  20. AMPUTATION AND REFLEX SYMPATHETIC DYSTROPHY

    NARCIS (Netherlands)

    GEERTZEN, JHB; EISMA, WH

    Reflex sympathetic dystrophy is a chronic pain syndrome characterized by chronic burning pain, restricted range of motion, oedema and vasolability. Patients are difficult to treat and the prognosis is very often poor. This report emphasizes that an amputation in case of a reflex sympathetic

  1. Portraying Reflexivity in Health Services Research.

    Science.gov (United States)

    Rae, John; Green, Bill

    2016-09-01

    A model is proposed for supporting reflexivity in qualitative health research, informed by arguments from Bourdieu and Finlay. Bourdieu refers to mastering the subjective relation to the object at three levels-the overall social space, the field of specialists, and the scholastic universe. The model overlays Bourdieu's levels of objectivation with Finlay's three stages of research (pre-research, data collection, and data analysis). The intersections of these two ways of considering reflexivity, displayed as cells of a matrix, pose questions and offer prompts to productively challenge health researchers' reflexivity. Portraiture is used to show how these challenges and prompts can facilitate such reflexivity, as illustrated in a research project. © The Author(s) 2016.

  2. Lecithin Prevents Cortical Cytoskeleton Reorganization in Rat Soleus Muscle Fibers under Short-Term Gravitational Disuse.

    Science.gov (United States)

    Ogneva, Irina V; Biryukov, Nikolay S

    2016-01-01

    The aim of this study was to prevent the cortical cytoskeleton reorganization of rat soleus muscle fibers under short-term gravitational disuse. Once a day, we injected the right soleus muscle with 0.5 ml lecithin at a concentration of 200 mg/ml and the left soleus muscle with a diluted solution in an equal volume for 3 days prior to the experiment. To simulate microgravity conditions in rats, an anti-orthostatic suspension was used according to the Ilyin-Novikov method modified by Morey-Holton et al. for 6 hours. The following groups of soleus muscle tissues were examined: "C", "C+L", "HS", and "HS+L". The transversal stiffness of rat soleus muscle fibers after 6 hours of suspension did not differ from that of the control group for the corresponding legs; there were no differences between the groups without lecithin «C» and «HS» or between the groups with lecithin "C+L" and "HS+L". However, lecithin treatment for three days resulted in an increase in cell stiffness; in the "C+L" group, cell stiffness was significantly higher by 22.7% (p lecithin treatment: the beta-actin and gamma-actin mRNA content in group "C+L" increased by 200% compared with that of group "C", and beta-tubulin increased by 100% (as well as the mRNA content of tubulin-binding proteins Ckap5, Tcp1, Cct5 and Cct7). In addition, desmin mRNA content remained unchanged in all of the experimental groups. As a result of the lecithin injections, there was a redistribution of the mRNA content of genes encoding actin monomer- and filament-binding proteins in the direction of increasing actin polymerization and filament stability; the mRNA content of Arpc3 and Lcp1 increased by 3- and 5-fold, respectively, but the levels of Tmod1 and Svil decreased by 2- and 5-fold, respectively. However, gravitational disuse did not result in changes in the mRNA content of Arpc3, Tmod1, Svil or Lcp1. Anti-orthostatic suspension for 6 hours resulted in a decrease in the mRNA content of alpha-actinin-4 (Actn4) and

  3. Altering length and velocity feedback during a neuro-musculoskeletal simulation of normal gait contributes to hemiparetic gait characteristics.

    Science.gov (United States)

    Jansen, Karen; De Groote, Friedl; Aerts, Wouter; De Schutter, Joris; Duysens, Jacques; Jonkers, Ilse

    2014-04-30

    Spasticity is an important complication after stroke, especially in the anti-gravity muscles, i.e. lower limb extensors. However the contribution of hyperexcitable muscle spindle reflex loops to gait impairments after stroke is often disputed. In this study a neuro-musculoskeletal model was developed to investigate the contribution of an increased length and velocity feedback and altered reflex modulation patterns to hemiparetic gait deficits. A musculoskeletal model was extended with a muscle spindle model providing real-time length and velocity feedback of gastrocnemius, soleus, vasti and rectus femoris during a forward dynamic simulation (neural control model). By using a healthy subject's base muscle excitations, in combination with increased feedback gains and altered reflex modulation patterns, the effect on kinematics was simulated. A foot-ground contact model was added to account for the interaction effect between the changed kinematics and the ground. The qualitative effect i.e. the directional effect and the specific gait phases where the effect is present, on the joint kinematics was then compared with hemiparetic gait deviations reported in the literature. Our results show that increased feedback in combination with altered reflex modulation patterns of soleus, vasti and rectus femoris muscle can contribute to excessive ankle plantarflexion/inadequate dorsiflexion, knee hyperextension/inadequate flexion and increased hip extension/inadequate flexion during dedicated gait cycle phases. Increased feedback of gastrocnemius can also contribute to excessive plantarflexion/inadequate dorsiflexion, however in combination with excessive knee and hip flexion. Increased length/velocity feedback can therefore contribute to two types of gait deviations, which are both in accordance with previously reported gait deviations in hemiparetic patients. Furthermore altered modulation patterns, in particular the reduced suppression of the muscle spindle feedback during

  4. 26 CFR 1.1(h)-1 - Capital gains look-through rule for sales or exchanges of interests in a partnership, S...

    Science.gov (United States)

    2010-04-01

    ... exchanges of interests in a partnership, S corporation, or trust. 1.1(h)-1 Section 1.1(h)-1 Internal Revenue....1(h)-1 Capital gains look-through rule for sales or exchanges of interests in a partnership, S... transaction in which all realized gain is recognized, there shall be taken into account under section 1(h)(7...

  5. Rank-one operators in reflexive one-sided A-submodules

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    unital operator algebra A in B(H) completely. Furthermore we investigate the invariant subspace lattice Lat R and the reflexive hull Ref R, where R is the submodule generated by rank-one operators in U; in particular, if L is a subspace lattice, we obtain when the rank-one algebra R of Alg L is big enough to determined Alg L ...

  6. Too Busy for Reflexivity?

    DEFF Research Database (Denmark)

    Ratner, Helene

    What Danish school managers can teach STS researchers about epistemological ideals and pragmatic morals. Reflexivity has an ambivalent status in both anthropology and Science and Technology Studies. On the one hand, the critique of representation at the heart of the reflexivity debates of the 1980s...... highlighted non-symmetric relationships between observer and observed and accused the academic text of enacting a realist genre, concealing the relativism entailed in textual production (Clifford and Marcus 1986, Woolgar 1988, Ashmore 1989). On the other hand, the reflexivity program produced fears...... of a “corrosive relativism in which everything is but a more or less clever expression of opinion” (Geertz 1988:2, 3) and it has suffered the little flattering accusations of piling "layer upon layer of self-consciousness to no avail" (Latour 1988:170) with little “interest [for] … theoretically ambitious...

  7. Effect of a 17 day spaceflight on contractile properties of human soleus muscle fibres

    Science.gov (United States)

    Widrick, J. J.; Knuth, S. T.; Norenberg, K. M.; Romatowski, J. G.; Bain, J. L.; Riley, D. A.; Karhanek, M.; Trappe, S. W.; Trappe, T. A.; Costill, D. L.; hide

    1999-01-01

    1. Soleus biopsies were obtained from four male astronauts 45 days before and within 2 h after a 17 day spaceflight. 2. For all astronauts, single chemically skinned post-flight fibres expressing only type I myosin heavy chain (MHC) developed less average peak Ca2+ activated force (Po) during fixed-end contractions (0.78 +/- 0. 02 vs. 0.99 +/- 0.03 mN) and shortened at a greater mean velocity during unloaded contractions (Vo) (0.83 +/- 0.02 vs. 0.64 +/- 0.02 fibre lengths s-1) than pre-flight type I fibres. 3. The flight-induced decline in absolute Po was attributed to reductions in fibre diameter and/or Po per fibre cross-sectional area. Fibres from the astronaut who experienced the greatest relative loss of peak force also displayed a reduction in Ca2+ sensitivity. 4. The elevated Vo of the post-flight slow type I fibres could not be explained by alterations in myosin heavy or light chain composition. One alternative possibility is that the elevated Vo resulted from an increased myofilament lattice spacing. This hypothesis was supported by electron micrographic analysis demonstrating a reduction in thin filament density post-flight. 5. Post-flight fibres shortened at 30 % higher velocities than pre-flight fibres at external loads associated with peak power output. This increase in shortening velocity either reduced (2 astronauts) or prevented (2 astronauts) a post-flight loss in fibre absolute peak power (microN (fibre length) s-1). 6. The changes in soleus fibre diameter and function following spaceflight were similar to those observed after 17 days of bed rest. Although in-flight exercise countermeasures probably reduced the effects of microgravity, the results support the idea that ground-based bed rest can serve as a model of human spaceflight. 7. In conclusion, 17 days of spaceflight decreased force and increased shortening velocity of single Ca2+-activated muscle cells expressing type I MHC. The increase in shortening velocity greatly reduced the impact

  8. The passive of reflexive verbs in Icelandic

    Directory of Open Access Journals (Sweden)

    Hlíf Árnadóttir

    2011-10-01

    Full Text Available The Reflexive Passive in Icelandic is reminiscent of the so-called New Passive (or New Impersonal in that the oblique case of a passivized object NP is preserved. As is shown by recent surveys, however, speakers who accept the Reflexive Passive do not necessarily accept the New Passive, whereas conversely, speakers who accept the New Passive do also accept the Reflexive Passive. Based on these results we suggest that there is a hierarchy in the acceptance of passive sentences in Icelandic, termed the Passive Acceptability Hierarchy. The validity of this hierarchy is confirmed by our diachronic corpus study of open access digital library texts from Icelandic journals and newspapers dating from the 19th and 20th centuries (tímarit.is. Finally, we sketch an analysis of the Reflexive Passive, proposing that the different acceptability rates of the Reflexive and New Passives lie in the argument status of the object. Simplex reflexive pronouns are semantically dependent on the verbs which select them, and should therefore be analyzed as syntactic arguments only, and not as semantic arguments of these verbs.

  9. The stretch reflex and the contributions of C David Marsden

    Directory of Open Access Journals (Sweden)

    Kalyan B Bhattacharyya

    2017-01-01

    Full Text Available The stretch reflex or myotatic reflex refers to the contraction of a muscle in response to its passive stretching by increasing its contractility as long as the stretch is within physiological limits. For ages, it was thought that the stretch reflex was of short latency and it was synonymous with the tendon reflex, subserving the same spinal reflex arc. However, disparities in the status of the two reflexes in certain clinical situations led Marsden and his collaborators to carry out a series of experiments that helped to establish that the two reflexes had different pathways. That the two reflexes are dissociated has been proved by the fact that the stretch reflex and the tendon reflex, elicited by stimulation of the same muscle, have different latencies, that of the stretch reflex being considerably longer. They hypothesized that the stretch reflex had a transcortical course before it reached the spinal motor neurons for final firing. Additionally, the phenomenon of stimulus-sensitive cortical myoclonus lent further evidence to the presence of the transcortical loop where the EEG correlate preceded the EMG discharge. This concept has been worked out by later neurologists in great detail , and the general consensus is that indeed, the stretch reflex is endowed with a conspicuous transcortical component.

  10. Patterned sensory nerve stimulation enhances the reactivity of spinal Ia inhibitory interneurons.

    Science.gov (United States)

    Kubota, Shinji; Hirano, Masato; Morishita, Takuya; Uehara, Kazumasa; Funase, Kozo

    2015-03-25

    Patterned sensory nerve stimulation has been shown to induce plastic changes in the reciprocal Ia inhibitory circuit. However, the mechanisms underlying these changes have not yet been elucidated in detail. The aim of the present study was to determine whether the reactivity of Ia inhibitory interneurons could be altered by patterned sensory nerve stimulation. The degree of reciprocal Ia inhibition, the conditioning effects of transcranial magnetic stimulation (TMS) on the soleus (SOL) muscle H-reflex, and the ratio of the maximum H-reflex amplitude versus maximum M-wave (H(max)/M(max)) were examined in 10 healthy individuals. Patterned electrical nerve stimulation was applied to the common peroneal nerve every 1 s (100 Hz-5 train) at the motor threshold intensity of tibialis anterior muscle to induce activity changes in the reciprocal Ia inhibitory circuit. Reciprocal Ia inhibition, the TMS-conditioned H-reflex amplitude, and H(max)/M(max) were recorded before, immediately after, and 15 min after the electrical stimulation. The patterned electrical nerve stimulation significantly increased the degree of reciprocal Ia inhibition and decreased the amplitude of the TMS-conditioned H-reflex in the short-latency inhibition phase, which was presumably mediated by Ia inhibitory interneurons. However, it had no effect on H(max)/M(max). Our results indicated that patterned sensory nerve stimulation could modulate the activity of Ia inhibitory interneurons, and this change may have been caused by the synaptic modification of Ia inhibitory interneuron terminals. These results may lead to a clearer understanding of the spinal cord synaptic plasticity produced by repetitive sensory inputs. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

  11. Accessory soleus muscle: a case report and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Palaniappan, M. (Leicester Royal Infirmary (United Kingdom). Dept. of Radiology Royal Liverpool Children' s Hospital (United Kingdom). Dept. of Radiology); Rajesh, A.; Rickett, A. (Leicester Royal Infirmary (United Kingdom). Dept. of Radiology); Kershaw, C.J. (Leicester Royal Infirmary (United Kingdom). Dept. of Orthopaedics)

    1999-08-01

    Accessory soleus muscle is a rare condition which presents as a soft-tissue mass medial to the calcaneum and distal Achilles tendon. Though congenital in origin, it manifests in the second and third decades of life as a soft-tissue mass due to muscle hypertrophy. Patients may be asymptomatic or present with a painful ankle mass. It is important to be aware of this condition when interpreting CT or MRI of the ankle, which show characteristic findings of a normal muscle in an abnormal location. (orig.) With 4 figs., 12 refs.

  12. Oedema and fatty degeneration of the soleus and gastrocnemius muscles on MR images in patients with Achilles tendon abnormalities.

    Science.gov (United States)

    Hoffmann, Adrienne; Mamisch, Nadja; Buck, Florian M; Espinosa, Norman; Pfirrmann, Christian W A; Zanetti, Marco

    2011-09-01

    The purpose of this study was to evaluate the frequency of oedema and fatty degeneration of the soleus and gastrocnemius muscles in patients with Achilles tendon abnormalities. Forty-five consecutive patients (mean 51 years; range 14-84 years) with achillodynia were examined with magnetic resonance (MR) images of the calf. The frequency of oedema and fatty degeneration in the soleus and gastrocnemius muscles was determined in patients with normal tendons, tendinopathy and in patients with a partial tear or a complete tear of the Achilles tendon. Oedema was encountered in 35% (7/20) of the patients with tendinopathy (n = 20; range 13-81 years), and in 47% (9/19) of the patients with partial tears or complete tears (n = 19; 28-78 years). Fatty degeneration was encountered in 10% (2/20) of the patients with tendinopathy, and in 32% (6/19) of the patients with tears. The prevalence of fatty degeneration was significantly more common in patients with a partial or complete tear compared with the patients with a normal Achilles tendon (p = 0.032 and p = 0.021, respectively). Oedema and fatty degeneration of the soleus and gastrocnemius muscles are common in patients with Achilles tendon abnormalities.

  13. Two weeks of metformin treatment induces AMPK-dependent enhancement of insulin-stimulated glucose uptake in mouse soleus muscle

    Science.gov (United States)

    Kristensen, Jonas Møller; Treebak, Jonas T.; Schjerling, Peter; Goodyear, Laurie

    2014-01-01

    Metformin-induced activation of the 5′-AMP-activated protein kinase (AMPK) has been associated with enhanced glucose uptake in skeletal muscle, but so far no direct causality has been examined. We hypothesized that an effect of in vivo metformin treatment on glucose uptake in mouse skeletal muscles is dependent on AMPK signaling. Oral doses of metformin or saline treatment were given to muscle-specific kinase dead (KD) AMPKα2 mice and wild-type (WT) littermates either once or chronically for 2 wk. Soleus and extensor digitorum longus muscles were used for measurements of glucose transport and Western blot analyses. Chronic treatment with metformin enhanced insulin-stimulated glucose uptake in soleus muscles of WT (∼45%, P metformin treatment. Insulin signaling at the level of Akt and TBC1D4 protein expression as well as Akt Thr308/Ser473 and TBC1D4 Thr642/Ser711 phosphorylation were not changed by metformin treatment. Also, protein expressions of Rab4, GLUT4, and hexokinase II were unaltered after treatment. The acute metformin treatment did not affect glucose uptake in muscle of either of the genotypes. In conclusion, we provide novel evidence for a role of AMPK in potentiating the effect of insulin on glucose uptake in soleus muscle in response to chronic metformin treatment. PMID:24644243

  14. O conceito de reflexão de Hegel como crítica aos conceitos de essência e de reflexão tradicionais

    Directory of Open Access Journals (Sweden)

    Christian Iber

    2017-02-01

    Full Text Available O presente artigo ilumina o específico do conceito de reflexão de Hegel em cinco momentos. Em um primeiro momento, delineia-se um esboço do conceito de reflexão na lógica da essência de Hegel. Em um segundo momento, o conceito de reflexão de Hegel é apresentado como estrutura lógica objetiva em contraste com a reflexão subjetiva da consciência e do entendimento, com a qual, ao mesmo tempo, o conceito de essência ontológica independente da reflexão é submetido a uma crítica. Do novo conceito de reflexão de Hegel resulta, em terceiro lugar, uma adaptação radical do círculo vicioso na teoria tradicional da reflexão da autoconsciência. Num quarto momento, lança-se um olhar sobre o conceito de reflexão anterior de Hegel como pensar do entendimento que separa, do qual o conceito de reflexão posterior se distingue. Por fim, apresenta-se, em quinto lugar, a lógica da reflexão de Hegel como crítica à fundação ontológica da reflexão em Schelling. O conceito de reflexão de Hegel se mostra, com isto, como crítica da metafísica ontológica tradicional e como fundação de uma metafísica da relacionalidade absoluta que supera a relatividade do pensar moderno do entendimento.

  15. Tuning of gravity-dependent and gravity-independent vertical angular VOR gain changes by frequency of adaptation.

    Science.gov (United States)

    Yakushin, Sergei B

    2012-06-01

    The gain of the vertical angular vestibulo-ocular reflex (aVOR) was adaptively increased and decreased in a side-down head orientation for 4 h in two cynomolgus monkeys. Adaptation was performed at 0.25, 1, 2, or 4 Hz. The gravity-dependent and -independent gain changes were determined over a range of head orientations from left-side-down to right-side-down at frequencies from 0.25 to 10 Hz, before and after adaptation. Gain changes vs. frequency data were fit with a Gaussian to determine the frequency at which the peak gain change occurred, as well as the tuning width. The frequency at which the peak gravity-dependent gain change occurred was approximately equal to the frequency of adaptation, and the width increased monotonically with increases in the frequency of adaptation. The gravity-independent component was tuned to the adaptive frequency of 0.25 Hz but was uniformly distributed over all frequencies when the adaptation frequency was 1-4 Hz. The amplitude of the gravity-independent gain changes was larger after the aVOR gain decrease than after the gain increase across all tested frequencies. For the aVOR gain decrease, the phase lagged about 4° for frequencies below the adaptation frequency and led for frequencies above the adaptation frequency. For gain increases, the phase relationship as a function of frequency was inverted. This study demonstrates that the previously described dependence of aVOR gain adaptation on frequency is a property of the gravity-dependent component of the aVOR only. The gravity-independent component of the aVOR had a substantial tuning curve only at an adaptation frequency of 0.25 Hz.

  16. 4-H & FFA Livestock Projects: Life Skills Gained and Knowledge Learned

    Directory of Open Access Journals (Sweden)

    Lyle N. Holmgren

    2007-06-01

    Full Text Available Junior Livestock shows are one of the most popular 4-H and FFA projects in Utah. Thousands of youth participate in these shows from every county in Utah. County extension agents and FFA advisors spend much time with livestock committees, leaders, parents, and youth engaged in livestock shows. Can public funds spent on salaries be justified for county 4-H extension agents and FFA advisors who work with junior livestock shows? To help answer this question, 413 youth involved in livestock shows in Utah were surveyed in 2001. Youth were asked to share skills learned from their livestock projects. Value statements along with specific content skills were measured in the survey. The results indicate that from their 4-H and FFA projects, youth learned to accept responsibility, follow instructions, gain self-confidence, follow instructions, “do the right thing” as well as a variety of other values and content skills.

  17. Relationship between vomiting reflex during esophagogastroduodenoscopy and dyspepsia symptoms.

    Science.gov (United States)

    Enomoto, Shotaro; Watanabe, Mika; Yoshida, Takeichi; Mukoubayashi, Chizu; Moribata, Kosaku; Muraki, Yosuke; Shingaki, Naoki; Deguchi, Hisanobu; Ueda, Kazuki; Inoue, Izumi; Maekita, Takao; Iguchi, Mikitaka; Tamai, Hideyuki; Kato, Jun; Fujishiro, Mitsuhiro; Oka, Masashi; Mohara, Osamu; Ichinose, Masao

    2012-09-01

    Although frequent vomiting reflexes during esophagogastroduodenoscopy (EGD) causes suffering in patients, very few studies have investigated the characteristics of subjects who frequently develop vomiting reflexes. This study examined the incidence of the vomiting reflex and related factors, especially upper gastrointestinal symptoms, among individuals undergoing transoral EGD. Subjects included 488 consecutive adults (mean age, 56.1 ± 8.9 years) who underwent transoral EGD for gastric cancer screening between February 2010 and March 2011. All procedures were performed by an endoscopist with 15 years of experience. Based on a questionnaire survey using the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG), symptoms (dyspepsia and acid reflux symptoms) and the number of vomiting reflexes during EGD were recorded. Of the 488 subjects, 271 (56%) developed vomiting reflexes (mean, 4.2 times). This reflex-positive group was younger (54.3 ± 9.5 years) than the reflex-negative group (58.3 ± 7.7 years, P reflex-positive group with a high FSSG dyspepsia score (2.27 ± 2.57 vs 1.23 ± 1.84; P acid reflux symptom score (1.96 ± 2.22 vs 1.34 ± 2.14; P reflex-negative group. Multivariate analysis also showed a significant correlation between these four factors and the occurrence of vomiting reflexes. Using an FSSG dyspepsia score of 1 as the cut-off offered 68% sensitivity and 57% specificity for predicting the occurrence of vomiting reflexes. Based on FSSG questionnaire responses on upper gastrointestinal symptoms, dyspepsia symptoms, in particular, are related to presence of vomiting reflexes during EGD. © 2012 The Authors. Digestive Endoscopy © 2012 Japan Gastroenterological Endoscopy Society.

  18. Lecithin Prevents Cortical Cytoskeleton Reorganization in Rat Soleus Muscle Fibers under Short-Term Gravitational Disuse

    Science.gov (United States)

    Biryukov, Nikolay S.

    2016-01-01

    The aim of this study was to prevent the cortical cytoskeleton reorganization of rat soleus muscle fibers under short-term gravitational disuse. Once a day, we injected the right soleus muscle with 0.5 ml lecithin at a concentration of 200 mg/ml and the left soleus muscle with a diluted solution in an equal volume for 3 days prior to the experiment. To simulate microgravity conditions in rats, an anti-orthostatic suspension was used according to the Ilyin-Novikov method modified by Morey-Holton et al. for 6 hours. The following groups of soleus muscle tissues were examined: «C», «C+L», «HS», and «HS+L». The transversal stiffness of rat soleus muscle fibers after 6 hours of suspension did not differ from that of the control group for the corresponding legs; there were no differences between the groups without lecithin «C» and «HS» or between the groups with lecithin «C+L» and «HS+L». However, lecithin treatment for three days resulted in an increase in cell stiffness; in the «C+L» group, cell stiffness was significantly higher by 22.7% (p lecithin treatment: the beta-actin and gamma-actin mRNA content in group «C+L» increased by 200% compared with that of group «C», and beta-tubulin increased by 100% (as well as the mRNA content of tubulin-binding proteins Ckap5, Tcp1, Cct5 and Cct7). In addition, desmin mRNA content remained unchanged in all of the experimental groups. As a result of the lecithin injections, there was a redistribution of the mRNA content of genes encoding actin monomer- and filament-binding proteins in the direction of increasing actin polymerization and filament stability; the mRNA content of Arpc3 and Lcp1 increased by 3- and 5-fold, respectively, but the levels of Tmod1 and Svil decreased by 2- and 5-fold, respectively. However, gravitational disuse did not result in changes in the mRNA content of Arpc3, Tmod1, Svil or Lcp1. Anti-orthostatic suspension for 6 hours resulted in a decrease in the mRNA content of alpha

  19. Accumulation of silver from drinking water into cerebellum and musculus soleus in mice

    International Nuclear Information System (INIS)

    Pelkonen, Kai H.O.; Heinonen-Tanski, Helvi; Haenninen, Osmo O.P.

    2003-01-01

    In spite of the general toxicity, ecotoxicity and sparsely known metabolism of silver, WHO allows silver ions (Ag) up to 0.1 mg/l in drinking water disinfection. In order to determine the accumulation and distribution of silver in a mammalian body, mice were given for 1 and 2 weeks drinking water containing a 3-fold lower concentration, namely 0.03 mg/l silver ions as silver nitrate labelled with 110m Ag. The silver concentrations in different tissues were analysed by gamma radioactivity. The saturation of tissues with silver seems to occur quickly, as there were no statistical differences between silver contents of mice tissues in spite of the study design that mice were administered silver for 1 or 2 weeks. The highest concentrations were found in musculus soleus (m. soleus), cerebellum, spleen, duodenum, and myocardial muscle in the rank order. Concentrations of silver in musculus gastrocnemius (m. gastrocnemius) were found to correlate negatively with cerebrum and positively with blood and kidneys. The accumulation of silver into organs and tissues important in motor functions may be of relevance especially in emergency and catastrophe situations in which accurate motor functions may be critical. A re-evaluation of the present recommendations on the use of silver salts for disinfection of drinking water might be necessary

  20. Adding Stiffness to the Foot Modulates Soleus Force-Velocity Behaviour during Human Walking

    Science.gov (United States)

    Takahashi, Kota Z.; Gross, Michael T.; van Werkhoven, Herman; Piazza, Stephen J.; Sawicki, Gregory S.

    2016-07-01

    Previous studies of human locomotion indicate that foot and ankle structures can interact in complex ways. The structure of the foot defines the input and output lever arms that influences the force-generating capacity of the ankle plantar flexors during push-off. At the same time, deformation of the foot may dissipate some of the mechanical energy generated by the plantar flexors during push-off. We investigated this foot-ankle interplay during walking by adding stiffness to the foot through shoes and insoles, and characterized the resulting changes in in vivo soleus muscle-tendon mechanics using ultrasonography. Added stiffness decreased energy dissipation at the foot (p < 0.001) and increased the gear ratio (i.e., ratio of ground reaction force and plantar flexor muscle lever arms) (p < 0.001). Added foot stiffness also altered soleus muscle behaviour, leading to greater peak force (p < 0.001) and reduced fascicle shortening speed (p < 0.001). Despite this shift in force-velocity behaviour, the whole-body metabolic cost during walking increased with added foot stiffness (p < 0.001). This increased metabolic cost is likely due to the added force demand on the plantar flexors, as walking on a more rigid foot/shoe surface compromises the plantar flexors’ mechanical advantage.

  1. Differential expression of FGF receptors and of myogenic regulatory factors in primary cultures of satellite cells originating from fast (EDL) and slow (Soleus) twitch rat muscles.

    Science.gov (United States)

    Martelly, I; Soulet, L; Bonnavaud, S; Cebrian, J; Gautron, J; Barritault, D

    2000-11-01

    In the rat, the fast and slow twitch muscles respectively Extensor digitorum longus (EDL) and Soleus present differential characteristics during regeneration. This suggests that their satellite cells responsible for muscle growth and repair represent distinct cellular populations. We have previously shown that satellite cells dissociated from Soleus and grown in vitro proliferate more readily than those isolated from EDL muscle. Fibroblast growth factors (FGFs) are known as regulators of myoblast proliferation and several studies have revealed a relationship between the response of myoblasts to FGF and the expression of myogenic regulatory factors (MRF) of the MyoD family by myoblasts. Therefore, we presently examined the possibility that the satellite cells isolated from EDL and Soleus muscles differ in the expression of FGF receptors (FGF-R) and of MRF expression. FGF-R1 and -R4 were strongly expressed in proliferating cultures whereas FGF-R2 and R3 were not detected in these cultures. In differentiating cultures, only -R1 was present in EDL satellite cells while FGF-R4 was also still expressed in Soleus cells. Interestingly, the unconventional receptor for FGF called cystein rich FGF receptor (CFR), of yet unknown function, was mainly detected in EDL satellite cell cultures. Soleus and EDL satellite cell cultures also differed in the expression MRFs. These results are consistent with the notion that satellite cells from fast and slow twitch muscles belong to different types of myogenic cells and suggest that satellite cells might play distinct roles in the formation and diversification of fast and slow fibres.

  2. A near catastrophe from trigeminocardiac reflex

    Directory of Open Access Journals (Sweden)

    Parmod K Bithal

    2017-01-01

    Full Text Available Trigeminocardiac reflex is a brainstem reflex that results from stimulation of any branch of the trigeminal nerve along its course. It produces a constellation of signs and symptoms decrease in blood pressure (BP and heart rate, dysrhythmias, apnoea and increased gastric motility. We present a case of 80-year-old female patient who developed alarming hypotension and bradycardia during craniotomy for meningioma excision resulting from this reflex. In the face of refractory hypotension despite administering ephedrine and phenylephrine, we had to resort to adrenaline to restore her normal BP.

  3. Modulation of the cough reflex by GABAA receptors in the caudal ventral respiratory group of the rabbit

    Directory of Open Access Journals (Sweden)

    Elenia eCinelli

    2012-10-01

    Full Text Available We have previously shown that the caudal ventral respiratory group (cVRG is a possible site of action of some antitussive drugs and plays a crucial role in determining both the expiratory and inspiratory components of the cough motor pattern. In addition, it has been reported that medullary expiratory neurons of the cVRG are subject to potent GABAergic gain modulation. This study was devoted to investigate the role of cVRG GABAA receptors in the control of baseline respiratory activity and cough responses to mechanical and chemical (citric acid stimulation of the tracheobronchial tree. To this purpose, bilateral microinjections (30-50 nl of bicuculline or muscimol were performed into the cVRG of pentobarbital sodium-anesthetized, spontaneously breathing rabbits. Bicuculline (1 mM increased peak abdominal activity and respiratory frequency due to decreases in TE. Cough responses were potentiated mainly owing to increases in the cough number. The recovery was observed within ~ 2 h. On the contrary, muscimol (0.3 mM abolished abdominal activity and decreased respiratory frequency due to increases in TE. In addition, cough responses were progressively reduced and completely suppressed within ~ 20 min. Partial recovery of cough responses was achieved after ~ 3 h or within ~ 5 min following bicuculline microinjections at the same locations. The sneeze reflex induced by mechanical stimulation of the nasal mucosa persisted following bicuculline and muscimol microinjections. However, the number and intensity of expiratory thrusts were enhanced by bicuculline and suppressed by muscimol. The results provide evidence that a potent GABAA-mediated inhibitory modulation is exerted at the level of the cVRG not only on respiratory activity, but also on cough and sneeze reflex responses.

  4. Pain sensation and nociceptive reflex excitability in surgical patients and human volunteers

    DEFF Research Database (Denmark)

    Dahl, J B; Erichsen, C J; Fuglsang-Frederiksen, A

    1992-01-01

    Pain threshold, nociceptive flexion reflex (NFR) threshold and responses to suprathreshold stimulation were investigated in 15 female patients (mean age 32 yr (range 22-48 yr)) before and 68 (range 48-96) h after gynaecological laparotomy. Control measurements were performed in 17 healthy human v...

  5. Vestibulo-Ocular Reflex Abnormalities in Posterior Semicircular Canal Benign Paroxysmal Positional Vertigo: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Tayyebe Fallahnezhad

    2017-09-01

    Full Text Available Introduction: Benign paroxysmal positional vertigo (BPPV, involving the semicircular canals, is one of the most common diseases of the inner ear. The video head impulse test (vHIT is a new test that examines the function of the canals. This study aimed to investigate the vestibulo-ocular reflex (VOR gain, gain asymmetry and saccades after stimulating all six canals in patients definitively diagnosed with posterior semicircular canal BPPV (PSC-BPPV.   Materials and Methods: Twenty-nine unilateral PSC-BPPV patients with normal oculographic and caloric results were enrolled in this study. vHIT was performed on six canals, and VOR gain, gain asymmetry and saccades were measured.   Results: Sixteen (55.17% patients had abnormal posterior canal VOR gains in the ipsilesional ear. VOR gains in both horizontal canals were within normal limits. Superior canal VOR gains were mostly lower than normal and were not correlated to PSC abnormalities (P>0.05. No corrective saccades could be observed.   Conclusion: VOR gain in the direction of the posterior semicircular canal may be reduced in PSC-BPPV patients. Evaluation of PSC-VOR parameters could be beneficial, although superior canal measurements should be interpreted with caution.

  6. Musculus soleus of rats at physical activity and L-carnitine and creatine phosphate effect

    Directory of Open Access Journals (Sweden)

    Irina A. Khutorskaya

    2017-09-01

    Full Text Available Introduction: The study of the effect of metabolic drugs on the histochemical characteristics of soleus muscle is relevant for solving the problem of providing the training process in Russia with non-doping drugs for safe correction of the consequences of intense physical activity in athletes. Materials and Methods: Dynamic physical activity in rats (n = 24 was simulated by swimming “to the limit” with weighting of 10 % of body weight (20 days, 1 time per day. The experimental animals were divided into four groups (6 animals each: № 1 – control, № 2 – swimming + isotonic NaCl solution, № 3 and № 4 – swimming + L-carnitine or creatine phosphate 100.0 mg/kg daily intraperitoneally. The object of the study was musculus soleus. Differentiation of muscle fibers was carried out by the intensity of histochemical activity of succinate dehydrogenase (SDG and alkaline stable adenosine triphosphate (ATP of myosin. The percentage of muscle fibers was evaluated and their diameter was defined by the direct morphometry. The obtained data were treated statistically by Student’s T-test. Results: Swimming of the animals “to the limit” do not affect the ratio of fibers with different phenotypes in the soleus muscle. This indicator is genetically determined and was not modified by L-carnitine and creatine phosphate. Dynamic physical activity promotes the development of hypertrophy of muscle fibers of various types. The investigated medicaments of the metabolic type either do not influence on the formation of exerciseinduced hypertrophy (predominantly creatine phosphate or reduce the intensity of the hypertrophic process (predominantly L-carnitine under dynamic physical activity. Discussion and Conclusions: The obtained data indicate L-carnitine and creatine phosphate do not have an anabolic effect. Taking into account the relevant data on ability of L-carnitine and creatine phosphate to effectively correct a negative effects of intensive

  7. Attentional modulation of reflex cough.

    Science.gov (United States)

    Janssens, Thomas; Silva, Mitchell; Davenport, Paul W; Van Diest, Ilse; Dupont, Lieven J; Van den Bergh, Omer

    2014-07-01

    Reflex cough is a defensive response generated in the brainstem in response to chemical and mechanical stimulation of the airways. However, converging evidence shows that reflex cough is also influenced by central neural control processes. In this study, we investigate whether reflex cough can be modulated by attentional focus on either external stimuli or internal cough-related stimuli. Healthy volunteers (N = 24; seven men; age range, 18-25 years) completed four blocks of citric acid-induced cough challenges while, simultaneously, auditory stimuli were presented. Within each block, four concentrations were administered (30, 100, 300 and 1,000 mM, randomized). During two subsequent blocks, participants focused their attention externally (counting tones). During the other two blocks, participants focused their attention internally (counting coughs). The order of attentional focus was counterbalanced across participants. Ratings of the urge to cough were collected after each challenge. Cough frequency was determined by audio recording. Cough frequency was higher when participants focused their attention internally vs externally (P Reflex cough can be modulated by attentional focus. Internally focused attention may be a mechanism involved in excessive (idiopathic) cough, while an external focus may be introduced as part of treatments targeting excessive cough.

  8. Why New Spinal Cord Plasticity Does Not Disrupt Old Motor Behaviors.

    Science.gov (United States)

    Chen, Yi; Chen, Lu; Wang, Yu; Chen, Xiang Yang; Wolpaw, Jonathan R

    2017-08-23

    When new motor learning changes the spinal cord, old behaviors are not impaired; their key features are preserved by additional compensatory plasticity. To explore the mechanisms responsible for this compensatory plasticity, we transected the spinal dorsal ascending tract before or after female rats acquired a new behavior-operantly conditioned increase or decrease in the right soleus H-reflex-and examined an old behavior-locomotion. Neither spinal dorsal ascending tract transection nor H-reflex conditioning alone impaired locomotion. Nevertheless, when spinal dorsal ascending tract transection and H-reflex conditioning were combined, the rats developed a limp and a tilted posture that correlated in direction and magnitude with the H-reflex change. When the right H-reflex was increased by conditioning, the right step lasted longer than the left and the right hip was higher than the left; when the right H-reflex was decreased by conditioning, the opposite occurred. These results indicate that ascending sensory input guides the compensatory plasticity that normally prevents the plasticity underlying H-reflex change from impairing locomotion. They support the concept of the state of the spinal cord as a negotiated equilibrium that reflects the concurrent influences of all the behaviors in an individual's repertoire; and they support the new therapeutic strategies this concept introduces. SIGNIFICANCE STATEMENT The spinal cord provides a reliable final common pathway for motor behaviors throughout life. Until recently, its reliability was explained by the assumption that it is hardwired; but it is now clear that the spinal cord changes continually as new behaviors are acquired. Nevertheless, old behaviors are preserved. This study shows that their preservation depends on sensory feedback from the spinal cord to the brain: if feedback is removed, the acquisition of a new behavior may disrupt an old behavior. In sum, when a new behavior changes the spinal cord, sensory

  9. Effect of plaster cast immobilization on the turnover rates of soluble proteins and lactate dehydrogenase isoenzymes of rabbit M. soleus

    Energy Technology Data Exchange (ETDEWEB)

    Edes, I.; Dosa, E.; Sohar, I.; Guba, F. (Orvostudomanyi Egyetem, Szeged (Hungary). Biokemiai Tanszek)

    1982-01-01

    In atrophized muscle the decreases of the activity of LDH isoenzymes can be explained partly by a 15 per cent decrease of the enzyme synthesis and partly by a 25 per cent increase in catabolism. The quantities of the soluble proteins and LDH were measured after intravenously administered /sup 3/H-leucin incorporation, from the musculus soleus. LDH was isolated by means of affinity chromatography. Radioactivity was determined in a Packard Tri-Carb scintillation counter. The synthesis rate of soluble proteins barely changed during immobilization. In the atrophized muscle the decrease of the amount of soluble proteins could be almost exclusively interpreted in terms of a 25 per cent enchancement of degradative process. The accelerated catabolism is most probably due to the proteolytic enzymes activated by immobilization.

  10. Short-term adaptations in spinal cord circuits evoked by repetitive transcranial magnetic stimulation: possible underlying mechanisms

    DEFF Research Database (Denmark)

    Perez, Monica A.; Lungholt, Bjarke K.S.; Nielsen, Jens Bo

    2005-01-01

    Repetitive transcranial magnetic stimulation (rTMS) has been shown to induce adaptations in cortical neuronal circuitries. In the present study we investigated whether rTMS, through its effect on corticospinal pathways, also produces adaptations at the spinal level, and what the neuronal mechanisms...... that the depression of the H-reflex by rTMS can be explained, at least partly, by an increased presynaptic inhibition of soleus Ia afferents. In contrast, rTMS had no effect on disynaptic reciprocal Ia inhibition from ankle dorsiflexors to plantarflexors. We conclude that a train of rTMS may modulate transmission...

  11. Wh-filler-gap dependency formation guides reflexive antecedent search

    Directory of Open Access Journals (Sweden)

    Michael eFrazier

    2015-10-01

    Full Text Available Prior studies on online sentence processing have shown that the parser can resolve non-local dependencies rapidly and accurately. This study investigates the interaction between the processing of two such non-local dependencies: wh-filler-gap dependencies (WhFGD and reflexive-antecedent dependencies. We show that reflexive-antecedent dependency resolution is sensitive to the presence of a WhFGD, and argue that the filler-gap dependency established by WhFGD resolution is selected online as the antecedent of a reflexive dependency. We investigate the processing of constructions like (1, where two NPs might be possible antecedents for the reflexive, namely which cowgirl and Mary. Even though Mary is linearly closer to the reflexive, the only grammatically licit antecedent for the reflexive is the more distant wh-NP, which cowgirl. 1. Which cowgirl did Mary expect to have injured herself due to negligence?Four eye-tracking text-reading experiments were conducted on examples like (1, differing in whether the embedded clause was non-finite (1 and 3 or finite (2 and 4, and in whether the tail of the wh-dependency intervened between the reflexive and its closest overt antecedent (1 and 2 or the wh-dependency was associated with a position earlier in the sentence (3 and 4.The results of Experiments 1 and 2 indicate the parser accesses the result of WhFGD formation during reflexive antecedent search. The resolution of a wh-dependency alters the representation that reflexive antecedent search operates over, allowing the grammatical but linearly distant antecedent to be accessed rapidly. In the absence of a long-distance WhFGD (Exp. 3 and 4, wh-NPs were not found to impact reading times of the reflexive, indicating that the parser's ability to select distant wh-NPs as reflexive antecedents crucially involves syntactic structure.

  12. Reflexivity and social justice

    DEFF Research Database (Denmark)

    Maksimovic, Tijana; Jakobsen, Helle Nordentoft

    2017-01-01

    Career practitioners’ reflexive understanding of their professional role as change agents in career guidance and counselling practices has a major impact on how social justice can be achieved. This entitles an awareness of the way in which guidance and counselling practices are embedded in the co......Career practitioners’ reflexive understanding of their professional role as change agents in career guidance and counselling practices has a major impact on how social justice can be achieved. This entitles an awareness of the way in which guidance and counselling practices are embedded...

  13. Lecithin Prevents Cortical Cytoskeleton Reorganization in Rat Soleus Muscle Fibers under Short-Term Gravitational Disuse.

    Directory of Open Access Journals (Sweden)

    Irina V Ogneva

    Full Text Available The aim of this study was to prevent the cortical cytoskeleton reorganization of rat soleus muscle fibers under short-term gravitational disuse. Once a day, we injected the right soleus muscle with 0.5 ml lecithin at a concentration of 200 mg/ml and the left soleus muscle with a diluted solution in an equal volume for 3 days prior to the experiment. To simulate microgravity conditions in rats, an anti-orthostatic suspension was used according to the Ilyin-Novikov method modified by Morey-Holton et al. for 6 hours. The following groups of soleus muscle tissues were examined: "C", "C+L", "HS", and "HS+L". The transversal stiffness of rat soleus muscle fibers after 6 hours of suspension did not differ from that of the control group for the corresponding legs; there were no differences between the groups without lecithin «C» and «HS» or between the groups with lecithin "C+L" and "HS+L". However, lecithin treatment for three days resulted in an increase in cell stiffness; in the "C+L" group, cell stiffness was significantly higher by 22.7% (p < 0.05 compared with that of group "C". The mRNA content of genes encoding beta- and gamma-actin and beta-tubulin did not significantly differ before and after suspension in the corresponding groups. However, there was a significant increase in the mRNA content of these genes after lecithin treatment: the beta-actin and gamma-actin mRNA content in group "C+L" increased by 200% compared with that of group "C", and beta-tubulin increased by 100% (as well as the mRNA content of tubulin-binding proteins Ckap5, Tcp1, Cct5 and Cct7. In addition, desmin mRNA content remained unchanged in all of the experimental groups. As a result of the lecithin injections, there was a redistribution of the mRNA content of genes encoding actin monomer- and filament-binding proteins in the direction of increasing actin polymerization and filament stability; the mRNA content of Arpc3 and Lcp1 increased by 3- and 5-fold, respectively

  14. Consumers' purchase of organic food products. A matter of convenience and reflexive practices.

    Science.gov (United States)

    Hjelmar, Ulf

    2011-04-01

    The aim of this study was to gain insight into the purchase of organic food products by consumers and to explore the main factors driving this process. This paper uses evidence from 16 in-depth interviews with consumers in Denmark carried out in 2008-2009. On the basis of the analysis two broad concepts are suggested: convenience behaviours and reflexive practices. Convenience behaviours are characteristic of pragmatic organic consumers. This type of shopping behaviour requires organic foods to be available in the local supermarket, they have to be clearly visible (preferably with an eco-label), and the price differential vis-à-vis conventional products have to be minimal. The analysis also showed that politically/ethically minded consumers have reflexive practices when purchasing organic food products: health considerations, ethical considerations (animal welfare), political considerations (environmentalism) and quality considerations (taste) play an important part for these consumers. Reflexive shopping practices can be sparked by life events (e.g. having children), "shocking" news about conventional food products and similar events, and news capable of creating a "cognitive dissonance" among consumers. The Danish case illustrates that the government needs to actively implement reforms and promote activities which make organic products a convenient choice for the pragmatic oriented consumer if their market share is to increase substantially. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Physical training prevents body weight gain but does not modify adipose tissue gene expression

    Science.gov (United States)

    Higa, T.S.; Bergamo, F.C.; Mazzucatto, F.; Fonseca-Alaniz, M.H.; Evangelista, F.S.

    2012-01-01

    The relationship of body weight (BW) with white adipose tissue (WAT) mass and WAT gene expression pattern was investigated in mice submitted to physical training (PT). Adult male C57BL/6 mice were submitted to two 1.5-h daily swimming sessions (T, N = 18), 5 days/week for 4 weeks or maintained sedentary (S, N = 15). Citrate synthase activity increased significantly in the T group (P weight gain compared to T mice (4.06 ± 0.43 vs 0.38 ± 0.28 g, P weights of gastrocnemius and soleus muscles, lung, kidney, and adrenal gland were not different. Liver and heart were larger and the spleen was smaller in T compared to S mice (P < 0.05). Food intake was higher in T than S mice (4.7 ± 0.2 vs 4.0 ± 0.3 g/animal, P < 0.05) but oxygen consumption at rest did not differ between groups. T animals showed higher serum leptin concentration compared to S animals (6.37 ± 0.5 vs 3.11 ± 0.12 ng/mL). WAT gene expression pattern obtained by transcription factor adipocyte determination and differentiation-dependent factor 1, fatty acid synthase, malic enzyme, hormone-sensitive lipase, adipocyte lipid binding protein, leptin, and adiponectin did not differ significantly between groups. Collectively, our results showed that PT prevents BW gain and maintains WAT mass due to an increase in food intake and unchanged resting metabolic rate. These responses are closely related to unchanged WAT gene expression patterns. PMID:22666778

  16. Oral sapropterin augments reflex vasoconstriction in aged human skin through noradrenergic mechanisms.

    Science.gov (United States)

    Stanhewicz, Anna E; Alexander, Lacy M; Kenney, W Larry

    2013-10-01

    Reflex vasoconstriction is attenuated in aged skin due to a functional loss of adrenergic vasoconstriction. Bioavailability of tetrahydrobiopterin (BH4), an essential cofactor for catecholamine synthesis, is reduced with aging. Locally administered BH4 increases vasoconstriction through adrenergic mechanisms in aged human skin. We hypothesized that oral sapropterin (Kuvan, a pharmaceutical BH4) would augment vasoconstriction elicited by whole-body cooling and tyramine perfusion in aged skin. Ten healthy subjects (age 75 ± 2 yr) ingested sapropterin (10 mg/kg) or placebo in a randomized, double-blind crossover design. Venous blood samples were collected prior to, and 3 h following ingestion. Three intradermal microdialysis fibers were placed in the forearm skin for local delivery of 1) lactated Ringer, 2) 5 mM BH4, and 3) 5 mM yohimbine + 1 mM propranolol (Y+P; to inhibit adrenergic vasoconstriction). Red cell flux was measured at each site by laser-Doppler flowmetry (LDF) as reflex vasoconstriction was induced by lowering and then clamping whole-body skin temperature (Tsk) using a water-perfused suit. Following whole-body cooling, subjects were rewarmed and 1 mM tyramine was perfused at each site to elicit endogenous norepinephrine release from the perivascular nerve terminal. Cutaneous vascular conductance was calculated as CVC = LDF/mean arterial pressure and expressed as change from baseline (ΔCVC). Plasma BH4 was elevated 3 h after ingestion of sapropterin (43.8 ± 3 vs. 19.1 ± 2 pmol/ml; P effect on reflex vasoconstriction at the BH4-perfused or Y+P-perfused sites. Sapropterin increased pharmacologically induced vasoconstriction at the Ringer site (-0.19 ± 0.03 vs. -0.08 ± 0.02 ΔCVC; P = 0.01). There was no difference in pharmacologically induced vasoconstriction between treatments at the BH4-perfused site (-0.16 ± 0.04 vs. -0.14 ± 0.03 ΔCVC; P = 0.60) or the Y+P-perfused site (-0.05 ± 0.02 vs.-0.06 ± 0.02 ΔCVC; P = 0.79). Sapropterin increases

  17. Inhibition of micturition reflex by activation of somatic afferents in posterior femoral cutaneous nerve.

    Science.gov (United States)

    Tai, Changfeng; Shen, Bing; Mally, Abhijith D; Zhang, Fan; Zhao, Shouguo; Wang, Jicheng; Roppolo, James R; de Groat, William C

    2012-10-01

    This study determined if activation of somatic afferents in posterior femoral cutaneous nerve (PFCN) could modulate the micturition reflex recorded under isovolumetric conditions in α-chloralose anaesthetized cats. PFCN stimulation inhibited reflex bladder activity and significantly (P acid (AA). The optimal frequency for PFCN stimulation-induced bladder inhibition was between 3 and 10 Hz, and a minimal stimulation intensity of half of the threshold for inducing anal twitching was required. Bilateral pudendal nerve transection eliminated PFCN stimulation-induced anal twitching but did not change the stimulation-induced bladder inhibition, excluding the involvement of pudendal afferent or efferent axons in PFCN afferent inhibition.Mechanical or electrical stimulation on the skin surface in the PFCN dermatome also inhibited bladder activity. Prolonged (2 × 30 min) PFCN stimulation induced a post-stimulation inhibition that persists for at least 2 h. This study revealed a new cutaneous-bladder reflex activated by PFCN afferents. Although the mechanisms and physiological functions of this cutaneous-bladder reflex need to be further studied, our data raise the possibility that stimulation of PFCN afferents might be useful clinically for the treatment of overactive bladder symptoms.

  18. O conceito de reflexão de Hegel como crítica aos conceitos de essência e de reflexão tradicionais

    OpenAIRE

    Christian Iber

    2017-01-01

    O presente artigo ilumina o específico do conceito de reflexão de Hegel em cinco momentos. Em um primeiro momento, delineia-se um esboço do conceito de reflexão na lógica da essência de Hegel. Em um segundo momento, o conceito de reflexão de Hegel é apresentado como estrutura lógica objetiva em contraste com a reflexão subjetiva da consciência e do entendimento, com a qual, ao mesmo tempo, o conceito de essência ontológica independente da reflexão é submetido a uma crítica. Do novo conceito d...

  19. IGF-II is up-regulated and myofibres are hypertrophied in regenerating soleus of mice lacking FGF6

    International Nuclear Information System (INIS)

    Armand, Anne-Sophie; Lecolle, Sylvie; Launay, Thierry; Pariset, Claude; Fiore, Frederic; Della Gaspera, Bruno; Birnbaum, Daniel; Chanoine, Christophe; Charbonnier, Frederic

    2004-01-01

    Important functions in myogenesis have been proposed for FGF6, a member of the fibroblast growth factor family accumulating almost exclusively in the myogenic lineage. However, the use of FGF6(-/-) mutant mice gave contradictory results and the role of FGF6 during myogenesis remains largely unclear. Using FGF6(-/-) mice, we first analysed the morphology of the regenerated soleus following cardiotoxin injection and showed hypertrophied myofibres in soleus of the mutant mice as compared to wild-type mice. Secondly, to examine the function of the IGF family in the hypertrophy process, we used semiquantitative and real-time RT-PCR assays and Western blots to monitor the expression of the insulin-like growth factors (IGF-I and IGF-II), their receptors [type I IGF receptor (IGF1R) and IGF-II receptor (IGF2R)], and of a binding protein IGFBP-5 in regenerating soleus muscles of FGF6(-/-) knockout mice vs. wild-type mice. In the mutant, both IGF-II and IGF2R, but not IGF-I and IGF1R, were strongly up-regulated, whereas IGFBP5 was down-regulated, strongly suggesting that, in the absence of FGF6, the mechanisms leading to myofibre hypertrophy were mediated specifically by an IGF-II/IGF2R signalling pathway distinct from the classic mechanism involving IGF-I and IGF1R previously described for skeletal muscle hypertrophy. The potential regulating role of IGFBP5 on IGF-II expression is also discussed. This report shows for the first time a specific role for FGF6 in the regulation of myofibre size during a process of in vivo myogenesis

  20. [Effects of morphine on pupillary light reflex in monkeys].

    Science.gov (United States)

    Meng, Zhi-Qiang; Zhang, Yu-Hua; Chen, Nan-Hui; Miao, Ying-Da; Hu, Xin-Tian; Ma, Yuan-Ye

    2010-06-01

    The pupil size of both human and other animals can be affected by light. Many kinds of psychiatrical and psychological disorders, such as drug abuse, associate with abnormal properties of pupillary light reflex. Thus, the properties of pupillary light reflex could serve as an indicator for drug abuse detection. However, the effect of drug abuse on pupillary light reflex is till unclear. To assess the effects of addictive drugs on pupillary light reflex quantificationally, in the present study, we examined the effects of morphine on pupil diameter and pupillary light reflex in rhesus monkeys. By measuring the pupil diameter at different timing points before and after the administration of morphine, we found that morphine administration reduced the diameter of pupil and decreased the constriction rate. Our present results provide an experimental support for applying the properties of pupillary light reflex as a reference in addicts' detection.

  1. Effect of triiodothyronine (T3) excess on fatty acid metabolism in the soleus muscle from endurance-trained rats.

    Science.gov (United States)

    Górecka, M; Synak, M; Brzezińska, Z; Dąbrowski, J; Żernicka, E

    2016-04-01

    We studied whether short-term administration of triiodothyronine (T3) for the last 3 days of endurance training would influence the rate of uptake of palmitic acid (PA) as well as metabolism in rat soleus muscle, in vitro. Training per se did not affect the rate of PA uptake by the soleus; however, an excess of T3 increased the rate of this process at 1.5 mmol/L PA, as well as the rate that at which PA was incorporated into intramuscular triacylglycerols (TG). The rate of TG synthesis in trained euthyroid rats was reduced after exercise (1.5 mmol/L PA). The rate of PA oxidation in all of the trained rats immediately after exercise was enhanced by comparison with the sedentary values. Hyperthyroidism additionally increased the rate of this process at 1.5 mmol/L PA. After a recovery period, the rate of PA oxidation returned to the control values in both the euthyroid and the hyperthyroid groups. Examination of the high-energy phosphate levels indicated that elevated PA oxidation after exercise-training in euthyroid rats was associated with stable ATP levels and increased ADP and AMP levels, thus reducing energy cellular potential (ECP). In the hyperthyroid rats, levels of ADP and AMP were increased in the sedentary as well as the exercise-trained rats. ECP levels were high as a result of high levels of ATP and decreased levels of ADP and AMP in hyperthyroid rats after the recovery period. In conclusion, short-term hyperthyroidism accelerates PA utilization in well-trained soleus muscle.

  2. The comparison of application of two different frequencies of TENS on excitability of Hoffmann reflex

    Directory of Open Access Journals (Sweden)

    Akbari M

    2001-08-01

    Full Text Available The aim of this investigation is to compare the effect of applying two transcutaneous electrical nerve stimulation (TENS current with different frequencies (2 Hz & 100 Hz on Hoffmann reflex recorded from gastrosoleus muscle of healthy people. Forty female subjects between 20 to 30 years of age were participated in this quasi-experimental design. Twenty of them were exposed to the 100 Hz current and the remaining 20 to 2 Hz current on dermatome S1 root. The excitability of the alpha motoneurone was measured by H-reflex amplitude (peak to peak max/2 before and after the application of the TENS current for 30 minutes. The reflex was recorded and at measured before (TO and after the application of TENS at different times (T1, T% and T10 up to 10 minutes. The mean values were compared by multiple paired T test (alpha=0.00825. The results indicate a considerable decrement in Hoffmann reflex amplitude after application of 100 Hz current in comarison with that of before the application. The effect last for 10 minutes after the TENS application, whereas the application of 2 Hz current results in increment of the Hoffmann reflex amplitude. The 5 and 10 minutes interval test dose not show any significance and the results were attenuated befor 5 minutes. As a conclusion high frequency of TENS (100 Hz has an inhibitory effect on excitability of alpha motor neurone reflex lasting for 10 minutes, while low frequency of TENS (2 Hz has an facilatory effect on the same motoneurone with short lasting effect.

  3. Using ESO Reflex with Web Services

    Science.gov (United States)

    Järveläinen, P.; Savolainen, V.; Oittinen, T.; Maisala, S.; Ullgrén, M. Hook, R.

    2008-08-01

    ESO Reflex is a prototype graphical workflow system, based on Taverna, and primarily intended to be a flexible way of running ESO data reduction recipes along with other legacy applications and user-written tools. ESO Reflex can also readily use the Taverna Web Services features that are based on the Apache Axis SOAP implementation. Taverna is a general purpose Web Service client, and requires no programming to use such services. However, Taverna also has some restrictions: for example, no numerical types such integers. In addition the preferred binding style is document/literal wrapped, but most astronomical services publish the Axis default WSDL using RPC/encoded style. Despite these minor limitations we have created simple but very promising test VO workflow using the Sesame name resolver service at CDS Strasbourg, the Hubble SIAP server at the Multi-Mission Archive at Space Telescope (MAST) and the WESIX image cataloging and catalogue cross-referencing service at the University of Pittsburgh. ESO Reflex can also pass files and URIs via the PLASTIC protocol to visualisation tools and has its own viewer for VOTables. We picked these three Web Services to try to set up a realistic and useful ESO Reflex workflow. They also demonstrate ESO Reflex abilities to use many kind of Web Services because each of them requires a different interface. We describe each of these services in turn and comment on how it was used

  4. Prevalence of family history in patients with reflex syncope

    DEFF Research Database (Denmark)

    Holmegard, Haya N; Benn, Marianne; Kaijer, Michelle Nymann

    2013-01-01

    Reflex syncope is defined by a rapid transient loss of consciousness caused by global cerebral hypoperfusion resulting from vasodilatation and/or bradycardia attributable to inappropriate cardiovascular reflexes. A hereditary component has been suggested, but prevalence of family history may differ...... among subtypes of reflex syncope, as these have different autonomic responses and pathogeneses may be diverse. The present study aimed to assess the prevalence of a positive family history of syncope and cardiovascular characteristics in patients with cardioinhibitory and vasodepressor reflex syncope....... Patients (n=74) were classified into subtypes of reflex syncope - cardioinhibition/asystole (Vasovagal Syncope International Study subtypes II-B [VASIS II-B], n=38) or vasodepressor (VASIS III, n=36) - using the head-up tilt test. Family history was obtained by questionnaires supplemented by interview...

  5. Cortical involvement in anticipatory postural reactions in man

    DEFF Research Database (Denmark)

    Petersen, Tue Hvass; Rosenberg, Kasper; Petersen, Nicolas Caesar

    2009-01-01

    All movements are accompanied by postural reactions which ensure that the balance of the body is maintained. It has not been resolved that to what extent the primary motor cortex and corticospinal tract are involved in the control of these reactions. Here, we investigated the contribution...... of the corticospinal tract to the activation of the soleus (SOL) muscle in standing human subjects (n = 10) in relation to voluntary heel raise, anticipatory postural activation of the soleus muscle when the subject pulled a handle and to reflex activation of the soleus muscle when the subject was suddenly pulled...... was observed prior to EMG onset for the external perturbation. These data suggest that the primary motor cortex is involved in activating the SOL muscle as part of an anticipatory postural reaction....

  6. (Re)constructing Reflexivity: A Relational Constructionist Approach

    NARCIS (Netherlands)

    Hosking, D.M.; Pluut, B.

    2010-01-01

    This article distinguishes three discourses of reflexivity in relation to human inquiry. One of these arises from a post-modern, relational constructionist perspective which radically re-conceptualizes reflexivity: (a) as a local and co-constructed process oriented towards the question (b) how are

  7. Ultimate concerns in late modernity: Archer, Bourdieu and reflexivity.

    Science.gov (United States)

    Farrugia, David; Woodman, Dan

    2015-12-01

    Through a critique of Margaret Archer's theory of reflexivity, this paper explores the theoretical contribution of a Bourdieusian sociology of the subject for understanding social change. Archer's theory of reflexivity holds that conscious 'internal conversations' are the motor of society, central both to human subjectivity and to the 'reflexive imperative' of late modernity. This is established through critiques of Bourdieu, who is held to erase creativity and meaningful personal investments from subjectivity, and late modernity is depicted as a time when a 'situational logic of opportunity' renders embodied dispositions and the reproduction of symbolic advantages obsolete. Maintaining Archer's focus on 'ultimate concerns' in a context of social change, this paper argues that her theory of reflexivity is established through a narrow misreading and rejection of Bourdieu's work, which ultimately creates problems for her own approach. Archer's rejection of any pre-reflexive dimensions to subjectivity and social action leaves her unable to sociologically explain the genesis of 'ultimate concerns', and creates an empirically dubious narrative of the consequences of social change. Through a focus on Archer's concept of 'fractured reflexivity', the paper explores the theoretical necessity of habitus and illusio for understanding the social changes that Archer is grappling with. In late modernity, reflexivity is valorized just as the conditions for its successful operation are increasingly foreclosed, creating 'fractured reflexivity' emblematic of the complex contemporary interaction between habitus, illusio, and accelerating social change. © London School of Economics and Political Science 2015.

  8. Reflexive Aero Structures for Enhanced Survivability, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group Inc. (CRG) proposes to develop an advanced reflexive structure system to increase the survivability of aerostructures. This reflexive...

  9. Anticausatives are weak scalar expressions, not reflexive expressions

    Directory of Open Access Journals (Sweden)

    Florian Schäfer

    2016-07-01

    Full Text Available We discuss conceptual and empirical arguments from Germanic, Romance and Slavic languages against an analysis treating anticausative verbs as derived from their lexical causative counterparts under reflexivization. Instead, we defend the standard account to the semantics of the causative alternation according to which anticausatives in general, and anticausatives marked with reflexive morphology in particular, denote simple one-place inchoative events that are logically entailed by their lexical causative counterparts. Under such an account, anticausative verbs are weak scalar expressions that stand in a semantico-pragmatic opposition to their strong lexical causative counterparts. Due to this scalar relation, the use of an anticausative can trigger the implicature that the use of its lexical causative counterpart is too strong. As usual with implicatures, they can be ‘metalinguistically’ denied, cancelled, or reinforced and we argue that these mechanisms explain all central empirical facts brought up in the literature in favor of a treatment of anticausatives as semantically reflexive predicates. Our results reinforce the view that the reflexive morphemes used in many (Indo-European languages to mark anticausatives do not necessarily trigger reflexive semantics. However, we also show that a string involving a reflexively marked (anti-causative verb can be forced into a semantically reflexive construal under particular conceptual or grammatical circumstances.

  10. Reflexive Planning as Design and Work

    DEFF Research Database (Denmark)

    Lissandrello, Enza; Grin, John

    2011-01-01

    in planning emerges as a new tool for generating critical knowledge and dialogue that can synthesise the perspectives of multiple actors in a common understanding, existing structural constraints and a collective imagination of alternative future possibilities. Such research highlights the potential......In recent years, planning theorists have advanced various interpretations of the notion of reflexivity, inspired by American pragmatism, complexity theory, hermeneutics, discursive and collaborative planning. Scholars agree that “reflexivity” has a strong temporal dimension: it not only aims...... to solve present planning problems, but to imagine and understand alternative trajectories for future action. This article explores the practical utility of reflexivity for planners, through a case study that focuses on a project to promote sustainable development in the Port of Amsterdam. Reflexivity...

  11. Fibre type composition of soleus and extensor digitorum longus muscles in normal female inbred Lewis rats

    Czech Academy of Sciences Publication Activity Database

    Soukup, Tomáš; Zachařová, Gisela; Smerdu, V.

    2002-01-01

    Roč. 104, č. 4 (2002), s. 399-405 ISSN 0065-1281 R&D Projects: GA ČR GA304/00/1653 Grant - others:CZ - SI Czech-Slovenian Intergovernmental S&T Co-operation(XC) - Institutional research plan: CEZ:AV0Z5011922 Keywords : inbred Lewis rats * skeletal muscles * soleus and EDL muscles Subject RIV: FH - Neurology Impact factor: 0.867, year: 2002

  12. Effects of insulin and epinephrine on Na+-K+ and glucose transport in soleus muscle

    International Nuclear Information System (INIS)

    Clausen, T.; Flatman, J.A.

    1987-01-01

    To identify possible cause-effect relationships between changes in active Na + -K + transport, resting membrane potential, and glucose transport, the effects of insulin and epinephrine were compared in rat soleus muscle. Epinephrine, which produced twice as large a hyperpolarization as insulin, induced only a modest increase in 14 C-labeled sugar transport. Ouabain, at a concentration (10 -3 M) sufficient to block active Na + -K + transport and the hyperpolarization induced by the two hormones, did not interfere with sugar transport stimulation. After Na + loading in K + -free buffer, the return to K + -containing standard buffer caused marked stimulation of active 22 Na + - 42 K + transport, twice the hyperpolarization produced by insulin but no change in sugar transport. The insulin-induced activation of the 22 Na + - 42 K + pump leads to decreased intracellular 22 Na + concentration and hyperpolarization, but none of these events can account for the concomitant activation of the glucose transport system. The stimulating effect of insulin on active Na + -K + transport was not suppressed by amiloride, indicating that in intact skeletal muscle it is not elicited by a primary increase in Na + influx via the Na + /H + -exchange system

  13. The development of the pupillary light reflex and menace response in neonatal lambs and kids.

    Science.gov (United States)

    Raoofi, Afshin; Mirfakhraie, Pejman; Yourdkhani, Sorush

    2011-03-01

    The aim of this study was to investigate the development of the pupillary light reflex and menace response in neonatal lambs and goat kids. Thirty lambs and 33 kids were assessed daily from birth until the pupillary light reflex and menace response had become established. All animals had a controlled pupillary light reflex within 20 h of birth. Lambs and kids had developed menace responses by 8 ± 3 and 14 ± 2 days, respectively. The Mann-Whitney test revealed a significant difference (P kids developed a menace response. Male kids developed this response significantly (P = 0.006) later than females. There was no sex difference in the menace response in the lambs. Overall, the findings indicated that lambs develop a menace response earlier than kids, and female kids develop this response more rapidly than their male counterparts. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Voluntary Control of the Near Reflex: A Case Report

    Directory of Open Access Journals (Sweden)

    Serpil Akar

    2014-03-01

    Full Text Available Spasm of the near reflex is a rare disorder that involves intermittent and variable episodes of esotropia, pseudomyopia, and pupillary myosis. It is usually functional in origin and is seen mainly in young patients. Treatment options for spasm of the near reflex have had variable success. In instances where the etiology of spasm of the near reflex was suspected to be hysteria, psychotherapy has proven beneficial. We report the case of an 11-year-old girl who had functional spasm of the near reflex. The symptoms persisted for two years. Symptomatic relief was achieved by cycloplegia and spectacle correction (added plus lenses at near. The patient also underwent psychological counseling. In our case, the functional spasm of the near reflex spontaneously resolved after 2 years. (Turk J Ophthalmol 2014; 44: 161-3

  15. In vivo 1D and 2D correlation MR spectroscopy of the soleus muscle at 7T

    Science.gov (United States)

    Ramadan, Saadallah; Ratai, Eva-Maria; Wald, Lawrence L.; Mountford, Carolyn E.

    2010-05-01

    AimThis study aims to (1) undertake and analyse 1D and 2D MR correlation spectroscopy from human soleus muscle in vivo at 7T, and (2) determine T1 and T2 relaxation time constants at 7T field strength due to their importance in sequence design and spectral quantitation. MethodSix healthy, male volunteers were consented and scanned on a 7T whole-body scanner (Siemens AG, Erlangen, Germany). Experiments were undertaken using a 28 cm diameter detunable birdcage coil for signal excitation and an 8.5 cm diameter surface coil for signal reception. The relaxation time constants, T1 and T2 were recorded using a STEAM sequence, using the 'progressive saturation' method for the T1 and multiple echo times for T2. The 2D L-Correlated SpectroscopY (L-COSY) method was employed with 64 increments (0.4 ms increment size) and eight averages per scan, with a total time of 17 min. ResultsT1 and T2 values for the metabolites of interest were determined. The L-COSY spectra obtained from the soleus muscle provided information on lipid content and chemical structure not available, in vivo, at lower field strengths. All molecular fragments within multiple lipid compartments were chemically shifted by 0.20-0.26 ppm at this field strength. 1D and 2D L-COSY spectra were assigned and proton connectivities were confirmed with the 2D method. ConclusionIn vivo 1D and 2D spectroscopic examination of muscle can be successfully recorded at 7T and is now available to assess lipid alterations as well as other metabolites present with disease. T1 and T2 values were also determined in soleus muscle of male healthy volunteers.

  16. Recruitment and rate coding organisation for soleus motor units across entire range of voluntary isometric plantar flexions.

    Science.gov (United States)

    Oya, Tomomichi; Riek, Stephan; Cresswell, Andrew G

    2009-10-01

    Unlike upper limb muscles, it remains undocumented as to how motor units in the soleus muscle are organised in terms of recruitment range and discharge rates with respect to their recruitment and de-recruitment thresholds. The possible influence of neuromodulation, such as persistent inward currents (PICs) on lower limb motor unit recruitment and discharge rates has also yet to be reported. To address these issues, electromyographic (EMG) activities from the soleus muscle were recorded using selective branched-wire intramuscular electrodes during ramp-and-hold contractions with intensities up to maximal voluntary contraction (MVC). The multiple single motor unit activities were then derived using a decomposition technique. The onset-offset hysteresis of motor unit discharge, i.e. a difference between recruitment and de-recruitment thresholds, as well as PIC magnitude calculated by a paired motor unit analysis were used to examine the neuromodulatory effects on discharge behaviours, such as minimum firing rate, peak firing rate and degree of increase in firing rate. Forty-two clearly identified motor units from five subjects revealed that soleus motor units are recruited progressively from rest to contraction strengths close to 95% of MVC, with low-threshold motor units discharging action potentials slower at their recruitment and with a lower peak rate than later recruited high-threshold units. This observation is in contrast to the 'onion skin phenomenon' often reported for the upper limb muscles. Based on positive correlations of the peak discharge rates, initial rates and recruitment order of the units with the magnitude of the onset-offset hysteresis and not PIC contribution, we conclude that discharge behaviours among motor units appear to be related to a variation in an intrinsic property other than PICs.

  17. Gain-scheduled {{\\mathscr{H}}}_{\\infty } buckling control of a circular beam-column subject to time-varying axial loads

    Science.gov (United States)

    Schaeffner, Maximilian; Platz, Roland

    2018-06-01

    For slender beam-columns loaded by axial compressive forces, active buckling control provides a possibility to increase the maximum bearable axial load above that of a purely passive structure. In this paper, an approach for gain-scheduled {{\\mathscr{H}}}∞ buckling control of a slender beam-column with circular cross-section subject to time-varying axial loads is investigated experimentally. Piezo-elastic supports with integrated piezoelectric stack actuators at the beam-column ends allow an active stabilization in arbitrary lateral directions. The axial loads on the beam-column influence its lateral dynamic behavior and, eventually, cause the beam-column to buckle. A reduced modal model of the beam-column subject to axial loads including the dynamics of the electrical components is set up and calibrated with experimental data. Particularly, the linear parameter-varying open-loop plant is used to design a model-based gain-scheduled {{\\mathscr{H}}}∞ buckling control that is implemented in an experimental test setup. The beam-column is loaded by ramp- and step-shaped time-varying axial compressive loads that result in a lateral deformation of the beam-column due to imperfections, such as predeformation, eccentric loading or clamping moments. The lateral deformations and the maximum bearable loads of the beam-column are analyzed and compared for the beam-column with and without gain-scheduled {{\\mathscr{H}}}∞ buckling control or, respectively, active and passive configuration. With the proposed gain-scheduled {{\\mathscr{H}}}∞ buckling control it is possible to increase the maximum bearable load of the active beam-column by 19% for ramp-shaped axial loads and to significantly reduce the beam-column deformations for step-shaped axial loads compared to the passive structure.

  18. Deprivation and Recovery of Sleep in Succession Enhances Reflexive Motor Behavior.

    Science.gov (United States)

    Sprenger, Andreas; Weber, Frederik D; Machner, Bjoern; Talamo, Silke; Scheffelmeier, Sabine; Bethke, Judith; Helmchen, Christoph; Gais, Steffen; Kimmig, Hubert; Born, Jan

    2015-11-01

    Sleep deprivation impairs inhibitory control over reflexive behavior, and this impairment is commonly assumed to dissipate after recovery sleep. Contrary to this belief, here we show that fast reflexive behaviors, when practiced during sleep deprivation, is consolidated across recovery sleep and, thereby, becomes preserved. As a model for the study of sleep effects on prefrontal cortex-mediated inhibitory control in humans, we examined reflexive saccadic eye movements (express saccades), as well as speeded 2-choice finger motor responses. Different groups of subjects were trained on a standard prosaccade gap paradigm before periods of nocturnal sleep and sleep deprivation. Saccade performance was retested in the next morning and again 24 h later. The rate of express saccades was not affected by sleep after training, but slightly increased after sleep deprivation. Surprisingly, this increase augmented even further after recovery sleep and was still present 4 weeks later. Additional experiments revealed that the short testing after sleep deprivation was sufficient to increase express saccades across recovery sleep. An increase in speeded responses across recovery sleep was likewise found for finger motor responses. Our findings indicate that recovery sleep can consolidate motor disinhibition for behaviors practiced during prior sleep deprivation, thereby persistently enhancing response automatization. © The Author 2015. Published by Oxford University Press.

  19. 21 CFR 890.1450 - Powered reflex hammer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... hammer. (a) Identification. A powered reflex hammer is a motorized device intended for medical purposes...

  20. Outside home. Notes on reflexivity

    Directory of Open Access Journals (Sweden)

    Mara Clemente

    2017-01-01

    The paper proffers the idea in which a “reflexive process” on subjectivity can involve and/or hopefully involve the entire experience of the researcher, going beyond the borders of a single research. In the process, unexpected elements of subjectivity can come into play; in other cases the meaning attributed to them can change in time or can have a role different from what had been expected. Some elements, objects of epistemological analyses, as imposed by a reflexive approach, can become objects of attention also on the phenomenological level.

  1. The Multiple Faces of Reflexive Research Designs

    Directory of Open Access Journals (Sweden)

    Karl H. Müller

    2015-10-01

    Full Text Available Reflexive research can be grouped into five clusters with circular relations between two elements x ↔ x, namely circular relations between observers, between scientific building blocks like concepts, theories or models, between systemic levels, between rules and rule systems or as circular relations or x ↔ y between these four components. By far the most important cluster is the second cluster which becomes reflexive through a re-entry operation RE into a scientific element x and which establishes its circular formation as x(x. Many of the research problems in these five clusters in reflexivity research are still unexplored and pose grand challenges for future research.

  2. A Prototype Analysis of Spanish Indeterminate Reflexive Constructions.

    Science.gov (United States)

    Turley, Jeffrey S.

    1998-01-01

    Discussion of the Spanish indeterminate reflexive construction, the impersonal reflexive, finds that prototype theory allows this subjectless Spanish construction to be included within the category of generally subject-bearing indeterminates in Romance languages. (MSE)

  3. Physical training prevents body weight gain but does not modify adipose tissue gene expression

    Energy Technology Data Exchange (ETDEWEB)

    Higa, T.S. [Escola de Artes, Ciências e Humanidades, Universidade de São Paulo, São Paulo, SP (Brazil); Bergamo, F.C. [Escola de Educação Física e Esporte, Universidade de São Paulo, São Paulo, SP (Brazil); Mazzucatto, F. [Escola de Artes, Ciências e Humanidades, Universidade de São Paulo, São Paulo, SP (Brazil); Fonseca-Alaniz, M.H. [Instituto do Coração, Departamento de Medicina-LIM13, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Evangelista, F.S. [Escola de Artes, Ciências e Humanidades, Universidade de São Paulo, São Paulo, SP (Brazil); Escola de Educação Física e Esporte, Universidade de São Paulo, São Paulo, SP (Brazil); Instituto do Coração, Departamento de Medicina-LIM13, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

    2012-06-08

    The relationship of body weight (BW) with white adipose tissue (WAT) mass and WAT gene expression pattern was investigated in mice submitted to physical training (PT). Adult male C57BL/6 mice were submitted to two 1.5-h daily swimming sessions (T, N = 18), 5 days/week for 4 weeks or maintained sedentary (S, N = 15). Citrate synthase activity increased significantly in the T group (P < 0.05). S mice had a substantial weight gain compared to T mice (4.06 ± 0.43 vs 0.38 ± 0.28 g, P < 0.01). WAT mass, adipocyte size, and the weights of gastrocnemius and soleus muscles, lung, kidney, and adrenal gland were not different. Liver and heart were larger and the spleen was smaller in T compared to S mice (P < 0.05). Food intake was higher in T than S mice (4.7 ± 0.2 vs 4.0 ± 0.3 g/animal, P < 0.05) but oxygen consumption at rest did not differ between groups. T animals showed higher serum leptin concentration compared to S animals (6.37 ± 0.5 vs 3.11 ± 0.12 ng/mL). WAT gene expression pattern obtained by transcription factor adipocyte determination and differentiation-dependent factor 1, fatty acid synthase, malic enzyme, hormone-sensitive lipase, adipocyte lipid binding protein, leptin, and adiponectin did not differ significantly between groups. Collectively, our results showed that PT prevents BW gain and maintains WAT mass due to an increase in food intake and unchanged resting metabolic rate. These responses are closely related to unchanged WAT gene expression patterns.

  4. Physical training prevents body weight gain but does not modify adipose tissue gene expression

    International Nuclear Information System (INIS)

    Higa, T.S.; Bergamo, F.C.; Mazzucatto, F.; Fonseca-Alaniz, M.H.; Evangelista, F.S.

    2012-01-01

    The relationship of body weight (BW) with white adipose tissue (WAT) mass and WAT gene expression pattern was investigated in mice submitted to physical training (PT). Adult male C57BL/6 mice were submitted to two 1.5-h daily swimming sessions (T, N = 18), 5 days/week for 4 weeks or maintained sedentary (S, N = 15). Citrate synthase activity increased significantly in the T group (P < 0.05). S mice had a substantial weight gain compared to T mice (4.06 ± 0.43 vs 0.38 ± 0.28 g, P < 0.01). WAT mass, adipocyte size, and the weights of gastrocnemius and soleus muscles, lung, kidney, and adrenal gland were not different. Liver and heart were larger and the spleen was smaller in T compared to S mice (P < 0.05). Food intake was higher in T than S mice (4.7 ± 0.2 vs 4.0 ± 0.3 g/animal, P < 0.05) but oxygen consumption at rest did not differ between groups. T animals showed higher serum leptin concentration compared to S animals (6.37 ± 0.5 vs 3.11 ± 0.12 ng/mL). WAT gene expression pattern obtained by transcription factor adipocyte determination and differentiation-dependent factor 1, fatty acid synthase, malic enzyme, hormone-sensitive lipase, adipocyte lipid binding protein, leptin, and adiponectin did not differ significantly between groups. Collectively, our results showed that PT prevents BW gain and maintains WAT mass due to an increase in food intake and unchanged resting metabolic rate. These responses are closely related to unchanged WAT gene expression patterns

  5. Physical training prevents body weight gain but does not modify adipose tissue gene expression

    Directory of Open Access Journals (Sweden)

    T.S. Higa

    2012-10-01

    Full Text Available The relationship of body weight (BW with white adipose tissue (WAT mass and WAT gene expression pattern was investigated in mice submitted to physical training (PT. Adult male C57BL/6 mice were submitted to two 1.5-h daily swimming sessions (T, N = 18, 5 days/week for 4 weeks or maintained sedentary (S, N = 15. Citrate synthase activity increased significantly in the T group (P < 0.05. S mice had a substantial weight gain compared to T mice (4.06 ± 0.43 vs 0.38 ± 0.28 g, P < 0.01. WAT mass, adipocyte size, and the weights of gastrocnemius and soleus muscles, lung, kidney, and adrenal gland were not different. Liver and heart were larger and the spleen was smaller in T compared to S mice (P < 0.05. Food intake was higher in T than S mice (4.7 ± 0.2 vs 4.0 ± 0.3 g/animal, P < 0.05 but oxygen consumption at rest did not differ between groups. T animals showed higher serum leptin concentration compared to S animals (6.37 ± 0.5 vs 3.11 ± 0.12 ng/mL. WAT gene expression pattern obtained by transcription factor adipocyte determination and differentiation-dependent factor 1, fatty acid synthase, malic enzyme, hormone-sensitive lipase, adipocyte lipid binding protein, leptin, and adiponectin did not differ significantly between groups. Collectively, our results showed that PT prevents BW gain and maintains WAT mass due to an increase in food intake and unchanged resting metabolic rate. These responses are closely related to unchanged WAT gene expression patterns.

  6. Capillarity, oxidative capacity and fibre composition of the soleus and gastrocnemius muscles of rats in hypothyroidism.

    Science.gov (United States)

    Sillau, A H

    1985-01-01

    Muscle capillarity, mean and maximal diffusion distances and muscle fibre composition were evaluated in frozen sections stained for myosin ATPase of the soleus and the white area of the gastrocnemius medial head (gastrocnemius) of rats made hypothyroid by the injection of propylthiouracil (PTU) (50 mg kg-1) every day for 21 or 42 days. Oxygen consumption in the presence of excess ADP and Pi with pyruvate plus malate as substrates and the activity of cytochrome c oxidase were measured in muscle homogenates. Treatment with PTU decreased body oxygen consumption and the concentration of triiodothyronine in plasma. The capacity of the soleus and gastrocnemius muscles' homogenates to oxidize pyruvate plus malate and their cytochrome c oxidase activity were reduced after 21 or 42 days of treatment with PTU. Fibre composition in the soleus muscle was changed by treatment with PTU. There was a decrease in the proportion of type IIa or fast glycolytic oxidative fibres and an increase in type I or slow oxidative fibres. After 21 days of PTU administration there was also an increase in the proportion of fibres classified as IIc. The changes in fibre composition are believed to be the result of changes in the types of myosin synthesized by the fibres. Therefore, the fibres classified as IIc are, most probably, IIa fibres in the process of changing their myosin to that of the type I fibres. No changes in fibre composition were evident in the white area of the gastrocnemius medial head, an area made up of IIb or fast glycolytic fibres. The indices of capillarity: capillary density and capillary to fibre ratio, as well as mean and maximal diffusion distances from the capillaries, were not changed by the treatment with PTU in the muscles studied. The lack of changes in capillarity in spite of significant changes in oxidative capacity indicates that in skeletal muscle capillarity is not necessarily related to the oxidative capacity of the fibres. PMID:3989729

  7. Acoustic Reflex Screening of Conductive Hearing Loss for Third Window Disorders.

    Science.gov (United States)

    Hong, Robert S; Metz, Christopher M; Bojrab, Dennis I; Babu, Seilesh C; Zappia, John; Sargent, Eric W; Chan, Eleanor Y; Naumann, Ilka C; LaRouere, Michael J

    2016-02-01

    This study examines the effectiveness of acoustic reflexes in screening for third window disorders (eg, superior semicircular canal dehiscence) prior to middle ear exploration for conductive hearing loss. Case series with chart review. Outpatient tertiary otology center. A review was performed of 212 ears with acoustic reflexes, performed as part of the evaluation of conductive hearing loss in patients without evidence of chronic otitis media. The etiology of hearing loss was determined from intraoperative findings and computed tomography imaging. The relationship between acoustic reflexes and conductive hearing loss etiology was assessed. Eighty-eight percent of ears (166 of 189) demonstrating absence of all acoustic reflexes had an ossicular etiology of conductive hearing loss. Fifty-two percent of ears (12 of 23) with at least 1 detectable acoustic reflex had a nonossicular etiology. The positive and negative predictive values for an ossicular etiology were 89% and 57% when acoustic reflexes were used alone for screening, 89% and 39% when third window symptoms were used alone, and 94% and 71% when reflexes and symptoms were used together, respectively. Acoustic reflex testing is an effective means of screening for third window disorders in patients with a conductive hearing loss. Questioning for third window symptoms should complement screening. The detection of even 1 acoustic reflex or third window symptom (regardless of reflex status) should prompt further workup prior to middle ear exploration. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  8. Prenatal exposure to a low fipronil dose disturbs maternal behavior and reflex development in rats.

    Science.gov (United States)

    Udo, Mariana S B; Sandini, Thaísa M; Reis, Thiago M; Bernardi, Maria Martha; Spinosa, Helenice S

    2014-01-01

    Fipronil (FPN) is a phenylpyrazole insecticide used in veterinary services and agriculture, and it is of considerable concern to public health. It inhibits the chloride channels associated with gamma-amino butyric acid (GABA) receptors in mammals and also inhibits the chloride channels associated with GABA and glutamate (Glu) receptors in insects. In this study, a commercial product containing fipronil was orally administered to pregnant Wistar rats at dose levels of 0.1, 1.0, or 10.0mg/kg/day from the sixth to twentieth day of gestation (n=10 pregnant rats/group). Its toxicity was evaluated based on maternal toxicity, reproductive quality, maternal behavior, and offspring physical as well as reflex development. All parameters observed in the observed offspring were assigned to one ink-marked couple in each litter (n=20 animals/group - 10 males and 10 females). The offspring couple represented the litter. Slight maternal toxicity presented during the second week of gestation for each fipronil dose and during the third gestational week at the highest dose due to lower chow intake. However, no effects were observed for gestational weight gain or gestation time, and the reproductive quality was not impaired, which suggests no adverse maternal effects from the doses during pregnancy. Moreover, the lowest fipronil dose compromised the active and reflexive maternal responses, but the highest dose induced a stereotyped active response without interfering in the reflexive reaction. For offspring development, no differences in physical growth parameters were observed between the groups. However, considering reflex development, our results showed that negative geotaxis reflex development was delayed in the offspring at the lowest fipronil dose, and palmar grasp was lost earlier at the lowest and intermediate fipronil doses. These results suggest that the alterations observed herein may be due to either the GABAergic system or endocrine disruption, considering that fipronil

  9. Reflex epilepsy: triggers and management strategies

    Directory of Open Access Journals (Sweden)

    Okudan ZV

    2018-01-01

    Full Text Available Zeynep Vildan Okudan,1 Çiğdem Özkara2 1Department of Neurology, Bakirkoy Dr Sadi Konuk Education and Research Hospital, 2Department of Neurology and Clinical Neurophysiology, Cerrahpasa Faculty of Medicine, University of Istanbul, Istanbul, Turkey Abstract: Reflex epilepsies (REs are identified as epileptic seizures that are consistently induced by identifiable and objective-specific triggers, which may be an afferent stimulus or by the patient’s own activity. RE may have different subtypes depending on the stimulus characteristic. There are significant clinical and electrophysiologic differences between different RE types. Visual stimuli-sensitive or photosensitive epilepsies constitute a large proportion of the RE and are mainly related to genetic causes. Reflex epilepsies may present with focal or generalized seizures due to specific triggers, and sometimes seizures may occur spontaneously. The stimuli can be external (light flashes, hot water, internal (emotion, thinking, or both and should be distinguished from triggering precipitants, which most epileptic patients could report such as emotional stress, sleep deprivation, alcohol, and menstrual cycle. Different genetic and acquired factors may play a role in etiology of RE. This review will provide a current overview of the triggering factors and management of reflex seizures. Keywords: seizure, reflex epilepsy, photosensitivity, hot water, reading, thinking

  10. Reflex responses of lip muscles in young and older women.

    Science.gov (United States)

    Wohlert, A B

    1996-06-01

    The perioral reflex in response to innocuous mechanical stimulation of the lip vermilion was studied in 20 young and 20 older women. Responses to stimuli at the right and left sides of both the upper and lower lips were recorded. Results show significant specificity of response, especially for upper lip sites. Reflex response at the site of stimulation was greatest in amplitude and shortest in latency, followed by response at sites ipsilateral to the site of stimulation. Younger subjects showed greater localizing tendency than older subjects. Stimulation was significantly less likely to produce a reflex response in the older group. When reflex responses did occur, they were significantly lower in amplitude and longer in latency than the responses of the younger group. Nonetheless, reflex responses were common in both groups, with responses at the site of stimulation occurring 78% of the time in older women and 90% of the time in younger women. Every participant showed at least one reflex response to lip stimulation. Results suggest decreasing complexity of synaptic drive to the perioral system in old age but also show that reflexive response does not deteriorate completely, remaining an available element for motor control in normal older women.

  11. Cerebellar interaction with the acoustic reflex.

    Science.gov (United States)

    Jastreboff, P J

    1981-01-01

    The involvement of the cerebellar vermis in the acoustic reflex was analyzed in 12 cats, decerebrated or in pentobarbital anesthesia. Anatomical data suggested the existence of a connection of lobules VIII with the ventral cochlear nucleus. Single cell recording and evoked potential techniques demonstrated the existence of the acoustic projection to lobulus VIII. Electrical stimulation of this area changed the tension of the middle ear muscle and caused evoked potential responses in the caudal part of the ventral cochlear nucleus. Electrical stimulation of the motor nucleus of the facial nerve evoked a slow wave in the recording taken from the surrounding of the cochlear round window. A hypothesis is proposed which postulates the involvement of the acoustic reflex in space localization of acoustic stimuli and the action of cerebellar vermis in order to assure the stability and plasticity of the acoustic reflex arc.

  12. Reflex syncope: Diagnosis and treatment

    Directory of Open Access Journals (Sweden)

    Richard Sutton

    2017-12-01

    Full Text Available For the diagnosis of reflex syncope, diligent history-building with the patient and a witness is required. In the Emergency Department (ED, the assessment of syncope is a challenge which may be addressed by an ED Observation Unit or by a referral to a Syncope Unit. Hospital admission is necessary for those with life-threatening cardiac conditions although risk stratification remains an unsolved problem. Other patients may be investigated with less urgency by carotid sinus massage (>40 years, tilt testing, and electrocardiogram loop recorder insertion resulting in a clear cause for syncope. Management includes, in general terms, patient education, avoidance of circumstances in which syncope is likely, increase in fluid and salt consumption, and physical counter-pressure maneuvers. In older patients, those that will benefit from cardiac pacing are now well defined. In all patients, the benefit of drug therapy is often disappointing and there remains no ideal drug. A role for catheter ablation may emerge for the highly symptomatic reflex syncope patient. Keywords: Cardiac pacing, Catheter ablation, Diagnosis, Drugs, Management, Reflex syncope

  13. Trigeminal cardiac reflex and cerebral blood flow regulation

    Directory of Open Access Journals (Sweden)

    Dominga Lapi

    2016-10-01

    Full Text Available The stimulation of some facial regions is known to trigger the trigemino-cardiac reflex: the main stimulus is represented by the contact of the face with water. This phenomenon called diving reflex induces a set of reactions in the cardiovascular and respiratory systems occurring in all mammals, especially marine (whales, seals. During the immersion of the face in the water, the main responses are aimed at reducing the oxygen consumption of the organism. Accordingly reduction in heart rate, peripheral vasoconstriction, blood pooling in certain organs, especially the heart and brain, and an increase in blood pressure have been reported. Moreover, the speed and intensity of the reflex is inversely proportional to the temperature of the water: more cold the water, more reactions as described are strong. In the case of deep diving an additional effect, such as blood deviation, has been reported: the blood is requested within the lungs, to compensate for the increase in the external pressure, preventing them from collapsing.The trigeminal-cardiac reflex is not just confined to the diving reflex; recently it has been shown that a brief proprioceptive stimulation (10 min by jaw extension in rats produces interesting effects both at systemic and cerebral level, reducing the arterial blood pressure and vasodilating the pial arterioles. The arteriolar dilation is associated with rhythmic diameter changes characterized by an increase in the endothelial activity. Fascinating the stimulation of trigeminal nerve is able to activated the nitric oxide release by vascular endothelial. Therefore the aim of this review was to highlight the effects due to trigeminal cardiac reflex induced by a simple mandibular extension, because produced opposite effects compared to those elicited by the diving reflex as it induces hypotension and modulation of cerebral arteriolar tone.

  14. The acoustic reflex threshold in aging ears.

    Science.gov (United States)

    Silverman, C A; Silman, S; Miller, M H

    1983-01-01

    This study investigates the controversy regarding the influence of age on the acoustic reflex threshold for broadband noise, 500-, 1000-, 2000-, and 4000-Hz activators between Jerger et al. [Mono. Contemp. Audiol. 1 (1978)] and Jerger [J. Acoust. Soc. Am. 66 (1979)] on the one hand and Silman [J. Acoust. Soc. Am. 66 (1979)] and others on the other. The acoustic reflex thresholds for broadband noise, 500-, 1000-, 2000-, and 4000-Hz activators were evaluated under two measurement conditions. Seventy-two normal-hearing ears were drawn from 72 subjects ranging in age from 20-69 years. The results revealed that age was correlated with the acoustic reflex threshold for BBN activator but not for any of the tonal activators; the correlation was stronger under the 1-dB than under the 5-dB measurement condition. Also, the mean acoustic reflex thresholds for broadband noise activator were essentially similar to those reported by Jerger et al. (1978) but differed from those obtained in this study under the 1-dB measurement condition.

  15. Sympathetic reflex control of blood flow in human peripheral tissues

    DEFF Research Database (Denmark)

    Henriksen, O

    1991-01-01

    Sympathetic vasoconstrictor reflexes are essential for the maintenance of arterial blood pressure in upright position. It has been generally believed that supraspinal sympathetic vasoconstrictor reflexes elicited by changes in baroreceptor activity play an important role. Recent studies on human...... sympathetic vasoconstrictor reflexes are blocked. Blood flow has been measure by the local 133Xe-technique. The results indicate the presence of spinal as well as supraspinal sympathetic vasoconstrictor reflexes to human peripheral tissues. Especially is emphasized the presence of a local sympathetic veno...... skeletal muscle, cutaneous and subcutaneous tissues of the limbs indicate that the situation is more complex. Measurements have been carried out during acute as well as chronic sympathetic denervation. Spinal sympathetic reflex mechanisms have been evaluated in tetraplegic patients, where supraspinal...

  16. A simple measurement hammer for quantitative reflex studies

    NARCIS (Netherlands)

    Stam, J.; van Leeuwen, J. R.

    1984-01-01

    A reflex hammer for measurement of the mechanical stimulus strength was designed. Combined with standard EMG equipment this instrument permits the study of both stimulus-response relations and latencies of myotatic reflexes. Some results in normal subjects are discussed

  17. Reflexive fatherhood in everyday life

    DEFF Research Database (Denmark)

    Westerling, Allan

    2015-01-01

    This article looks at fathering practices in Denmark, using the findings from a research project on everyday family life in Denmark. It takes a social psychological perspective and employs discursive psychology and theories about reflexive modernisation. It shows how fathers orient towards intimacy...... in their relationships with their children. Moreover, it discusses how fathers’ relatedness reflects individualisation and detraditionalisation. It is argued that reflexive modernisation entails subjective orientations that enable novel pathways to intimacy in contemporary father–child relationships. Through...... this analysis and discussion, the article offers a way to understand the complexities of fathering in everyday life from the perspective of fathers....

  18. Medial gastrocnemius and soleus muscle-tendon unit, fascicle, and tendon interaction during walking in children with cerebral palsy.

    Science.gov (United States)

    Barber, Lee; Carty, Chris; Modenese, Luca; Walsh, John; Boyd, Roslyn; Lichtwark, Glen

    2017-08-01

    This study investigates the in vivo function of the medial gastrocnemius and soleus muscle-tendon units (MTU), fascicles, and tendons during walking in children with cerebral palsy (CP) and an equinus gait pattern. Fourteen children with CP (9 males, 5 females; mean age 10y 6mo, standard deviation [SD] 2y 11mo; GMFCS level I=8, II=6), and 10 typically developing (6 males, 4 females; mean age 10y, SD 2y 1mo) undertook full body 3D gait analysis and simultaneous B-mode ultrasound images of the medial gastrocnemius and soleus fascicles during level walking. Fascicle lengths were analysed using a semi-automated tracking algorithm and MTUs using OpenSim. Statistical parametric mapping (two-sample t-test) was used to compare differences between groups (ppower during push-off (p=0.015) and positive work (ppower and positive work in the children with CP may be attributed to reduced active medial gastrocnemius fascicle shortening. These findings suggest a reliance on passive force generation for forward propulsion during equinus gait. © 2017 Mac Keith Press.

  19. Manual compression and reflex syncope in native renal biopsy.

    Science.gov (United States)

    Takeuchi, Yoichi; Ojima, Yoshie; Kagaya, Saeko; Aoki, Satoshi; Nagasawa, Tasuku

    2018-03-14

    Complications associated with diagnostic native percutaneous renal biopsy (PRB) must be minimized. While life threatening major complications has been extensively investigated, there is little discussion regarding minor bleeding complications, such as a transient hypotension, which directly affect patients' quality of life. There is also little evidence supporting the need for conventional manual compression following PRB. Therefore, this study evaluated the relationship between minor and major complications incidence in patients following PRB with or without compression. This single-center, retrospective study included 456 patients (compression group: n = 71; observation group: n = 385). The compression group completed 15 min of manual compression and 4 h of subsequent strict bed rest with abdominal bandage. The observation group completed 2 h of strict bed rest only. The primary outcome of interest was transient symptomatic hypotension (minor event). Of the 456 patients, 26 patients encountered intraoperative and postoperative transient hypotension, which were considered reflex syncope without tachycardia. Univariate analysis showed that symptomatic transient hypotension was significantly associated with compression. This association remained significant, even after adjustment of covariates using multivariate logistic regression analysis (adjusted odds ratio 3.27; 95% confidential interval 1.36-7.82; P = 0.0078). Manual compression and abdominal bandage significantly increased the frequency of reflex syncope during native PRB. It is necessary to consider the potential benefit and risk of compression maneuvers for each patient undergoing this procedure.

  20. Reflexive intergroup bias in third-party punishment.

    Science.gov (United States)

    Yudkin, Daniel A; Rothmund, Tobias; Twardawski, Mathias; Thalla, Natasha; Van Bavel, Jay J

    2016-11-01

    Humans show a rare tendency to punish norm-violators who have not harmed them directly-a behavior known as third-party punishment. Research has found that third-party punishment is subject to intergroup bias, whereby people punish members of the out-group more severely than the in-group. Although the prevalence of this behavior is well-documented, the psychological processes underlying it remain largely unexplored. Some work suggests that it stems from people's inherent predisposition to form alliances with in-group members and aggress against out-group members. This implies that people will show reflexive intergroup bias in third-party punishment, favoring in-group over out-group members especially when their capacity for deliberation is impaired. Here we test this hypothesis directly, examining whether intergroup bias in third-party punishment emerges from reflexive, as opposed to deliberative, components of moral cognition. In 3 experiments, utilizing a simulated economic game, we varied participants' group relationship to a transgressor, measured or manipulated the extent to which they relied on reflexive or deliberative judgment, and observed people's punishment decisions. Across group-membership manipulations (American football teams, nationalities, and baseball teams) and 2 assessments of reflexive judgment (response time and cognitive load), reflexive judgment heightened intergroup bias, suggesting that such bias in punishment is inherent to human moral cognition. We discuss the implications of these studies for theories of punishment, cooperation, social behavior, and legal practice. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  1. Snout and Visual Rooting Reflexes in Infantile Autism. Brief Report.

    Science.gov (United States)

    Minderaa, Ruud B.; And Others

    1985-01-01

    The authors conducted extensive neurological evaluations of 42 autistic individuals and were surprised to discover a consistently positive snout reflex in most of them. Difficulties with assessing the reflex are noted. The authors then reassessed the Ss for a series of primitive reflexes which are interpreted as signs of diffuse cortical brain…

  2. The influence of reflexive educational environment on students ...

    African Journals Online (AJOL)

    The influence of reflexive educational environment on students' reflection development in ... based on them) from which, as they integrate, a reflexive personality style is developed. ... (narrative, dialogical, cognitive and axiological) are the factors influencing the outcome of social adaptation. ... AJOL African Journals Online.

  3. In Vivo Real-Time Imaging of Exogenous HGF-Triggered Cell Migration in Rat Intact Soleus Muscles

    International Nuclear Information System (INIS)

    Ishido, Minenori; Kasuga, Norikatsu

    2012-01-01

    The transplantation of myogenic cells is a potentially effective therapy for muscular dystrophy. However, this therapy has achieved little success because the diffusion of transplanted myogenic cells is limited. Hepatocyte growth factor (HGF) is one of the primary triggers to induce myogenic cell migration in vitro. However, to our knowledge, whether exogenous HGF can trigger the migration of myogenic cells (i.e. satellite cells) in intact skeletal muscles in vivo has not been reported. We previously reported a novel in vivo real-time imaging method in rat skeletal muscles. Therefore, the present study examined the relationship between exogenous HGF treatment and cell migration in rat intact soleus muscles using this imaging method. As a result, it was indicated that the cell migration velocity was enhanced in response to increasing exogenous HGF concentration in skeletal muscles. Furthermore, the expression of MyoD was induced in satellite cells in response to HGF treatment. We first demonstrated in vivo real-time imaging of cell migration triggered by exogenous HGF in intact soleus muscles. The experimental method used in the present study will be a useful tool to understand further the regulatory mechanism of HGF-induced satellite cell migration in skeletal muscles in vivo

  4. [Human physiology: images and practices of the reflex].

    Science.gov (United States)

    Wübben, Yvonne

    2010-01-01

    The essay examines the function of visualizations and practices in the formation of the reflex concept from Thomas Willis to Marshall Hall. It focuses on the specific form of reflex knowledge that images and practices can contain. In addition, the essay argues that it is through visual representations and experimental practices that technical knowledge is transferred to the field of human reflex physiology. When using technical metaphors in human physiology authors often seem to feel obliged to draw distinctions between humans, machines and animals. On closer scrutiny, these distinctions sometimes fail to establish firm borders between the human and the technical.

  5. Nociceptive flexion reflexes during analgesic neurostimulation in man.

    Science.gov (United States)

    García-Larrea, L; Sindou, M; Mauguière, F

    1989-11-01

    Nociceptive flexion reflexes of the lower limbs (RIII responses) have been studied in 21 patients undergoing either epidural (DCS, n = 16) or transcutaneous (TENS, n = 5) analgesic neurostimulation (AN) for chronic intractable pain. Flexion reflex RIII was depressed or suppressed by AN in 11 patients (52.4%), while no modification was observed in 9 cases and a paradoxical increase during AN was evidenced in 1 case. In all but 2 patients, RIII changes were rapidly reversible after AN interruption. RIII depression was significantly associated with subjective pain relief, as assessed by conventional self-rating; moreover, in 2 patients it was possible to ameliorate the pain-suppressing effects of AN by selecting those stimulation parameters (intensity and frequency) that maximally depressed nociceptive reflex RIII. We recorded 2 cases of RIII attenuation after contralateral neurostimulation. AN appeared to affect nociceptive reflexes rather selectively, with no or very little effect on other cutaneous, non-nociceptive responses. Recording of RIII reflexes is relatively simple to implement as a routine paraclinical procedure. It facilitates the objective assessment of AN efficacy and may help to choose the most appropriate parameters of neurostimulation. In addition, RIII behavior in patients could be relevant to the understanding of some of the mechanisms involved in AN-induced pain relief.

  6. Key Markers of mTORC1-Dependent and mTORC1-Independent Signaling Pathways Regulating Protein Synthesis in Rat Soleus Muscle During Early Stages of Hindlimb Unloading.

    Science.gov (United States)

    Mirzoev, Timur; Tyganov, Sergey; Vilchinskaya, Natalia; Lomonosova, Yulia; Shenkman, Boris

    2016-01-01

    The purpose of the study was to assess the amount of rRNA and phosphorylation status of the key markers of mTORC1-dependent (70s6k, 4E-BP1) and mTORC1-independent (GSK-3β, AMPK) signaling pathways controlling protein synthesis in rat soleus during early stages of mechanical unloading (hindlimb suspension (HS) for 1-, 3- and 7 days). The content of the key signaling molecules of various anabolic signaling pathways was determined by Western-blotting. The amount of 28S rRNA was evaluated by RT-PCR. The rate of protein synthesis was assessed using in-vivo SUnSET technique. HS for 3 and 7 days induced a significant (pprotein synthesis in soleus muscle in comparison with control. HS within 24 hours resulted in a significant (pprotein synthesis in rat soleus during early stages of simulated microgravity is associated with impaired ribosome biogenesis as well as reduced activity of mTORC1-independent signaling pathways. © 2016 The Author(s) Published by S. Karger AG, Basel.

  7. Differences in neurotransmitter systems of ventrolateral periaqueductal gray between the micturition reflex and nociceptive regulation: An in vivo microdialysis study.

    Science.gov (United States)

    Kitta, Takeya; Mitsui, Takahiko; Kanno, Yukiko; Chiba, Hiroki; Moriya, Kimihiko; Yoshioka, Mitsuhiro; Shinohara, Nobuo

    2016-07-01

    To elucidate the possible involvement of glutamate and serotonin (5-hydroxytryptamine) neurons in the ventrolateral midbrain periaqueductal gray during noxious stimulation. The study was carried out by evoking a noxious stimulation by acetic acid in an animal model of cystitis. Changes in glutamate and 5-hydroxytryptamine in the periaqueductal gray during the micturition reflex and acetic acid-induced cystitis were determined using in vivo microdialysis combined with cystometry in rats. Extracellular glutamate levels slightly, but significantly, increased during the micturition reflex induced by saline infusion into the bladder. Intravesical infusion of acetic acid facilitated the micturition reflex characterized by increases in voiding pressure and decreases in the intercontraction interval. Glutamate levels were markedly increased by acetic acid, and this enhancement was sustained for at least 3 h. 5-Hydroxytryptamine levels, which were not altered during the micturition reflex, were increased after intravesical infusion of acetic acid. The results suggest that periaqueductal gray glutamate and 5-hydroxytryptamine neurons differentially participate in the modulation of both nociception and the micturition reflex. Furthermore, periaqueductal gray 5-hydroxytryptamine levels appear to reflect the nociceptive stimuli. © 2016 The Japanese Urological Association.

  8. Correlation of augmented startle reflex with brainstem electrophysiological responses in Tay-Sachs disease.

    Science.gov (United States)

    Nakamura, Sadao; Saito, Yoshiaki; Ishiyama, Akihiko; Sugai, Kenji; Iso, Takashi; Inagaki, Masumi; Sasaki, Masayuki

    2015-01-01

    To clarify the evolution of an augmented startle reflex in Tay-Sachs disease and compare the temporal relationship between this reflex and brainstem evoked potentials. Clinical and electrophysiological data from 3 patients with Tay-Sachs disease were retrospectively collected. The augmented startle reflex appeared between the age of 3 and 17 months and disappeared between the age of 4 and 6 years. Analysis of brainstem auditory evoked potentials revealed that poor segregation of peak I, but not peak III, coincided with the disappearance of the augmented startle reflex. A blink reflex with markedly high amplitude was observed in a patient with an augmented startle reflex. The correlation between the augmented startle reflex and the preservation of peak I but not peak III supports the theory that the superior olivary nucleus is dispensable for this reflex. The blink reflex with high amplitudes may represent augmented excitability of reticular formation at the pontine tegmentum in Tay-Sachs disease, where the pattern generators for the augmented startle and blink reflexes may functionally overlap. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  9. Acute Gastrocnemius-Soleus Complex Injuries in National Football League Athletes.

    Science.gov (United States)

    Werner, Brian C; Belkin, Nicole S; Kennelly, Steve; Weiss, Leigh; Barnes, Ronnie P; Potter, Hollis G; Warren, Russell F; Rodeo, Scott A

    2017-01-01

    Lower extremity muscle injuries are common in professional football. Although less common than hamstring or quadriceps injuries in National Football League (NFL) athletes, calf injuries occur with relative frequency and have not previously been studied. To evaluate gastrocnemius-soleus complex muscle injuries over the past 13 years from a single NFL team to determine the incidence of such injuries, their imaging characteristics, and return to play after such injuries and any correlation between imaging findings and prolonged return to play. Case series; Level of evidence, 4. A retrospective review of all acute calf muscle injuries on a single NFL team from 2003 to 2015 was performed. Player demographics and return-to-play data were obtained from the medical records. All available magnetic resonance images (MRIs) were reviewed by a musculoskeletal radiologist for specific imaging findings that correlated with return to play. A total of 27 calf injuries in 24 NFL players were reviewed, yielding an incidence of 2.3 acute calf injuries per year on a single NFL team. Of these 27 injuries, 20 (74%) were isolated injuries to the gastrocnemius muscle, 4 (15%) were isolated injuries to the soleus muscle, and the remaining 3 injuries (11%) involved both. Defensive players were more likely to sustain injuries ( P = .043). The mean time to return to play for all 27 players was 17.4 ± 14.6 days (range, 3-62 days). MRIs were available in 14 of the 27 injuries. The average size of the fascial defect ( P = .032) and the presence of a fluid collection ( P = .031) both correlated with return to play of longer than 2 weeks. Although less common than hamstring or quadriceps muscle injuries, calf muscle injuries occur with relative frequency in the NFL, and more so in defensive players. The majority of these injuries occur in the gastrocnemius and result in significant disability, with at least 2 weeks of missed playing time on average. MRI may have an important role in the evaluation

  10. Student Mobility and Transnational Social Ties as Factors of Reflexivity

    Directory of Open Access Journals (Sweden)

    Tea Golob

    2018-03-01

    Full Text Available The article seeks to develop and apply new quantitative measurement instruments capable of significantly improving understanding of the relationship between the transnational mobility and transnational social ties of students, along with their reflexive capacities. With a focus on students building their personal networks, educational and professional activities that extend beyond the nation’s borders and organising their day-to-day routines in transnational social spaces, we analyse the role of mobility in their reflexive capacities. Applying a tool that is line with Archer’s theory and indicators to measure reflexivity, and transnational social ties as proposed by Molina et al., we analyse data collected via an on-line survey questionnaire administered to Slovenian students. In addition, students from the Middle East (Lebanon and the USA (Hawai’i are added for comparative purposes. The results of path analysis show the Slovenian students’ mobility as such implies higher scores for meta reflexivity, combined with lower scores for communicative and fractured reflexivity. Further, social transactions reaching beyond one’s physical localities in terms of transnational social ties implies they have higher levels of reflexivity in general.

  11. Recombinant Uncarboxylated Osteocalcin Per Se Enhances Mouse Skeletal Muscle Glucose Uptake in both Extensor Digitorum Longus and Soleus Muscles

    Directory of Open Access Journals (Sweden)

    Xuzhu Lin

    2017-11-01

    Full Text Available Emerging evidence suggests that undercarboxylated osteocalcin (ucOC improves muscle glucose uptake in rodents. However, whether ucOC can directly increase glucose uptake in both glycolytic and oxidative muscles and the possible mechanisms of action still need further exploration. We tested the hypothesis that ucOC per se stimulates muscle glucose uptake via extracellular signal-regulated kinase (ERK, adenosine monophosphate-activated protein kinase (AMPK, and/or the mechanistic target of rapamycin complex 2 (mTORC2-protein kinase B (AKT-AKT substrate of 160 kDa (AS160 signaling cascade. Extensor digitorum longus (EDL and soleus muscles from male C57BL/6 mice were isolated, divided into halves, and then incubated with ucOC with or without the pretreatment of ERK inhibitor U0126. ucOC increased muscle glucose uptake in both EDL and soleus. It also enhanced phosphorylation of ERK2 (Thr202/Tyr204 and AS160 (Thr642 in both muscle types and increased mTOR phosphorylation (Ser2481 in EDL only. ucOC had no significant effect on the phosphorylation of AMPKα (Thr172. The inhibition of ucOC-induced ERK phosphorylation had limited effect on ucOC-stimulated glucose uptake and AS160 phosphorylation in both muscle types, but appeared to inhibit the elevation in AKT phosphorylation only in EDL. Taken together, ucOC at the physiological range directly increased glucose uptake in both EDL and soleus muscles in mouse. The molecular mechanisms behind this ucOC effect on muscle glucose uptake seem to be muscle type-specific, involving enhanced phosphorylation of AS160 but limitedly modulated by ERK phosphorylation. Our study suggests that, since ucOC increases muscle glucose uptake without insulin, it could be considered as a potential agent to improve muscle glucose uptake in insulin resistant conditions.

  12. Reflexivity: The Creation of Liminal Spaces--Researchers, Participants, and Research Encounters.

    Science.gov (United States)

    Enosh, Guy; Ben-Ari, Adital

    2016-03-01

    Reflexivity is defined as the constant movement between being in the phenomenon and stepping outside of it. In this article, we specify three foci of reflexivity--the researcher, the participant, and the encounter--for exploring the interview process as a dialogic liminal space of mutual reflection between researcher and participant. Whereas researchers' reflexivity has been discussed extensively in the professional discourse, participants' reflexivity has not received adequate scholarly attention, nor has the promise inherent in reflective processes occurring within the encounter. © The Author(s) 2015.

  13. Probabilities on Streams and Reflexive Games

    Directory of Open Access Journals (Sweden)

    Andrew Schumann

    2014-01-01

    Full Text Available Probability measures on streams (e.g. on hypernumbers and p-adic numbers have been defined. It was shown that these probabilities can be used for simulations of reflexive games. In particular, it can be proved that Aumann's agreement theorem does not hold for these probabilities. Instead of this theorem, there is a statement that is called the reflexion disagreement theorem. Based on this theorem, probabilistic and knowledge conditions can be defined for reflexive games at various reflexion levels up to the infinite level. (original abstract

  14. Researching Reflexively With Patients and Families: Two Studies Using Video-Reflexive Ethnography to Collaborate With Patients and Families in Patient Safety Research.

    Science.gov (United States)

    Collier, Aileen; Wyer, Mary

    2016-06-01

    Patient safety research has to date offered few opportunities for patients and families to be actively involved in the research process. This article describes our collaboration with patients and families in two separate studies, involving end-of-life care and infection control in acute care. We used the collaborative methodology of video-reflexive ethnography, which has been primarily used with clinicians, to involve patients and families as active participants and collaborators in our research. The purpose of this article is to share our experiences and findings that iterative researcher reflexivity in the field was critical to the progress and success of each study. We present and analyze the complexities of reflexivity-in-the-field through a framework of multilayered reflexivity. We share our lessons here for other researchers seeking to actively involve patients and families in patient safety research using collaborative visual methods. © The Author(s) 2015.

  15. Learning reflexively from a health promotion professional development program in Canada.

    Science.gov (United States)

    Tremblay, Marie-Claude; Richard, Lucie; Brousselle, Astrid; Beaudet, Nicole

    2014-09-01

    In recent decades, reflexivity has received much attention in the professional education and training literature, especially in the public health and health promotion fields. Despite general agreement on the importance of reflexivity, there appears to be no consensus on how to assess reflexivity or to conceptualize the different forms developed among professionals and participants of training programs. This paper presents an analysis of the reflexivity outcomes of the Health Promotion Laboratory, an innovative professional development program aimed at supporting practice changes among health professionals by fostering competency development and reflexivity. More specifically, this paper explores the difference between two levels of reflexivity (formative and critical) and highlights some implications of each for practice. Data were collected through qualitative interviews with participants from two intervention sites. Results showed that involvement in the Health Promotion Laboratory prompted many participants to modify their vision of their practice and professional role, indicating an impact on reflexivity. In many cases, new understandings seem to have played a formative function in enabling participants to improve their practice and their role as health promoters. The reflective process also served a critical function culminating in a social and moral understanding of the impacts on society of the professionals' practices and roles. This type of outcome is greatly desired in health promotion, given the social justice and equity concerns of this field of practice. By redefining the theoretical concept of reflexivity on two levels and discussing their impacts on practice, this study supports the usefulness of both levels of reflexivity. © The Author (2013). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Study of Achilles Tendon Reflex in Normal Korean and Various Thyroid Diseases

    International Nuclear Information System (INIS)

    Kang, Jin Yung; Kim, Kwang Won; Yae, Sung Bo; Lee, Hong Kyu; Koh, Chang Soon

    1975-01-01

    In an attempt to establish the diagnostic value of Achilles tendon reflex and to determine the normal value of Achilles tendon reflex time in normal Korean, the author measured the Achilles tendon reflex time by photomotograph. This study was carried out in 272 cases with various thyroid diseases and 340 normal Korean. 1) The Achilles tendon reflex time in normal Korean was like this, between 11 years old and 20 years old; male (62 cases); 250±27 msec, female (36 cases); 266±27 msec, between 21 years old and 30 years old; male (38 cases); 271±27 msec, female (21 cases); 284±27 msec, between 31 years old and 40 years old; male (26 cases); 275±25 msec, female (29 cases); 291±27 msec, between 41 years old and 50 years old; male (20 cases); 286±35 msec, female (24 cases); 307±42 msec, between 51 years old and 60 years old, male (20 cases); 296±33 msec, female (20 cases); 318±46 msec, over 61 years; male (24 cases) 301±33 msec, female (20 cases); 325±35 msec. The Achilles tendon reflex time was delayed with increasing age and delayed in the female. 2) The Achilles tendon reflex time was markedly shortened to 221±20 msec in untreated hyperthyroidism. 3) The Achilles tendon reflex time was markedly delayed to 435±59 msec in hypothyroidism. 4) The Achilles tendon reflex time was not changed significantly in other thyroid diseases with norms thyroid function. 5) The Achilles tendon reflex time showed good correlationship with ETR, T 3 RU, 131 I thyroid uptake and serum TSH. 6) Reproducibility of Achilles tendon reflex time was good, and no significant difference between left and right was noted. 7) Diagnostic accuracy of Achilles tendon reflex time was 71% in hyperthyroidism and 90% in hypothyroidism. 8) The Achilles tendon reflex time showed useful test to evaluate the clinical course of the hyperthyroidism.

  17. Effects of whole body vibration on motor unit recruitment and threshold.

    Science.gov (United States)

    Pollock, Ross D; Woledge, Roger C; Martin, Finbarr C; Newham, Di J

    2012-02-01

    Whole body vibration (WBV) has been suggested to elicit reflex muscle contractions but this has never been verified. We recorded from 32 single motor units (MU) in the vastus lateralis of 7 healthy subjects (34 ± 15.4 yr) during five 1-min bouts of WBV (30 Hz, 3 mm peak to peak), and the vibration waveform was also recorded. Recruitment thresholds were recorded from 38 MUs before and after WBV. The phase angle distribution of all MUs during WBV was nonuniform (P recruitment threshold after WBV and average recruitment threshold; the lowest threshold MUs increased recruitment threshold (P = 0.008) while reductions were observed in the higher threshold units (P = 0.031). We investigated one possible cause of changed thresholds. Presynaptic inhibition in the soleus was measured in 8 healthy subjects (29 ± 4.6 yr). A total of 30 H-reflexes (stimulation intensity 30% Mmax) were recorded before and after WBV: 15 conditioned by prior stimulation (60 ms) of the antagonist and 15 unconditioned. There were no significant changes in the relationship between the conditioned and unconditioned responses. The consistent phase angle at which each MU fired during WBV indicates the presence of reflex muscle activity similar to the tonic vibration reflex. The varying response in high- and low-threshold MUs may be due to the different contributions of the mono- and polysynaptic pathways but not presynaptic inhibition.

  18. Avian reflex and electroencephalogram responses in different states of consciousness.

    Science.gov (United States)

    Sandercock, Dale A; Auckburally, Adam; Flaherty, Derek; Sandilands, Victoria; McKeegan, Dorothy E F

    2014-06-22

    Defining states of clinical consciousness in animals is important in veterinary anaesthesia and in studies of euthanasia and welfare assessment at slaughter. The aim of this study was to validate readily observable reflex responses in relation to different conscious states, as confirmed by EEG analysis, in two species of birds under laboratory conditions (35-week-old layer hens (n=12) and 11-week-old turkeys (n=10)). We evaluated clinical reflexes and characterised electroencephalograph (EEG) activity (as a measure of brain function) using spectral analyses in four different clinical states of consciousness: conscious (fully awake), semi-conscious (sedated), unconscious-optimal (general anaesthesia), unconscious-sub optimal (deep hypnotic state), as well as assessment immediately following euthanasia. Jaw or neck muscle tone was the most reliable reflex measure distinguishing between conscious and unconscious states. Pupillary reflex was consistently observed until respiratory arrest. Nictitating membrane reflex persisted for a short time (power (PTOT) significantly increased, whereas median (F50) and spectral edge (F95) frequencies significantly decreased. This study demonstrates that EEG analysis can differentiate between clinical states (and loss of brain function at death) in birds and provides a unique integration of reflex responses and EEG activity. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Intrapartum synthetic oxytocin reduce the expression of primitive reflexes associated with breastfeeding.

    Science.gov (United States)

    Marín Gabriel, Miguel A; Olza Fernández, Ibone; Malalana Martínez, Ana M; González Armengod, Carmen; Costarelli, Valeria; Millán Santos, Isabel; Fernández-Cañadas Morillo, Aurora; Pérez Riveiro, Pilar; López Sánchez, Francisco; García Murillo, Lourdes

    2015-05-01

    Several synthetic peptide manipulations during the time surrounding birth can alter the specific neurohormonal status in the newborn brain. This study is aimed at assessing whether intrapartum oxytocin administration has any effect on primitive neonatal reflexes and determining whether such an effect is dose-dependent. A cohort prospective study was conducted at a tertiary hospital. Mother-infant dyads who received intrapartum oxytocin (n=53) were compared with mother-infant dyads who did not receive intrapartum oxytocin (n=45). Primitive neonatal reflexes (endogenous, antigravity, motor, and rhythmic reflexes) were quantified by analyzing videotaped breastfeeding sessions in a biological nurturing position. Two observers blind to the group assignment and the oxytocin dose analyzed the videotapes and assesed the newborn's state of consciousness according to the Brazelton scale. The release of all rhythmic reflexes (p=0.01), the antigravity reflex (p=0.04), and total primitive neonatal reflexes (p=0.02) in the group exposed to oxytocin was lower than in the group not exposed to oxytocin. No correlations were observed between the dose of oxytocin administered and the percentage of primitive neonatal reflexes released (r=0.03; p=0.82). Intrapartum oxytocin administration might inhibit the expression of several primitive neonatal reflexes associated with breastfeeding. This correlation does not seem to be dose-dependent.

  20. Reflex epileptic mechanisms in humans: Lessons about natural ictogenesis.

    Science.gov (United States)

    Wolf, Peter

    2017-06-01

    The definition of reflex epileptic seizures is that specific seizure types can be triggered by certain sensory or cognitive stimuli. Simple triggers are sensory (most often visual, more rarely tactile or proprioceptive; simple audiogenic triggers in humans are practically nonexistent) and act within seconds, whereas complex triggers like praxis, reading and talking, and music are mostly cognitive and work within minutes. The constant relation between a qualitatively, often even quantitatively, well-defined stimulus and a specific epileptic response provides unique possibilities to investigate seizure generation in natural human epilepsies. For several reflex epileptic mechanisms (REMs), this has been done. Reflex epileptic mechanisms have been reported less often in focal lesional epilepsies than in idiopathic "generalized" epilepsies (IGEs) which are primarily genetically determined. The key syndrome of IGE is juvenile myoclonic epilepsy (JME), where more than half of the patients present reflex epileptic traits (photosensitivity, eye closure sensitivity, praxis induction, and language-induced orofacial reflex myocloni). Findings with multimodal investigations of cerebral function concur to indicate that ictogenic mechanisms in IGEs largely (ab)use preexisting functional anatomic networks (CNS subsystems) normally serving highly complex physiological functions (e.g., deliberate complex actions and linguistic communication) which supports the concept of system epilepsy. Whereas REMs in IGEs, thus, are primarily function-related, in focal epilepsies, they are primarily localization-related. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic". Copyright © 2015 Elsevier Inc. All rights reserved.

  1. FEFsem neuronal response during combined volitional and reflexive pursuit.

    Science.gov (United States)

    Bakst, Leah; Fleuriet, Jérome; Mustari, Michael J

    2017-05-01

    Although much is known about volitional and reflexive smooth eye movements individually, much less is known about how they are coordinated. It is hypothesized that separate cortico-ponto-cerebellar loops subserve these different types of smooth eye movements. Specifically, the MT-MST-DLPN pathway is thought to be critical for ocular following eye movements, whereas the FEF-NRTP pathway is understood to be vital for volitional smooth pursuit. However, the role that these loops play in combined volitional and reflexive behavior is unknown. We used a large, textured background moving in conjunction with a small target spot to investigate the eye movements evoked by a combined volitional and reflexive pursuit task. We also assessed the activity of neurons in the smooth eye movement subregion of the frontal eye field (FEFsem). We hypothesized that the pursuit system would show less contribution from the volitional pathway in this task, owing to the increased involvement of the reflexive pathway. In accordance with this hypothesis, a majority of FEFsem neurons (63%) were less active during pursuit maintenance in a combined volitional and reflexive pursuit task than during purely volitional pursuit. Interestingly and surprisingly, the neuronal response to the addition of the large-field motion was highly correlated with the neuronal response to a target blink. This suggests that FEFsem neuronal responses to these different perturbations-whether the addition or subtraction of retinal input-may be related. We conjecture that these findings are due to changing weights of both the volitional and reflexive pathways, as well as retinal and extraretinal signals.

  2. Orthodontic treatment-induced temporal alteration of jaw-opening reflex excitability.

    Science.gov (United States)

    Sasaki, Au; Hasegawa, Naoya; Adachi, Kazunori; Sakagami, Hiroshi; Suda, Naoto

    2017-10-01

    The impairment of orofacial motor function during orthodontic treatment needs to be addressed, because most orthodontic patients experience pain and motor excitability would be affected by pain. In the present study, the temporal alteration of the jaw-opening reflex excitability was investigated to determine if orthodontic treatment affects orofacial motor function. The excitability of jaw-opening reflex evoked by electrical stimulation on the gingiva and recorded bilaterally in the anterior digastric muscles was evaluated at 1 (D1), 3 (D3), and 7 days (D7) after orthodontic force application to the teeth of right side; morphological features (e.g., osteoclast genesis and tooth movement) were also evaluated. To clarify the underlying mechanism of orthodontic treatment-induced alteration of orofacial motor excitability, analgesics were administrated for 1 day. At D1 and D3, orthodontic treatment significantly decreased the threshold for inducing the jaw-opening reflex but significantly increased the threshold at D7. Other parameters of the jaw-opening reflex were also evaluated (e.g., latency, duration and area under the curve of anterior digastric muscles activity), and only the latency of the D1 group was significantly different from that of the other groups. Temporal alteration of the jaw-opening reflex excitability was significantly correlated with changes in morphological features. Aspirin (300 mg·kg -1 ·day -1 ) significantly increased the threshold for inducing the jaw-opening reflex, whereas a lower dose (75-150 mg·kg -1 ·day -1 ) of aspirin or acetaminophen (300 mg·kg -1 ·day -1 ) failed to alter the jaw-opening reflex excitability. These results suggest that an increase of the jaw-opening reflex excitability can be induced acutely by orthodontic treatment, possibly through the cyclooxygenase activation. NEW & NOTEWORTHY It is well known that motor function is affected by pain, but the effect of orthodontic treatment-related pain on the trigeminal

  3. Reflexivity as a control factor of personal coping behavior

    OpenAIRE

    BEKHTER A.A.

    2014-01-01

    The article deals with the issue of coping behavior control. The author defines the criteria, levels and aspects of reflexivity within the framework of personal coping behavior. In conclusion the author describes the key facets of coping behavior control and how reflexivity affects them.

  4. Isometric and Dynamic Control of Neck Muscles : Reflexive contributions and muscle synergies

    NARCIS (Netherlands)

    De Bruijn, E.

    2014-01-01

    It is well established that the central nervous system (CNS) stabilizes the head using reflexive feedback and cocontraction. The major reflexive pathways in the neck are through muscle spindles generating the cervicocollic reflex (CCR) and through the vestibular organ generating the vestibulocollic

  5. Comparison of Stretch Reflex Torques in Ankle Dorsiflexors and Plantarflexors

    National Research Council Canada - National Science Library

    Tung, J

    2001-01-01

    ...) ankle muscles, Pulse, step, and a combination of random perturbation and step inputs were used to identify the reflex and intrinsic contributions to the measured torque, TA reflex torques were very...

  6. Habituation and adaptation of the vestibuloocular reflex: a model of differential control by the vestibulocerebellum

    Science.gov (United States)

    Cohen, H.; Cohen, B.; Raphan, T.; Waespe, W.

    1992-01-01

    We habituated the dominant time constant of the horizontal vestibuloocular reflex (VOR) of rhesus and cynomolgus monkeys by repeated testing with steps of velocity about a vertical axis and adapted the gain of the VOR by altering visual input with magnifying and reducing lenses. After baseline values were established, the nodulus and ventral uvula of the vestibulocerebellum were ablated in two monkeys, and the effects of nodulouvulectomy and flocculectomy on VOR gain adaptation and habituation were compared. The VOR time constant decreased with repeated testing, rapidly at first and more slowly thereafter. The gain of the VOR was unaffected. Massed trials were more effective than distributed trials in producing habituation. Regardless of the schedule of testing, the VOR time constant never fell below the time constant of the semicircular canals (approximately 5 s). This finding indicates that only the slow component of the vestibular response, the component produced by velocity storage, was habituated. In agreement with this, the time constant of optokinetic after-nystagmus (OKAN) was habituated concurrently with the VOR. Average values for VOR habituation were obtained on a per session basis for six animals. The VOR gain was adapted by natural head movements in partially habituated monkeys while they wore x 2.2 magnifying or x 0.5 reducing lenses. Adaptation occurred rapidly and reached about +/- 30%, similar to values obtained using forced rotation. VOR gain adaptation did not cause additional habituation of the time constant. When the VOR gain was reduced in animals with a long VOR time constant, there were overshoots in eye velocity that peaked at about 6-8 s after the onset or end of constant-velocity rotation. These overshoots occurred at times when the velocity storage integrator would have been maximally activated by semicircular canal input. Since the activity generated in the canals is not altered by visual adaptation, this finding indicates that the gain

  7. ESO Reflex: a graphical workflow engine for data reduction

    Science.gov (United States)

    Hook, Richard; Ullgrén, Marko; Romaniello, Martino; Maisala, Sami; Oittinen, Tero; Solin, Otto; Savolainen, Ville; Järveläinen, Pekka; Tyynelä, Jani; Péron, Michèle; Ballester, Pascal; Gabasch, Armin; Izzo, Carlo

    ESO Reflex is a prototype software tool that provides a novel approach to astronomical data reduction by integrating a modern graphical workflow system (Taverna) with existing legacy data reduction algorithms. Most of the raw data produced by instruments at the ESO Very Large Telescope (VLT) in Chile are reduced using recipes. These are compiled C applications following an ESO standard and utilising routines provided by the Common Pipeline Library (CPL). Currently these are run in batch mode as part of the data flow system to generate the input to the ESO/VLT quality control process and are also exported for use offline. ESO Reflex can invoke CPL-based recipes in a flexible way through a general purpose graphical interface. ESO Reflex is based on the Taverna system that was originally developed within the UK life-sciences community. Workflows have been created so far for three VLT/VLTI instruments, and the GUI allows the user to make changes to these or create workflows of their own. Python scripts or IDL procedures can be easily brought into workflows and a variety of visualisation and display options, including custom product inspection and validation steps, are available. Taverna is intended for use with web services and experiments using ESO Reflex to access Virtual Observatory web services have been successfully performed. ESO Reflex is the main product developed by Sampo, a project led by ESO and conducted by a software development team from Finland as an in-kind contribution to joining ESO. The goal was to look into the needs of the ESO community in the area of data reduction environments and to create pilot software products that illustrate critical steps along the road to a new system. Sampo concluded early in 2008. This contribution will describe ESO Reflex and show several examples of its use both locally and using Virtual Observatory remote web services. ESO Reflex is expected to be released to the community in early 2009.

  8. Reflex epilepsy: a review

    Directory of Open Access Journals (Sweden)

    Karim Nikkhah

    2017-01-01

    Full Text Available Interesting phenomena of reflex epileptic syndromes are characterized by epileptic seizures each one induced by specific stimulus with a variety of types. Simple triggers, which lead to seizures within seconds, are of sensory type (most commonly visual, most rarely tactile or proprioceptive stimuli. Complex triggers, which are mostly of cognitive type such as praxis, reading, talking, and music, usually induce the epileptic event within minutes. It should differ from what most epileptic patients report as provocative precipitants for seizures (such as emotional stress, fatigue, fever, sleep deprivation, alcohol, and menstrual cycle. The identification of a specific trigger is not only important for patients or their parents to avoid seizures, but also it might help neurologists to choose the most effective antiepileptic drug for each case. In addition, research in this area may possibly reveal some underlying pathophysiology of epileptic phenomena in the brain.In this review, we briefly introduce reported reflex epileptic seizures, their clinical features and management.

  9. Reflexive Dressing: Rethinking Retro

    Directory of Open Access Journals (Sweden)

    Stella North

    2016-03-01

    Full Text Available This article undertakes a philosophical exploration of the act we know, or think we know, as ‘dressing’. Inhabiting, in thought, the moment in which we dress, I examine some of its constituent mechanisms, attending to the impulses by which dressing is generated out of subjective experience.  When those impulses are temporally marked, as they are in the case of retro dress, this generation is a two-pronged process, in which the holding of the body in time, and the holding of time in the body, recalibrate one another. The process of ‘dressing,’ in this understanding, has a reflexivity which is double; it entails the turning of the body, with dress as medium, towards itself, and the turning of present experience towards some felt notion of the past. Reflexively dressing, we are always becoming ourselves, and becoming other than ourselves, at once; a movement of circuitous internalisation and externalisation by which the ambiguation inherent in material experience is realised.

  10. Reflexive anaphor resolution in spoken language comprehension: Structural constraints and beyond

    Directory of Open Access Journals (Sweden)

    Kaili eClackson

    2014-08-01

    Full Text Available We report results from an eye-tracking during listening study examining English-speaking adults’ online processing of reflexive pronouns, and specifically whether the search for an antecedent is restricted to syntactically appropriate positions. Participants listened to a short story where the recipient of an object was introduced with a reflexive, and were asked to identify the object recipient as quickly as possible. This allowed for the recording of participants’ offline interpretation of the reflexive, response times, and eye movements on hearing the reflexive. Whilst our offline results show that the ultimate interpretation for reflexives was constrained by binding principles, the response time and eye-movement data revealed that during processing participants were temporarily distracted by a structurally inappropriate competitor antecedent when this was prominent in the discourse. These results indicate that in addition to binding principles, online referential decisions are also affected by discourse-level information.

  11. Reflexive anaphor resolution in spoken language comprehension: structural constraints and beyond

    Science.gov (United States)

    Clackson, Kaili; Heyer, Vera

    2014-01-01

    We report results from an eye-tracking during listening study examining English-speaking adults’ online processing of reflexive pronouns, and specifically whether the search for an antecedent is restricted to syntactically appropriate positions. Participants listened to a short story where the recipient of an object was introduced with a reflexive, and were asked to identify the object recipient as quickly as possible. This allowed for the recording of participants’ offline interpretation of the reflexive, response times, and eye movements on hearing the reflexive. Whilst our offline results show that the ultimate interpretation for reflexives was constrained by binding principles, the response time, and eye-movement data revealed that during processing participants were temporarily distracted by a structurally inappropriate competitor antecedent when this was prominent in the discourse. These results indicate that in addition to binding principles, online referential decisions are also affected by discourse-level information. PMID:25191290

  12. H-index is important for postural control for people with impaired foot sole sensation.

    Directory of Open Access Journals (Sweden)

    Shuqi Zhang

    Full Text Available People with Peripheral Neuropathy (PN, especially those with impaired sensory inputs through the small-afferent fiber (type II afferent fibers reflex loop (SAF, might depend more on the large-afferent fiber (type I afferent fibers reflex loop (LAF for postural control.To examine whether the function of the LAF reflex loop, reflected by the H-reflex and ankle joint proprioception, influences postural control when the SAF reflex loop is impaired, as indicated by reduced foot sole cutaneous sensation.Thirteen participants (8 women, 5 men diagnosed with PN and 12 age-matched controls (7 women, 5 men completed the testing protocol. Measures of interest included the H-index, active (AAP and passive (PAP ankle proprioception, plantar pressure sensitivity (PPS, average sway velocity (VAVG and area (A95 during 30 seconds eyes-closed standing, 6-minute walk distance (6MWD and timed up-and-go duration (TUG.Statistically significant group-dependent regression was observed between VAVG and H-index. Compared to the control group, the PN group demonstrated reduced PPS (2.0 ± 1.9 vs. 4.2 ± 1.2, P < .05 and H-index (63.6 ± 10.9 vs. 76.4 ± 16.0, P < .05, greater VAVG (3.5 ± 2.1 vs. 1.6 ± 0.6 cm/s, P < .05 and A95 (10.0 ± 10.1 vs. 2.5 ± 1.5 cm2, P < .05, shorter 6MWD (442.2 ± 93.0 vs. 525.3 ± 68.2 m, P < .05, and longer TUG (9.4 ± 1.6 vs. 6.5 ± 1.3 s, P < .05. Within the PN group, but not the control group, the H-index was correlated with VAVG (r = -.56, P < .05. Moreover, within the PN group only, PAP scores were correlated with 6MWD (r = -.68, P < .05 and TUG (r = -.59, P < .05 performance. No other statistically significant group difference, correlation or group-dependent regression was observed.VAVG, 6MWD, and TUG correlated with LAF reflex loop function observed among those with impaired functioning of the SAF reflex loop. This observation suggests that the LAF reflex loop may be critical to the control of balance in those individuals suffering

  13. Management of Reflex Anoxic Seizures

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2013-10-01

    Full Text Available Investigators at the Roald Dahl EEG Unit, Alder Hey Children’s NHS Foundation, Liverpool, UK, review the definition, pathophysiology, clinical presentation, and management of reflex anoxic seizures (RAS in children.

  14. Role of spared pathways in locomotor recovery after body-weight-supported treadmill training in contused rats.

    Science.gov (United States)

    Singh, Anita; Balasubramanian, Sriram; Murray, Marion; Lemay, Michel; Houle, John

    2011-12-01

    Body-weight-supported treadmill training (BWSTT)-related locomotor recovery has been shown in spinalized animals. Only a few animal studies have demonstrated locomotor recovery after BWSTT in an incomplete spinal cord injury (SCI) model, such as contusion injury. The contribution of spared descending pathways after BWSTT to behavioral recovery is unclear. Our goal was to evaluate locomotor recovery in contused rats after BWSTT, and to study the role of spared pathways in spinal plasticity after BWSTT. Forty-eight rats received a contusion, a transection, or a contusion followed at 9 weeks by a second transection injury. Half of the animals in the three injury groups were given BWSTT for up to 8 weeks. Kinematics and the Basso-Beattie-Bresnahan (BBB) test assessed behavioral improvements. Changes in Hoffmann-reflex (H-reflex) rate depression property, soleus muscle mass, and sprouting of primary afferent fibers were also evaluated. BWSTT-contused animals showed accelerated locomotor recovery, improved H-reflex properties, reduced muscle atrophy, and decreased sprouting of small caliber afferent fibers. BBB scores were not improved by BWSTT. Untrained contused rats that received a transection exhibited a decrease in kinematic parameters immediately after the transection; in contrast, trained contused rats did not show an immediate decrease in kinematic parameters after transection. This suggests that BWSTT with spared descending pathways leads to neuroplasticity at the lumbar spinal level that is capable of maintaining locomotor activity. Discontinuing training after the transection in the trained contused rats abolished the improved kinematics within 2 weeks and led to a reversal of the improved H-reflex response, increased muscle atrophy, and an increase in primary afferent fiber sprouting. Thus continued training may be required for maintenance of the recovery. Transected animals had no effect of BWSTT, indicating that in the absence of spared pathways this

  15. A new hypothesis of cause of syncope: trigeminocardiac reflex during extraction of teeth.

    Science.gov (United States)

    Arakeri, Gururaj; Arali, Veena

    2010-02-01

    Transient Loss Of Consciousness (TLOC) or vasovagal syncope is well known phenomenon in dental/maxillofacial surgery. Despite considerable study of vasovagal syncope, its pathophysiology remains to be fully elucidated. After having encountered a case of trigeminocardiac reflex after extraction of maxillary first molar we observed and studied 400 extractions under local anesthesia to know the relation between trigeminocardiac reflex and syncope. We make hypothesis that trigeminocardiac reflex which is usually seen under general anesthesia when all sympathetic reflexes are blunted can also occur under local anesthesia during extractions of maxillary molars (dento-cardiac reflex) and mediate syncope.

  16. High-power ion beam generation with an inverse reflex tetrode

    International Nuclear Information System (INIS)

    Pasour, J.A.; Mahaffey, R.A.; Golden, J.; Kapetanakos, C.A.

    1980-01-01

    A new reflexing-electron ion source is described. The device produces a unidirectional ion beam with relatively high efficiency even when the applied magnetic field exceeds the self-field. This new source operates at a low, constant impedance during much of the applied voltage pulse and is better matched to available high-power, low-impedance generators than previous reflexing-electron devices. Proton pulses with peak current approx.500 kA have been produced with the inverse reflex tetrode coupled to the Gamble II generator

  17. The Role of Transformational Leadership in Enhancing Team Reflexivity

    NARCIS (Netherlands)

    M.C. Schippers (Michaéla); D.N. den Hartog (Deanne); P.L. Koopman (Paul); D.L. van Knippenberg (Daan)

    2007-01-01

    textabstractTeam reflexivity, or the extent to which teams reflect upon and modify their functioning, has been identified as a key factor in the effectiveness of work teams. As yet, however, little is known about the factors that play a role in enhancing team reflexivity, and it is thus important to

  18. The role of transformational leadership in enhancing team reflexivity

    NARCIS (Netherlands)

    Schippers, M.C.; den Hartog, D.N.; Koopman, P.L.; van Knippenberg, D.

    2008-01-01

    Team reflexivity, or the extent to which teams reflect upon and modify their functioning, has been identified as a key factor in the effectiveness of work teams. As yet, however, little is known about the factors that play a role in enhancing team reflexivity, and it is thus important to develop

  19. Vestibular Compensation in Unilateral Patients Often Causes Both Gain and Time Constant Asymmetries in The VOR

    Directory of Open Access Journals (Sweden)

    Mina eRanjbaran

    2016-03-01

    Full Text Available The vestibulo-ocular reflex (VOR is essential in our daily life to stabilize retinal images during head movements. Balanced vestibular functionality secures optimal reflex performance which can be distorted in case of peripheral vestibular lesions. Luckily, vestibular compensation in different neuronal sites restores VOR function to some extent over time. Studying vestibular compensation gives insight into the possible mechanisms for plasticity in the brain.In this work, novel experimental analysis tools are employed to reevaluate the VOR characteristics following unilateral vestibular lesions and compensation. Our results suggest that following vestibular lesions, asymmetric performance of the VOR is not only limited to its gain. Vestibular compensation also causes asymmetric dynamics, i.e. different time constants for the VOR during leftward or rightward passive head rotation. Potential mechanisms for these experimental observations are provided using simulation studies.

  20. Deprivation and Recovery of Sleep in Succession Enhances Reflexive Motor Behavior

    OpenAIRE

    Sprenger, Andreas; Weber, Frederik D.; Machner, Bjoern; Talamo, Silke; Scheffelmeier, Sabine; Bethke, Judith; Helmchen, Christoph; Gais, Steffen; Kimmig, Hubert; Born, Jan

    2015-01-01

    Sleep deprivation impairs inhibitory control over reflexive behavior, and this impairment is commonly assumed to dissipate after recovery sleep. Contrary to this belief, here we show that fast reflexive behaviors, when practiced during sleep deprivation, is consolidated across recovery sleep and, thereby, becomes preserved. As a model for the study of sleep effects on prefrontal cortex-mediated inhibitory control in humans, we examined reflexive saccadic eye movements (express saccades), as w...

  1. Trigeminocardiac reflex during endoscopic juvenile nasopharyngeal angiofibroma surgery: an appraisal.

    Science.gov (United States)

    Sharma, Shilpee Bhatia; Janakiram, Trichy Narayanan; Baxi, Hina; Chinnasamy, Balamurugan

    2017-07-01

    Juvenile nasopharyngeal angiofibroma is a locally aggressive benign tumour which has propensity to erode the skull base. The tumour spreads along the pathways of least resistance and is in close proximity to the extracranial part of trigeminal nerve. Advancements in expanded approaches for endoscopic excision of tumours in infratemporal fossa and pterygopalatine fossa increase the vulnerability for the trigeminocardiac reflex. The manipulation of nerve and its branches during tumour dissection can lead to sensory stimulation and thus inciting the reflex. The aim of our study is to report the occurrence of trigeminocardiac reflex in endoscopic excision of juvenile nasopharyngeal angiofibroma. To describe the occurence of trigeminocardiac reflex during endoscopic endonasal excision of juvenile nasopharyngeal angiofibroma. We studied the occurrence of TCR in 15 patients (out of 242 primary cases and 52 revision cases) operated for endoscopic endonasal excision of JNA. The drop in mean arterial blood pressure and heart rate were observed and measured. To the best of our knowledge of English literature, this is the first case series reporting TCR as complication in endoscopic excision of JNA. occurence of this reflex has been mentioned in various occular, maxillofacial surgeries but its occurence during endoscopic excision of JNA has never been reported before. Manifestation of trigeminocardiac reflex during surgery can alter the course of the surgery and is a potential threat to life. It is essential for the anesthetist and surgeons to be familiar with the presentations, preventive measures and management protocols.

  2. Cocaine potentiates ketamine-induced loss of the righting reflex and sleeping time in mice. Role of catecholamines.

    Science.gov (United States)

    Vanderwende, C; Spoerlein, M T; Lapollo, J

    1982-07-01

    Cocaine in graded doses potentiated ketamine-induced loss of the righting reflex and sleeping time. Potentiation of drug-induced sleep with cocaine was not a generalized phenomenon inasmuch as it had no effect on sleep induced by pentobarbital or hexobarbital and decreased sleep induced by phenobarbital. Pentylenetetrazole reduced ketamine sleep but d-amphetamine had a potentiative action. dl-alpha-Methyl-p-tyrosine methyl ester itself increased both the number losing the righting reflex and the sleeping time induced by ketamine. However, the effect cocaine on sleeping time was blocked 3 h after the dl-alpha-methyl-p-tyrosine methyl ester was given. The alpha and beta adrenergic blocking drugs, phenoxybenzamine and propranolol, increased the number of animals losing the righting reflex with ketamine, and phenoxybenzamine lengthened the sleeping time. Alpha and beta adrenergic agonists, l-phenylephrine and isoproterenol, increased the number of animals going to sleep with ketamine but did not significantly alter how long they would sleep. The agonists had no effect on the cocaine interaction with ketamine, whereas the antagonists blocked the effect of cocaine. Both stimulation and blockade of dopamine receptors led to increased loss of the righting reflex and sleeping time with ketamine but only receptor blockade antagonized the effect of cocaine on ketamine-induced sleep. Thus, both the noradrenergic and dopaminergic systems appear to be involved in the ability of cocaine to potentiate ketamine-induced sleep.

  3. From Incidental, Mechanically-Induced Arrhythmias to Reflex-Defined Arrhythmogenicity: On The Track of The Ternary Reflex System Resemblance to The "Infancy" of New Era or Rediscovery.

    Science.gov (United States)

    Stirbys, Petras

    2016-01-01

    The underlying pathophysiology of supraventricular and ventricular arrhythmias remains a matter of intense investigation. Though evolving, the contemporary explanations do not encompass all aspects of arrhythmogenicity. An improved understanding of arrhythmia substrate is needed to augment therapeutic capabilities. Our observation and literature sources demonstrate relatively high incidence of transitory arrhythmias which are non-intentionally generated by the endocardial lead/catheter manipulation. These findings are interesting and potentially may crystallize the reflex-dependent proarrhythmic cardiac activity. Herein we suggest the "reflexogenic arrhythmogenicity" concept extending an overall spectrum of known hypotheses. Cardiovascular reflex action can be categorized into three-tiered levels - intra-cellular, inter-cellular and inter-organic. The first two levels of the triplicate system reside within the cardiac anatomical landmarks (in fact intramurally, intra-organically), however the third one implicates central (cerebral) activity which boomerangs back via centripetal and centrifugal connections. These levels likely compose synoptic ternary reflex set system which may be validated in future studies. To hypothesize, coordinated mutual reciprocity of reflex activity results in stabilization of heart rhythm in robust heart. Any stressful cardiac event may lead to the shift of the rhythm toward unfavorable clinical entity probably via the loss of the influence of dominant reflex. Overall, an interaction and likely intrinsic inter-tiered competition along with possible interplay between physiological and pathological reflexes may be treated as contributing factors for the inception and maintaining of arrhythmias and cardiac performance as well. These assumptions await further documentation. If such a tenet were recognized, the changes in the clinical approach to arrhythmia management might be anticipated, preferably by selective reflex suppression or

  4. Gain scheduling using the Youla parameterization

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    1999-01-01

    Gain scheduling controllers are considered in this paper. The gain scheduling problem where the scheduling parameter vector cannot be measured directly, but needs to be estimated is considered. An estimation of the scheduling vector has been derived by using the Youla parameterization. The use...... in connection with H_inf gain scheduling controllers....

  5. Emotion, reflexivity and social change in the era of extreme fossil fuels.

    Science.gov (United States)

    Davidson, Debra J

    2018-05-09

    Reflexivity is an important sociological lens through which to examine the means by which people engage in actions that contribute to social reproduction or social elaboration. Reflexivity theorists have largely overlooked the central place of emotions in reflexive processing, however, thus missing opportunities to enhance our understanding of reflexivity by capitalizing on recent scholarship on emotions emanating from other fields of inquiry. This paper explores the role of emotion in reflexivity, with a qualitative analysis of social responses to hydraulic fracturing in Alberta, Canada, utilizing narrative analysis of long-form interviews with rural landowners who have experienced direct impacts from hydraulic fracturing, and have attempted to voice their concerns in the public sphere. Based on interviews with a selection of two interview participants, the paper highlights the means by which emotions shape reflexivity in consequential ways, beginning with personal and highly individualized emotional responses to contingent situations, which then factor into the social interactions engaged in the pursuit of personal projects. The shared emotional context that emerges then plays a substantial role in shaping outcomes and their implications for social stasis or change. This study exemplifies the extent to which reflexive processing in response to breaches in the social order can be emotionally tumultuous affairs, constituting a significant personal toll that many may be unwilling to pay. © London School of Economics and Political Science 2018.

  6. Affective Modulation of the Startle Eyeblink and Postauricular Reflexes in Autism Spectrum Disorder

    Science.gov (United States)

    Dichter, Gabriel S.; Benning, Stephen D.; Holtzclaw, Tia N.; Bodfish, James W.

    2010-01-01

    Eyeblink and postauricular reflexes to standardized affective images were examined in individuals without (n = 37) and with (n = 20) autism spectrum disorders (ASDs). Affective reflex modulation in control participants replicated previous findings. The ASD group, however, showed anomalous reflex modulation patterns, despite similar self-report…

  7. Action of vanillin (Vanilla planifolia) on the morphology of tibialis anterior and soleus muscles after nerve injury.

    Science.gov (United States)

    Peretti, Ana Luiza; Antunes, Juliana Sobral; Lovison, Keli; Kunz, Regina Inês; Castor, Lidyane Regina Gomes; Brancalhão, Rose Meire Costa; Bertolini, Gladson Ricardo Flor; Ribeiro, Lucinéia de Fátima Chasko

    2017-01-01

    To evaluate the action of vanillin (Vanilla planifolia) on the morphology of tibialis anterior and soleus muscles after peripheral nerve injury. Wistar rats were divided into four groups, with seven animals each: Control Group, Vanillin Group, Injury Group, and Injury + Vanillin Group. The Injury Group and the Injury + Vanillin Group animals were submitted to nerve injury by compression of the sciatic nerve; the Vanillin Group and Injury + Vanillin Group, were treated daily with oral doses of vanillin (150mg/kg) from the 3rd to the 21st day after induction of nerve injury. At the end of the experiment, the tibialis anterior and soleus muscles were dissected and processed for light microscopy and submitted to morphological analysis. The nerve compression promoted morphological changes, typical of denervation, and the treatment with vanillin was responsible for different responses in the studied muscles. For the tibialis anterior, there was an increase in the number of satellite cells, central nuclei and fiber atrophy, as well as fascicular disorganization. In the soleus, only increased vascularization was observed, with no exacerbation of the morphological alterations in the fibers. The treatment with vanillin promoted increase in intramuscular vascularization for the muscles studied, with pro-inflammatory potential for tibialis anterior, but not for soleus muscle. Avaliar a ação da vanilina (Vanilla planifolia) sobre a morfologia dos músculos tibial anterior e sóleo após lesão nervosa periférica. Ratos Wistar foram divididos em quatro grupos, com sete animais cada, sendo Grupo Controle, Grupo Vanilina, Grupo Lesão e Grupo Lesão + Vanilina. Os animais dos Grupos Lesão e Grupo Lesão + Vanilina foram submetidos à lesão nervosa por meio da compressão do nervo isquiático, e os Grupos Vanilina e Grupo Lesão + Vanilina foram tratados diariamente com doses orais de vanilina (150mg/kg) do 3o ao 21o dia após a indução da lesão nervosa. Ao término do

  8. THE CONCEPT OF REFLEXIVE MANAGEMENT OF CONSUMER DEMAND

    Directory of Open Access Journals (Sweden)

    Maryna Mavrina

    2017-11-01

    Full Text Available Development of theoretical approaches of demand management is conducted from the moment of awareness of the importance of this concept. Many models of individual consumers were developed. However, to predict the reaction of consumers to the commercial policy of the enterprise, exact methods do not exist yet because the available ones are mostly empirical in nature. Models of behaviour often do not provide the expected result because they use an erroneous approach to the analysis of the mechanism of demand formation. The subject of the research is the theoretical and methodological basis, methods of assessment, and reflexive management of consumer demand of commercial enterprises. The purpose of the paper is developing a concept of reflexive management of consumer demand. To achieve the research goal, the following tasks are set and solved: to substantiate the theoretical and methodological foundations of reflexive consumer management, to analyse existing approaches to the modelling of consumer behaviour; to improve the model of consumer behaviour; to develop a concept of reflexive management of consumer behaviour. Methodology. In the paper, we use such methods and approaches to research as: reflexive approach (phenomenological method, behavioural economic theory, marketing approach, abstract-logical analysis, analysis of theoretical approaches to the modelling of consumer behaviour. Results. Modern approaches to modelling of consumer behaviour are mostly empirical in nature and have shortcomings of general models. In them, there is no description of specific situations of the purchase of goods. They cannot be quantified. Therefore, they cannot be practical models. But they have a weighty advantage in a comprehensive look at motivated purchases, what makes it possible to evaluate the relevance of individual variables and to understand the fundamental processes of consumer behaviour. It makes possible to identify the variables necessary for the

  9. The ubiquitous reflex and its critics in post-revolutionary Russia.

    Science.gov (United States)

    Sirotkina, Irina

    2009-03-01

    In the last century, the reflex was more than a scientific concept: it was a cultural idiom that could be used to various aims--political, scholarly, and artistic. In Russia in the 1920s, the reflex became a ubiquitous notion and a current word, part of the revolutionary discourse and, finally, a password to modernity. Two major factors contributed to it: physiological theories of the reflex, widespread in Russia at the early twentieth-century, and the materialist philosophy backed after the Revolution by the Communist party. Everybody who wished to be modern and materialist, in conformity with the official communist views, had to refer to reflexes. Yet, even in this period, the concept was not unproblematic and was criticized by some scientists, philosophers, artists and even Party members. In the paper, I describe both the array of uses of the term and the criticism it received in political, scientific and artistic discourses. It is not uncommon that, taking their origins in culture and common language, scientific concepts later return there in the form of metaphors. Similarly, the reflex was made into a rigorous scientific concept in the nineteenth century but, in the next century, it circulated as a cultural idiom penetrating various areas of political, artistic and academic life.

  10. Exercise training in Tgαq*44 mice during the progression of chronic heart failure: cardiac vs. peripheral (soleus muscle) impairments to oxidative metabolism.

    Science.gov (United States)

    Grassi, Bruno; Majerczak, Joanna; Bardi, Eleonora; Buso, Alessia; Comelli, Marina; Chlopicki, Stefan; Guzik, Magdalena; Mavelli, Irene; Nieckarz, Zenon; Salvadego, Desy; Tyrankiewicz, Urszula; Skórka, Tomasz; Bottinelli, Roberto; Zoladz, Jerzy A; Pellegrino, Maria Antonietta

    2017-08-01

    Cardiac function, skeletal (soleus) muscle oxidative metabolism, and the effects of exercise training were evaluated in a transgenic murine model (Tgα q *44) of chronic heart failure during the critical period between the occurrence of an impairment of cardiac function and the stage at which overt cardiac failure ensues (i.e., from 10 to 12 mo of age). Forty-eight Tgα q *44 mice and 43 wild-type FVB controls were randomly assigned to control groups and to groups undergoing 2 mo of intense exercise training (spontaneous running on an instrumented wheel). In mice evaluated at the beginning and at the end of training we determined: exercise performance (mean distance covered daily on the wheel); cardiac function in vivo (by magnetic resonance imaging); soleus mitochondrial respiration ex vivo (by high-resolution respirometry); muscle phenotype [myosin heavy chain (MHC) isoform content; citrate synthase (CS) activity]; and variables related to the energy status of muscle fibers [ratio of phosphorylated 5'-AMP-activated protein kinase (AMPK) to unphosphorylated AMPK] and mitochondrial biogenesis and function [peroxisome proliferative-activated receptor-γ coactivator-α (PGC-1α)]. In the untrained Tgα q *44 mice functional impairments of exercise performance, cardiac function, and soleus muscle mitochondrial respiration were observed. The impairment of mitochondrial respiration was related to the function of complex I of the respiratory chain, and it was not associated with differences in CS activity, MHC isoforms, p-AMPK/AMPK, and PGC-1α levels. Exercise training improved exercise performance and cardiac function, but it did not affect mitochondrial respiration, even in the presence of an increased percentage of type 1 MHC isoforms. Factors "upstream" of mitochondria were likely mainly responsible for the improved exercise performance. NEW & NOTEWORTHY Functional impairments in exercise performance, cardiac function, and soleus muscle mitochondrial respiration

  11. From Children of the Garbage Bins to Citizens : A reflexive ethnographic study on the care of “street children”

    OpenAIRE

    Kaime-Atterhög, Wanjiku

    2012-01-01

    The aim of the study on which this thesis is based was to gain an understanding of the life situation of street children in Kenya and to investigate how caring institutions care for these children.  A reflexive ethnographic approach was used to facilitate entry into the children’s sub-culture and the work contexts of the caregivers to better understand how the children live on the streets and how the caregivers work with the children. A fundamental aim of the research was to develop intervent...

  12. Evaluation of cranial tibial and extensor carpi radialis reflexes before and after anesthetic block in cats.

    Science.gov (United States)

    Tudury, Eduardo Alberto; de Figueiredo, Marcella Luiz; Fernandes, Thaiza Helena Tavares; Araújo, Bruno Martins; Bonelli, Marília de Albuquerque; Diogo, Camila Cardoso; Silva, Amanda Camilo; Santos, Cássia Regina Oliveira; Rocha, Nadyne Lorrayne Farias Cardoso

    2017-02-01

    Objectives This study aimed to test the extensor carpi radialis and cranial tibial reflexes in cats before and after anesthetic block of the brachial and lumbosacral plexus, respectively, to determine whether they depend on a myotatic reflex arc. Methods Fifty-five cats with a normal neurologic examination that were referred for elective gonadectomy were divided into group 1 (29 cats) for testing the extensor carpi radialis reflex, and group 2 (26 cats) for testing the cranial tibial reflex. In group 1, the extensor carpi radialis reflex was tested after anesthetic induction and 15 mins after brachial plexus block with lidocaine. In group 2, the cranial tibial, withdrawal and patellar reflexes were elicited in 52 hindlimbs and retested 15 mins after epidural anesthesia. Results In group 1, before the anesthetic block, 55.17% of the cats had a decreased and 44.83% had a normal extensor carpi radialis reflex. After the block, 68.96% showed a decreased and 27.59% a normal reflex. No cat had an increased or absent reflex before anesthetic block. In group 2, prior to the anesthetic block, 15.38% of the cats had a decreased cranial tibial reflex and 84.62% had a normal response, whereas after the block it was decreased in 26.92% and normal in 73.08% of the cats. None of the cats had an increased or absent reflex. Regarding the presence of both reflexes before and after anesthetic block, there was no significant difference at 1% ( P = 0.013). Conclusions and relevance The extensor carpi radialis and cranial tibial reflexes in cats are not strictly myotatic reflexes, as they are independent of the reflex arc, and may be idiomuscular responses. Therefore, they are not reliable for neurologic examination in this species.

  13. Evidence that the cortical motor command for the initiation of dynamic plantarflexion consists of excitation followed by inhibition

    DEFF Research Database (Denmark)

    Taube, Wolfgang; Lundbye-Jensen, Jesper; Schubert, Martin

    2011-01-01

    by conditioning the soleus H-reflex with different interstimulus intervals by cervicomedullary stimulation (CMS-conditioning) and transcranial magnetic stimulation (TMS) of M1 (M1-conditioning). This technique provides a precise time course of facilitation and inhibition. CMS- and M1-conditioning produced......At the onset of dynamic movements excitation of the motor cortex (M1) is spatially restricted to areas representing the involved muscles whereas adjacent areas are inhibited. The current study elucidates whether the cortical motor command for dynamic contractions is also restricted to a certain...... population of cortical neurons responsible for the fast corticospinal projections. Therefore, corticospinal transmission was assessed with high temporal resolution during dynamic contractions after both, magnetic stimulation over M1 and the brainstem. The high temporal resolution could be obtained...

  14. Otolith and canal reflexes in human standing

    Science.gov (United States)

    Cathers, Ian; Day, Brian L; Fitzpatrick, Richard C

    2005-01-01

    We used galvanic vestibular stimulation (GVS) to identify human balance reflexes of the semicircular canals and otolith organs. The experiment used a model of vestibular signals arising from GVS modulation of the net signal from vestibular afferents. With the head upright, the model predicts that the GVS-evoked canal signal indicates lateral head rotation while the otolith signal indicates lateral tilt or acceleration. Both signify body sway transverse to the head. With the head bent forward, the model predicts that the canal signal indicates body spin about a vertical axis but the otolith signal still signifies lateral body motion. Thus, we compared electromyograms (EMG) in the leg muscles and body sway evoked by GVS when subjects stood with the head upright or bent forward. With the head upright, GVS evoked a large sway in the direction of the anodal electrode. This response was abolished with the head bent forward leaving only small, oppositely directed, transient responses at the start and end of the stimulus. With the head upright, GVS evoked short-latency (60–70 ms), followed by medium-latency (120 ms) EMG responses, of opposite polarity. Bending the head forward abolished the medium-latency but preserved the short-latency response. This is compatible with GVS evoking separate otolithic and canal reflexes, indicating that balance is controlled by independent canal and otolith reflexes, probably through different pathways. We propose that the short-latency reflex and small transient sway are driven by the otolith organs and the medium-latency response and the large sway are driven by the semicircular canals. PMID:15618274

  15. Major alteration of the pathological phenotype in gamma irradiated mdx soleus muscles

    Energy Technology Data Exchange (ETDEWEB)

    Weller, B.; Karpati, G.; Lehnert, S.; Carpenter, S. (Montreal Neurological Institute, McGill University, Quebec (Canada))

    1991-07-01

    Two thousand rads of gamma irradiation delivered to the lower legs of ten day old normal and x-chromosome linked muscular dystrophy (mdx) mice caused significant inhibition of tibial bone and soleus muscle fiber growth. In the irradiated mdx solei, there was a major loss of muscle fibers, lack of central nucleation, and some endomysial fibrosis. These features were caused by a failure of regeneration of muscle fibers due to impaired proliferative capacity of satellite cells. Gamma irradiation transforms the late pathological phenotype of mdx muscles, so that in one major aspect (muscle fiber loss) they resemble muscles in Duchenne muscular dystrophy. However, extensive endomysial fibrosis which is another characteristic feature of Duchenne muscular dystrophy did not develop. This experimental model could be useful for the functional investigation of possible beneficial effects of therapeutic interventions in mdx dystrophy.

  16. Major alteration of the pathological phenotype in gamma irradiated mdx soleus muscles

    International Nuclear Information System (INIS)

    Weller, B.; Karpati, G.; Lehnert, S.; Carpenter, S.

    1991-01-01

    Two thousand rads of gamma irradiation delivered to the lower legs of ten day old normal and x-chromosome linked muscular dystrophy (mdx) mice caused significant inhibition of tibial bone and soleus muscle fiber growth. In the irradiated mdx solei, there was a major loss of muscle fibers, lack of central nucleation, and some endomysial fibrosis. These features were caused by a failure of regeneration of muscle fibers due to impaired proliferative capacity of satellite cells. Gamma irradiation transforms the late pathological phenotype of mdx muscles, so that in one major aspect (muscle fiber loss) they resemble muscles in Duchenne muscular dystrophy. However, extensive endomysial fibrosis which is another characteristic feature of Duchenne muscular dystrophy did not develop. This experimental model could be useful for the functional investigation of possible beneficial effects of therapeutic interventions in mdx dystrophy

  17. Shoulder reflexes

    DEFF Research Database (Denmark)

    Diederichsen, L.; Krogsgaard, M.; Voigt, Michael

    2002-01-01

    long latency (300 ms) excitatory reflex has been found when nerves in the capsule were stimulated electrically during shoulder surgery. In addition, when the anterior-inferior capsule was excited in conscious humans with modest amplitude electrical stimuli during muscle activity, a strong inhibition...... activity around the shoulder. This has implications for rehabilitation and shoulder surgery.......Dynamic shoulder stability is dependent on muscular coordination and sensory inputs. In the shoulder, mechanoreceptors are found in the coracoacromial ligament, the rotator cuff tendons, the musculotendinous junctions of the rotator cuff and in the capsule. The number of receptors in the capsule...

  18. An Intelligent Computerized Stretch Reflex Measurement System For Clinical And Investigative Neurology

    Science.gov (United States)

    Flanagan, P. M.; Chutkow, J. G.; Riggs, M. T.; Cristiano, V. D.

    1987-05-01

    We describe the design of a reliable, user-friendly preprototype system for quantifying the tendon stretch reflexes in humans and large mammals. A hand-held, instrumented reflex gun, the impactor of which contains a single force sensor, interfaces with a computer. The resulting test system can deliver sequences of reproducible stimuli at graded intensities and adjustable durations to a muscle's tendon ("tendon taps"), measure the impacting force of each tap, and record the subsequent reflex muscle contraction from the same tendon -- all automatically. The parameters of the reflex muscle contraction include latency; mechanical threshold; and peak time, peak magnitude, and settling time. The results of clinical tests presented in this paper illustrate the system's potential usefulness in detecting neurologic dysfunction affecting the tendon stretch reflexes, in documenting the course of neurologic illnesses and their response to therapy, and in clinical and laboratory neurologic research.

  19. Orthodoxy and reflexivity in international comparative analysis

    DEFF Research Database (Denmark)

    Lind, Jens; Valkenburg, Ben

    2002-01-01

    This contribution aims at four points.First we want to argue why we think a reflexive social science is more adequate than the orthodox consensus. In current practice much of the criticism on the orthodox consensus is shared on a theoretical level, without considering the implications and acting...... upon the consequences on the level of empirical research. We want to avoid that, so our second and third subject will be the practical implications of reflexivity for empirical research as well as for social policy. Our discussion on these subjects is based on the practical experiences in the INPART...

  20. The reflexive case study method

    DEFF Research Database (Denmark)

    Rittenhofer, Iris

    2015-01-01

    This paper extends the international business research on small to medium-sized enterprises (SME) at the nexus of globalization. Based on a conceptual synthesis across disciplines and theoretical perspectives, it offers management research a reflexive method for case study research of postnational...

  1. Reconceptualizing reflexivity and dissonance in professional and personal domains.

    Science.gov (United States)

    Brooks, Ann

    2008-09-01

    Debates around 'reflexivity' and the construction of the gendered self within late modernity have occupied the attention of both 'reflexive modernization' theorists (Beck, Giddens and Lash 1994; Beck and Beck-Gernsheim 1996; Giddens 1991, 1992) as well as gender and feminist theorists. While theorists such as Beck and Giddens have been preoccupied with establishing the connection between reflexivity and the construction of the 'non-gendered' self, gender and feminist theorists have sought to amplify the debate by exploring the intersecting nexus of contemporary theorizing, more fully within this context. This paper explores the theoretical underpinnings of these debates and their application to specific professional and personal domains. I consider three case studies to assess these issues as outlined in my own work, Brooks 2006, and in the work of Wajcman and Martin 2002, and McDowell 1997, which draw on empirical research and explore changes to gender identity within professional and personal domains. I conclude that there is little evidence in the research presented here of any systematic reconfiguring of gender identities leading to a detraditionalization of gender as suggested by the 'reflexive modernization' theorists.

  2. Modulation of the masseteric reflex by gastric vagal afferents.

    Science.gov (United States)

    Pettorossi, V E

    1983-04-01

    Several investigations have shown that the vagal nerve can affect the reflex responses of the masticatory muscles acting at level either of trigeminal motoneurons or of the mesencephalic trigeminal nucleus (MTN). The present experiments have been devoted to establish the origin of the vagal afferent fibres involved in modulating the masseteric reflex. In particular, the gastric vagal afferents were taken into consideration and selective stimulations of such fibres were performed in rabbit. Conditioning electrical stimulation of truncus vagalis ventralis (TVV) reduced the excitability of the MTN cells as shown by a decrease of the antidromic response recorded from the semilunar ganglion and elicited by MTN single-shock electrical stimulation. Sympathetic and cardiovascular influences were not involved in these responses. Mechanical stimulation of gastric receptors, by means of gastric distension, clearly diminished the amplitude of twitch tension of masseteric reflex and inhibited the discharge frequency of proprioceptive MTN units. The effect was phasic and depended upon the velocity of distension. Thus the sensory volleys originating from rapid adapting receptors reach the brain stem through vagal afferents and by means of a polysynaptic connection inhibits the masseteric reflex at level of MTN cells.

  3. Measurement of nucleotide exchange rate constants in single rabbit soleus myofibrils during shortening and lengthening using a fluorescent ATP analog.

    Science.gov (United States)

    Shirakawa, I; Chaen, S; Bagshaw, C R; Sugi, H

    2000-02-01

    The kinetics of displacement of a fluorescent nucleotide, 2'(3')-O-[N[2-[[Cy3]amido]ethyl]carbamoyl]-adenosine 5'-triphosphate (Cy3-EDA-ATP), bound to rabbit soleus muscle myofibrils were studied using flash photolysis of caged ATP. Use of myofibrils from this slow twitch muscle allowed better resolution of the kinetics of nucleotide exchange than previous studies with psoas muscle myofibrils (, Biophys. J. 73:2033-2042). Soleus myofibrils in the presence of Cy3-EDA-nucleotides (Cy3-EDA-ATP or Cy3-EDA-ADP) showed selective fluorescence staining of the A-band. The K(m) for Cy3-EDA-ATP and the K(d) for Cy3-EDA-ADP binding to the myofibril A-band were 1.9 microM and 3.8 microM, respectively, indicating stronger binding of nucleotide to soleus cross-bridges compared to psoas cross-bridges (2.6 microM and 50 microM, respectively). After flash photolysis of caged ATP, the A-band fluorescence of the myofibril in the Cy3-EDA-ATP solution under isometric conditions decayed exponentially with a rate constant of 0.045 +/- 0.007 s(-1) (n = 32) at 10 degrees C, which was about seven times slower than that for psoas myofibrils. When a myofibril was allowed to shorten with a constant velocity, the nucleotide displacement rate constant increased from 0.066 s(-1) (isometric) to 0.14 s(-1) at 20 degrees C with increasing shortening velocity up to 0.1 myofibril length/s (V(max), the shortening velocity under no load was approximately 0. 2 myofibril lengths/s). The rate constant was not significantly affected by an isovelocity stretch of up to 0.1 myofibril lengths/s. These results suggest that the cross-bridge kinetics are not significantly affected at higher strain during lengthening but depend on the lower strain during shortening. These data also indicate that the interaction distance between a cross-bridge and the actin filament is at least 16 nm for a single cycle of the ATPase.

  4. The effect of mindfulness meditation on cough reflex sensitivity.

    Science.gov (United States)

    Young, E C; Brammer, C; Owen, E; Brown, N; Lowe, J; Johnson, C; Calam, R; Jones, S; Woodcock, A; Smith, J A

    2009-11-01

    Chronic cough is common, and medical treatment can be ineffective. Mindfulness is a psychological intervention that aims to teach moment-to-moment non-judgemental awareness of thoughts, feelings and sensations. 30 healthy subjects and 30 patients with chronic cough were studied in two sequential trials. For both studies, cough reflex sensitivity to citric acid (C5) was measured on two occasions, with urge to cough rated following each inhalation; between challenges subjects were randomised to (1) no intervention, (2) mindfulness or (3) no intervention but modified cough challenge (subjects suppress coughing). For the healthy volunteers, measures were 1 h apart and mindfulness was practised for 15 min. For the patients with chronic cough measures were 1 week apart and mindfulness was practised daily for 30 min. In healthy volunteers, median change (interquartile range (IQR)) in cough reflex sensitivity (logC5) for no intervention, mindfulness and suppression was +1.0 (0.0 to +1.3), +2.0 (+1.0 to +3.0) and +3.0 (+2.8 to +3.0) doubling concentrations (p = 0.003); there were significant reductions for both mindfulness (p = 0.043) and suppression (p = 0.002) over no intervention. In patients with cough, median change (IQR) in logC5 for no intervention, mindfulness training and voluntary suppression was 0.0 (-1.0 to +1.0), +1.0 (-0.3 to +1.0) and +1.0 (+1.0 to +2.0) doubling concentrations (p = 0.046); there was a significant reduction for suppression (p = 0.02) but not mindfulness (p = 0.35). Urge to cough did not change after mindfulness compared with control in either healthy subjects (p = 0.33) or those with chronic cough (p = 0.47). Compared with control, mindfulness decreased cough reflex sensitivity in healthy volunteers, but did not alter cough threshold in patients with chronic cough. Both groups were able to suppress cough responses to citric acid inhalation.

  5. Emotional Dissonance and Burnout: The Moderating Role of Team Reflexivity and Re-Evaluation.

    Science.gov (United States)

    Andela, Marie; Truchot, Didier

    2017-08-01

    The aim of the present study was to better understand the relationship between emotional dissonance and burnout by exploring the buffering effects of re-evaluation and team reflexivity. The study was conducted with a sample of 445 nurses and healthcare assistants from a general hospital. Team reflexivity was evaluated with the validation of the French version of the team reflexivity scale (Facchin, Tschan, Gurtner, Cohen, & Dupuis, 2006). Burnout was measured with the MBI General Survey (Schaufeli, Leiter, Maslach, & Jackson, 1996). Emotional dissonance and re-evaluation were measured with the scale developed by Andela, Truchot, & Borteyrou (2015). With reference to Rimé's theoretical model (2009), we suggested that both dimensions of team reflexivity (task and social reflexivity) respond to both psychological necessities induced by dissonance (cognitive clarification and socio-affective necessities). Firstly, results indicated that emotional dissonance was related to burnout. Secondly, regression analysis confirmed the buffering role of re-evaluation and social reflexivity on the emotional exhaustion of emotional dissonance. Overall, results contribute to the literature by highlighting the moderating effect of re-evaluation and team reflexivity in analysing the relationship between emotional dissonance and burnout. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Inhibition of reflex vagal bradycardia by a central action of 5-hydroxytryptophan.

    OpenAIRE

    Tadepalli, A. S.

    1980-01-01

    1 Vagally mediated reflex bradycardia was elicited in spinal cats with intravenous pressor doses of noradrenaline. Administration of 5-hydroxytryptophan (1.5 and 3 mg total dose) into the fourth cerebral ventricle reduced the reflex bradycardia. 2 Inhibition of central amino acid decarboxylase with R044602 prevented the effects of 5-hydroxytryptophan. After intravenous administration of 5-hydroxytryptophan, vagal reflex bradycardia was not affected. 3 Results suggest that 5-hydroxytryptophan ...

  7. Fundamental Principles underlying Motor Reflexes

    NARCIS (Netherlands)

    K. Zhou (Kuikui)

    2017-01-01

    markdownabstractThe cerebellum has been suggested to be involved in motor control ever since the early 19th century. The motor control ranges from timing and strength of simple reflexes to multiple joint/limb coordination and complex motor sequence acquisition. The current thesis discusses the

  8. Corticospinal and Spinal Excitabilities Are Modulated during Motor Imagery Associated with Somatosensory Electrical Nerve Stimulation

    Directory of Open Access Journals (Sweden)

    E. Traverse

    2018-01-01

    Full Text Available Motor imagery (MI, the mental simulation of an action, influences the cortical, corticospinal, and spinal levels, despite the lack of somatosensory afferent feedbacks. The aim of this study was to analyze the effect of MI associated with somatosensory stimulation (SS on the corticospinal and spinal excitabilities. We used transcranial magnetic stimulation and peripheral nerve stimulation to induce motor-evoked potentials (MEP and H-reflexes, respectively, in soleus and medialis gastrocnemius (MG muscles of the right leg. Twelve participants performed three tasks: (1 MI of submaximal plantar flexion, (2 SS at 65 Hz on the posterior tibial nerve with an intensity below the motor threshold, and (3 MI + SS. MEP and H-reflex amplitudes were recorded before, during, and after the tasks. Our results confirmed that MI increased corticospinal excitability in a time-specific manner. We found that MI+SS tended to potentiate MEP amplitude of the MG muscle compared to MI alone. We confirmed that SS decreased spinal excitability, and this decrease was partially compensated when combined with MI, especially for the MG muscle. The increase of CSE could be explained by a modulation of the spinal inhibitions induced by SS, depending on the amount of afferent feedbacks.

  9. Acid-sensing ion channels contribute to the metaboreceptor component of the exercise pressor reflex

    OpenAIRE

    McCord, Jennifer L.; Tsuchimochi, Hirotsugu; Kaufman, Marc P.

    2009-01-01

    The exercise pressor reflex is evoked by both mechanical and metabolic stimuli arising in contracting skeletal muscle. Recently, the blockade of acid-sensing ion channels (ASICs) with amiloride and A-316567 attenuated the reflex. Moreover, amiloride had no effect on the mechanoreceptor component of the reflex, prompting us to determine whether ASICs contributed to the metaboreceptor component of the exercise pressor reflex. The metaboreceptor component can be assessed by measuring mean arteri...

  10. Effects of brainstem lesions on the masseter inhibitory reflex. Functional mechanisms of reflex pathways

    NARCIS (Netherlands)

    Ongerboer de Visser, B. W.; Cruccu, G.; Manfredi, M.; Koelman, J. H.

    1990-01-01

    The masseter inhibitory reflex (MIR) was investigated in 16 patients with localized brainstem lesions involving the trigeminal system. The MIR consists of two phases of EMG silence (S1 and S2) evoked by stimulation of the mental nerve during maximal clenching of the teeth. The extent of the lesions

  11. Hip proprioceptors preferentially modulate reflexes of the leg in human spinal cord injury

    Science.gov (United States)

    Onushko, Tanya; Hyngstrom, Allison

    2013-01-01

    Stretch-sensitive afferent feedback from hip muscles has been shown to trigger long-lasting, multijoint reflex responses in people with chronic spinal cord injury (SCI). These reflexes could have important implications for control of leg movements during functional activities, such as walking. Because the control of leg movement relies on reflex regulation at all joints of the limb, we sought to determine whether stretch of hip muscles modulates reflex activity at the knee and ankle and, conversely, whether knee and ankle stretch afferents affect hip-triggered reflexes. A custom-built servomotor apparatus was used to stretch the hip muscles in nine chronic SCI subjects by oscillating the legs about the hip joint bilaterally from 10° of extension to 40° flexion. To test whether stretch-related feedback from the knee or ankle would be affected by hip movement, patellar tendon percussions and Achilles tendon vibration were delivered when the hip was either extending or flexing. Surface electromyograms (EMGs) and joint torques were recorded from both legs. Patellar tendon percussions and Achilles tendon vibration both elicited reflex responses local to the knee or ankle, respectively, and did not influence reflex responses observed at the hip. Rather, the movement direction of the hip modulated the reflex responses local to the joint. The patellar tendon reflex amplitude was larger when the perturbation was delivered during hip extension compared with hip flexion. The response to Achilles vibration was modulated by hip movement, with an increased tonic component during hip flexion compared with extension. These results demonstrate that hip-mediated sensory signals modulate activity in distal muscles of the leg and appear to play a unique role in modulation of spastic muscle activity throughout the leg in SCI. PMID:23615544

  12. Spasm of the near reflex: a spectrum of anomalies.

    Science.gov (United States)

    Goldstein, J H; Schneekloth, B B

    1996-01-01

    Spasm of the near reflex has been characterized as the variable appearance of pseudomyopia, convergent strabismus and miosis. These characteristics may appear together or separately. In addition, abnormalities of accommodation may appear not only as pseudomyopia, but may also be manifest in cases with significant hypermetropia in which the patient is unable to relax accommodation even when plus lenses are used. The intent of this review is to identify the various clinical presentations of anomalies of the entire near reflex as well as the component parts. The relationship to functional and organic disorders are discussed as well as the related neuroanatomy. We suggest that one may more readily understand the clinical manifestations as a spectrum of anomalies of the near reflex rather than a multitude of disconnected entities.

  13. Reflex peripheral vasoconstriction is diminished in older men.

    Science.gov (United States)

    Kenney, W L; Armstrong, C G

    1996-02-01

    The purpose of this study was to compare reflex control of limb blood flow in healthy young (Y; 26 +/- 2 yr) and older (O;61 +/- 2 yr) men during whole body cooling under resting conditions. To better isolate the effect of chronological age, the two age groups (n = 6 per group) were closely matched for maximal oxygen uptake, body surface area, skinfold thickness, and fat-free weight. Subjects sat in an environmentally controlled chamber clad in standardized (0.6-clo) light cotton clothing at a dry-bulb temperature (Tdb) of 28 degrees C. After 30 min, Tdb was decreased by 2 degrees C every 5 min until Tdb = 10 degrees C, where it was held constant for the remainder of the 120-min session. Esophageal and mean skin temperatures were monitored continuously. Forearm blood flow (FBF) was measured every 5 min by venous occlusion plethysmography by using a mercury-in-Silastic strain gauge while arm temperature between the wrist and elbow was clamped at 37.2 +/- 0.1 degrees C by localized warm air heating. In this way, limb vasoconstriction was driven solely by thermoregulatory reflexes and not by direct effects of localized cooling. Mean skin temperature decreased at a similar rate and to a similar extent (by approximately 6 degrees C over a 2-h period) in both age groups, whereas esophageal temperature was relatively unaffected. In response to the local heating, the Y group maintained a significantly higher FBF than did the O group during the initial 30 min but decreased FBF during the cooling phase at a greater rate and to a greater extent than did the O group, leading to a significantly lower FBF during the final 30 min (at Tdb = 10 degrees C). Because there was no age difference in the mean arterial pressure response, similar effects of age were seen on forearm vascular conductance (FBF/mean arterial pressure). It was concluded that older men have a diminished reflex limb vasoconstrictor response to skin cooling. Furthermore, this difference in control of peripheral

  14. Three-dimensional analysis of otolith-ocular reflex during eccentric rotation in humans.

    Science.gov (United States)

    Takimoto, Yasumitsu; Imai, Takao; Okumura, Tomoko; Takeda, Noriaki; Inohara, Hidenori

    2016-10-01

    When a participant is rotated while displaced from the axis of rotation (eccentric rotation, ER), both rotational stimulation and linear acceleration are applied to the participant. As linear acceleration stimulates the otolith, the vestibulo-ocular reflex (VOR) caused by the otolith (linear VOR; lVOR) would be induced during ER. Ten participants were rotated sinusoidally at a maximum angular velocity of 50°/s and at frequencies of 0.1, 0.3, 0.5, and 0.7Hz. The radius of rotation during ER was 90cm. The participants sat on a chair at three different positions: on the axis (center rotation, CR), at 90cm backward from the axis (nose-in ER, NI-ER) and at 90cm forward from the axis (nose-out ER, NO-ER). Their eye movements during rotation were recorded and analyzed three-dimensionally. The VOR gain during NI-ER was lower at 0.5 and 0.7Hz, and that during NO-ER was higher at 0.3, 0.5, and 0.7Hz than during CR. These results indicate that lVOR actually worked at 0.5 and 0.7Hz during ER and that the enhancement and decline of the VOR gain relative to the VOR gain during CR was seen in humans. Thus, we suggest that otolith function can be assessed via rotational testing of NI-ER and NO-ER. Copyright © 2016 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

  15. The Gateway Reflex, a Novel Neuro-Immune Interaction for the Regulation of Regional Vessels

    Directory of Open Access Journals (Sweden)

    Yuki Tanaka

    2017-10-01

    Full Text Available The gateway reflex is a new phenomenon that explains how immune cells bypass the blood–brain barrier to infiltrate the central nervous system (CNS and trigger neuroinflammation. To date, four examples of gateway reflexes have been discovered, each described by the stimulus that evokes the reflex. Gravity, electricity, pain, and stress have all been found to create gateways at specific regions of the CNS. The gateway reflex, the most recently discovered of the four, has also been shown to upset the homeostasis of organs in the periphery through its action on the CNS. These reflexes provide novel therapeutic targets for the control of local neuroinflammation and organ function. Each gateway reflex is activated by different neural activations and induces inflmammation at different regions in the CNS. Therefore, it is theoretically possible to manipulate each independently, providing a novel therapeutic strategy to control local neuroinflammation and peripheral organ homeostasis.

  16. [Developing team reflexivity as a learning and working tool for medical teams].

    Science.gov (United States)

    Riskin, Arieh; Bamberger, Peter

    2014-01-01

    Team reflexivity is a collective activity in which team members review their previous work, and develop ideas on how to modify their work behavior in order to achieve better future results. It is an important learning tool and a key factor in explaining the varying effectiveness of teams. Team reflexivity encompasses both self-awareness and agency, and includes three main activities: reflection, planning, and adaptation. The model of briefing-debriefing cycles promotes team reflexivity. Its key elements include: Pre-action briefing--setting objectives, roles, and strategies the mission, as well as proposing adaptations based on what was previously learnt from similar procedures; Post-action debriefing--reflecting on the procedure performed and reviewing the extent to which objectives were met, and what can be learnt for future tasks. Given the widespread attention to team-based work systems and organizational learning, efforts should be made toward ntroducing team reflexivity in health administration systems. Implementation could be difficult because most teams in hospitals are short-lived action teams formed for a particular event, with limited time and opportunity to consciously reflect upon their actions. But it is precisely in these contexts that reflexive processes have the most to offer instead of the natural impulsive collective logics. Team reflexivity suggests a potential solution to the major problems of iatorgenesis--avoidable medical errors, as it forces all team members to participate in a reflexive process together. Briefing-debriefing technology was studied mainly in surgical teams and was shown to enhance team-based learning and to improve quality-related outcomes and safety.

  17. A tapetal-like fundus reflex in a healthy male

    DEFF Research Database (Denmark)

    Schatz, Patrik; Bregnhøj, Jesper; Arvidsson, Henrik

    2012-01-01

    To report on the retinal function and structure in a 37-year-old male who presented with a tapetal-like reflex (TLR) indistinguishable from that seen in female carriers of X-linked retinitis pigmentosa (XLRP).......To report on the retinal function and structure in a 37-year-old male who presented with a tapetal-like reflex (TLR) indistinguishable from that seen in female carriers of X-linked retinitis pigmentosa (XLRP)....

  18. Age-Related Differences in Corticospinal Excitability during Observation and Motor Imagery of Balance Tasks.

    Science.gov (United States)

    Mouthon, Audrey A; Ruffieux, Jan; Keller, Martin; Taube, Wolfgang

    2016-01-01

    Postural control declines across adult lifespan. Non-physical balance training has been suggested as an alternative to improve postural control in frail/immobilized elderly people. Previous studies showed that this kind of training can improve balance control in young and older adults. However, it is unclear whether the brain of young and older adults is activated differently during mental simulations of balance tasks. For this purpose, soleus (SOL) and tibialis motor evoked potentials (MEPs) and SOL H-reflexes were elicited while 15 elderly (mean ± SD = 71 ± 4.6 years) and 15 young participants (mean ± SD = 27 ± 4.6 years) mentally simulated static and dynamic balance tasks using motor imagery (MI), action observation (AO) or the combination of AO and MI (AO + MI). Young subjects displayed significant modulations of MEPs that depended on the kind of mental simulation and the postural task. Elderly adults also revealed differences between tasks, but not between mental simulation conditions. Furthermore, the elderly displayed larger MEP facilitation during mental simulation (AGE-GROUP; F (1,28) = 5.9; p = 0.02) in the SOL muscle compared to the young and a task-dependent modulation of the tibialis background electromyography (bEMG) activity. H-reflex amplitudes and bEMG in the SOL showed neither task- nor age-dependent modulation. As neither mental simulation nor balance tasks modulated H-reflexes and bEMG in the SOL muscle, despite large variations in the MEP-amplitudes, there seems to be an age-related change in the internal cortical representation of balance tasks. Moreover, the modulation of the tibialis bEMG in the elderly suggests that aging partially affects the ability to inhibit motor output.

  19. Low Incidence Of Extensor Plantar Reflex In Newborns In An ...

    African Journals Online (AJOL)

    Healthy term newborns with Apgar score of 8 and above at one minute were recruited into the study consecutively in a maternity hospital in Ibadan, Nigeria. The plantar reflex was elicited by stroking the lateral side of the sole with firm pressure, between 24 - 48 hours after delivery. Results Of 461 newborns, the plantar reflex ...

  20. Reliability and comparison of gain values with occurrence of saccades in the EyeSeeCam video head impulse test (vHIT)

    DEFF Research Database (Denmark)

    Hviid Korsager, Leise Elisabeth; Schmidt, Jesper Hvass; Faber, Christian

    2016-01-01

    . There is a lack of knowledge regarding the reliability of the two parameters. The objective was to investigate the reliability of vHIT by comparing gain values between examiners on the same subjects, and to see how differences affected the occurrence of saccades. SUBJECTS: 25 subjects who had undergone cochlear...... coefficient (ICC) of the gain values between examiners ranged from 0.62 to 0.70. Differences in gain values amongst examiners did not seem to affect the occurrence of saccades in the same patient. The occurrence of saccades, therefore, seems to be more reliable than the gain value in the evaluation......The vHIT (video head impulse test) investigates the vestibular function in two ways: a VOR (vestibulo-ocular reflex) gain value and a head impulse diagram. From the diagram covert and overt saccades can be detected. Evaluation of the vestibular function based on vHIT depends on both parameters...

  1. Effects of long-duration bed rest on structural compartments of m. soleus in man

    Science.gov (United States)

    Belozerova, I.; Shenkman, B.; Mazin, M.; Leblanc, A.; LeBlanc, A. D. (Principal Investigator)

    2001-01-01

    Magnetic resonance imaging (MRI), histomorphometry and electron microscopy of muscle demonstrate that long-term exposure to actual or simulated weightlessness (including head down bed rest) leads to decreased volume of antigravity muscles in mammals. In muscles interbundle space is occupied by the connective tissue. Rat studies show that hindlimb unloading induces muscle fiber atrophy along with increase in muscle non-fiber connective tissue compartment. Beside that, usually 20% of the muscle fiber volume is comprised by non-contractile (non-myofibrillar) compartment. The aim of the present study was to compare changes in muscle volume, and in muscle fiber size with alterations in myofibrillar apparatus, and in connective tissue compartment in human m. soleus under conditions of 120 day long head down bed rest (HDBR).

  2. Functionality of the contralateral biceps femoris reflex response during human walking

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas; Geertsen, Svend Sparre; Sinkjaer, Thomas

    2014-01-01

    of the body in order to maintain dynamic equilibrium during walking. Therefore, we hypothesized that if we suddenly slowed the treadmill participants were walking on, the cBF reflex would be inhibited because the necessity to break the forward progression of the body would be decreased. Conversely, if we...... the treadmill velocity was altered concurrently or 50 ms after knee perturbation onset. These results, together with the finding that the cBF reflex response is under some cortical control [1], strongly suggest a functional role for the cBF reflex during walking that is adaptable to the environmental situation....

  3. Effects of hypothyroidism on the sensitivity of glycolysis and glycogen synthesis to insulin in the soleus muscle of the rat.

    Science.gov (United States)

    Dimitriadis, G D; Leighton, B; Parry-Billings, M; West, D; Newsholme, E A

    1989-01-01

    1. The effects of hypothyroidism on the sensitivity of glycolysis and glycogen synthesis to insulin were investigated in the isolated, incubated soleus muscle of the rat. 2. Hypothyroidism, which was induced by administration of propylthiouracil to the rats, decreased fasting plasma levels of free fatty acids and increased plasma levels of glucose but did not significantly change plasma levels of insulin. 3. The sensitivity of the rates of glycogen synthesis to insulin was increased at physiological, but decreased at supraphysiological, concentrations of insulin. 4. The rates of glycolysis in the hypothyroid muscles were decreased at all insulin concentrations studied and the EC50 for insulin was increased more than 8-fold; the latter indicates decreased sensitivity of this process to insulin. However, at physiological concentrations of insulin, the rates of glucose phosphorylation in the soleus muscles of hypothyroid rats were not different from controls. This suggests that hypothyroidism affects glucose metabolism in muscle not by affecting glucose transport but by decreasing the rate of glucose 6-phosphate conversion to lactate and increasing the rate of conversion of glucose 6-phosphate to glycogen. 5. The rates of glucose oxidation were decreased in the hypothyroid muscles at all insulin concentrations. PMID:2649073

  4. VizieR Online Data Catalog: RefleX : X-ray-tracing code (Paltani+, 2017)

    Science.gov (United States)

    Paltani, S.; Ricci, C.

    2017-11-01

    We provide here the RefleX executable, for both Linux and MacOSX, together with the User Manual and example script file and output file Running (for instance): reflex_linux will produce the file reflex.out Note that the results may differ slightly depending on the OS, because of slight differences in some implementations numerical computations. The difference are scientifically meaningless. (5 data files).

  5. Motricidade reflexa na morte cerebral The reflex activity in the brain death

    Directory of Open Access Journals (Sweden)

    Wilson L. Sanvito

    1972-03-01

    Full Text Available O diagnóstico de morte cerebral está baseado em critérios clínicos, eletrencefalográficos e angiográficos. Do ponto de vista clínico deve ser evidenciado o seguinte quadro: coma profundo, midríase paralítica bilateral, ausência de reação a qualquer estímulo externo, apnéia, arreflexia superficial e profunda. Do ponto de vista eletrencefalográfico são necessários dois registros, separados por um intervalo de 24 horas, evidenciando traçados iselétricos. No presente trabalho são estudados 15 pacientes com morte cerebral comprovada do ponto de vista clínico e eletrencefalográfico. Em 8 pacientes havia persistência de atividade reflexa durante a fase de morte cerebral (reflexos profundos e/ou superficiais. Fenômenos de automatismos medulares também foram verificados em 3 pacientes.The diagnosis of brain death is based in clinical, electroencephalographic and angiographic data. The criteria for diagnosis of brain death are: deep coma with unreceptivity and unresponsiveness, no movements or breathing (the patient's respiration must be maintained artificially, bilateral dilated and fixed pupils, absence of corneal reflexes, no response to caloric test, absence of deep tendon reflexes and of the superficial abdominal and plantar reflexes, isoelectric EEG maintained for twenty-four hours. The purpose of this study was to observe the natural clinical courses of 15 patients with brain death, specially the data concerning the deep and superficial reflexes. From 15 patients fulfilling the criteria of brain death, 8 maintained spinal reflexes up to the time of cardiac arrest; in five of these patients the superficial abdominal reflexes were present and the reflexes of spinal automatism could be elicited. These results show that the absence of deep and superficial reflexes can't be considered as essencial for the diagnosis of brain death.

  6. Erecting Closets and Outing Ourselves: Uncomfortable Reflexivity and Community-Based Research

    Science.gov (United States)

    Reed, Sarah J.; Miller, Robin Lin; Nnawulezi, Nkiru; Valenti, Maria T.

    2012-01-01

    Feminist scholars and community psychologists have argued that reflexivity is a necessary component to conducting socially conscious research. Reflexivity, however, is rarely evident in community psychology. In this article, we share the uncomfortable realities that surfaced during a community-based research project in which we adapted and…

  7. Triceps surae short latency stretch reflexes contribute to ankle stiffness regulation during human running.

    Directory of Open Access Journals (Sweden)

    Neil J Cronin

    Full Text Available During human running, short latency stretch reflexes (SLRs are elicited in the triceps surae muscles, but the function of these responses is still a matter of controversy. As the SLR is primarily mediated by Ia afferent nerve fibres, various methods have been used to examine SLR function by selectively blocking the Ia pathway in seated, standing and walking paradigms, but stretch reflex function has not been examined in detail during running. The purpose of this study was to examine triceps surae SLR function at different running speeds using Achilles tendon vibration to modify SLR size. Ten healthy participants ran on an instrumented treadmill at speeds between 7 and 15 km/h under 2 Achilles tendon vibration conditions: no vibration and 90 Hz vibration. Surface EMG from the triceps surae and tibialis anterior muscles, and 3D lower limb kinematics and ground reaction forces were simultaneously collected. In response to vibration, the SLR was depressed in the triceps surae muscles at all speeds. This coincided with short-lasting yielding at the ankle joint at speeds between 7 and 12 km/h, suggesting that the SLR contributes to muscle stiffness regulation by minimising ankle yielding during the early contact phase of running. Furthermore, at the fastest speed of 15 km/h, the SLR was still depressed by vibration in all muscles but yielding was no longer evident. This finding suggests that the SLR has greater functional importance at slow to intermediate running speeds than at faster speeds.

  8. Muscle and reflex changes with varying joint angle in hemiparetic stroke

    Directory of Open Access Journals (Sweden)

    Alibiglou Laila

    2008-02-01

    Full Text Available Abstract Background Despite intensive investigation, the origins of the neuromuscular abnormalities associated with spasticity are not well understood. In particular, the mechanical properties induced by stretch reflex activity have been especially difficult to study because of a lack of accurate tools separating reflex torque from torque generated by musculo-tendinous structures. The present study addresses this deficit by characterizing the contribution of neural and muscular components to the abnormally high stiffness of the spastic joint. Methods Using system identification techniques, we characterized the neuromuscular abnormalities associated with spasticity of ankle muscles in chronic hemiparetic stroke survivors. In particular, we systematically tracked changes in muscle mechanical properties and in stretch reflex activity during changes in ankle joint angle. Modulation of mechanical properties was assessed by applying perturbations at different initial angles, over the entire range of motion (ROM. Experiments were performed on both paretic and non-paretic sides of stroke survivors, and in healthy controls. Results Both reflex and intrinsic muscle stiffnesses were significantly greater in the spastic/paretic ankle than on the non-paretic side, and these changes were strongly position dependent. The major reflex contributions were observed over the central portion of the angular range, while the intrinsic contributions were most pronounced with the ankle in the dorsiflexed position. Conclusion In spastic ankle muscles, the abnormalities in intrinsic and reflex components of joint torque varied systematically with changing position over the full angular range of motion, indicating that clinical perceptions of increased tone may have quite different origins depending upon the angle where the tests are initiated. Furthermore, reflex stiffness was considerably larger in the non-paretic limb of stroke patients than in healthy control subjects

  9. A critical reflexive Perspective on othering in collaborative knowledge production

    DEFF Research Database (Denmark)

    Jakobsen, Helle Nordentoft; Olesen, Birgitte Ravn

    2018-01-01

    Purpose The purpose of the article is to show power mechanisms of in- and exclusion in moments where certain participants appeared to be othered in two collaborative research and development projects in a health care setting. Design/methodology/approach The article contributes to critical......-reflexive analyses of reflexive processes within collaborative knowledge production We use an analytical framework combining Bakhtin and Foucault to investigate processes of inclusion and exclusion in the interplay between dominant and subordinated voices in a moment-by-moment analysis of two incidents from...... interdisciplinary workshops. Findings The analysis illuminates how differences between voices challenge participants’ reflexive awareness and lead to the reproduction of contextual power and knowledge hierarchies and the concomitant silencing of particular participants. Thus, the findings draw attention...

  10. The Reflexive Principle of Sociological Theorization

    Directory of Open Access Journals (Sweden)

    R T Ubaidullayeva

    2013-12-01

    Full Text Available The article attempts to describe the reflexive principle in theory-making, which integrates the basic modern methodological paradigms and lays the foundation for the development of sociology. On the basis of the theoretical ideas of P. Bourdieu, A. Giddens and P. Ricoeur the author defines the concept of social reflexion and reveals its peculiarities in sociology as compared to reflexion in philosophy. According to the author, the fulfillment of reflexive functions in sociology is connected with the task of analyzing the complex structure of the polysemantic object, considering the specific quality of the subjects and their various trends of development. The presence of the poles — objectivity-subjectivity, rationality-irrationality, consciousness-unconsciousness etc, requires a reproduction of the dichotomies engendering them in social life and development of cognitive methods for their study in sociology.

  11. Inhibition of Stat3 signaling ameliorates atrophy of the soleus muscles in mice lacking the vitamin D receptor.

    Science.gov (United States)

    Gopinath, Suchitra D

    2017-01-25

    Although skeletal muscle wasting has long been observed as a clinical outcome of impaired vitamin D signaling, precise molecular mechanisms that mediate the loss of muscle mass in the absence of vitamin D signaling are less clear. To determine the molecular consequences of vitamin D signaling, we analyzed the role of signal transducer and activator of transcription 3 (Stat3) signaling, a known contributor to various muscle wasting pathologies, in skeletal muscles. We isolated soleus (slow) and tibialis anterior (fast) muscles from mice lacking the vitamin D receptor (VDR -/- ) and used western blot analysis, quantitative RTPCR, and pharmacological intervention to analyze muscle atrophy in VDR -/- mice. We found that slow and fast subsets of muscles of the VDR -/- mice displayed elevated levels of phosphorylated Stat3 accompanied by an increase in Myostatin expression and signaling. Consequently, we observed reduced activity of mammalian target of rapamycin (mTOR) signaling components, ribosomal S6 kinase (p70S6K) and ribosomal S6 protein (rpS6), that regulate protein synthesis and cell size, respectively. Concomitantly, we observed an increase in atrophy regulators and a block in autophagic gene expression. An examination of the upstream regulation of Stat3 levels in VDR -/- muscles revealed an increase in IL-6 protein expression in the soleus, but not in the tibialis anterior muscles. To investigate the involvement of satellite cells (SCs) in atrophy in VDR -/- mice, we found that there was no significant deficit in SC numbers in VDR -/- muscles compared to the wild type. Unlike its expression within VDR -/- fibers, Myostatin levels in VDR -/- SCs from bulk muscles were similar to those of wild type. However, VDR -/- SCs induced to differentiate in culture displayed increased p-Stat3 signaling and Myostatin expression. Finally, VDR -/- mice injected with a Stat3 inhibitor displayed reduced Myostatin expression and function and restored active p70S6K and rpS6

  12. Effect of propolis alcoholic extract on the weight gain, carcass traits and cecal pH of growing rabbits

    Directory of Open Access Journals (Sweden)

    Joseli Alves Ferreira Zanato

    2007-06-01

    Full Text Available The objective of this experiment was to evaluate the effect of different rates of propolis alcoholic extract (PAE on the weight gain, carcass traits and cecal pH of growing rabbits. Forty White New Zealand rabbits were distributed in a completely randomized experimental design consisting of four treatments and ten replicates per treatment. The rabbits were allocated individually in wire cages containing a nipple drinker and a semi-automatic feeder. The treatments were: T1 = control, T2 = 1ml of ethanol, T3 = 0.8ml of PAE, and T4 = 1.5ml of PAE. Commercial feed and water were provided ad libitum to the animals, and the treatment with cereal alcohol and PAE was administered orally using a 2ml syringe. It was concluded that the addition of PAE to the rabbits’ feeding resulted in weight gain, carcass traits and cecal pH similar to those of animals which received the diets with ethanol without any addition, except for the paw weight, that was higher in the rabbits which were given PAE, and for the gastric system, that had a higher weight in the rabbits which received no addition to their diet.

  13. Grounded theory research: literature reviewing and reflexivity.

    Science.gov (United States)

    McGhee, Gerry; Marland, Glenn R; Atkinson, Jacqueline

    2007-11-01

    This paper is a report of a discussion of the arguments surrounding the role of the initial literature review in grounded theory. Researchers new to grounded theory may find themselves confused about the literature review, something we ourselves experienced, pointing to the need for clarity about use of the literature in grounded theory to help guide others about to embark on similar research journeys. The arguments for and against the use of a substantial topic-related initial literature review in a grounded theory study are discussed, giving examples from our own studies. The use of theoretically sampled literature and the necessity for reflexivity are also discussed. Reflexivity is viewed as the explicit quest to limit researcher effects on the data by awareness of self, something seen as integral both to the process of data collection and the constant comparison method essential to grounded theory. A researcher who is close to the field may already be theoretically sensitized and familiar with the literature on the study topic. Use of literature or any other preknowledge should not prevent a grounded theory arising from the inductive-deductive interplay which is at the heart of this method. Reflexivity is needed to prevent prior knowledge distorting the researcher's perceptions of the data.

  14. Collaborative Research in Contexts of Inequality: The Role of Social Reflexivity

    Science.gov (United States)

    Leibowitz, Brenda; Bozalek, Vivienne; Farmer, Jean; Garraway, James; Herman, Nicoline; Jawitz, Jeff; McMillan, Wendy; Mistri, Gita; Ndebele, Clever; Nkonki, Vuyisile; Quinn, Lynn; van Schalkwyk, Susan; Vorster, Jo-Anne; Winberg, Chris

    2017-01-01

    This article reports on the role and value of social reflexivity in collaborative research in contexts of extreme inequality. Social reflexivity mediates the enablements and constraints generated by the internal and external contextual conditions impinging on the research collaboration. It fosters the ability of participants in a collaborative…

  15. Turtle Flexion Reflex Motor Patterns Show Windup, Mediated Partly by L-type Calcium Channels

    Directory of Open Access Journals (Sweden)

    Keith P. Johnson

    2017-10-01

    Full Text Available Windup is a form of multisecond temporal summation in which identical stimuli, delivered seconds apart, trigger increasingly strong neuronal responses. L-type Ca2+ channels have been shown to play an important role in the production of windup of spinal cord neuronal responses, initially in studies of turtle spinal cord and later in studies of mammalian spinal cord. L-type Ca2+ channels have also been shown to contribute to windup of limb withdrawal reflex (flexion reflex in rats, but flexion reflex windup has not previously been described in turtles and its cellular mechanisms have not been studied. We studied windup of flexion reflex motor patterns, evoked with weak mechanical and electrical stimulation of the dorsal hindlimb foot skin and assessed via a hip flexor (HF nerve recording, in spinal cord-transected and immobilized turtles in vivo. We found that an L-type Ca2+ channel antagonist, nifedipine, applied at concentrations of 50 μM or 100 μM to the hindlimb enlargement spinal cord, significantly reduced windup of flexion reflex motor patterns, while lower concentrations of nifedipine had no such effect. Nifedipine similarly reduced the amplitude of an individual flexion reflex motor pattern evoked by a stronger mechanical stimulus, in a dose-dependent manner, suggesting that L-type Ca2+ channels contribute to each flexion reflex as well as to multisecond summation of flexion reflex responses in turtles. We also found that we could elicit flexion reflex windup consistently using a 4-g von Frey filament, which is not usually considered a nociceptive stimulus. Thus, it may be that windup can be evoked by a wide range of tactile stimuli and that L-type calcium channels contribute to multisecond temporal summation of diverse tactile stimuli across vertebrates.

  16. A reflexing electron microwave amplifier for rf particle accelerator applications

    International Nuclear Information System (INIS)

    Fazio, M.V.; Hoeberling, R.F.

    1988-01-01

    The evolution of rf-accelerator technology toward high-power, high-current, low-emittance beams produces an ever-increasing demand for efficient, very high power microwave power sources. The present klystron technology has performed very well but is not expected to produce reliable gigawatt peak-power units in the 1- to 10-GHz regime. Further major advancements must involve other types of sources. The reflexing-electron class of sources can produce microwave powers at the gigawatt level and has demonstrated operation from 800-MHz to 40-GHz. The pulse length appears to be limited by diode closure, and reflexing-electron devices have been operated in a repetitively pulsed mode. A design is presented for a reflexing electron microwave amplifier that is frequency and phase locked. In this design, the generated microwave power can be efficiently coupled to one or several accelerator loads. Frequency and phase-locking capability may permit parallel-source operation for higher power. The low-frequency (500-MHz to 10-GHz) operation at very high power required by present and proposed microwave particle accelerators makes an amplifier, based on reflexing electron phenomena, a candidate for the development of new accelerator power sources. (author)

  17. Effects of muscle activation on shear between human soleus and gastrocnemius muscles.

    Science.gov (United States)

    Finni, T; Cronin, N J; Mayfield, D; Lichtwark, G A; Cresswell, A G

    2017-01-01

    Lateral connections between muscles provide pathways for myofascial force transmission. To elucidate whether these pathways have functional roles in vivo, we examined whether activation could alter the shear between the soleus (SOL) and lateral gastrocnemius (LG) muscles. We hypothesized that selective activation of LG would decrease the stretch-induced shear between LG and SOL. Eleven volunteers underwent a series of knee joint manipulations where plantar flexion force, LG, and SOL muscle fascicle lengths and relative displacement of aponeuroses between the muscles were obtained. Data during a passive full range of motion were recorded, followed by 20° knee extension stretches in both passive conditions and with selective electrical stimulation of LG. During active stretch, plantar flexion force was 22% greater (P stronger (stiffer) connectivity between the two muscles, at least at flexed knee joint angles, which may serve to facilitate myofascial force transmission. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Fixed Pupillary Light Reflex due to Peripheral Neuropathy after Liver Transplantation

    Directory of Open Access Journals (Sweden)

    Kwan Hyung Kim

    2015-08-01

    Full Text Available A 46-year-old female patient was admitted to the intensive care unit (ICU after liver transplantation. About an hour later after the ICU admission, she had no pupillary light reflex. Both pupils were also fixed at 5 mm. Patients who undergo liver transplantation are susceptible to neurologic disorders including hepatic encephalopathy, thromboembolism and intracranial hemorrhage. Abnormal pupillary light reflex usually indicates a serious neurologic emergency in these patients; however, benign neurologic disorders such as peripheral autonomic neuropathy or Holmes-Adie syndrome should also be considered. We experienced a case of fixed pupillary light reflex after liver transplantation diagnosed as peripheral autonomic neuropathy.

  19. Intralimb and Interlimb Cutaneous Reflexes during Locomotion in the Intact Cat.

    Science.gov (United States)

    Hurteau, Marie-France; Thibaudier, Yann; Dambreville, Charline; Danner, Simon M; Rybak, Ilya A; Frigon, Alain

    2018-04-25

    When the foot contacts an obstacle during locomotion, cutaneous inputs activate spinal circuits to ensure dynamic balance and forward progression. In quadrupeds, this requires coordinated reflex responses between the four limbs. Here, we investigated the patterns and phasic modulation of cutaneous reflexes in forelimb and hindlimb muscles evoked by inputs from all four limbs. Five female cats were implanted to record muscle activity and to stimulate the superficial peroneal and superficial radial nerves during locomotion. Stimulating these nerves evoked short-, mid-, and longer-latency excitatory and/or inhibitory responses in all four limbs that were phase-dependent. The largest responses were generally observed during the peak activity of the muscle. Cutaneous reflexes during mid-swing were consistent with flexion of the homonymous limb and accompanied by modification of the stance phases of the other three limbs, by coactivating flexors and extensors and/or by delaying push-off. Cutaneous reflexes during mid-stance were consistent with stabilizing the homonymous limb by delaying and then facilitating its push-off and modifying the support phases of the homolateral and diagonal limbs, characterized by coactivating flexors and extensors, reinforcing extensor activity and/or delaying push-off. The shortest latencies of homolateral and diagonal responses were consistent with fast-conducting disynaptic or trisynaptic pathways. Descending homolateral and diagonal pathways from the forelimbs to the hindlimbs had a higher probability of eliciting responses compared with ascending pathways from the hindlimbs to the forelimbs. Thus, in quadrupeds, intralimb and interlimb reflexes activated by cutaneous inputs ensure dynamic coordination of the four limbs, producing a whole-body response. SIGNIFICANCE STATEMENT The skin contains receptors that, when activated, send inputs to spinal circuits, signaling a perturbation. Rapid responses, or reflexes, in muscles of the

  20. Effect of straining on diaphragmatic crura with identification of the straining-crural reflex. The "reflex theory" in gastroesophageal competence

    Directory of Open Access Journals (Sweden)

    El Sibai Olfat

    2004-09-01

    Full Text Available Abstract Background The role of the crural diaphragm during increased intra-abdominal pressure is not exactly known. We investigated the hypothesis that the crural diaphragm undergoes reflex phasic contraction on elevation of the intra-abdominal pressure with a resulting increase of the lower esophageal pressure and prevention of gastro-esophageal reflux. Methods The esophageal pressure and crural diaphragm electromyographic responses to straining were recorded in 16 subjects (10 men, 6 women, age 36.6 ± 11.2 SD years during abdominal hernia repair. The electromyogram of crural diaphragm was recorded by needle electrode inserted into the crural diaphragm, and the lower esophageal pressure by a saline-perfused catheter. The study was repeated after crural anesthetization and after crural infiltration with saline. Results The crural diaphragm exhibited resting electromyographic activity which showed a significant increase on sudden (coughing, p Conclusions Straining effected an increase of the electromyographic activity of the crural diaphragm and of the lower esophageal pressure. This effect is suggested to be reflex in nature and to be mediated through the "straining-crural reflex". The crural diaphragm seems to play a role in the lower esophageal competence mechanism. Further studies are required to assess the clinical significance of the current results in gastro-esophageal reflux disease and hiatus hernia.

  1. Neuromuscular adaptations to 4 weeks of intensive drop jump training in well-trained athletes

    DEFF Research Database (Denmark)

    Alkjær, Tine; Meyland, Jacob; Raffalt, Peter C

    2013-01-01

    This study examined the effects of 4 weeks of intensive drop jump training in well-trained athletes on jumping performance and underlying changes in biomechanics and neuromuscular adaptations. Nine well-trained athletes at high national competition level within sprinting and jumping disciplines...... participated in the study. The training was supervised and augmented feedback on performance was used to ensure maximal training intensity. The drop jumps were performed with minimal contact time and maximal jumping height. Assessment of performance during training showed effects of motor learning. Before...... and after the training intervention maximal isometric muscle strength, the biomechanics, muscle activity pattern of the lower extremities and the soleus H-reflex and V-wave during drop jumping were measured. Maximal jump height and performance index (PI) defined as jumping height divided by contact time...

  2. The legacy of care as reflexive learning.

    Science.gov (United States)

    García, Marta Rodríguez; Moya, Jose Luis Medina

    2016-06-14

    to analyze whether the tutor's use of reflexive strategies encourages the students to reflect. The goal is to discover what type of strategies can help to achieve this and how tutors and students behave in the practical context. a qualitative and ethnographic focus was adopted. Twenty-seven students and 15 tutors from three health centers participated. The latter had received specific training on reflexive clinical tutoring. The analysis was developed through constant comparisons of the categories. the results demonstrate that the tutors' use of reflexive strategies such as didactic questioning, didactic empathy and pedagogical silence contributes to encourage the students' reflection and significant learning. reflexive practice is key to tutors' training and students' learning. analisar se o uso de estratégias reflexivas por parte da tutora de estágio clínico estimula a reflexão nos estudantes. A intenção é descobrir qual tipo de estratégias podem ajudar a fazê-lo e como as tutoras e os estudantes se comportam no contexto prático. foi adotado um enfoque qualitativo de cunho etnográfico em que participaram 27 estudantes e 15 tutores de três centros de saúde que haviam recebido formação específica sobre tutoria clínica reflexiva. A análise foi realizada por meio de comparações constantes das categorias. os resultados demonstram que o uso de estratégias reflexivas como a interrogação didática, a empatia didática e o silêncio pedagógico por parte das tutoras, contribui para fomentar a reflexão do estudante e sua aprendizagem significativa. a prática reflexiva é a chave para a formação dos tutores e para a aprendizagem dos estudantes. analizar si el uso de estrategias reflexivas por parte de la tutora de prácticas clínicas fomenta la reflexión en los estudiantes. Se trata de conocer qué tipo de estrategias pueden ayudar a hacerlo y cómo se comportan tutoras y estudiantes en el contexto práctico. se ha utilizado un enfoque

  3. Propranolol, but not naloxone, enhances spinal reflex bladder activity and reduces pudendal inhibition in cats.

    Science.gov (United States)

    Rogers, Marc J; Xiao, Zhiying; Shen, Bing; Wang, Jicheng; Schwen, Zeyad; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2015-01-01

    This study examined the role of β-adrenergic and opioid receptors in spinal reflex bladder activity and in the inhibition induced by pudendal nerve stimulation (PNS) or tibial nerve stimulation (TNS). Spinal reflex bladder contractions were induced by intravesical infusion of 0.25% acetic acid in α-chloralose-anesthetized cats after an acute spinal cord transection (SCT) at the thoracic T9/T10 level. PNS or TNS at 5 Hz was applied to inhibit these spinal reflex contractions at 2 and 4 times the threshold intensity (T) for inducing anal or toe twitch, respectively. During a cystrometrogram (CMG), PNS at 2T and 4T significantly (P reflex bladder contractions. After administering propranolol (3 mg/kg iv, a β₁/β₂-adrenergic receptor antagonist), the effects of 2T and 4T PNS on bladder capacity were significantly (P reflex bladder contractions or PNS inhibition. At the end of experiments, hexamethonium (10 mg/kg iv, a ganglionic blocker) significantly (P reflex bladder contractions. This study indicates an important role of β₁/β₂-adrenergic receptors in pudendal inhibition and spinal reflex bladder activity. Copyright © 2015 the American Physiological Society.

  4. Biophysical characterization of the short QT mutation hERG-N588K reveals a mixed gain-and loss-of-function

    DEFF Research Database (Denmark)

    Grunnet, M.; Diness, T.G.; Hansen, R.S.

    2008-01-01

    The short QT syndrome is a newly discovered pro-arrhythmic condition, which may cause ventricular fibrillation and sudden death. Short QT can originate from the apparent gain-of-function mutation N588K in the hERG potassium channel that conducts repolarising I(Kr) current. The present study...

  5. The medial olivocochlear reflex in children during active listening.

    Science.gov (United States)

    Smith, Spencer B; Cone, Barbara

    2015-08-01

    To determine if active listening modulates the strength of the medial olivocochlear (MOC) reflex in children. Click-evoked otoacoustic emissions (CEOAEs) were recorded from the right ear in quiet and in four test conditions: one with contralateral broadband noise (BBN) only, and three with active listening tasks wherein attention was directed to speech embedded in contralateral BBN. Fifteen typically-developing children (ranging in age from 8 to14 years) with normal hearing. CEOAE levels were reduced in every condition with contralateral acoustic stimulus (CAS) when compared to preceding quiet conditions. There was an additional systematic decrease in CEOAE level with increased listening task difficulty, although this effect was very small. These CEOAE level differences were most apparent in the 8-18 ms region after click onset. Active listening may change the strength of the MOC reflex in children, although the effects reported here are very subtle. Further studies are needed to verify that task difficulty modulates the activity of the MOC reflex in children.

  6. Single Canonical Model of Reflexive Memory and Spatial Attention

    Science.gov (United States)

    Patel, Saumil S.; Red, Stuart; Lin, Eric; Sereno, Anne B.

    2015-01-01

    Many neurons in the dorsal and ventral visual stream have the property that after a brief visual stimulus presentation in their receptive field, the spiking activity in these neurons persists above their baseline levels for several seconds. This maintained activity is not always correlated with the monkey’s task and its origin is unknown. We have previously proposed a simple neural network model, based on shape selective neurons in monkey lateral intraparietal cortex, which predicts the valence and time course of reflexive (bottom-up) spatial attention. In the same simple model, we demonstrate here that passive maintained activity or short-term memory of specific visual events can result without need for an external or top-down modulatory signal. Mutual inhibition and neuronal adaptation play distinct roles in reflexive attention and memory. This modest 4-cell model provides the first simple and unified physiologically plausible mechanism of reflexive spatial attention and passive short-term memory processes. PMID:26493949

  7. Single Canonical Model of Reflexive Memory and Spatial Attention.

    Science.gov (United States)

    Patel, Saumil S; Red, Stuart; Lin, Eric; Sereno, Anne B

    2015-10-23

    Many neurons in the dorsal and ventral visual stream have the property that after a brief visual stimulus presentation in their receptive field, the spiking activity in these neurons persists above their baseline levels for several seconds. This maintained activity is not always correlated with the monkey's task and its origin is unknown. We have previously proposed a simple neural network model, based on shape selective neurons in monkey lateral intraparietal cortex, which predicts the valence and time course of reflexive (bottom-up) spatial attention. In the same simple model, we demonstrate here that passive maintained activity or short-term memory of specific visual events can result without need for an external or top-down modulatory signal. Mutual inhibition and neuronal adaptation play distinct roles in reflexive attention and memory. This modest 4-cell model provides the first simple and unified physiologically plausible mechanism of reflexive spatial attention and passive short-term memory processes.

  8. Pains and Gains from China’s Experiences with Emerging Epidemics: From SARS to H7N9

    Directory of Open Access Journals (Sweden)

    Pengfei Wei

    2016-01-01

    Full Text Available Over the recent decades, China experienced several emerging virus outbreaks including those caused by the severe acute respiratory syndrome- (SARS- coronavirus (Cov, H5N1 virus, and H7N9 virus. The SARS tragedy revealed faults in China’s infectious disease prevention system, propelling the Chinese government to enact reforms that enabled better combating of the subsequent H1N1 and H7N9 avian flu epidemics. The system is buttressed by three fundamental, mutually reinforcing components: (1 enduring government administration reforms, including legislation establishing a unified public health emergency management system; (2 prioritized funding for biotechnology and biomedicine industrialization, especially in the areas of pathogen identification, drug production, and the development of vaccines and diagnostics; and (3 increasing investment for public health and establishment of a rapid-response infectious diseases prevention and control system. China is now using its hard-gained experience to support the fight against Ebola in Africa and the Middle East Respiratory Syndrome in its own country.

  9. Human investigations into the exercise pressor reflex

    DEFF Research Database (Denmark)

    Secher, Niels H; Amann, Markus

    2012-01-01

    During exercise, neural input from skeletal muscles reflexly maintains or elevates blood pressure (BP) despite a maybe fivefold increase in vascular conductance. This exercise pressor reflex is illustrated by similar heart rate (HR) and BP responses to electrically induced and voluntary exercise....... The importance of the exercise pressor reflex for tight cardiovascular regulation during dynamic exercise is supported by studies using pharmacological blockade of lower limb muscle afferent nerves. These experiments show attenuation of the increase in BP and cardiac output when exercise is performed...... with attenuated neural feedback. Additionally, there is no BP response to electrically induced exercise with paralysing epidural anaesthesia or when similar exercise is evoked in paraplegic patients. Furthermore, BP decreases when electrically induced exercise is carried out in tetraplegic patients. The lack...

  10. Capital Gains Taxation and House Price Fluctuations

    DEFF Research Database (Denmark)

    Fuest, Clemens; Nielsen, Søren Bo

    2004-01-01

    Recent years have seen large swings in house prices in many countries. Motivated by housing price variations, proposals for taxing capital gains on housing have repeatedly been put forth. The idea seems to be that such taxes would curb the redistribution occurring between those owning houses...... and those trying to get into the market for owner-occupied housing. Our paper shows that at least in simple settings, a tax on real capital gains on housing will only lead to even bigger price swings and will not be able to redistribute between people appearing on either side of the housing market.......Keywords: capital gains tax, housing market, price fluctuationsJEL-Classification: H23, H24, R 31.Addresses:...

  11. Vestibuloocular reflex dynamics during high-frequency and high-acceleration rotations of the head on body in rhesus monkey.

    Science.gov (United States)

    Huterer, Marko; Cullen, Kathleen E

    2002-07-01

    For frequencies >10 Hz, the vestibuloocular reflex (VOR) has been primarily investigated during passive rotations of the head on the body in humans. These prior studies suggest that eye movements lag head movements, as predicted by a 7-ms delay in the VOR reflex pathways. However, Minor and colleagues recently applied whole-body rotations of frequencies unity (1.1 at 5 Hz vs. 1.2 at 25 Hz), and phase lag increased only slightly with frequency (from 2 degrees at 5 Hz to 11 degrees at 25 Hz, a marked contrast to the 63 degrees lag at 25 Hz predicted by a 7-ms VOR latency). Furthermore, VOR response dynamics were comparable in darkness and when viewing a target and did not vary with peak velocity. Although monkeys offered less resistance to the initial cycles of applied head motion, the gain and phase of the VOR did not vary for early versus late cycles, suggesting that an efference copy of the motor command to the neck musculature did not alter VOR response dynamics. In addition, VOR dynamics were also probed by applying transient head perturbations with much greater accelerations (peak acceleration >15,000 degrees /s(2)) than have been previously employed. The VOR latency was between 5 and 6 ms, and mean gain was close to unity for two of the three animals tested. A simple linear model well described the VOR responses elicited by sinusoidal and transient head on body rotations. We conclude that the VOR is compensatory over a wide frequency range in monkeys and has similar response dynamics during passive rotation of the head on body as during passive rotation of the whole body in space.

  12. Involvement of ERK phosphorylation in brainstem neurons in modulation of swallowing reflex in rats

    Science.gov (United States)

    Tsujimura, Takanori; Kondo, Masahiro; Kitagawa, Junichi; Tsuboi, Yoshiyuki; Saito, Kimiko; Tohara, Haruka; Ueda, Koichiro; Sessle, Barry J; Iwata, Koichi

    2009-01-01

    In order to evaluate the neuronal mechanisms underlying functional abnormalities of swallowing in orofacial pain patients, this study investigated the effects of noxious orofacial stimulation on the swallowing reflex, phosphorylated extracellular signal-regulated kinase (pERK) and γ-aminobutyric acid (GABA) immunohistochemical features in brainstem neurons, and also analysed the effects of brainstem lesioning and of microinjection of GABA receptor agonist or antagonist into the nucleus tractus solitarii (NTS) on the swallowing reflex in anaesthetized rats. The swallowing reflex elicited by topical administration of distilled water to the pharyngolaryngeal region was inhibited after capsaicin injection into the facial (whisker pad) skin or lingual muscle. The capsaicin-induced inhibitory effect on the swallowing reflex was itself depressed after the intrathecal administration of MAPK kinase (MEK) inhibitor. No change in the capsaicin-induced inhibitory effect was observed after trigeminal spinal subnucleus caudalis lesioning, but the inhibitory effect was diminished by paratrigeminal nucleus (Pa5) lesioning. Many pERK-like immunoreactive neurons in the NTS showed GABA immunoreactivity. The local microinjection of the GABAA receptor agonist muscimol into the NTS produced a significant reduction in swallowing reflex, and the capsaicin-induced depression of the swallowing reflex was abolished by microinjection of the GABAA receptor antagonist bicuculline into the NTS. The present findings suggest that facial skin–NTS, lingual muscle–NTS and lingual muscle–Pa5–NTS pathways are involved in the modulation of swallowing reflex by facial and lingual pain, respectively, and that the activation of GABAergic NTS neurons is involved in the inhibition of the swallowing reflex following noxious stimulation of facial and intraoral structures. PMID:19124539

  13. Involvement of ERK phosphorylation in brainstem neurons in modulation of swallowing reflex in rats.

    Science.gov (United States)

    Tsujimura, Takanori; Kondo, Masahiro; Kitagawa, Junichi; Tsuboi, Yoshiyuki; Saito, Kimiko; Tohara, Haruka; Ueda, Koichiro; Sessle, Barry J; Iwata, Koichi

    2009-02-15

    In order to evaluate the neuronal mechanisms underlying functional abnormalities of swallowing in orofacial pain patients, this study investigated the effects of noxious orofacial stimulation on the swallowing reflex, phosphorylated extracellular signal-regulated kinase (pERK) and gamma-aminobutyric acid (GABA) immunohistochemical features in brainstem neurons, and also analysed the effects of brainstem lesioning and of microinjection of GABA receptor agonist or antagonist into the nucleus tractus solitarii (NTS) on the swallowing reflex in anaesthetized rats. The swallowing reflex elicited by topical administration of distilled water to the pharyngolaryngeal region was inhibited after capsaicin injection into the facial (whisker pad) skin or lingual muscle. The capsaicin-induced inhibitory effect on the swallowing reflex was itself depressed after the intrathecal administration of MAPK kinase (MEK) inhibitor. No change in the capsaicin-induced inhibitory effect was observed after trigeminal spinal subnucleus caudalis lesioning, but the inhibitory effect was diminished by paratrigeminal nucleus (Pa5) lesioning. Many pERK-like immunoreactive neurons in the NTS showed GABA immunoreactivity. The local microinjection of the GABA(A) receptor agonist muscimol into the NTS produced a significant reduction in swallowing reflex, and the capsaicin-induced depression of the swallowing reflex was abolished by microinjection of the GABA(A) receptor antagonist bicuculline into the NTS. The present findings suggest that facial skin-NTS, lingual muscle-NTS and lingual muscle-Pa5-NTS pathways are involved in the modulation of swallowing reflex by facial and lingual pain, respectively, and that the activation of GABAergic NTS neurons is involved in the inhibition of the swallowing reflex following noxious stimulation of facial and intraoral structures.

  14. Primary reflex persistence in children with reading difficulties (dyslexia): a cross-sectional study.

    Science.gov (United States)

    McPhillips, Martin; Jordan-Black, Julie-Anne

    2007-03-02

    The primary reflex system emerges during fetal life and is inhibited during the first year after birth. Our aim was to examine the effects of persistence of this early neurological system on the attainment of core literacy skills in dyslexic and non-dyslexic poor readers. We assessed the prevalence of a persistent primary reflex in a cross-sectional, representative sample of children (n=739) aged 7-9 years old attending mainstream primary school in Northern Ireland using standardised educational tests, and a clinical diagnostic test for a primary reflex (the asymmetrical tonic neck reflex (ATNR)). Multiple regression analyses, involving all of the sample children, revealed that persistence of the ATNR was significantly predictive of attainments in reading (t=-8.34, pschooling, the attainment of core educational skills may be affected by the persistence of a brainstem mediated reflex system that should have been inhibited in the first year after birth. Furthermore, these findings suggest that dyslexia is not a distinct category of poor reading, and that it may be more valid to term all poor readers as dyslexic irrespective of IQ.

  15. Modeling gravity-dependent plasticity of the angular vestibuloocular reflex with a physiologically based neural network.

    Science.gov (United States)

    Xiang, Yongqing; Yakushin, Sergei B; Cohen, Bernard; Raphan, Theodore

    2006-12-01

    A neural network model was developed to explain the gravity-dependent properties of gain adaptation of the angular vestibuloocular reflex (aVOR). Gain changes are maximal at the head orientation where the gain is adapted and decrease as the head is tilted away from that position and can be described by the sum of gravity-independent and gravity-dependent components. The adaptation process was modeled by modifying the weights and bias values of a three-dimensional physiologically based neural network of canal-otolith-convergent neurons that drive the aVOR. Model parameters were trained using experimental vertical aVOR gain values. The learning rule aimed to reduce the error between eye velocities obtained from experimental gain values and model output in the position of adaptation. Although the model was trained only at specific head positions, the model predicted the experimental data at all head positions in three dimensions. Altering the relative learning rates of the weights and bias improved the model-data fits. Model predictions in three dimensions compared favorably with those of a double-sinusoid function, which is a fit that minimized the mean square error at every head position and served as the standard by which we compared the model predictions. The model supports the hypothesis that gravity-dependent adaptation of the aVOR is realized in three dimensions by a direct otolith input to canal-otolith neurons, whose canal sensitivities are adapted by the visual-vestibular mismatch. The adaptation is tuned by how the weights from otolith input to the canal-otolith-convergent neurons are adapted for a given head orientation.

  16. Cortical tremor: a variant of cortical reflex myoclonus.

    Science.gov (United States)

    Ikeda, A; Kakigi, R; Funai, N; Neshige, R; Kuroda, Y; Shibasaki, H

    1990-10-01

    Two patients with action tremor that was thought to originate in the cerebral cortex showed fine shivering-like finger twitching provoked mainly by action and posture. Surface EMG showed relatively rhythmic discharge at a rate of about 9 Hz, which resembled essential tremor. However, electrophysiologic studies revealed giant somatosensory evoked potentials (SEPs) with enhanced long-loop reflex and premovement cortical spike by the jerk-locked averaging method. Treatment with beta-blocker showed no effect, but anticonvulsants such as clonazepam, valproate, and primidone were effective to suppress the tremor and the amplitude of SEPs. We call this involuntary movement "cortical tremor," which is in fact a variant of cortical reflex myoclonus.

  17. The effects of team reflexivity on psychological well-being in manufacturing teams.

    Science.gov (United States)

    Chen, Jingqiu; Bamberger, Peter A; Song, Yifan; Vashdi, Dana R

    2018-04-01

    While the impact of team reflexivity (a.k.a. after-event-reviews, team debriefs) on team performance has been widely examined, we know little about its implications on other team outcomes such as member well-being. Drawing from prior team reflexivity research, we propose that reflexivity-related team processes reduce demands, and enhance control and support. Given the centrality of these factors to work-based strain, we posit that team reflexivity, by affecting these factors, may have beneficial implications on 3 core dimensions of employee burnout, namely exhaustion, cynicism, and inefficacy (reduced personal accomplishment). Using a sample of 469 unskilled manufacturing workers employed in 73 production teams in a Southern Chinese factory, we implemented a time lagged, quasi-field experiment, with half of the teams trained in and executing an end-of-shift team debriefing, and the other half assigned to a control condition and undergoing periodic postshift team-building exercises. Our findings largely supported our hypotheses, demonstrating that relative to team members assigned to the control condition, those assigned to the reflexivity condition experienced a significant improvement in all 3 burnout dimensions over time. These effects were mediated by control and support (but not demands) and amplified as a function of team longevity. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  18. Swedish Massage and Abnormal Reflexes of Children with Spastic Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Vida Alizad

    2007-09-01

    Full Text Available Objectives: Massage therapy is one of the most widely used complementary and alternative medicine therapies for children. This study was conducted to determine the effect of wedish massage on abnormal reflexes in children with spastic cerebral palsy (CP. Methods: This study was a single blind clinical trial conducted on forty children with spastic CP who were recruited from clinics of the University of Social Welfare & Rehabilitation Sciences. They were randomly assigned to intervention and control groups. The routine occupational therapy (OT techniques were performed during a 3 month-period in both groups. The intervention group also received Swedish massage for 30 minutes before every OT session. Primary, spinal, brain stem, midbrain, cortical and automatic reflexes were evaluated at the beginning of the study and 3 months later. The data analysis was done by parametric and nonparametric tests. Results: Finally, thirteen subjects in the intervention group and 14 subjects in the control group were remained and studied. The average ages in the intervention and control groups were 49.5 and 42.1 months respectively. There were no statistically significant differences in abnormal reflexes in the intervention group in comparison to the control (P>0.05. Discussion: Adding Swedish massage to traditional OT techniques had no significant effects on abnormal reflexes in children with spastic cerebral palsy. Evidently more research is required in order to completely reject the effects of Swedish massage on abnormal reflexes of children with CP.

  19. Computer simulation model of reflex e-beam systems coupled to an external circuit

    International Nuclear Information System (INIS)

    Jungwirth, K.; Stavinoha, P.

    1982-01-01

    Dynamics of ions and relativistic electrons in various high-voltage reflexing systems (reflex diodes and triodes) was investigated numerically by means of 1 1/2-dimensional PIC simulation model OREBIA. Its perfected version OREBIA-REX also accounts for system coupling to an external power source circuit, thus yielding the currents and applied voltage self-consistently. Various modes of operation of reflex diode and triode were studied using both models. It is shown that neglecting the influence of the external circuit can lead to seve--re overestimation of both ion currents and electron accumulation rates. In coupled systems with ions repeated collapses of impedance due to electron-ion relaxation processes are observed. The current and voltage pulses calculated for several reflex diodes and triodes with and without ions are presented. (J.U.)

  20. Local Injections of Superoxide Dismutase Attenuate the Exercise Pressor Reflex in Rats with Femoral Artery Occlusion

    Directory of Open Access Journals (Sweden)

    Jihong Xing

    2018-02-01

    Full Text Available The exercise pressor reflex is amplified in patients with peripheral artery disease (PAD and in an experimental PAD model of rats induced by femoral artery occlusion. Heightened blood pressure worsens the restricted blood flow directed to the limbs in this disease. The purpose of this study was to determine the role played by muscle oxidative stress in regulating the augmented pressor response to static exercise in PAD. We hypothesized that limb ischemia impairs muscle superoxide dismutase (SOD thereby leading to abnormal autonomic responsiveness observed in PAD animals, and a chronic compensation of SOD for anti-oxidation improves the exaggerated exercise pressor reflex. Our data show that femoral occlusion decreased the protein levels of SOD in ischemic muscle as compared with control muscle. Downregulation of SOD appeared to a greater degree in the oxidative (red muscle than in the glycolytic (white muscle under the condition of muscle ischemia. In addition, the exercise pressor response was assessed during electrically induced static contraction. The data demonstrates that the enhancement of the exercise pressor reflex was significantly attenuated after tempol (a mimetic of SOD, 30 mg over a period of 72 h was administered into the occluded hindlimb. In the occluded rats, mean arterial pressure (MAP response was 26 ± 3 mmHg with no tempol and 12 ± 2 mmHg with tempol application (P < 0.05 vs. group with no tempol; n = 6 in each group. There were no differences in muscle tension development (time-tension index: 12.1 ± 1.2 kgs with no tempol and 13.5 ± 1.1 kgs with tempol; P > 0.05 between groups. In conclusion, SOD is lessened in the ischemic muscles and supplement of SOD improves the amplified exercise pressor reflex, which is likely beneficial to the restricted blood flow to the limbs in PAD.

  1. Role of spinal metabotropic glutamate receptor 5 in pudendal inhibition of the nociceptive bladder reflex in cats.

    Science.gov (United States)

    Reese, Jeremy N; Rogers, Marc J; Xiao, Zhiying; Shen, Bing; Wang, Jicheng; Schwen, Zeyad; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2015-04-15

    This study examined the role of spinal metabotropic glutamate receptor 5 (mGluR5) in the nociceptive C-fiber afferent-mediated spinal bladder reflex and in the inhibtion of this reflex by pudendal nerve stimulation (PNS). In α-chloralose-anesthetized cats after spinal cord transection at the T9/T10 level, intravesical infusion of 0.25% acetic acid irritated the bladder, activated nociceptive C-fiber afferents, and induced spinal reflex bladder contractions of low amplitude (reflexes were responsible for a major component of the contractions. This study shows that spinal mGluR5 plays an important role in the nociceptive C-fiber afferent-mediated spinal bladder reflex and in pudendal inhibition of this spinal reflex. Copyright © 2015 the American Physiological Society.

  2. Reflexive journaling on emotional research topics: ethical issues for team researchers.

    Science.gov (United States)

    Malacrida, Claudia

    2007-12-01

    Traditional epistemological concerns in qualitative research focus on the effects of researchers' values and emotions on choices of research topics, power relations with research participants, and the influence of researcher standpoints on data collection and analysis. However, the research process also affects the researchers' values, emotions, and standpoints. Drawing on reflexive journal entries of assistant researchers involved in emotionally demanding team research, this article explores issues of emotional fallout for research team members, the implications of hierarchical power imbalances on research teams, and the importance of providing ethical opportunities for reflexive writing about the challenges of doing emotional research. Such reflexive approaches ensure the emotional safety of research team members and foster opportunities for emancipatory consciousness among research team members.

  3. How Can Hypnodontics Manage Severe Gag Reflex for Root Canal Therapy? A Case Report

    Science.gov (United States)

    Ramazani, Mohsen; zarenejad, Nafiseh; Parirokh, Masoud; Zahedpasha, Samir

    2016-01-01

    In endodontics, severe involuntary gagging can have a severe impact on treatment procedure. There are many ways to ease the gag reflex, one of which is hypnosis. A 34-year-old male was referred for root canal treatment of a molar tooth. He had not received any dental treatments for the past nine years due to fear of severe gag reflex. Three hypnotic sessions based upon eye fixation, progressive muscle relaxation and guided imagery techniques were spent for psychosomatic management. The gag reflex was controlled and reduced to a normal level, and the required dental treatments including root canal therapy and restoration were performed successfully. This report shows that hypnosis can control gag reflex for dental treatments. PMID:27141226

  4. Educational Strategies to Enhance Reflexivity Among Clinicians and Health Professional Students: A Scoping Study

    Directory of Open Access Journals (Sweden)

    Rachel Landy

    2016-09-01

    Full Text Available Reflexivity involves the ability to understand how one's social locations and experiences of advantage or disadvantage have shaped the way one understands the world. The capacity for reflexivity is crucial because it informs clinical decisions, which can lead to improvements in service delivery and patient outcomes. In this article, we present a scoping study that explored educational strategies designed to enhance reflexivity among clinicians and/or health profession students. We reviewed articles and grey literature that address the question: What is known about strategies for enhancing reflexivity among clinicians and students in health professional training programs? We searched multiple databases using keywords including: reflexivity, reflective, allied health professionals, pedagogy, learning, and education. The search strategy was iterative and involved three reviews. Each abstract was independently reviewed by two team members. Sixty-eight texts met the inclusion criteria. There was great diversity among the educational strategies and among health professions. Commonalities across strategies were identified related to reflective writing, experiential learning, classroom-based activities, continuing education, and online learning. We also summarize the 19 texts that evaluated educational strategies to enhance reflexivity. Further research and education is urgently needed for more equitable and socially-just health care. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1603140

  5. The Reflexive Nature of Reading as Ethnographic Practice: Editorial Note

    Directory of Open Access Journals (Sweden)

    Wolff-Michael Roth

    2004-01-01

    Full Text Available In this editorial, I suggest that not only is reading published texts a way of doing ethno­graph­ic research, but also reading concretely realizes itself in the productions of new texts that reproduce the cultural practices that are analyzed in the published text. Reading as ethnographic method is therefore a reflexive project. I provide a dialectical framework for theorizing the reflexive nature of reading. URN: urn:nbn:de:0114-fqs0401390

  6. Selective depletion of spinal monoamines changes the rat soleus EMG from a tonic to a more phasic pattern

    DEFF Research Database (Denmark)

    Kiehn, Ole; Erdal, Jesper; Eken, Torsten

    1996-01-01

    subarachnoid space and gross-EMG recording electrodes in the soleus muscle. EMG recordings were performed in control conditions and at different times after intrathecal administration of either 40-55 μg 5,6-dihydroxytryptamine (5,6-DHT) and 40-55 μg 6-hydroxydopamine (6-OHDA) or 80 μg 5,7-dihydroxytryptamine...... (5,7-DHT) alone. The depletions were evaluated biochemically in brains and spinal cords after recordings. 3. In agreement with previous studies the intrathecal administration of neurotoxins caused a reduction of the noradrenaline (NA) and serotonin (5-HT) content of the lumbar spinal cord to about 2...

  7. Reflex control of the spine and posture: a review of the literature from a chiropractic perspective

    Directory of Open Access Journals (Sweden)

    Schlappi Mark

    2005-08-01

    Full Text Available Abstract Objective This review details the anatomy and interactions of the postural and somatosensory reflexes. We attempt to identify the important role the nervous system plays in maintaining reflex control of the spine and posture. We also review, illustrate, and discuss how the human vertebral column develops, functions, and adapts to Earth's gravity in an upright position. We identify functional characteristics of the postural reflexes by reporting previous observations of subjects during periods of microgravity or weightlessness. Background Historically, chiropractic has centered around the concept that the nervous system controls and regulates all other bodily systems; and that disruption to normal nervous system function can contribute to a wide variety of common ailments. Surprisingly, the chiropractic literature has paid relatively little attention to the importance of neurological regulation of static upright human posture. With so much information available on how posture may affect health and function, we felt it important to review the neuroanatomical structures and pathways responsible for maintaining the spine and posture. Maintenance of static upright posture is regulated by the nervous system through the various postural reflexes. Hence, from a chiropractic standpoint, it is clinically beneficial to understand how the individual postural reflexes work, as it may explain some of the clinical presentations seen in chiropractic practice. Method We performed a manual search for available relevant textbooks, and a computer search of the MEDLINE, MANTIS, and Index to Chiropractic Literature databases from 1970 to present, using the following key words and phrases: "posture," "ocular," "vestibular," "cervical facet joint," "afferent," "vestibulocollic," "cervicocollic," "postural reflexes," "spaceflight," "microgravity," "weightlessness," "gravity," "posture," and "postural." Studies were selected if they specifically tested any or

  8. Parasympathetic Nervous System Dysfunction, as Identified by Pupil Light Reflex, and Its Possible Connection to Hearing Impairment.

    Directory of Open Access Journals (Sweden)

    Yang Wang

    Full Text Available Although the pupil light reflex has been widely used as a clinical diagnostic tool for autonomic nervous system dysfunction, there is no systematic review available to summarize the evidence that the pupil light reflex is a sensitive method to detect parasympathetic dysfunction. Meanwhile, the relationship between parasympathetic functioning and hearing impairment is relatively unknown.To 1 review the evidence for the pupil light reflex being a sensitive method to evaluate parasympathetic dysfunction, 2 review the evidence relating hearing impairment and parasympathetic activity and 3 seek evidence of possible connections between hearing impairment and the pupil light reflex.Literature searches were performed in five electronic databases. All selected articles were categorized into three sections: pupil light reflex and parasympathetic dysfunction, hearing impairment and parasympathetic activity, pupil light reflex and hearing impairment.Thirty-eight articles were included in this review. Among them, 36 articles addressed the pupil light reflex and parasympathetic dysfunction. We summarized the information in these data according to different types of parasympathetic-related diseases. Most of the studies showed a difference on at least one pupil light reflex parameter between patients and healthy controls. Two articles discussed the relationship between hearing impairment and parasympathetic activity. Both studies reported a reduced parasympathetic activity in the hearing impaired groups. The searches identified no results for pupil light reflex and hearing impairment.As the first systematic review of the evidence, our findings suggest that the pupil light reflex is a sensitive tool to assess the presence of parasympathetic dysfunction. Maximum constriction velocity and relative constriction amplitude appear to be the most sensitive parameters. There are only two studies investigating the relationship between parasympathetic activity and hearing

  9. Parasympathetic Nervous System Dysfunction, as Identified by Pupil Light Reflex, and Its Possible Connection to Hearing Impairment.

    Science.gov (United States)

    Wang, Yang; Zekveld, Adriana A; Naylor, Graham; Ohlenforst, Barbara; Jansma, Elise P; Lorens, Artur; Lunner, Thomas; Kramer, Sophia E

    2016-01-01

    Although the pupil light reflex has been widely used as a clinical diagnostic tool for autonomic nervous system dysfunction, there is no systematic review available to summarize the evidence that the pupil light reflex is a sensitive method to detect parasympathetic dysfunction. Meanwhile, the relationship between parasympathetic functioning and hearing impairment is relatively unknown. To 1) review the evidence for the pupil light reflex being a sensitive method to evaluate parasympathetic dysfunction, 2) review the evidence relating hearing impairment and parasympathetic activity and 3) seek evidence of possible connections between hearing impairment and the pupil light reflex. Literature searches were performed in five electronic databases. All selected articles were categorized into three sections: pupil light reflex and parasympathetic dysfunction, hearing impairment and parasympathetic activity, pupil light reflex and hearing impairment. Thirty-eight articles were included in this review. Among them, 36 articles addressed the pupil light reflex and parasympathetic dysfunction. We summarized the information in these data according to different types of parasympathetic-related diseases. Most of the studies showed a difference on at least one pupil light reflex parameter between patients and healthy controls. Two articles discussed the relationship between hearing impairment and parasympathetic activity. Both studies reported a reduced parasympathetic activity in the hearing impaired groups. The searches identified no results for pupil light reflex and hearing impairment. As the first systematic review of the evidence, our findings suggest that the pupil light reflex is a sensitive tool to assess the presence of parasympathetic dysfunction. Maximum constriction velocity and relative constriction amplitude appear to be the most sensitive parameters. There are only two studies investigating the relationship between parasympathetic activity and hearing impairment

  10. Factitious lymphoedema as a psychiatric condition mimicking reflex sympathetic dystrophy: a case report

    Directory of Open Access Journals (Sweden)

    Nwaejike Nnamdi

    2008-06-01

    Full Text Available Abstract Introduction Reflex sympathetic dystrophy can result in severe disability with only one in five patients able to fully resume prior activities. Therefore, it is important to diagnose this condition early and begin appropriate treatment. Factitious lymphoedema can mimic reflex sympathetic dystrophy and is caused by self-inflicted tourniquets, blows to the arm or repeated skin irritation. Patients with factitious lymphoedema have an underlying psychiatric disorder but usually present to emergency or orthopaedics departments. Factitious lymphoedema can then be misdiagnosed as reflex sympathetic dystrophy. The treatment for factitious lymphoedema is dealing with the underlying psychiatric condition. Case presentation We share our experience of treating a 33-year-old man, who presented with factitious lymphoedema, initially diagnosed as reflex sympathetic dystrophy. Conclusion Awareness of this very similar differential diagnosis allows early appropriate treatment to be administered.

  11. Modification of Otolith-Ocular Reflexes, Motion Perception and Manual Control During Variable Radius Centrifugation Following Space Flight

    Science.gov (United States)

    Wood, Scott J.; Clarke, A. H.; Rupert, A. H.; Harm, D. L.; Clement, G. R.

    2009-01-01

    Two joint ESA-NASA studies are examining changes in otolith-ocular reflexes and motion perception following short duration space flights, and the operational implications of post-flight tilt-translation ambiguity for manual control performance. Vibrotactile feedback of tilt orientation is also being evaluated as a countermeasure to improve performance during a closed-loop nulling task. Data is currently being collected on astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation is utilized to elicit otolith reflexes in the lateral plane without concordant roll canal cues. Unilateral centrifugation (400 deg/s, 3.5 cm radius) stimulates one otolith positioned off-axis while the opposite side is centered over the axis of rotation. During this paradigm, roll-tilt perception is measured using a subjective visual vertical task and ocular counter-rolling is obtained using binocular video-oculography. During a second paradigm (216 deg/s, less than 20 cm radius), the effects of stimulus frequency (0.15 - 0.6 Hz) are examined on eye movements and motion perception. A closed-loop nulling task is also performed with and without vibrotactile display feedback of chair radial position. Data collection is currently ongoing. Results to date suggest there is a trend for perceived tilt and translation amplitudes to be increased at the low and medium frequencies on landing day compared to pre-flight. Manual control performance is improved with vibrotactile feedback. One result of this study will be to characterize the variability (gain, asymmetry) in both otolith-ocular responses and motion perception during variable radius centrifugation, and measure the time course of post-flight recovery. This study will also address how adaptive changes in otolith-mediated reflexes correspond to one's ability to perform closed-loop nulling tasks following G-transitions, and whether manual control performance can be improved

  12. Study of high frequency instabilities on a cold cathode reflex discharge; Contribution a l'etude des instabilites a haute frequence dans la decharge reflex a cathodes froides

    Energy Technology Data Exchange (ETDEWEB)

    Gregoire, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-06-01

    The cold cathode reflex discharge develops a cathode sheath of several hundreds of volts, which accelerates electrons released from the cathode to high velocities along the lines of the axial magnetic field. On the studied pressure range (4.10{sup -4} torr < p < 2.10{sup -2} torr) the plasma density is about 10{sup 11} cm{sup -3}. Under certain conditions high frequency (1 5000 MHz) instabilities appear. These instabilities are found to profoundly modify the mean characteristics of the discharge. In particular, particle flow across the lines of magnetic field is found to be considerably greater than that predicted by classical diffusion theory. Theoretical considerations are presented with complementary experimental results. They show that the high frequency instabilities are a result of the fast electronic assembly accelerated through the cathode sheath. (author) [French] Dans certaines conditions, qui sont precisees, des instabilites a haute frequence (1 5000 MHz) se developpent dans la decharge reflex a cathodes froides. Lorsque le plasma (n {approx_equal}10{sup 11} cm{sup -3}) est instable, les caracteristiques moyennes de la decharge sont profondement alterees. Les fuites de particules a travers les lignes de forces du champ magnetique statique applique deviennent en particulier trop importantes pour que le seul effet classique des collisions binaires puisse les expliquer. L'ionisation du gaz est assuree par une assemblee electronique qui acquiert dans les gaines cathodiques ({approx_equal} 500 volts) une vitesse, parallele au champ magnetique, importante. La discussion de resultats theoriques et une experience complementaire montrent que cette population d'electrons rapides, tres distincte de celle des electrons lents du plasma pour les pressions les plus faibles du domaine etudie (4.10{sup -4} torr < p < 2.10{sup -2} torr), est responsable des instabilites a haute frequence observees. (auteur)

  13. Comparative proteomic profiling of soleus, extensor digitorum longus, flexor digitorum brevis and interosseus muscles from the mdx mouse model of Duchenne muscular dystrophy.

    Science.gov (United States)

    Carberry, Steven; Brinkmeier, Heinrich; Zhang, Yaxin; Winkler, Claudia K; Ohlendieck, Kay

    2013-09-01

    Duchenne muscular dystrophy is due to genetic abnormalities in the dystrophin gene and represents one of the most frequent genetic childhood diseases. In the X-linked muscular dystrophy (mdx) mouse model of dystrophinopathy, different subtypes of skeletal muscles are affected to a varying degree albeit the same single base substitution within exon 23 of the dystrophin gene. Thus, to determine potential muscle subtype-specific differences in secondary alterations due to a deficiency in dystrophin, in this study, we carried out a comparative histological and proteomic survey of mdx muscles. We intentionally included the skeletal muscles that are often used for studying the pathomechanism of muscular dystrophy. Histological examinations revealed a significantly higher degree of central nucleation in the soleus and extensor digitorum longus muscles compared with the flexor digitorum brevis and interosseus muscles. Muscular hypertrophy of 20-25% was likewise only observed in the soleus and extensor digitorum longus muscles from mdx mice, but not in the flexor digitorum brevis and interosseus muscles. For proteomic analysis, muscle protein extracts were separated by fluorescence two-dimensional (2D) gel electrophoresis. Proteins with a significant change in their expression were identified by mass spectrometry. Proteomic profiling established an altered abundance of 24, 17, 19 and 5 protein species in the dystrophin-deficient soleus, extensor digitorum longus, flexor digitorum brevis and interosseus muscle, respectively. The key proteomic findings were verified by immunoblot analysis. The identified proteins are involved in the contraction-relaxation cycle, metabolite transport, muscle metabolism and the cellular stress response. Thus, histological and proteomic profiling of muscle subtypes from mdx mice indicated that distinct skeletal muscles are differentially affected by the loss of the membrane cytoskeletal protein, dystrophin. Varying degrees of perturbed protein

  14. Peripheral δ-opioid receptors attenuate the exercise pressor reflex.

    Science.gov (United States)

    Leal, Anna K; Yamauchi, Katsuya; Kim, Joyce; Ruiz-Velasco, Victor; Kaufman, Marc P

    2013-10-15

    In rats with ligated femoral arteries, the exercise pressor reflex is exaggerated, an effect that is attenuated by stimulation of peripheral μ-opioid receptors on group IV metabosensitive afferents. In contrast, δ-opioid receptors are expressed mostly on group III mechanosensitive afferents, a finding that prompted us to determine whether stimulation of these opioid receptors could also attenuate the exaggerated exercise pressor reflex in "ligated" rats. We found femoral arterial injection of [D-Pen2,D-Pen5]enkephalin (DPDPE; 1.0 μg), a δ-opioid agonist, significantly attenuated the pressor and cardioaccelerator components of the exercise pressor reflex evoked by hindlimb muscle contraction in both rats with ligated and patent femoral arteries. DPDPE significantly decreased the pressor responses to muscle mechanoreflex activation, evoked by tendon stretch, in ligated rats only. DPDPE (1.0 μg) had no effect in either group on the pressor and cardioaccelerator responses to capsaicin (0.2 μg), which primarily stimulates group IV afferents. DPDPE (1.0 μg) had no effect on the pressor and cardioaccelerator responses to lactic acid (24 mM), which stimulates group III and IV afferents, in rats with patent femoral arteries but significantly decreased the pressor response in ligated rats. Western blots revealed the amount of protein comprising the δ-opioid receptor was greater in dorsal root ganglia innervating hindlimbs with ligated femoral arteries than in dorsal root ganglia innervating hindlimbs with patent femoral arteries. Our findings support the hypothesis that stimulation of δ-opioid receptors on group III afferents attenuated the exercise pressor reflex.

  15. Team performance in the Italian NHS: the role of reflexivity.

    Science.gov (United States)

    Urbini, Flavio; Callea, Antonino; Chirumbolo, Antonio; Talamo, Alessandra; Ingusci, Emanuela; Ciavolino, Enrico

    2018-04-09

    Purpose The purpose of this paper is twofold: first, to investigate the goodness of the input-process-output (IPO) model in order to evaluate work team performance within the Italian National Health Care System (NHS); and second, to test the mediating role of reflexivity as an overarching process factor between input and output. Design/methodology/approach The Italian version of the Aston Team Performance Inventory was administered to 351 employees working in teams in the Italian NHS. Mediation analyses with latent variables were performed via structural equation modeling (SEM); the significance of total, direct, and indirect effect was tested via bootstrapping. Findings Underpinned by the IPO framework, the results of SEM supported mediational hypotheses. First, the application of the IPO model in the Italian NHS showed adequate fit indices, showing that the process mediates the relationship between input and output factors. Second, reflexivity mediated the relationship between input and output, influencing some aspects of team performance. Practical implications The results provide useful information for HRM policies improving process dimensions of the IPO model via the mediating role of reflexivity as a key role in team performance. Originality/value This study is one of a limited number of studies that applied the IPO model in the Italian NHS. Moreover, no study has yet examined the role of reflexivity as a mediator between input and output factors in the IPO model.

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

    Science.gov (United States)

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

    2014-02-01

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

  17. Medial olivocochlear reflex interneurons are located in the posteroventral cochlear nucleus: a kainic acid lesion study in guinea pigs.

    Science.gov (United States)

    de Venecia, Ronald K; Liberman, M Charles; Guinan, John J; Brown, M Christian

    2005-07-11

    The medial olivocochlear (MOC) reflex arc is probably a three-neuron pathway consisting of type I spiral ganglion neurons, reflex interneurons in the cochlear nucleus, and MOC neurons that project to the outer hair cells of the cochlea. We investigated the identity of MOC reflex interneurons in the cochlear nucleus by assaying their regional distribution using focal injections of kainic acid. Our reflex metric was the amount of change in the distortion product otoacoustic emission (at 2f(1)-f(2)) just after onset of the primary tones. This metric for MOC reflex strength has been shown to depend on an intact reflex pathway. Lesions involving the posteroventral cochlear nucleus (PVCN), but not the other subdivisions, produced long-term decreases in MOC reflex strength. The degree of cell loss within the dorsal part of the PVCN was a predictor of whether the lesion affected MOC reflex strength. We suggest that multipolar cells within the PVCN have the distribution and response characteristics appropriate to be the MOC reflex interneurons. (c) 2005 Wiley-Liss, Inc.

  18. Two Reflexivities in Current Social Science: Remarks on an Absent Debate

    Directory of Open Access Journals (Sweden)

    Andreas Langenohl

    2009-02-01

    Full Text Available This paper traces and compares two different uses of the category of reflexivity in contemporary methodological debates in the social sciences. While a first use is strongly influenced by the textual turn in cultural anthropology, a second use is aligned with Pierre BOURDIEU's notion of "scientific reflexivity." Whereas the first use postulates an epistemological break with scientific modernity and argues for a perpetual contextualization and interrelation of research results and methods, BOURDIEU defends sociology’s claim of objectivity, which, according to him, can be redeemed through a reflexive objectification of sociological practice. Up to the present these two uses have existed in almost complete isolation from each other. They represent alternating reactions to, and reconstructions and translations of, poststructuralism and postmodernism in the social sciences. URN: urn:nbn:de:0114-fqs090297

  19. Danish Working Environment Regulation. How reflexive - how political? -a Scandinavian case

    DEFF Research Database (Denmark)

    Koch, Christian

    an understanding of the directions of the reforms made in this period. The paper operate with two analytical perspectives: The reflexive regulation perspective and the political process perspective. Danish working environment regulation is discussed through the general political initiatives taken, and through four...... specific regulation topics: The Occupational Health Services (OHS), regulation of the psychological working environment, the 'Monotonous Repeated Work'-plan and the workers' compensation. Taking the last twenty years' development as a whole the main developments in the regulation is a further shift...... in balance between material and reflexive regulation elements to the benefit of the latter. But although the reflexive elements seem to stabilize, they are vulnerable to a loss of legitimacy and changes in the political pattern.The impact on enterprise power patterns is summed up in a polarization thesis...

  20. Reflexive Aero Structures for Enhanced Survivability, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group Inc. (CRG) will develop an advanced reflexive structure technology system to increase the survivability of future systems constructed of...

  1. Effects of long-term microgravitation exposure on cell respiration of the rat musculus soleus fibers.

    Science.gov (United States)

    Veselova, O M; Ogneva, I V; Larina, I M

    2011-07-01

    Cell respiration of the m. soleus fibers was studied in Wistar rats treated with succinic acid and exposed to microgravitation for 35 days. The results indicated that respiration rates during utilization of endogenous and exogenous substrates and the maximum respiration rate decreased in animals subjected to microgravitation without succinate treatment. The respiration rate during utilization of exogenous substrate did not increase in comparison with that on endogenous substrates. Succinic acid prevented the decrease in respiration rate on endogenous substrates and the maximum respiration rate. On the other hand, the respiration rate on exogenous substrates was reduced in vivarium control rats receiving succinate in comparison with intact control group. That could indicate changed efficiency of complex I of the respiratory chain due to reciprocal regulation of the tricarbonic acid cycle.

  2. The Use of Restoring Resources of the Survival Roles and Reflex Patterns in MNRI® (Reflex Integration Interactive Training of Personality Growth and Interpersonal Relations

    Directory of Open Access Journals (Sweden)

    Masgutova S.K.

    2017-12-01

    Full Text Available Personality growth as a socio-psychological problem is a multi-complex phenomenon that targets Self-identity, Self-actualization, and other areas. During the last decade scientists started studying other factors limiting the personality growth, such as stress and post-trauma. However, the Survival Roles, the socio-individual patterns based on neurophysiological and psychological defense mechanisms blocking the personality Self-actualization, social interaction and professional business qualities, are rarely discussed. Thus this study based on Survival Roles may extend the personality growth oriented concepts and therapy modality tools. This study showed a correlation between Survival Role patterns, stress resilience, and survival reflexes (integrative units of the nervous system functions. Comparative data on 464 business professionals from high management jobs (Study Group — n=340, and Control Group — n=124 participated in this research which found 70.9 % (n=329 of the total group was in stress. This stress activated socio-individual Survival Roles and protective reflex patterns which responded with reactivity, over-protection, non-constructive interactions with others and limited business strategies. The MNRI® reflex integrative training used in this study demonstrated improvement of functions of the protective reflex patterns effected positively the survival mechanisms including increased stress resilience, and decreased negative effect of Survival Roles. MNRI® proposes a new paradigm in the realm of personality growth and socio-interpersonal activity, and supports the neurophysiological aspects to optimize the overall quality of life of business professionals from a variety of high management business areas.

  3. On reflexivity and the conduct of the self in everyday life: reflections on Bourdieu and Archer.

    Science.gov (United States)

    Akram, Sadiya; Hogan, Anthony

    2015-12-01

    This article provides a critique of the concept of reflexivity in social theory today and argues against the tendency to define agency exclusively in terms of reflexivity. Margaret Archer, in particular, is highlighted as a key proponent of this thesis. Archer argues that late modernity is characterized by reflexivity but, in our view, this position neglects the impact of more enduring aspects of agency, such as the routinization of social life and the role of the taken-for-granted. These concepts were pivotal to Bourdieu and Giddens' theorization of everyday life and action and to Foucault's understanding of technologies of the self. We offer Bourdieu's habitus as a more nuanced approach to theorizing agency, and provide an alternative account of reflexivity. Whilst accepting that reflexivity is a core aspect of agency, we argue that it operates to a backdrop of the routinization of social life and operates from within and not outside of habitus. We highlight the role of the breach in reflexivity, suggesting that it opens up a critical window for agents to initiate change. The article suggests caution in over-ascribing reflexivity to agency, instead arguing that achieving reflexivity and change is a difficult and fraught process, which has emotional and moral consequences. The effect of this is that people often prefer the status quo, rather than to risk change and uncertainty. © London School of Economics and Political Science 2015.

  4. Diagnostic utility of the acoustic reflex in predicting hearing in paediatric populations.

    Science.gov (United States)

    Pérez-Villa, Yolanda E; Mena-Ramírez, María E; Aguirre, Laura E Chamlati; Mora-Magaña, Ignacio; Gutiérrez-Farfán, Ileana S

    2014-01-01

    The sensitivity of prediction of acoustic reflex, in determining the level of hearing loss, is especially useful in paediatric populations. It is based on the difference between the pure tone stapedius reflex threshold and contralateral white noise. The white noise threshold was 60 dB and that of pure tone was 80 dB. Our objective was to determine the diagnostic sensitivity of the prediction of the acoustic reflex. We studied children aged <10 years, from October 2011 to May 2012, by measuring the acoustic reflex with white noise and pure tone. We used contrast tests, with X2 and student t-test. Concordance was measured with Kappa. Results were considered significant at P≤.05. Our protocol was approved by Institutional Ethics Committee. Informed consent was obtained from the parents in all cases. Prediction of normal hearing was 0.84 for the right ear and 0.78 in left ear, while for hearing loss of an unspecified grade, it was 0.98 for the right ear and 0.96 in the left ear. Kappa value was 0.7 to 0.6 for the right ear and left ear. The acoustic reflex is of little diagnostic utility in predicting the degree of hearing loss, but it predicts more than 80% of normal hearing. The clinical utility of the reflex is indisputable, as it is an objective method, simple and rapid to use, that can be performed from birth and whose results are independent of the cooperation and willingness of the subject. It is proposed as an obligatory part of hearing screening. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Otorrinolaringología y Patología Cérvico-Facial. All rights reserved.

  5. Does diurnal variation in cough reflex testing exist in healthy young adults?

    Science.gov (United States)

    Perry, Sarah; Huckabee, Maggie-Lee

    2017-05-01

    The aim of this study was to investigate whether diurnal variation in cough reflex sensitivity exists in healthy young adults when a tidal-breathing method is used. Fifty-three participants (19-37 years) underwent cough reflex testing on two occasions: once in the morning (between 9 am - midday) and once in the afternoon (between 2-5 pm). The order of testing was counter-balanced. Within each assessment, participants inhaled successively higher citric acid concentrations via a facemask, with saline solution randomly interspersed to control for a placebo response. The lowest concentration that elicited a reflexive cough response was recorded. Morning cough thresholds (mean=0.6mol/L) were not different from afternoon cough thresholds (mean=0.6mol/L), p=0.16, T=101, r=-0.14. We found no evidence of diurnal variability in cough reflex testing. There was, however, an order effect irrespective of time of day, confirming that healthy participants are able to volitionally modulate their cough response. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Veias soleares: bases anatômicas e seu papel na origem da trombose venosa profunda em membro inferior Soleus veins: anatomic basis and their role in the origin of deep venous lower limb thrombosis

    Directory of Open Access Journals (Sweden)

    Carlos Miguel Gomes Sequeira

    2007-08-01

    Full Text Available OBJETIVO: Estudar o número, a setorização e a terminação das veias soleares. MÉTODOS: Em 100 pernas de 50 cadáveres, excluídos aqueles com alterações congênitas ou adquiridas dos membros inferiores, foram realizadas, a fresco, na região crural posterior, dissecções anatômicas minuciosas, estratigráficas. Após o rebatimento da pele, foram realizadas a individualização das veias superficiais e perfurantes, rebatimento da tela subcutânea e da fáscia, individualização e rebatimento dos músculos gastrocnêmio e plantar, desinserção tibial do músculo sóleo, individualização das veias soleares e o estudo morfométrico. A região foi dividida em seis setores: súpero-medial, súpero-lateral, médio-medial, médio-lateral, ínfero-medial e ínfero-lateral. No estudo estatístico utilizaram-se os testes não-paramétricos Wilcoxon e Friedman. RESULTADOS: Foram encontradas 4.679 veias soleares. O setor com maior número de veias soleares foi o súpero-lateral com 1.529 veias (32,7%, seguido do médio-medial com 1.256 veias (26,8% e do médio-lateral com 975 veias (20,8%. As terminações ocorreram em veias comunicantes (1.207 veias - 25,8%, veias tibiais posteriores (964 veias - 20,6%, veias fibulares (709 veias - 15,2% e em mais 32 tipos (1799 veias - 38,4%. CONCLUSÃO: A drenagem venosa do músculo sóleo é realizada por um grande número de veias soleares, freqüentemente localizadas nos setores súpero-lateral, médio-medial e médio-lateral, terminando comumente em veias tibiais posteriores e fibulares e, em veias comunicantes.OBJECTIVE: Study of the number, sectorization and termination of the soleus veins. METHODS: Meticulous, stratigraphical, anatomical dissections were carried out in the posterior crural region of 100 legs of 50 fresh cadavers. Those belonging to subjects with congenital or acquired pathologies in the lower limbs were disregarded. After the skin was reflected on both sides, dissection of superficial

  7. Motor-neuron pool excitability of the lower leg muscles after acute lateral ankle sprain.

    Science.gov (United States)

    Klykken, Lindsey W; Pietrosimone, Brian G; Kim, Kyung-Min; Ingersoll, Christopher D; Hertel, Jay

    2011-01-01

    Neuromuscular deficits in leg muscles that are associated with arthrogenic muscle inhibition have been reported in people with chronic ankle instability, yet whether these neuromuscular alterations are present in individuals with acute sprains is unknown. To compare the effect of acute lateral ankle sprain on the motor-neuron pool excitability (MNPE) of injured leg muscles with that of uninjured contralateral leg muscles and the leg muscles of healthy controls. Case-control study. Laboratory. Ten individuals with acute ankle sprains (6 females, 4 males; age= 19.2 ± 3.8 years, height= 169.4 ± 8.5 cm, mass= 66.3 ± 11.6 kg) and 10 healthy individuals(6 females,4 males; age= 20.6 ± 4.0 years, height = 169.9 ± 10.6 cm, mass= 66.3 ± 10.2 kg) participated. The independent variables were group (acute ankle sprain, healthy) and limb (injured, uninjured). Separate dependent t tests were used to determine differences in MNPE between legs. The MNPE of the soleus, fibularis longus, and tibialis anterior was measured by the maximal Hoffmann reflex (H(max)) and maximal muscle response (M(max)) and was then normalized using the H(max):M(max) ratio. The soleus MNPE in the ankle-sprain group was higher in the injured limb (H(max):M(max) = 0.63; 95% confidence interval [Cl],0.46, 0.80) than the uninjured limb (H(max):M(max) = 0.47; 95%Cl, 0.08, 0.93)(t(6) = 3.62,P =.01).In the acute ankle-sprain group, tibialis anterior MNPE tended to be lower in the injured ankle (H(max):M(max) =0.06; 95% Cl, 0.01, 0.10) than in the uninjured ankle (H(max):M(max) =0.22; 95%Cl, 0.09, 0.35),but this finding was not different (t(9) =-2.01, P =.07). No differences were detected between injured (0.22; 95% Cl, 0.14, 0.29) and uninjured (0.25; 95%Cl, 0.12, 0.38) ankles for the fibularis longus in the ankle-sprain group (t(9) =-0.739, P =.48). We found no side-to-side differences in any muscle among the healthy group. Facilitated MNPE was present in the involved soleus muscle of patients with acute

  8. H2O2 INDUCES DELAYED HYPEREXCITABILITY IN NUCLEUS TRACTUS SOLITARII NEURONS

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    Ostrowski, Tim D.; Hasser, Eileen M.; Heesch, Cheryl M.; Kline, David D.

    2014-01-01

    Hydrogen peroxide (H2O2) is a stable reactive oxygen species and potent neuromodulator of cellular and synaptic activity. Centrally, endogenous H2O2 is elevated during bouts of hypoxia-reoxygenation, a variety of disease states, and aging. The nucleus tractus solitarii (nTS) is the central termination site of visceral afferents for homeostatic reflexes and contributes to reflex alterations during these conditions. We determined the extent to which H2O2 modulates synaptic and membrane properties in nTS neurons in rat brainstem slices. Stimulation of the tractus solitarii (which contains the sensory afferent fibers) evoked synaptic currents that were not altered by 10 – 500 μM H2O2. However, 500 μM H2O2 modulated several intrinsic membrane properties of nTS neurons, including a decrease in input resistance, hyperpolarization of resting membrane potential (RMP) and action potential (AP) threshold (THR), and an initial reduction in AP discharge to depolarizing current. H2O2 increased conductance of barium-sensitive potassium currents, and block of these currents ablated H2O2-induced changes in RMP, input resistance and AP discharge. Following washout of H2O2 AP discharge was enhanced due to depolarization of RMP and a partially maintained hyperpolarization of THR. Hyperexcitability persisted with repeated H2O2 exposure. H2O2 effects on RMP and THR were ablated by intracellular administration of the antioxidant catalase, which was immunohistochemically identified in neurons throughout the nTS. Thus, H2O2 initially reduces excitability of nTS neurons that is followed by sustained hyperexcitability, which may play a profound role in cardiorespiratory reflexes. PMID:24397952

  9. Prognostic Value of Impaired Preoperative Ankle Reflex in Surgical Outcome of Lumbar Disc Herniation

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    Farzad Omidi-Kashani

    2016-01-01

    Full Text Available Background: Several prognostic factors exist influencing the outcome of surgical discectomy in the patients with lumbar disc herniation (LDH. The aim of this study is to evaluate the relationship between severity of preoperative impaired ankle reflex and outcomes of lumbar discectomy in the patients with L5-S1 LDH. Methods: We retrospectively evaluated 181 patients (108 male and 73 female who underwent simple discectomy in our orthopedic department from April 2009 to April 2013 and followed them up for more than one year. The mean age of the patients was 35.3±8.9 years old. Severity of reflex impairment was graded from 0 to 4+ and radicular pain and disability were assessed by visual analogue scale (VAS and Oswestry disability index (ODI questionnaires, respectively. Subjective satisfaction was also evaluated at the last follow-up visit. Chi-square and Kruskal-Wallis tests were used to compare qualitative variables. Results: Reflex impairment existed in 44.8% preoperatively that improved to 10% at the last follow-up visit. Statistical analyses could not find a significant relationship between the severity of impaired ankle reflex and sex or age (P=0.538 and P=0.709, respectively. There was a remarkable relationship between severity of reflex impairment and preoperative radicular pain or disability (P=0.012 and P=0.002, respectively. Kruskal-Wallis test showed that a more severity in ankle reflex impairment was associated with not only less improvement in postoperative pain and disability but also less satisfaction rate (P Conclusions: In the patients with L5-S1 LDH, more severe ankle reflex impairment is associated with less improvement in postoperative pain, disability, and subjective satisfaction.

  10. Evaluating Red Reflex and Surgeon Preference Between Nearly-Collimated and Focused Beam Microscope Illumination Systems.

    Science.gov (United States)

    Cionni, Robert J; Pei, Ron; Dimalanta, Ramon; Lubeck, David

    2015-08-01

    To evaluate the intensity and stability of the red reflex produced by ophthalmic surgical microscopes with nearly-collimated versus focused illumination systems and to assess surgeon preference in a simulated surgical setting. This two-part evaluation consisted of postproduction surgical video analysis of red reflex intensity and a microscope use and preference survey completed by 13 experienced cataract surgeons. Survey responses were based on bench testing and experience in a simulated surgical setting. A microscope with nearly-collimated beam illumination and two focused beam microscopes were assessed. Red reflex intensity and stability were greater with the nearly-collimated microscope illumination system. In the bench testing survey, surgeons reported that the red reflex was maintained over significantly greater distances away from pupillary center, and depth of focus was numerically greater with nearly-collimated illumination relative to focused illumination. Most participating surgeons (≥64%) reported a preference for the microscope with nearly-collimated illumination with regard to red reflex stability, depth of focus, visualization, surgical working distance, and perceived patient comfort. The microscope with nearly-collimated illumination produced a more intense and significantly more stable red reflex and was preferred overall by more surgeons. This is the first report of an attempt to quantify red reflex intensity and stability and to evaluate surgically-relevant parameters between microscope systems. The data and methods presented here may provide a basis for future studies attempting to quantify differences between surgical microscopes that may affect surgeon preference and microscope use in ophthalmic surgery.

  11. Role of Glucocorticoids in the Response to Unloading of Muscle Protein and Amino Acid Metabolism

    Science.gov (United States)

    Tischler, M. E.; Jaspers, S. R.

    1985-01-01

    Intact control (weight bearing) and suspended rats gained weight at a similar rate during a 6 day period. Adrenaectomized (adx) weight bearing rats gained less weight during this period while adrenalectomized suspended rats showed no significant weight gain. Cortisol treatment of both of these groups of animals caused a loss of body weight. Results from these studies show several important findings: (1) Metabolic changes in the extensor digitorum longus muscle of suspended rats are due primarily to increased circulating gluccorticoids; (2) Metabolic changes in the soleus due to higher steroid levels are probably potentiated by greater numbers of receptors; and (3) Not all metabolic responses in the unloaded soleus muscle are due to direct action of elevated glucocorticoids or increased sensitivity to these hormones.

  12. Plantar reflex excitability is increased in the evening in restless legs syndrome patients.

    Science.gov (United States)

    Dafkin, Chloe; Green, Andrew; Olivier, Benita; McKinon, Warrick; Kerr, Samantha

    2017-11-01

    To investigate if diurnal changes in spinal excitability (plantar reflex) occur in restless legs syndrome (RLS) participants compared to healthy matched controls. Thirteen RLS participants and 13 healthy control participants' plantar reflex responses were evaluated in the evening (PM) and the morning (AM). Plantar reflex responses were assessed electromyographically, using motion analysis (kinematically) and by subjective nociception (Visual Analogue Scale). RLS participants showed a circadian variation in plantar reflex responses whilst control participants did not. Evening ankle angle changes were larger and faster in RLS participants compared to morning responses. In addition RLS participants displayed significantly smaller change in ankle angle and significantly slower ankle movements in the evening and the morning as well as significantly lower lateral gastrocnemius maximum amplitude in the compared to control participants. The findings of the current study support the theory of RLS circadian fluctuations in spinal excitability. An unexpected finding was decreased plantar reflex responses in RLS participants compared to healthy control participants. However this finding supports the theory of mechanical hypoesthesia in RLS. The results of this study provide further insight into the pathophysiology of RLS, highlighting that not all sensory processing is affected in the same manner. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. A Study on the Effects of Bee Venom Aqua-Acupuncture on Writhing Reflex

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    Jeong Sun-Hee

    2000-07-01

    Full Text Available Introduction:In spite of the use of Bee Venom aqua-acupuncture in the clinics, the scientific evaluation on effects is not enough. Bee Venom aqua-acupuncture is used according to the stimulation of acupuncture point and the chemical effects of Bee Venom. The aims of this study is to investigate the analgegic effects of the Bee Venom aqua-acupuncture, through the change of writhing reflex Materials and Methods:Pain animal model was used acetic acid method. The changes of writhing reflex of the mice which were derived pain by injecting acetic acid into the abdomen, after stimulating Bee Venom aqua-acupuncture on Chungwan(CV12 and non acupuncture point on the backside were measured. Results:1. It showed that the writhing reflex were appeared on the groups which injected acetic acid only, and saline-acetic acid group(sample I, but not on the group bee venom-saline group(sample II. 2. The change of writhing reflex by Chungwan(CV12 Bee Venom aqua-acupuncture showed significant decrease in the order of Chungwan(CV12 Bee Venom aqua-acupuncture group III(2.5×10-3g/kg, II(2.5×10-4g/kg, and I(2.5×10-5g/kg, compared with control group. There were significant decrease of number of writhing reflex in 5~10, 10~15 and 15~20 minutes intervals of Chung wan(CV12 Bee Venom aqua-acupuncture group I, and in 0~5, 5~10, 10~15 and 15~20 minutes intervals of II and III, compared with control group. 3. The change of writhing reflex by non acupuncture point Bee Venom aqua-acupuncture showed significant decrease in the 0~5 and 5~10 minutes intervals and the total number of writhing reflex in 2.5×10-4g/kg group, compared with control group 4. The effects of writhing reflex of Chungwan(CV12 Bee Venom aqua-acupuncture group showed significant decrease, compared with non acupuncture point Bee Venom aqua-acupuncture group. Conclusion:This study shows that the Bee Venom aqua-acupuncture on Chungwan(CV12 decreases the numbers of writhing reflex. As the

  14. Creating safety by strengthening clinicians' capacity for reflexivity

    Science.gov (United States)

    2011-01-01

    This commentary explores the nature of creating safety in the here-and-now. Creating safety encompasses two dimensions: revisiting specific behaviours by focusing on substandard performance (reflection), and a more broad-ranging attention to everyday behaviours that are taken as given (reflexivity). The piece pays particular attention to this second dimension of creating safety. Two techniques that promote reflexivity are discussed: video-filming real-time, everyday clinical practice and inviting clinicians' feedback about their own footage, and reflecting on the knowledge and questions that patients and families have about their care, and about unexpected outcomes and clinical incidents. The piece concludes that feedback about everyday practice using these methods is critical to enhancing the safety of everyday activity. PMID:21450780

  15. A method of reflexive balancing in a pragmatic, interdisciplinary and reflexive bioethics.

    Science.gov (United States)

    Ives, Jonathan

    2014-07-01

    In recent years there has been a wealth of literature arguing the need for empirical and interdisciplinary approaches to bioethics, based on the premise that an empirically informed ethical analysis is more grounded, contextually sensitive and therefore more relevant to clinical practice than an 'abstract' philosophical analysis. Bioethics has (arguably) always been an interdisciplinary field, and the rise of 'empirical' (bio)ethics need not be seen as an attempt to give a new name to the longstanding practice of interdisciplinary collaboration, but can perhaps best be understood as a substantive attempt to engage with the nature of that interdisciplinarity and to articulate the relationship between the many different disciplines (some of them empirical) that contribute to the field. It can also be described as an endeavour to explain how different disciplinary approaches can be integrated to effectively answer normative questions in bioethics, and fundamental to that endeavour is the need to think about how a robust methodology can be articulated that successfully marries apparently divergent epistemological and metaethical perspectives with method. This paper proposes 'Reflexive Bioethics' (RB) as a methodology for interdisciplinary and empirical bioethics, which utilizes a method of 'Reflexive Balancing' (RBL). RBL has been developed in response to criticisms of various forms of reflective equilibrium, and is built upon a pragmatic characterization of Bioethics and a 'quasi-moral foundationalism', which allows RBL to avoid some of the difficulties associated with RE and yet retain the flexible egalitarianism that makes it intuitively appealing to many. © 2013 John Wiley & Sons Ltd.

  16. Genetic Influence on Slope Variability in a Childhood Reflexive Attention Task.

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    Rebecca A Lundwall

    Full Text Available Individuals are not perfectly consistent, and interindividual variability is a common feature in all varieties of human behavior. Some individuals respond more variably than others, however, and this difference may be important to understanding how the brain works. In this paper, we explore genetic contributions to response time (RT slope variability on a reflexive attention task. We are interested in such variability because we believe it is an important part of the overall picture of attention that, if understood, has the potential to improve intervention for those with attentional deficits. Genetic association studies are valuable in discovering biological pathways of variability and several studies have found such associations with a sustained attention task. Here, we expand our knowledge to include a reflexive attention task. We ask whether specific candidate genes are associated with interindividual variability on a childhood reflexive attention task in 9-16 year olds. The genetic makers considered are on 11 genes: APOE, BDNF, CHRNA4, COMT, DRD4, HTR4, IGF2, MAOA, SLC5A7, SLC6A3, and SNAP25. We find significant associations with variability with markers on nine and we discuss the results in terms of neurotransmitters associated with each gene and the characteristics of the associated measures from the reflexive attention task.

  17. Encouraging Reflexivity in Urban Geography Fieldwork: Study Abroad Experiences in Singapore and Malaysia

    Science.gov (United States)

    Glass, Michael R.

    2014-01-01

    Fieldwork in urban geography courses can encourage reflexivity among students regarding the cities they encounter. This article outlines how student reflexivity was encouraged within a new international field research course in Singapore and Malaysia. Drawing on examples from students' field exercises written during an intensive and occasionally…

  18. Reflexivity in the Interstices: A Tale of Reflexivity at Work in, during, and behind the Scenes

    Science.gov (United States)

    Wickens, Corrine M.; Cohen, James A.; Walther, Carol S.

    2017-01-01

    This article is a story of how the authors came to make sense of the significance of those words in relation to gender, race/ethnicity, and citizenship in writing a manuscript about L[subscript 1]L[subscript 2] acquisition. It is a tale about how Reflexivity wove itself into the conversations, into the writing, into the in-between spaces, the…

  19. The articulo-cardiac sympathetic reflex in spinalized, anesthetized rats.

    Science.gov (United States)

    Nakayama, Tomohiro; Suzuki, Atsuko; Ito, Ryuzo

    2006-04-01

    Somatic afferent regulation of heart rate by noxious knee joint stimulation has been proven in anesthetized cats to be a reflex response whose reflex center is in the brain and whose efferent arc is a cardiac sympathetic nerve. In the present study we examined whether articular stimulation could influence heart rate by this efferent sympathetic pathway in spinalized rats. In central nervous system (CNS)-intact rats, noxious articular movement of either the knee or elbow joint resulted in an increase in cardiac sympathetic nerve activity and heart rate. However, although in acutely spinalized rats a noxious movement of the elbow joint resulted in a significant increase in cardiac sympathetic nerve activity and heart rate, a noxious movement of the knee joint had no such effect and resulted in only a marginal increase in heart rate. Because this marginal increase was abolished by adrenalectomy suggests that it was due to the release of adrenal catecholamines. In conclusion, the spinal cord appears to be capable of mediating, by way of cardiac sympathetic nerves, the propriospinally induced reflex increase in heart rate that follows noxious stimulation of the elbow joint, but not the knee joint.

  20. Therapeutic effects of anti-gravity treadmill (AlterG) training on reflex hyper-excitability, corticospinal tract activities, and muscle stiffness in children with cerebral palsy.

    Science.gov (United States)

    Parvin, Sh; Taghiloo, A; Irani, A; Mirbagheri, M Mehdi

    2017-07-01

    We aimed to study therapeutic effects of antigravity treadmill (AlterG) training on reflex hyper-excitability, muscle stiffness, and corticospinal tract (CST) function in children with spastic hemiplegic cerebral palsy (CP). Three children received AlterG training 3 days per week for 8 weeks as experimental group. Each session lasted 45 minutes. One child as control group received typical occupational therapy for the same amount of time. We evaluated hyper-excitability of lower limb muscles by H-reflex response. We quantified muscle stiffness by sonoelastography images of the affected muscles. We quantified CST activity by transcranial magnetic stimulation (TMS). We performed the evaluations before and after training for both groups. H response latency and maximum M-wave amplitude were improved in experimental group after training compared to control group. Two children of experimental group had TMS response. Major parameters of TMS (i.e. peak-to-peak amplitude of motor evoked potential (MEP), latency of MEP, cortical silent period, and intensity of pulse) improved for both of them. Three parameters of texture analysis of sonoelastography images were improved for experimental group (i.e. contrast, entropy, and shear wave velocity). These findings indicate that AlterG training can improve reflexes, muscle stiffness, and CST activity in children with spastic hemiplegic CP and can be considered as a therapeutic tool to improve neuromuscular abnormalities occurring secondary to CP.

  1. Iterative Algorithm for Solving a Class of Quaternion Matrix Equation over the Generalized (P,Q-Reflexive Matrices

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    Ning Li

    2013-01-01

    Full Text Available The matrix equation ∑l=1uAlXBl+∑s=1vCsXTDs=F, which includes some frequently investigated matrix equations as its special cases, plays important roles in the system theory. In this paper, we propose an iterative algorithm for solving the quaternion matrix equation ∑l=1uAlXBl+∑s=1vCsXTDs=F over generalized (P,Q-reflexive matrices. The proposed iterative algorithm automatically determines the solvability of the quaternion matrix equation over generalized (P,Q-reflexive matrices. When the matrix equation is consistent over generalized (P,Q-reflexive matrices, the sequence {X(k} generated by the introduced algorithm converges to a generalized (P,Q-reflexive solution of the quaternion matrix equation. And the sequence {X(k} converges to the least Frobenius norm generalized (P,Q-reflexive solution of the quaternion matrix equation when an appropriate initial iterative matrix is chosen. Furthermore, the optimal approximate generalized (P,Q-reflexive solution for a given generalized (P,Q-reflexive matrix X0 can be derived. The numerical results indicate that the iterative algorithm is quite efficient.

  2. Neonatal exposure to citalopram, a serotonin selective reuptake inhibitor, programs a delay in the reflex ontogeny in rats Exposição neonatal ao citalopram, um inibidor seletivo da recaptação de serotonina, programa retardo na ontogênese reflexa em ratos

    Directory of Open Access Journals (Sweden)

    Teresa Cristina Bomfim de Jesus Deiró

    2008-01-01

    Full Text Available Serotonin influences the growth and development of the nervous system, as well as its behavioral manifestations. The possibility exists that increased brain serotonin availability in young animals modulates their neuro-behavioral responses. This study investigated the body weight gain and reflex ontogeny of neonatal rats treated during the suckling period with two doses of citalopram (5 mg, or 10 mg/kg, sc, daily. The time of the appearance of reflexes (palm grasp righting, free-fall righting, vibrissa placing, auditory startle response, negative geotaxis and cliff avoidance as well as the body weight evolution were recorded. In general, a delay in the time of reflex development and a reduced weight gain were observed in drug-treated animals. These findings suggest that serotoninergic mechanisms play a role in modulating body weight gain and the maturation of most reflex responses during the perinatal period in rats.A serotonina influencia o crescimento e o desenvolvimento do sistema nervoso e sua expressão comportamental. O aumento da disponibilidade de serotonina no cérebro de ratos jovens parece modular as respostas neurocomportamentais. Neste estudo, foram investigados o ganho de peso corporal e a ontogênese dos reflexos em ratos neonatos, tratados diariamente, durante o período de aleitamento, com duas doses de citalopram (5 ou 10 mg/Kg de peso corporal, via subcutânea. Foram avaliados, o tempo de aparecimento dos reflexos (preensão palmar, endireitamento, colocação pelas vibrissas, resposta ao susto, geotáxico negativo e aversão ao precipício, e a evolução do peso corporal. Foi observado atraso no tempo de desenvolvimento de alguns reflexos e redução no ganho de peso corporal. Os achados em ratos sugerem que as alterações no ganho de peso corporal e na maturação dos reflexos são programadas, durante o período perinatal, com participação de mecanismos serotoninérgicos de modulação.

  3. Dynamics of a stabilized motor defense conditioned reflex at different levels of motivation in irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Shtemberg, A S

    1982-05-01

    Postradiation dynamics of strengthened motor-defense conditioned reflex in rats-males irradiated with the doses of 94.111 and 137 Gy was studied. Phase disturbances of conditioned-reflex activity increased with enhancing irradiation dose have been revealed. Rapid recovery of conditioned reflex after short primary aggravation was a characteristic peculiarity. At that, the dynamics of relation of main nervous processes in cortex was noted for significant instability increasing with radiation syndrome development. Enhancement of force of electro-defense support promoted more effective strengthening of temporary connections and conditioned high stability of trained-reflex reactions during serious functional disturbances resulted from sublethal dose irradiation.

  4. Neurophysiology and Clinical Implications of the Laryngeal Adductor Reflex.

    Science.gov (United States)

    Domer, Amanda S; Kuhn, Maggie A; Belafsky, Peter C

    2013-09-01

    The laryngeal adductor reflex (LAR) is an involuntary protective response to stimuli in the larynx. The superior laryngeal nerve (SLN) acts as the afferent limb and the recurrent laryngeal nerve (RLN) as the efferent limb of this reflex, which is modulated by the central nervous system. Perhaps the most clinically significant application of the LAR is its use in laryngopharyngeal (LP) sensory discrimination testing. Importantly, aberrations in the LAR may predict dysphagia or portend clinical phenotypes of chronic cough, vocal cord dysfunction or pediatric apneas. LP sensation is a potential target for interventions addressing the aforementioned conditions though currently remains an area of active investigation.

  5. Time Course of the Response of Myofibrillar and Sarcoplasmic Protein Metabolism to Unweighting of the Soleus Muscle

    Science.gov (United States)

    Munoz, Kathryn A.; Satarug, Soisungwan; Tischler, Marc E.

    1993-01-01

    Contributions of altered in vivo protein synthesis and degradation to unweighting atrophy of the soleus muscle in tail-suspended young female rats were analyzed daily for up to 6 days. Specific changes in myofibrillar and sarcoplasmic proteins were also evaluated to assess their contributions to the loss of total protein. Synthesis of myofibrillar and sarcoplasmic proteins was estimated by intramuscular (IM) injection and total protein by intraperitoneal (IP) injection of flooding doses of H-3-phenylaianine. Total protein loss was greatest during the first 3 days following suspension and was a consequence of the loss of myofibrillar rather than sarcoplasmic proteins. However, synthesis of total myofibrillar and sarcoplasmic proteins diminished in parallel beginning in the first 24 hours. Therefore sarcoplasmic proteins must be spared due to a decrease in their degradation. In contrast, myofibrillar protein degradation increased, thus explaining the elevated degradation of the total pool. Following 72 hours of suspension, protein synthesis remained low, but the rate of myofibrillar protein loss diminished, suggesting a slowing of degradation. These various results show acute loss of protein during unweighting atrophy is a consequence of decreased synthesis and increased degradation of myofibrillar proteins, and sarcoplasmic proteins are spared due to slower degradation, likely explaining the sparing of plasma membrane receptors. Based on other published data, we propose that the slowing of atrophy after the initial response may be attributed to an increased effect of insulin.

  6. Selected cardiopulmonary values and baroreceptor reflex in conscious green iguanas (Iguana iguana).

    Science.gov (United States)

    Hernandez, Sonia M; Schumacher, Juergen; Lewis, Stephen J; Odoi, Agricola; Divers, Stephen J

    2011-11-01

    To determine selected cardiopulmonary values and baroreceptor response in conscious green iguanas (Iguana iguana) and to evaluate the use of blood gas analysis and pulse oximetry in this species. 15 healthy juvenile green iguanas. Baseline cardiopulmonary values were determined in 15 conscious iguanas breathing room air. Effects of 100% O(2) inspiration were also measured (n = 6), and the baroreceptor reflex was characterized by exponential sigmoidal curve fitting analysis. Conscious iguanas had a mean ± SD resting heart rate of 52 ± 8 beats/min, respiratory rate of 28 ± 6 breaths/min, and systolic, mean, and diastolic arterial blood pressures of 69 ± 10 mm Hg, 62 ± 12 mm Hg, and 56 ± 13 mm Hg, respectively. Mean arterial pH at 37°C was 7.29 ± 0.11, PaO(2) was 81 ± 10 mm Hg, and PaCO(2) was 42 ± 9 mm Hg; corrected for a body temperature of 30°C, mean arterial pH at 37°C was 7.382 ±0.12, PaO(2) was 54 ± 15 mm Hg, and PaCO(2) was 32 ± 7 mm Hg. Inspiration of 100% O(2) did not change heart and respiratory rates but increased PaO(2) to 486 ± 105 mm Hg (corrected value, 437 ± 96 mm Hg). A baroreceptor reflex was evident, with mean heart rates ranging from 30 ± 3 beats/min to 63 ± 5 beats/min and mean arterial blood pressures ranging from 42 ± 3 mm Hg to 58 ± 3 mm Hg. This study provided needed information on cardiopulmonary values in healthy green iguanas, the application and limitation of arterial and venous blood gas analysis, and the accuracy of pulse oximetry.

  7. Proteome-wide muscle protein fractional synthesis rates predict muscle mass gain in response to a selective androgen receptor modulator in rats.

    Science.gov (United States)

    Shankaran, Mahalakshmi; Shearer, Todd W; Stimpson, Stephen A; Turner, Scott M; King, Chelsea; Wong, Po-Yin Anne; Shen, Ying; Turnbull, Philip S; Kramer, Fritz; Clifton, Lisa; Russell, Alan; Hellerstein, Marc K; Evans, William J

    2016-03-15

    Biomarkers of muscle protein synthesis rate could provide early data demonstrating anabolic efficacy for treating muscle-wasting conditions. Androgenic therapies have been shown to increase muscle mass primarily by increasing the rate of muscle protein synthesis. We hypothesized that the synthesis rate of large numbers of individual muscle proteins could serve as early response biomarkers and potentially treatment-specific signaling for predicting the effect of anabolic treatments on muscle mass. Utilizing selective androgen receptor modulator (SARM) treatment in the ovariectomized (OVX) rat, we applied an unbiased, dynamic proteomics approach to measure the fractional synthesis rates (FSR) of 167-201 individual skeletal muscle proteins in triceps, EDL, and soleus. OVX rats treated with a SARM molecule (GSK212A at 0.1, 0.3, or 1 mg/kg) for 10 or 28 days showed significant, dose-related increases in body weight, lean body mass, and individual triceps but not EDL or soleus weights. Thirty-four out of the 94 proteins measured from the triceps of all rats exhibited a significant, dose-related increase in FSR after 10 days of SARM treatment. For several cytoplasmic proteins, including carbonic anhydrase 3, creatine kinase M-type (CK-M), pyruvate kinase, and aldolase-A, a change in 10-day FSR was strongly correlated (r(2) = 0.90-0.99) to the 28-day change in lean body mass and triceps weight gains, suggesting a noninvasive measurement of SARM effects. In summary, FSR of multiple muscle proteins measured by dynamics of moderate- to high-abundance proteins provides early biomarkers of the anabolic response of skeletal muscle to SARM. Copyright © 2016 the American Physiological Society.

  8. Research progress of the relationship between abnormal vestibular reflexes and adolescent idiopathic scoliosis

    Directory of Open Access Journals (Sweden)

    Yi-Lin Yang

    2017-01-01

    Full Text Available Adolescent idiopathic scoliosis (AIS is an agnogenic structural scoliosis occurring in adolescence, and the main diagnostic criteria is coronal Cobb angle >10°in total spine X-ray. Studies have shown that AIS may be associated with abnormal postural reflexes, vestibular system is an important component of postural reflexes and its mechanism in the occurrence and development of scoliosis has received wide attention in recent years. In the study, the research progress on the role of abnormal vestibular reflexes in the pathogenesis of AIS was mainly introduced to help the clinicians better understand the pathogenesis of AIS and provide new ideas for AIS study.

  9. CAROTID BODY CHEMO-REFLEX: A DRIVER OF AUTONOMIC ABNORMALITIES IN SLEEP APNEA

    Science.gov (United States)

    Prabhakar, Nanduri R.

    2016-01-01

    Carotid bodies are the principal peripheral chemoreceptors for detecting changes in arterial blood oxygen levels, and the resulting chemo-reflex is a potent regulator of the sympathetic tone, blood pressure, and breathing. Sleep apnea is a disease of the respiratory system affecting several million adult humans. Apneas occur during sleep often due to obstruction of the upper airway (obstructive sleep apnea, OSA) or due to defective respiratory rhythm generation by the central nervous system (central sleep apnea). Patients with sleep apnea exhibit several co-morbidities; most notable among them being the heightened sympathetic nerve activity, and hypertension. Emerging evidence suggests that intermittent hypoxia (IH) resulting from periodic apnea stimulates the carotid body and the ensuing chemo-reflex mediates the increased sympathetic tone and hypertension in sleep apnea patients. Rodent models of IH, simulating the O2 saturation profiles encountered during sleep apnea have provided important insights into the cellular and molecular mechanisms underlying the heightened carotid body chemo-reflex. This article describes how IH affects the carotid body function, and discusses the cellular, molecular and epigenetic mechanisms underlying the exaggerated chemo-reflex. PMID:27474260

  10. The mechano-gated channel inhibitor GsMTx4 reduces the exercise pressor reflex in decerebrate rats.

    Science.gov (United States)

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

    2016-02-01

    Mechanical and metabolic stimuli from contracting muscles evoke reflex increases in blood pressure, heart rate and sympathetic nerve activity. Little is known, however, about the nature of the mechano-gated channels on the thin fibre muscle afferents that contribute to evoke this reflex, termed the exercise pressor reflex. We determined the effect of GsMTx4, an inhibitor of mechano-gated Piezo channels, on the exercise pressor reflex evoked by intermittent contraction of the triceps surae muscles in decerebrated, unanaesthetized rats. GsMTx4 reduced the pressor, cardioaccelerator and renal sympathetic nerve responses to intermittent contraction but did not reduce the pressor responses to femoral arterial injection of compounds that stimulate the metabolically-sensitive thin fibre muscle afferents. Expression levels of Piezo2 channels were greater than Piezo1 channels in rat dorsal root ganglia. Our findings suggest that mechanically-sensitive Piezo proteins contribute to the generation of the mechanical component of the exercise pressor reflex in rats. Mechanical and metabolic stimuli within contracting skeletal muscles evoke reflex autonomic and cardiovascular adjustments. In cats and rats, gadolinium has been used to investigate the role played by the mechanical component of this reflex, termed the exercise pressor reflex. Gadolinium, however, has poor selectivity for mechano-gated channels and exerts multiple off-target effects. We tested the hypothesis that GsMTX4, a more selective mechano-gated channel inhibitor than gadolinium and a particularly potent inhibitor of mechano-gated Piezo channels, reduced the exercise pressor reflex in decerebrate rats. Injection of 10 μg of GsMTx4 into the arterial supply of the hindlimb reduced the peak pressor (control: 24 ± 5, GsMTx4: 12 ± 5 mmHg, P acid. Moreover, injection of 10 μg of GsMTx4 into the arterial supply of the hindlimb reduced the peak pressor (control: 24 ± 2, GsMTx4: 14 ± 3 mmHg, P reflex in

  11. Sympathetic β-adrenergic mechanism in pudendal inhibition of nociceptive and non-nociceptive reflex bladder activity.

    Science.gov (United States)

    Kadow, Brian T; Lyon, Timothy D; Zhang, Zhaocun; Lamm, Vladimir; Shen, Bing; Wang, Jicheng; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2016-07-01

    This study investigated the role of the hypogastric nerve and β-adrenergic mechanisms in the inhibition of nociceptive and non-nociceptive reflex bladder activity induced by pudendal nerve stimulation (PNS). In α-chloralose-anesthetized cats, non-nociceptive reflex bladder activity was induced by slowly infusing saline into the bladder, whereas nociceptive reflex bladder activity was induced by replacing saline with 0.25% acetic acid (AA) to irritate the bladder. PNS was applied at multiple threshold (T) intensities for inducing anal sphincter twitching. During saline infusion, PNS at 2T and 4T significantly (P reflex bladder activity. In addition to this peripheral mechanism, a central nervous system mechanism involving metabotropic glutamate 5 receptors also has a role in PNS inhibition. Copyright © 2016 the American Physiological Society.

  12. Review Essay: Grenzgänger Seeks Reflexive Methodology

    Directory of Open Access Journals (Sweden)

    Wolff-Michael Roth

    2002-09-01

    Full Text Available Reflexive Methodology reviews major strands of current thought in epistemology, philosophy, social science, and interpretive methods. The book falls short in that it neither does a thorough job reviewing the literature nor does it provide method-related advice useful to students. Grenzgängerin constitutes a collection of essays on a broad range of topics, but which are only loosely connected if at all. Drawing on DERRIDA and the notion of a historical science of the historical subject, I attempt to practice method, something I missed in both texts. I make explicit the historical nature of my own writing and the historical nature of my subject. I make explicit intertextuality and in the process practice reflexivity in the particular way I am writing. URN: urn:nbn:de:0114-fqs020328

  13. Faroese long-distance reflexives face off against Icelandic long-distance reflexives

    Directory of Open Access Journals (Sweden)

    Tania E. Strahan

    2009-01-01

    Full Text Available Long-distance reflexives (LDRs in Faroese are often compared to those in Icelandic, and are even considered to have the same distribution (Thráinsson et al., 2004. In this paper I evaluate the extent to which this is true. The results from recent fieldwork show that there are clear differences between the LDR in the two closely related languages, in particular that Faroese speakers often reject LDR sentences that contain a non-third person, and that Faroese LDR is often completely acceptable out of a non-complement clause. In addition, initial findings suggest that there may be dialectal variation with respect to at least these two aspects of LDR in Faroese.

  14. COMPARATIVE ANALYSIS OF PERSONALITY CORRELATES OF REFLEXIVITY IN THE CONTEXT OF PROFESSIONAL FORMATION OF THE TEACHER

    Directory of Open Access Journals (Sweden)

    T. V. Mayasova

    2017-01-01

    Full Text Available This article examines the reflexive, the most important professional quality of a teacher's personality in the context of professional development. Reflexivity is a basic property of the individual, whereby the awareness and regulation of the subject of their activities. As a personal correlates of reflexivity studied mental stability, individual styles of decision making (vigilance and avoidance, spontaneity, emotional intelligence (empathy and the ability to manage emotions of other people. The paper conducts a comparative analysis of reflexivity and qualities correlated with her young teachers, working in the specialty from 1 to 5 years and students from different areas of training of pedagogical University. Obtained in the course of the empirical research results confirmed that the process of professional development of teachers is the development of these qualities. Were no significant differences in the indicators options system the reflexivity, alertness,spontaneity, empathy, which differ among teachers and students.

  15. Plantar flexor stretch reflex responses to whole body loading/unloading during human walking

    DEFF Research Database (Denmark)

    Grey, Michael James; van Doornik, Johannes; Sinkjær, Thomas

    2002-01-01

    Numerous animal and human studies have shown that afferent information from the periphery contributes to the control of walking. In particular, recent studies have consistently shown that load receptor input is an important element of the locomotion control mechanism. The objective of this study...... perturbation during human walking. Three body load conditions were investigated: normal body load, a 30% increase in body load, and a 30% decrease in body load. Healthy subjects walked on a treadmill at approximately 3.6 km/h with the left ankle attached to a portable stretching device. Dorsiflexion...... strongly to the corrective response of the stretch reflex in the plantar flexor muscles during walking....

  16. Dilemmas and Deliberations in Reflexive Ethnographic Research

    Science.gov (United States)

    Robinson, Janean Valerie

    2014-01-01

    This paper traces insights into the challenges and dilemmas experienced whilst researching students' interpretations and understandings of the Behaviour Management in Schools policy in Western Australia. Journal records, supported by student transcripts, are woven together in a reflexive ethnographic journey--from the beginning phase of searching…

  17. sEMG during Whole-Body Vibration Contains Motion Artifacts and Reflex Activity

    Directory of Open Access Journals (Sweden)

    Karin Lienhard

    2015-01-01

    Full Text Available The purpose of this study was to determine whether the excessive spikes observed in the surface electromyography (sEMG spectrum recorded during whole-body vibration (WBV exercises contain motion artifacts and/or reflex activity. The occurrence of motion artifacts was tested by electrical recordings of the patella. The involvement of reflex activity was investigated by analyzing the magnitude of the isolated spikes during changes in voluntary background muscle activity. Eighteen physically active volunteers performed static squats while the sEMG was measured of five lower limb muscles during vertical WBV using no load and an additional load of 33 kg. In order to record motion artifacts during WBV, a pair of electrodes was positioned on the patella with several layers of tape between skin and electrodes. Spectral analysis of the patella signal revealed recordings of motion artifacts as high peaks at the vibration frequency (fundamental and marginal peaks at the multiple harmonics were observed. For the sEMG recordings, the root mean square of the spikes increased with increasing additional loads (p < 0.05, and was significantly correlated to the sEMG signal without the spikes of the respective muscle (r range: 0.54 - 0.92, p < 0.05. This finding indicates that reflex activity might be contained in the isolated spikes, as identical behavior has been found for stretch reflex responses evoked during direct vibration. In conclusion, the spikes visible in the sEMG spectrum during WBV exercises contain motion artifacts and possibly reflex activity.

  18. Reflexive Language and Ethnic Minority Activism in Hong Kong: A Trajectory-Based Analysis

    Science.gov (United States)

    Pérez-Milans, Miguel; Soto, Carlos

    2016-01-01

    This article engages with Archer's call to further research on reflexivity and social change under conditions of late modernity (2007, 2010, 2012) from the perspective of existing work on reflexive discourse in the language disciplines (Silverstein 1976, Lucy 1993). Drawing from a linguistic ethnography of the networked trajectories of a group of…

  19. Prevalence of Persistent Primary Reflexes and Motor Problems in Children with Reading Difficulties

    Science.gov (United States)

    McPhillips, M.; Sheehy, N.

    2004-01-01

    It has been shown that some children with reading difficulties have underlying developmental delay and that this may be related to the persistence of primary reflexes. This study investigated the prevalence of persistent primary reflexes in the ordinary primary school population and how this related to other cognitive and social factors. Three…

  20. Reflexive cartography a new perspective in mapping

    CERN Document Server

    Casti, Emanuela

    2015-01-01

    Reflexive Cartography addresses the adaptation of cartography, including its digital forms (GIS, WebGIS, PPGIS), to the changing needs of society, and outlines the experimental context aimed at mapping a topological space. Using rigorous scientific analysis based on statement consistency, relevance of the proposals, and model accessibility, it charts the transition from topographical maps created by state agencies to open mapping produced by citizens. Adopting semiotic theory to uncover the complex communicative mechanisms of maps and to investigate their ability to produce their own messages and new perspectives, Reflexive Cartography outlines a shift in our way of conceptualizing maps: from a plastic metaphor of reality, as they are generally considered, to solid tools that play the role of agents, assisting citizens as they think and plan their own living place and make sense of the current world. Applies a range of technologies to theoretical perspectives on mapping to innovatively map the world's geogr...

  1. Retrieval Interference in Syntactic Processing: The Case of Reflexive Binding in English.

    Science.gov (United States)

    Patil, Umesh; Vasishth, Shravan; Lewis, Richard L

    2016-01-01

    It has been proposed that in online sentence comprehension the dependency between a reflexive pronoun such as himself/herself and its antecedent is resolved using exclusively syntactic constraints. Under this strictly syntactic search account, Principle A of the binding theory-which requires that the antecedent c-command the reflexive within the same clause that the reflexive occurs in-constrains the parser's search for an antecedent. The parser thus ignores candidate antecedents that might match agreement features of the reflexive (e.g., gender) but are ineligible as potential antecedents because they are in structurally illicit positions. An alternative possibility accords no special status to structural constraints: in addition to using Principle A, the parser also uses non-structural cues such as gender to access the antecedent. According to cue-based retrieval theories of memory (e.g., Lewis and Vasishth, 2005), the use of non-structural cues should result in increased retrieval times and occasional errors when candidates partially match the cues, even if the candidates are in structurally illicit positions. In this paper, we first show how the retrieval processes that underlie the reflexive binding are naturally realized in the Lewis and Vasishth (2005) model. We present the predictions of the model under the assumption that both structural and non-structural cues are used during retrieval, and provide a critical analysis of previous empirical studies that failed to find evidence for the use of non-structural cues, suggesting that these failures may be Type II errors. We use this analysis and the results of further modeling to motivate a new empirical design that we use in an eye tracking study. The results of this study confirm the key predictions of the model concerning the use of non-structural cues, and are inconsistent with the strictly syntactic search account. These results present a challenge for theories advocating the infallibility of the human

  2. Clinical and electrophysiological findings in patients with phenylketonuria and epilepsy: Reflex features.

    Science.gov (United States)

    Yildiz Celik, Senay; Bebek, Nerses; Gurses, Candan; Baykan, Betul; Gokyigit, Aysen

    2018-03-23

    Phenylketonuria (PKU) is the most common form of amino acid metabolism disorders with autosomal recessive inheritance. The brain damage can be prevented by early diagnosis and a phenylalanine-restricted diet. Untreated or late-treated patients may show mental retardation and other cognitive dysfunctions, as well as motor disability and/or epilepsy. Three patients with PKU and epilepsy were recognized to have reflex epileptic features, and there were ten consecutive adult patients with PKU and epilepsy who were evaluated retrospectively. Medical history, ages at diagnosis and therapy onset, age at seizure onset, seizure types and reflex features, neurological findings, cranial imaging, electroencephalography (EEG) findings, and final clinical condition were evaluated. Reflex epilepsy features were examined in detail. The cases (6 females, 4 males) were diagnosed at ages between 3.5months and 12years. All patients had various degrees of mental-motor retardation and focal or generalized seizures with age at seizure onset varied between neonatal period and 15years. Three patients had febrile seizure, 3 patients had myoclonia, and 3 patients had status epilepticus. All patients had abnormal EEG findings except one. There was a slowing of background activity, and generalized discharges were observed in 7 patients; 3 of them had asymmetrical discharges. One patient had right hippocampal sclerosis (HS), and another patient had hypointensities in the basal ganglia and corpus callosum. Reflex features were clinically observed in 3 of the patients; however, EEG results did not show any related findings. One patient had reflex seizures triggered by photic stimuli, hot water, and startling; one by photic stimuli; and the other one by startling. Reports on the clinical and electrophysiological features of adult patients with PKU were scant. We emphasized that reflex clinical features may be observed in this metabolic disease, and focal epileptiform abnormalities and asymmetry

  3. Integrating Reflexivity in Livelihoods Research

    DEFF Research Database (Denmark)

    Prowse, Martin

    2010-01-01

    Much poverty and development research is not explicit about its methodology or philosophical foundations. Based on the extended case method of Burawoy and the epistemological standpoint of critical realism, this paper discusses a methodological approach for reflexive inductive livelihoods research...... that overcomes the unproductive social science dualism of positivism and social constructivism. The approach is linked to a conceptual framework and a menu of research methods that can be sequenced and iterated in light of research questions....

  4. The capsaicin cough reflex in patients with symptoms elicited by odorous chemicals

    DEFF Research Database (Denmark)

    Holst, H.; Arendt-Nielsen, Lars; Mosbech, H.

    2010-01-01

    between groups in age, body mass index or pulmonary function. The median C5 were 129 micromol/L (control group), 48 micromol/L (multiple chemical sensitivity patients), 32 micromol/L (eczema patients). The reporting of lower airway symptoms from odorous chemicals was significantly (p......Patients with multiple chemical sensitivity and eczema patients with airway symptoms elicited by odorous chemicals have enhanced cough reflex to capsaicin when applying the tidal breathing method. The aims of the present study were to test whether the capsaicin induced cough reflex was enhanced...... when applying the single breath inhalation method in similar groups of patients with symptoms related to odorous chemicals e.g. other persons wearing of perfume; and to investigate to what extent the reporting of lower airway symptoms influenced the cough reflex. Sixteen patients fulfilling Cullen...

  5. Spinal mechanism of micturition reflex inhibition by naftopidil in rats.

    Science.gov (United States)

    Sugaya, Kimio; Nishijima, Saori; Kadekawa, Katsumi; Ashitomi, Katsuhiro; Ueda, Tomoyuki; Yamamoto, Hideyuki

    2014-10-29

    We investigated the spinal mechanism through which naftopidil inhibits the micturition reflex by comparing the effects of noradrenaline and naftopidil in rats. The following were investigated: the influence of oral naftopidil on plasma monoamine and amino acid levels, the distribution of oral 14C-naftopidil, the effects of intravenous (IV) or intrathecal (IT) injection of noradrenaline or naftopidil on isovolumetric bladder contractions, amino acid levels in the lumbosacral spinal cord after IT noradrenaline or naftopidil, and the effects of IT naftopidil and strychnine and/or bicuculline on isovolumetric bladder contractions. Oral naftopidil decreased the plasma adrenaline level, while it increased the serotonin and glycine levels. After oral administration, 14C-naftopidil was detected in the spinal cord and cerebrum, as well as in plasma and the prostate gland. When the bladder volume was below the threshold for isovolumetric reflex contractions, IV (0.1mg) or IT (0.1μg) noradrenaline evoked bladder contractions, but IV (1mg) or IT (0.01-1μg) naftopidil did not. When the bladder volume was above the threshold for isovolumetric reflex contractions, IV or IT noradrenaline transiently abolished bladder contractions. IT noradrenaline decreased the levels of glycine and gamma-aminobutyric acid (GABA) in the lumbosacral cord, while IT naftopidil increased the GABA level. IT strychnine and/or bicuculline blocked the inhibitory effect of IT naftopidil on bladder contractions. Naftopidil inhibits the micturition reflex by blocking α1 receptors, as well as by the activation of serotonergic, glycinergic, and GABAergic neurons in the central nervous system. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Are the unken reflex and the aposematic colouration of Red-Bellied Toads efficient against bird predation?

    Science.gov (United States)

    Caorsi, Valentina Zaffaroni; Colombo, Patrick; Abadie, Michelle; Brack, Ismael Verrastro; Dasoler, Bibiana Terra; Borges-Martins, Márcio

    2018-01-01

    Aposematic signals as well as body behaviours may be important anti-predator defences. Species of the genus Melanophryniscus are characterised by having toxic lipophilic alkaloids in the skin and for presenting a red ventral colouration, which can be observed when they perform the behaviour called the unken reflex. Both the reflex behaviour and the colouration pattern are described as defence mechanisms. However, there are currently no studies testing their effectiveness against predators. This study aimed to test experimentally if both ventral conspicuous colouration and the unken reflex in Melanophryniscus cambaraensis function as aposematic signals against visually oriented predators (birds). We simulated the species studied using three different clay toad models as follows: (a) in a normal position with green coloured bodies, (b) in the unken reflex position with green coloured body and extremities and (c) in the unken reflex position with a green body and red extremities. Models were distributed on a known M. cambaraensis breeding site and in the adjacent forest. More than half of the attacks on the models were from birds; however, there was no preference for any model type. Thus, just the presence of the red colour associated with the motionless unken reflex position does not seem to prevent attacks from potential predators. It is possible that the effective aposematic signal in Melanophryniscus is achieved through the unken reflex movement together with the subsequent exhibition of the warning colouration and the secretion of toxins. PMID:29596437

  7. Biological Motion Cues Trigger Reflexive Attentional Orienting

    Science.gov (United States)

    Shi, Jinfu; Weng, Xuchu; He, Sheng; Jiang, Yi

    2010-01-01

    The human visual system is extremely sensitive to biological signals around us. In the current study, we demonstrate that biological motion walking direction can induce robust reflexive attentional orienting. Following a brief presentation of a central point-light walker walking towards either the left or right direction, observers' performance…

  8. Radiographic assessment of laryngeal reflexes in ketamine-anesthetized cats

    International Nuclear Information System (INIS)

    Robinson, E.P.; Johnston, G.R.

    1986-01-01

    The competence of the laryngeal closure reflexes of cats anesthetized with ketamine was assessed. Radiographic evaluations of the respiratory and digestive tracts were made after colloidal barium suspension was instilled into the pharynges of conscious and ketamine-anesthetized cats. There was a significant ketamine dose-related response of spread of contrast medium into the supraglottic laryngeal area and into the stomach 2 minutes after contrast medium was instilled into the pharynx (P less than 0.05). Cats did not aspirate contrast medium into the lower respiratory tract. Three ketamine-anesthetized cats aspirated contrast medium into the subglottic area of the larynx, and 2 of these cats also aspirated the material into the cranial part of the trachea. This material was coughed up and swallowed within 5 minutes. Transit time of contrast medium into the stomach seemed to be increased in 11 of the 15 cats given the larger dosages of ketamine (24, 36, 48 mg/kg of body weight), compared with that in conscious cats and those given ketamine at 12 mg/kg. Competent laryngeal protective reflexes in cats can be maintained with ketamine anesthesia. Contrast radiography could be used as a diagnostic aid in ketamine-anesthetized cats suspected of laryngeal reflex abnormalities

  9. Enhancement of the intrinsic defecation reflex by mosapride, a 5-HT4 agonist, in chronically lumbosacral denervated guinea pigs.

    Science.gov (United States)

    Kojima, Yu; Fujii, Hisao; Katsui, Renta; Nakajima, Yoshiyuki; Takaki, Miyako

    2006-10-01

    The defecation reflex is composed of rectal distension-evoked rectal (R-R) reflex contractions and synchronous internal anal sphincter (R-IAS) reflex relaxations in guinea pigs. These R-R and R-IAS reflexes are controlled via extrinsic sacral excitatory nerve pathway (pelvic nerves), lumbar inhibitory nerve pathways (colonic nerves) and by intrinsic cholinergic excitatory and nitrergic inhibitory nerve pathways. The effect of mosapride (a prokinetic benzamide) on the intrinsic reflexes, mediated via enteric 5-HT(4) receptors, was evaluated by measuring the mechanical activity of the rectum and IAS in anesthetized guinea pigs using an intrinsic R-R and R-IAS reflex model resulting from chronic (two to nine days) lumbosacral denervation (PITH). In this model, the myenteric plexus remains undamaged and the distribution of myenteric and intramuscular interstitial cells of Cajal is unchanged. Although R-R and R-IAS reflex patterns markedly changed, the reflex indices (reflex pressure or force curve-time integral) of both the R-R contractions and the synchronous R-IAS relaxations were unchanged. The frequency of the spontaneous R and IAS motility was also unchanged. Mosapride (0.1-1.0 mg/kg) dose-dependently increased both intrinsic R-R (maximum: 1.82) and R-IAS reflex indices (maximum: 2.76) from that of the control (1.0) 6-9 days following chronic PITH. The dose-response curve was similar to that in the intact guinea pig, and had shifted to the left from that in the guinea pig after acute PITH. A specific 5-HT(4) receptor antagonist, GR 113808 (1.0 mg/kg), decreased both reflex indices by approximately 50% and antagonized the effect of mosapride 1.0 mg/kg. This was quite different from the result in the intact guinea pig where GR 113808 (1.0 mg/kg) did not affect either of the reflex indices. The present results indicate that mosapride enhanced the intrinsic R-R and R-IAS reflexes and functionally compensated for the deprivation of extrinsic innervation. The actions of

  10. Concurrent neuromechanical and functional gains following upper-extremity power training post-stroke

    Directory of Open Access Journals (Sweden)

    Patten Carolynn

    2013-01-01

    Full Text Available Abstract Background Repetitive task practice is argued to drive neural plasticity following stroke. However, current evidence reveals that hemiparetic weakness impairs the capacity to perform, and practice, movements appropriately. Here we investigated how power training (i.e., high-intensity, dynamic resistance training affects recovery of upper-extremity motor function post-stroke. We hypothesized that power training, as a component of upper-extremity rehabilitation, would promote greater functional gains than functional task practice without deleterious consequences. Method Nineteen chronic hemiparetic individuals were studied using a crossover design. All participants received both functional task practice (FTP and HYBRID (combined FTP and power training in random order. Blinded evaluations performed at baseline, following each intervention block and 6-months post-intervention included: Wolf Motor Function Test (WMFT-FAS, Primary Outcome, upper-extremity Fugl-Meyer Motor Assessment, Ashworth Scale, and Functional Independence Measure. Neuromechanical function was evaluated using isometric and dynamic joint torques and concurrent agonist EMG. Biceps stretch reflex responses were evaluated using passive elbow stretches ranging from 60 to 180º/s and determining: EMG onset position threshold, burst duration, burst intensity and passive torque at each speed. Results Primary outcome: Improvements in WMFT-FAS were significantly greater following HYBRID vs. FTP (p = .049, regardless of treatment order. These functional improvements were retained 6-months post-intervention (p = .03. Secondary outcomes: A greater proportion of participants achieved minimally important differences (MID following HYBRID vs. FTP (p = .03. MIDs were retained 6-months post-intervention. Ashworth scores were unchanged (p > .05. Increased maximal isometric joint torque, agonist EMG and peak power were significantly greater following HYBRID vs. FTP (p p

  11. Práticas e reflexões de professoras numa pesquisa longitudinal

    Directory of Open Access Journals (Sweden)

    Edda Curi

    Full Text Available Analisa práticas e reflexões de professoras que participam de um grupo colaborativo no âmbito do Projeto Observatório da Educação, financiado pela Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes. Destaca a constituição do grupo, as ações desenvolvidas, as reflexões das professoras e as considerações que permitem avançar nos processos de ensino de Matemática e formação de professores. Examina cadernos de registros das professoras, atas de memória do grupo e depoimentos e apresenta a análise desse conteúdo, pela perspectiva de Bardin. Conclui ter havido avanços significativos nas práticas, pois o trabalho em grupo favoreceu o processo reflexivo das professoras sobre sua prática e seu desenvolvimento profissional, embora ainda existam fragilidades em algumas reflexões.

  12. Dissociative identity disorder and prepulse inhibition of the acoustic startle reflex

    Science.gov (United States)

    Dale, Karl Yngvar; Flaten, Magne Arve; Elden, Åke; Holte, Arne

    2008-01-01

    A group of persons with dissociative identity disorder (DID) was compared with a group of persons with other dissociative disorders, and a group of nondiagnosed controls with regard to prepulse inhibition (PPI) of the acoustic startle reflex. The findings suggest maladaptive attentional processes at a controlled level, but not at a preattentive automatic level, in persons with DID. The prepulse occupied more controlled attentional resources in the DID group compared with the other two groups. Preattentive automatic processing, on the other hand, was normal in the DID group. Moreover, startle reflexes did not habituate in the DID group. In conclusion, increased PPI and delayed habituation is consistent with increased vigilance in individuals with DID. The present findings of reduced habituation of startle reflexes and increased PPI in persons with DID suggest the operation of a voluntary process that directs attention away from unpleasant or threatening stimuli. Aberrant voluntary attentional processes may thus be a defining characteristic in DID. PMID:18830396

  13. Load Dependency of Postural Control--Kinematic and Neuromuscular Changes in Response to over and under Load Conditions.

    Science.gov (United States)

    Ritzmann, Ramona; Freyler, Kathrin; Weltin, Elmar; Krause, Anne; Gollhofer, Albert

    2015-01-01

    Load variation is associated with changes in joint torque and compensatory reflex activation and thus, has a considerable impact on balance control. Previous studies dealing with over (OL) and under loading (UL) used water buoyancy or additional weight with the side effects of increased friction and inertia, resulting in substantially modified test paradigms. The purpose of this study was to identify gravity-induced load dependency of postural control in comparable experimental conditions and to determine the underlying neuromuscular mechanisms. Balance performance was recorded under normal loading (NL, 1 g), UL (0.16 g 0.38 g) and OL (1.8 g) in monopedal stance. Center of pressure (COP) displacement and frequency distribution (low 0.15-0.5 Hz (LF), medium 0.5-2 Hz (MF), high 2-6 Hz (HF)) as well as ankle, knee and hip joint kinematics were assessed. Soleus spinal excitability was determined by H/M-recruitment curves (H/M-ratios). Compared to NL, OL caused an increase in ankle joint excursion, COP HF domain and H/M-ratio. Concomitantly, hip joint excursion and COP LF decreased. Compared to NL, UL caused modulations in the opposite direction: UL decreased ankle joint excursions, COP HF and H/M-ratio. Collaterally, hip joint excursion and COP LF increased. COP was augmented both in UL and in OL compared to NL. Subjects achieved postural stability in OL and UL with greater difficulty compared to NL. Reduced postural control was accompanied by modified balance strategies and compensatory reflex activation. With increasing load, a shift from hip to ankle strategy was observed. Accompanying, COP frequency distribution shifted from LF to HF and spinal excitability was enhanced. It is suggested that in OL, augmented ankle joint torques are compensated by quick reflex-induced postural reactions in distal muscles. Contrarily, UL is associated with diminished joint torques and thus, postural equilibrium may be controlled by the proximal segments to adjust the center of

  14. Load Dependency of Postural Control - Kinematic and Neuromuscular Changes in Response to over and under Load Conditions

    Science.gov (United States)

    Ritzmann, Ramona; Freyler, Kathrin; Weltin, Elmar; Krause, Anne; Gollhofer, Albert

    2015-01-01

    Introduction Load variation is associated with changes in joint torque and compensatory reflex activation and thus, has a considerable impact on balance control. Previous studies dealing with over (OL) and under loading (UL) used water buoyancy or additional weight with the side effects of increased friction and inertia, resulting in substantially modified test paradigms. The purpose of this study was to identify gravity-induced load dependency of postural control in comparable experimental conditions and to determine the underlying neuromuscular mechanisms. Methods Balance performance was recorded under normal loading (NL, 1g), UL (0.16g; 0.38g) and OL (1.8g) in monopedal stance. Center of pressure (COP) displacement and frequency distribution (low 0.15-0.5Hz (LF), medium 0.5-2Hz (MF), high 2-6Hz (HF)) as well as ankle, knee and hip joint kinematics were assessed. Soleus spinal excitability was determined by H/M-recruitment curves (H/M-ratios). Results Compared to NL, OL caused an increase in ankle joint excursion, COP HF domain and H/M-ratio. Concomitantly, hip joint excursion and COP LF decreased. Compared to NL, UL caused modulations in the opposite direction: UL decreased ankle joint excursions, COP HF and H/M-ratio. Collaterally, hip joint excursion and COP LF increased. COP was augmented both in UL and in OL compared to NL. Conclusion Subjects achieved postural stability in OL and UL with greater difficulty compared to NL. Reduced postural control was accompanied by modified balance strategies and compensatory reflex activation. With increasing load, a shift from hip to ankle strategy was observed. Accompanying, COP frequency distribution shifted from LF to HF and spinal excitability was enhanced. It is suggested that in OL, augmented ankle joint torques are compensated by quick reflex-induced postural reactions in distal muscles. Contrarily, UL is associated with diminished joint torques and thus, postural equilibrium may be controlled by the proximal

  15. Load Dependency of Postural Control--Kinematic and Neuromuscular Changes in Response to over and under Load Conditions.

    Directory of Open Access Journals (Sweden)

    Ramona Ritzmann

    Full Text Available Load variation is associated with changes in joint torque and compensatory reflex activation and thus, has a considerable impact on balance control. Previous studies dealing with over (OL and under loading (UL used water buoyancy or additional weight with the side effects of increased friction and inertia, resulting in substantially modified test paradigms. The purpose of this study was to identify gravity-induced load dependency of postural control in comparable experimental conditions and to determine the underlying neuromuscular mechanisms.Balance performance was recorded under normal loading (NL, 1 g, UL (0.16 g 0.38 g and OL (1.8 g in monopedal stance. Center of pressure (COP displacement and frequency distribution (low 0.15-0.5 Hz (LF, medium 0.5-2 Hz (MF, high 2-6 Hz (HF as well as ankle, knee and hip joint kinematics were assessed. Soleus spinal excitability was determined by H/M-recruitment curves (H/M-ratios.Compared to NL, OL caused an increase in ankle joint excursion, COP HF domain and H/M-ratio. Concomitantly, hip joint excursion and COP LF decreased. Compared to NL, UL caused modulations in the opposite direction: UL decreased ankle joint excursions, COP HF and H/M-ratio. Collaterally, hip joint excursion and COP LF increased. COP was augmented both in UL and in OL compared to NL.Subjects achieved postural stability in OL and UL with greater difficulty compared to NL. Reduced postural control was accompanied by modified balance strategies and compensatory reflex activation. With increasing load, a shift from hip to ankle strategy was observed. Accompanying, COP frequency distribution shifted from LF to HF and spinal excitability was enhanced. It is suggested that in OL, augmented ankle joint torques are compensated by quick reflex-induced postural reactions in distal muscles. Contrarily, UL is associated with diminished joint torques and thus, postural equilibrium may be controlled by the proximal segments to adjust the center of

  16. Cortical and spinal assessment - a comparative study using encephalography and the nociceptive withdrawal reflex

    DEFF Research Database (Denmark)

    Fischer, I W; Gram, M; Hansen, T M

    2017-01-01

    solution in randomized order. The electroencephalogram (EEG) was recorded during rest and during immersion of the hand into ice-water. Electrical stimulation of the sole of the foot was used to elicit the nociceptive withdrawal reflex and the reflex amplitude was recorded. RESULTS: Data from thirty...

  17. GENE RESPONSE OF THE GASTROCNEMIUS AND SOLEUS MUSCLES TO AN ACUTE AEROBIC RUN IN RATS

    Directory of Open Access Journals (Sweden)

    Michael J. McKenzie

    2011-06-01

    Full Text Available Genes can be activated or inhibited by signals within the tissues in response to an acute bout of exercise. It is unclear how a particular aerobic exercise bout may influence two muscles with similar actions to the activity. Therefore, the purposes of this investigation was to determine the gene response of selected genes involved in the "stress" response of the gastrocnemius (fast-twitch and soleus (slow-twitch muscles to a single two hour aerobic exercise bout in female Sprague-Dawley Rats at the 1 hour time point after the exercise. Exercised rats were run (n=8 for 2 hours at 20 m.min-1 and one hour after the completion of the bout had their soleus (S and gastrocnemius (G muscles removed. Age and timed matched sedentary control rats had both S and G muscles removed also. RNA was isolated from all muscles. Real-time PCR analysis was performed on the following genes: NFκB, TNFα, and Atf3. GAPDH was used as the housekeeping gene for both muscles. S muscle showed more genes altered (n = 52 vs G (n = 26. NFκB gene expression was 0.83 ± 0.14 in the exercised S but was + 1.36 ± 0.58 in the exercised G and was not significantly different between the muscles. TNFα was altered 1.30 ± 0. 34 in the exercised S and 1.36 ± 0.71 in the exercised G and was not significantly different between the muscles. The gene Atf3 was significantly altered at 4.97 ± 1.01 in the exercised S, while it was not significantly altered in the exercised G (0.70 ± 0.55. This study demonstrates that an acute bout of aerobic exercise can alter gene expression to a different extent in both the S and G muscles. It is highly likely that muscle recruitment was a factor which influenced the gene expression in theses muscles. It is interesting to note that some genes were similarly activated in these two muscles but other genes may demonstrate a varied response to the same exercise bout depending on the type of muscle

  18. Evaluation of the olivocochlear efferent reflex strength in the susceptibility to temporary hearing deterioration after music exposure in young adults

    Directory of Open Access Journals (Sweden)

    Keppler Hannah

    2014-01-01

    Full Text Available The objective of the current study was to evaluate the predictive role of the olivocochlear efferent reflex strength in temporary hearing deterioration in young adults exposed to music. This was based on the fact that a noise-protective role of the medial olivocochlear (MOC system was observed in animals and that efferent suppression (ES measured using contralateral acoustic stimulation (CAS of otoacoustic emissions (OAEs is capable of exploring the MOC system. Knowing an individual′s susceptibility to cochlear damage after noise exposure would enhance preventive strategies for noise-induced hearing loss. The hearing status of 28 young adults was evaluated using pure-tone audiometry, transient evoked OAEs (TEOAEs and distortion product OAEs (DPOAEs before and after listening to music using an MP3 player during 1 h at an individually determined loud listening level. CAS of TEOAEs was measured before music exposure to determine the amount of ES. Regression analysis showed a distinctive positive correlation between temporary hearing deterioration and the preferred gain setting of the MP3 player. However, no clear relationship between temporary hearing deterioration and the amount of ES was found. In conclusion, clinical measurement of ES, using CAS of TEOAEs, is not correlated with the amount of temporary hearing deterioration after 1 h music exposure in young adults. However, it is possible that the temporary hearing deterioration in the current study was insufficient to activate the MOC system. More research regarding ES might provide more insight in the olivocochlear efferent pathways and their role in auditory functioning.

  19. Evolutionary problems in non-reflexive spaces

    Czech Academy of Sciences Publication Activity Database

    Kružík, Martin; Zimmer, J.

    2010-01-01

    Roč. 16, č. 1 (2010), s. 1-22 ISSN 1262-3377 R&D Projects: GA AV ČR IAA1075402 Institutional research plan: CEZ:AV0Z10750506 Keywords : concentrations * energetic solution * energies with linear growth * oscillations * relaxation Subject RIV: BA - General Mathematics Impact factor: 1.084, year: 2009 http://library.utia.cas.cz/separaty/2008/MTR/kruzik-evolutionary problems in non-reflexive spaces.pdf

  20. The capsaicin cough reflex in patients with symptoms elicited by odorous chemicals

    DEFF Research Database (Denmark)

    Holst, H; Arendt-Nielsen, L; Mosbech, H

    2010-01-01

    Patients with multiple chemical sensitivity and eczema patients with airway symptoms elicited by odorous chemicals have enhanced cough reflex to capsaicin when applying the tidal breathing method. The aims of the present study were to test whether the capsaicin induced cough reflex was enhanced...... when applying the single breath inhalation method in similar groups of patients with symptoms related to odorous chemicals e.g. other persons wearing of perfume; and to investigate to what extent the reporting of lower airway symptoms influenced the cough reflex. Sixteen patients fulfilling Cullen......'s criteria for multiple chemical sensitivity and 15 eczema patients with airway symptoms elicited by odorous chemicals were compared with 29 age-matched, healthy controls. We measured C5--the capsaicin concentration causing five coughs or more--using the single breath inhalation test. No difference was found...

  1. The joint discourse 'reflexive sustainable development'. From weak towards strong sustainable development

    International Nuclear Information System (INIS)

    Nilsen, Heidi Rapp

    2010-01-01

    The purpose of this paper is to contribute towards moving the predominant situation of weak sustainable development (WSD) in the direction of strong sustainable development (SSD). More people - academics, politicians, bureaucrats and laymen alike - need to recognize SSD as an alternative to WSD. A joint discourse of WSD and SSD is suggested, called reflexive sustainable development. Here, advocates of WSD and SSD must argue for each specific case why their solution is better. This will expose, amongst other things, the ethical foundations which form part of resulting policy advice. Reflexive sustainable development is to be framed in discourse ethics, thereby remedying the power imbalance and allowing for substantial discussion. Reflexive sustainable development builds on a common theoretical base but will not lead to consensus in all matters. A family metaphor is introduced to inspire a discourse of both consensus and compromise. (author)

  2. Effects of gamma-aminobutyric acid on the Hering-Breuer inspiration-inhibiting reflex.

    Science.gov (United States)

    Aleksandrova, N P; Aleksandrov, V G; Ivanova, T G

    2010-02-01

    Acute experiments on rats were performed to study the effects of intraventricular microinjections of gamma-aminobutyric acid (GABA) on the volume-time parameters of external respiration and the inspiration-inhibiting Hering-Breuer reflex. The state of this reflex before and after GABA administration was assessed in terms of the extent of changes in the duration and amplitude of inspiratory oscillations in intrathoracic pressure in response to end-expiratory occlusion of the trachea. Administration of 20 microM GABA into the lateral ventricles of the brain decreased the minute ventilation (due to reductions in the respiratory frequency and respiratory volume), weakened respiratory muscle contractions, and decreased the peak airflow rate on inspiration and expiration. The response to end-expiratory occlusion decreased significantly after administration of GABA, demonstrating the involvement of GABAergic mechanisms in mediating the inspiration-inhibiting Hering-Breuer reflex.

  3. The Pivotal Role of the Parieto-Occipital Lobe in Card Game-Induced Reflex Epilepsy: A Voxel-Based Morphometry Study.

    Science.gov (United States)

    Park, Kang Min; Kim, Sung Eun; Lee, Byung In

    2016-01-01

    The pathogenesis of card game-induced reflex epilepsy has not been determined so far. The aim of this study was to evaluate structural abnormalities using voxel-based morphometry (VBM) analysis, which may give some clue about the pathogenesis in card game-induced reflex epilepsy. The 3 subjects were diagnosed with card game-induced reflex epilepsy. Evaluation involved a structured interview to obtain clinical information and brain MRI. In VBM analysis, Statistical Parametric Mapping 8 running on the MATLAB platform was employed to analyze the structural differences between patients with card game-induced reflex epilepsy and age- and sex-matched control subjects. The results of VBM analysis revealed that patients with card game-induced reflex epilepsy had significantly increased gray matter volume in the right occipital and parietal lobe. However, there were no structures with decreased gray matter volume in patients with card game-induced reflex epilepsy compared with control subjects. In addition, we found that the patients with card game-induced reflex epilepsy had onset of seizures in adulthood rather than in adolescence, and all of the patients were men. The parieto-occipital lobes might be partially involved in the neuronal network responsible for card game-induced reflex epilepsy. © 2016 S. Karger AG, Basel.

  4. Jaw-opening reflex and corticobulbar motor excitability changes during quiet sleep in non-human primates

    DEFF Research Database (Denmark)

    Yao, Dongyuan; Lavigne, Gilles J.; Lee, Jye-Chang

    2013-01-01

    Study Objective: To test the hypothesis that the reflex and corticobulbar motor excitability of jaw muscles is reduced during sleep. Design: Polysomnographic recordings in the electrophysiological study. Setting: University sleep research laboratories. Participants and Interventions: The reflex a...

  5. Do reflex seizures and spontaneous seizures form a continuum? - triggering factors and possible common mechanisms.

    Science.gov (United States)

    Irmen, Friederike; Wehner, Tim; Lemieux, Louis

    2015-02-01

    Recent changes in the understanding and classification of reflex seizures have fuelled a debate on triggering mechanisms of seizures and their conceptual organization. Previous studies and patient reports have listed extrinsic and intrinsic triggers, albeit their multifactorial and dynamic nature is poorly understood. This paper aims to review literature on extrinsic and intrinsic seizure triggers and to discuss common mechanisms among them. Among self-reported seizure triggers, emotional stress is most frequently named. Reflex seizures are typically associated with extrinsic sensory triggers; however, intrinsic cognitive or proprioceptive triggers have also been assessed. The identification of a trigger underlying a seizure may be more difficult if it is intrinsic and complex, and if triggering mechanisms are multifactorial. Therefore, since observability of triggers varies and triggers are also found in non-reflex seizures, the present concept of reflex seizures may be questioned. We suggest the possibility of a conceptual continuum between reflex and spontaneous seizures rather than a dichotomy and discuss evidence to the notion that to some extent most seizures might be triggered. Copyright © 2014 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  6. The Danish CSR Reporting Requirement as Reflexive Law

    DEFF Research Database (Denmark)

    Buhmann, Karin

    2013-01-01

    With effect for financial years beginning January 2009 or later, the Danish Financial Statements Act and related governmental regulations require large Danish companies and institutional investors to submit an annual Corporate Social Responsibility (CSR) report. Through application of reflexive law...

  7. Long-term depression-like plasticity of the blink reflex for the treatment of blepharospasm.

    Science.gov (United States)

    Kranz, Gottfried; Shamim, Ejaz A; Lin, Peter T; Kranz, George S; Hallett, Mark

    2013-04-01

    Our previous work showed a beneficial therapeutic effect on blepharospasm using slow repetitive transcranial magnetic stimulation, which produces a long-term depression (LTD)-like effect. High-frequency supraorbital electrical stimulation, asynchronous with the R2 component of the blink reflex, can also induce LTD-like effects on the blink reflex circuit in healthy subjects. Patients with blepharospasm have reduced inhibition of their blink recovery curves; therefore, a LTD-like intervention might normalize the blink reflex recovery (BRR) and have a favorable therapeutic effect. This is a randomized, sham-controlled, observer-blinded prospective study. In 14 blepharospasm patients, we evaluated the effects of high-frequency supraorbital stimulation on three separate treatment days. We applied 28 trains of nine stimuli, 400 Hz, either before or after the R2 or used sham stimulation. The primary outcome was the blink rate, number of spasms rated by a blinded physician and patient rating before, immediately after and 1 hour after stimulation while resting, reading, and talking; secondary outcome was the BRR. Stimulation "before" and "after" the R2 both showed a similar improvement as sham stimulation in physician rating, but patients felt significantly better with the before condition. Improvement in recovery of the blink reflex was noted only in the before condition. Clinical symptoms differed in the three baseline conditions (resting, reading, and talking). Stimulation before R2 increased inhibition in trigeminal blink reflex circuits in blepharospasm toward normal values and produced subjective, but not objective, improvement. Inhibition of the blink reflex pathway by itself appeared to be insufficient for a useful therapeutic effect. Copyright © 2013 Movement Disorder Society.

  8. Reversal of functional disorders by aspiration, expiration and cough reflexes and their voluntary counterparts

    Directory of Open Access Journals (Sweden)

    Zoltan eTomori

    2012-12-01

    Full Text Available Agonal gasping provoked by asphyxia can save ~15% of mammals even from untreated ventricular fibrillation, but it fails to revive infants with sudden infant death syndrome. Our systematic study of airway reflexes in cats and other animals indicated that in addition to cough, there are 2 distinct airway reflexes that may contribute to auto-resuscitation. Gasp- and sniff-like spasmodic inspirations can be elicited by nasopharyngeal stimulation, strongly activating the brainstem generator for inspiration, which is also involved in the control of gasping. This aspiration reflex (AspR is characterized by spasmodic inspiration without subsequent active expiration and can be elicited during agonal gasping, caused by brainstem trans-sections in cats. Stimulation of the larynx can activate the generator for expiration to evoke the expiration reflex, manifesting with prompt expiration without preceding inspiration. Stimulation of the oro-pharynx and lower airways provokes the cough reflex which results from activating of both generators. The powerful potential of the AspR resembling auto-resuscitation by gasping can influence the control mechanisms of vital functions, mediating reversal of various functional disorders.The AspR in cats interrupted hypoxic apnea, laryngo- and bronchospasm, apneusis and even transient asphyxic coma, and can normalize various hypo- and hyper-functional disorders. Introduction of a nasogastric catheter evoked similar spasmodic inspirations in premature infants and interrupted hiccough attacks in adults. Coughing on demand can prevent anaphylactic shock and resuscitate the pertinent subject. Sniff representing nasal inspiratory pressure and maximal inspiratory and expiratory pressures are voluntary counterparts of airway reflexes, and are useful for diagnosis and therapy of various cardio-respiratory and neuromuscular disorders.

  9. Ontogeny of mouse vestibulo-ocular reflex following genetic or environmental alteration of gravity sensing.

    Directory of Open Access Journals (Sweden)

    Mathieu Beraneck

    Full Text Available The vestibular organs consist of complementary sensors: the semicircular canals detect rotations while the otoliths detect linear accelerations, including the constant pull of gravity. Several fundamental questions remain on how the vestibular system would develop and/or adapt to prolonged changes in gravity such as during long-term space journey. How do vestibular reflexes develop if the appropriate assembly of otoliths and semi-circular canals is perturbed? The aim of present work was to evaluate the role of gravity sensing during ontogeny of the vestibular system. In otoconia-deficient mice (ied, gravity cannot be sensed and therefore maculo-ocular reflexes (MOR were absent. While canals-related reflexes were present, the ied deficit also led to the abnormal spatial tuning of the horizontal angular canal-related VOR. To identify putative otolith-related critical periods, normal C57Bl/6J mice were subjected to 2G hypergravity by chronic centrifugation during different periods of development or adulthood (Adult-HG and compared to non-centrifuged (control C57Bl/6J mice. Mice exposed to hypergravity during development had completely normal vestibulo-ocular reflexes 6 months after end of centrifugation. Adult-HG mice all displayed major abnormalities in maculo-ocular reflexe one month after return to normal gravity. During the next 5 months, adaptation to normal gravity occurred in half of the individuals. In summary, genetic suppression of gravity sensing indicated that otolith-related signals might be necessary to ensure proper functioning of canal-related vestibular reflexes. On the other hand, exposure to hypergravity during development was not sufficient to modify durably motor behaviour. Hence, 2G centrifugation during development revealed no otolith-specific critical period.

  10. [Spasm of the near reflex. Treatment with botulinum toxin].

    Science.gov (United States)

    Merino, P; Rojas, P; Gómez de Liaño, P; Franco Iglesias, G

    2015-05-01

    A 38-year old female with diplopia and esotropia, with limitation of ocular abduction in both eyes, with full abduction after doll's head rotation also being observed. She was diagnosed with spasm of the near reflex. Treatment with injections of botulinum toxin in both medial rectus has temporally resolved the convergence spasm. Near reflex spasm is characterized as miosis, pseudomyopia, and convergent strabismus that lead to diplopia, blurred vision, headache, and variable, progressive, and intermittent esotropia. As the spasm worsens there will be limited ocular versions and ductions simulating a sixth nerve palsy. Botulinum toxin may be effective in some cases. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  11. Bone mineral density in reflex sympathetic dystrophy

    International Nuclear Information System (INIS)

    Saghaphi, M.; Azarian, A.

    2002-01-01

    Objectives: Reflex Sympathetic Dystrophy (RSD) is a complex of symptoms that produce pain burning sensation, swelling, tenderness, autonomic and physical dysfunction in joint areas, particularly distal of a limb. Osteopenia or osteoporosis is an important finding that is produced gradually in involved limb. Three phase bone can scan help to diagnosis of RSD. The disease may be bilateral but is mostly unilateral. As it is believed that bone densitometry will show osteopenia more accurate than plain comparative radiographs of the involved limbs, we investigated in patients with RSD. Methods: During last three years, 8 patients with RSD were admitted. Bone mineral density was measured for 5 patients by DEXA method. The patients were 3 males and 2 females with age range of 20 to 48 years (mean 32 years). The involved areas were ankle and foot in 4, and wrist and hand in one patient. Results: Mean Bone Mineral Content (BMC) of 4 involved lower limbs were 475 +-73 grams comparing with 516+-72 grams of uninvolved limbs (p t h patient was not significant. conclusion: comparative bone mineral density in patients with RSD of the lower limbs contributes to more accurate diagnosis than plain radiographs

  12. When he can also be she: An ERP study of reflexive pronoun resolution in written Mandarin Chinese

    Directory of Open Access Journals (Sweden)

    Jui-Ju eSu

    2016-02-01

    Full Text Available The gender information in written Chinese third person pronouns is not symmetrically encoded: the character for he (他, with semantic radical 人, meaning human is used as a default referring to every individual, while the character for she (她, with semantic radical 女, meaning woman indicates females only. This critical feature could result in different patterns of processing of gender information in text, but this is an issue that has seldom been addressed in psycholinguistics. In Chinese, the written forms of the reflexive pronouns are composed of a pronoun plus the reflexive 自己/self (他自己/himself and 她自己/herself. The present study focuses on how such gender specificity interacts with the gender type of an antecedent, whether definitional (proper name or stereotypical (stereotypical role noun during reflexive pronoun resolution. In this event-related potential (ERP study, gender congruity between a reflexive pronoun and its antecedent was studied by manipulating the gender type of antecedents and the gender specificity of reflexive pronouns (default: 他自己/himself vs. specific: 她自己/herself. Results included a P200 attention related congruity effect for 他自己/himself and a P600 integration difficulty congruity effect for 她自己/herself. Reflexive pronoun specificity independently affected the P200 and N400 components. These results highlight the role of 他自己/himself as a default applicable to both genders and indicate that only the processing of 她自己/herself supports a two-stage model for anaphor resolution. While both reflexive pronouns are evaluated at the bonding stage, the processing of the gender-specific reflexive pronoun is completed in the resolution stage.

  13. Child-Computer Interaction at the Beginner Stage of Music Learning: Effects of Reflexive Interaction on Children's Musical Improvisation.

    Science.gov (United States)

    Addessi, Anna Rita; Anelli, Filomena; Benghi, Diber; Friberg, Anders

    2017-01-01

    In this article children's musical improvisation is investigated through the "reflexive interaction" paradigm. We used a particular system, the MIROR-Impro, implemented in the framework of the MIROR project (EC-FP7), which is able to reply to the child playing a keyboard by a "reflexive" output, mirroring (with repetitions and variations) her/his inputs. The study was conducted in a public primary school, with 47 children, aged 6-7. The experimental design used the convergence procedure, based on three sample groups allowing us to verify if the reflexive interaction using the MIROR-Impro is necessary and/or sufficient to improve the children's abilities to improvise. The following conditions were used as independent variables: to play only the keyboard, the keyboard with the MIROR-Impro but with not-reflexive reply, the keyboard with the MIROR-Impro with reflexive reply. As dependent variables we estimated the children's ability to improvise in solos, and in duets. Each child carried out a training program consisting of 5 weekly individual 12 min sessions. The control group played the complete package of independent variables; Experimental Group 1 played the keyboard and the keyboard with the MIROR-Impro with not-reflexive reply; Experimental Group 2 played only the keyboard with the reflexive system. One week after, the children were asked to improvise a musical piece on the keyboard alone (Solo task), and in pairs with a friend (Duet task). Three independent judges assessed the Solo and the Duet tasks by means of a grid based on the TAI-Test for Ability to Improvise rating scale. The EG2, which trained only with the reflexive system, reached the highest average results and the difference with EG1, which did not used the reflexive system, is statistically significant when the children improvise in a duet. The results indicate that in the sample of participants the reflexive interaction alone could be sufficient to increase the improvisational skills, and necessary

  14. Neural reflex pathways in intestinal inflammation: hypotheses to viable therapy.

    Science.gov (United States)

    Willemze, Rose A; Luyer, Misha D; Buurman, Wim A; de Jonge, Wouter J

    2015-06-01

    Studies in neuroscience and immunology have clarified much of the anatomical and cellular basis for bidirectional interactions between the nervous and immune systems. As with other organs, intestinal immune responses and the development of immunity seems to be modulated by neural reflexes. Sympathetic immune modulation and reflexes are well described, and in the past decade the parasympathetic efferent vagus nerve has been added to this immune-regulation network. This system, designated 'the inflammatory reflex', comprises an afferent arm that senses inflammation and an efferent arm that inhibits innate immune responses. Intervention in this system as an innovative principle is currently being tested in pioneering trials of vagus nerve stimulation using implantable devices to treat IBD. Patients benefit from this treatment, but some of the working mechanisms remain to be established, for instance, treatment is effective despite the vagus nerve not always directly innervating the inflamed tissue. In this Review, we will focus on the direct neuronal regulatory mechanisms of immunity in the intestine, taking into account current advances regarding the innervation of the spleen and lymphoid organs, with a focus on the potential for treatment in IBD and other gastrointestinal pathologies.

  15. Cultural Reflexivity and the Nostalgia for Glocal Consumer Culture: Insights from a Multicultural Multiple Migration Context

    DEFF Research Database (Denmark)

    Emontspool, Julie; Kjeldgaard, Dannie

    2013-01-01

    Purpose – The purpose of this article is to investigate consumption discourses in contexts characterized by multiple cultures and intercultural contacts, as multicultural contacts and multiple migrations challenge existing consumer acculturation models based on a dualistic process of acculturation....... This chapter explores empirically the character of cultural reflexivity and its expression in consumers’ discourses. Given that nostalgia is one prominent dimension of the migration conceptualization, we seek to understand how the role of nostalgia changes in contexts where consumers are decreasingly...... – On the basis of these findings, the article discusses cultural reflexivity in terms of naturalization and cultivation narratives (Wilk, 1999), proposing shifts between reflexive and routinized consumption practices as basis for consumers’ cultural reflexivity. Originality/value of chapter – The contribution...

  16. The late blink reflex response abnormality due to lesion of the lateral tegmental field

    NARCIS (Netherlands)

    Aramideh, M.; Ongerboer de Visser, B.W.; Koelman, J.H.T.M.; Majoie, C.B.L.; Holstege, G.

    We report on a blink reflex abnormality observed in two patients, which provides additional information on the central pathways mediating this reflex. Autopsy was performed in one patient and MRI in the other: In the first patient there was a small lesion at the dorsal middle third of the lateral

  17. The late blink reflex response abnormality due to lesion of the lateral tegmental field

    NARCIS (Netherlands)

    Aramideh, M.; Ongerboer de Visser, B. W.; Koelman, J. H.; Majoie, C. B.; Holstege, G.

    1997-01-01

    We report on a blink reflex abnormality observed in two patients, which provides additional information on the central pathways mediating this reflex. Autopsy was performed in one patient and MRI in the other. In the first patient there was a small lesion at the dorsal middle third of the lateral

  18. Reflexivity and the Politics of Knowledge: Researchers as "Brokers" and "Translators" of Educational Development

    Science.gov (United States)

    Sriprakash, Arathi; Mukhopadhyay, Rahul

    2015-01-01

    This paper interrogates the ways in which "reflexivity" has proliferated as a normative methodological discourse in the field of international and comparative education. We argue that the dominant approach to reflexivity foregrounds the standpoints of researchers and their subjects in a way that does not attend to the situated,…

  19. Can LENR Energy Gains Exceed 1000?

    Science.gov (United States)

    Nagel, David J.

    2011-03-01

    Energy gain is defined as the energy realized from reactions divided by the energy required to produce those reactions. Low Energy Nuclear Reactions (LENR) have already been measured to significantly exceed the energy gain of 10 projected from ITER,possibly 15 years from now. Electrochemical experiments using the Pd-D system have shown energy gains exceeding 10. Gas phase experiments with the Ni-H system were reported to yield energy gains of over 100. Neither of these reports has been adequately verified or reproduced. However, the question in the title still deserves consideration. If, as thought by many, it is possible to trigger nuclear reactions that yield MeV energies with chemical energies of the order of eV, then the most optimistic expectation is that LENR gains could approach one million. Hence, the very tentative answer to the question above is yes. However, if LENR could be initiated with some energy cost, and then continue to ``burn,'' very high energy gains might be realized. Consider a match and a pile of dry logs. The phenomenon termed ``heat after death'' will be examined to see if it might be the initial evidence for nuclear ``burning.''

  20. For reflexivity as an epistemic criterion of ontological coherence and virtuous social theorizing.

    Science.gov (United States)

    Bouzanis, Christoforos

    2017-12-01

    This article offers an approach that combines, on the one hand, the philosophical notion of reflexivity, which is related to the ideas of self-reference and paradox, and, on the other hand, the sociological discussion of epistemic reflexivity as a problem of coherence, which was mainly initiated by certain branches of ethnomethodology and social constructionism. This combinatory approach argues for reflexivity as an epistemic criterion of ontological coherence , which suggests that social ontologies should account for the possibility of self-reflective subjectivity - for otherwise they result in a paradoxical conclusion according to which a social scientist reflects on her or his ontological commitments even though these commitments deny her or him the capacity for self-reflection . This analysis presupposes that all human sciences are categorically premised on social ontologies; and it argues for an analytical distinction between self-reflection, which refers to the agential capacity for reflecting on one's own commitments, and the epistemic criterion of reflexivity hereby proposed. These two analytically distinct though interdependent socio-theoretical concepts are frequently conflated in the literature; thus, this article also aims at a 'clearing of the ground' that can be of categorical use to the human sciences.

  1. The effect of titrated fentanyl on suppressed cough reflex in healthy adult volunteers.

    Science.gov (United States)

    Kelly, H E; Shaw, G M; Brett, C N; Greenwood, F M; Huckabee, M L

    2016-05-01

    Cough suppression is part of the pharmacodynamic profile of opioids. We investigated the impact of clinical doses of fentanyl on suppressing the cough reflex. Thirteen volunteers received 2 μg.kg(-1) of fentanyl in a divided administration protocol. Three minutes after each administration and at 10 min intervals during washout, suppressed cough reflex testing with nebulised citric acid was performed and compared with fentanyl effect-site concentration. Mean (SD) citric acid concentration provoking cough increased from 0.5 (0.28) mol.l(-1) at baseline to 1.2 (0.50) mol.l(-1) after 2 μg.kg(-1) of fentanyl (p = 0.01). Mean (SD) fentanyl effect-site concentration after the final dose of fentanyl was 1.89 (0.05) ng.ml(-1) . A strong positive correlation was found between suppressed cough reflex thresholds and fentanyl effect-site concentrations during both fentanyl administration and washout phases of the study (r(2) = 0.79, p = 0.01). The mean (SD) length of time for return of suppressed cough response was 44.6 (18.8) min. Clinically relevant doses of fentanyl produced cough reflex suppression in healthy volunteers. © 2016 The Association of Anaesthetists of Great Britain and Ireland.

  2. Does electrical stimulation reduce spasticity after stroke? A randomized controlled study.

    Science.gov (United States)

    Bakhtiary, Amir H; Fatemy, Elham

    2008-05-01

    To investigate the therapeutic effect of electrical stimulation on plantarflexor spasticity in stroke patients. A randomized controlled clinical trial study. Rehabilitation clinic of Semnan University of Medical Sciences. Forty stroke patients (aged from 42 to 65 years) with ankle plantarflexor spasticity. Fifteen minutes of inhibitory Bobath techniques were applied to one experimental group and a combination of 9 minutes of electrical stimulation on the dorsiflexor muscles and inhibitory Bobath techniques was applied to another group for 20 sessions daily. Passive ankle joint dorsiflexion range of motion, dorsiflexion strength test, plantarflexor muscle tone by Modified Ashworth Scale and soleus muscle H-reflex. The mean change of passive ankle joint dorsiflexion in the combination therapy group was 11.4 (SD 4.79) degrees versus 6.1 (SD 3.09) degrees, which was significantly higher (P = 0.001). The mean change of plantarflexor muscle tonicity measured by the Modified Ashworth Scale in the combination therapy group was -1.6 (SD 0.5) versus -1.1 (SD 0.31) in the Bobath group (P = 0.001). Dorsiflexor muscle strength was also increased significantly (P = 0.04) in the combination therapy group (0.7 +/- 0.37) compared with the Bobath group (0.4 +/- 0.23). However, no significant change in the amplitude of H-reflex was found between combination therapy (-0.41 +/- 0.29) and Bobath (-0.3 +/- 0.28) groups. Therapy combining Bobath inhibitory technique and electrical stimulation may help to reduce spasticity effectively in stroke patients.

  3. A new method to determine reflex latency induced by high rate stimulation of the nervous system

    Directory of Open Access Journals (Sweden)

    Ilhan eKaracan

    2014-07-01

    Full Text Available High rate stimulations of the neuromuscular system, such as continuous whole body vibration, tonic vibration reflex and high frequency electrical stimulation, are used in the physiological research with an increasing interest. In these studies, the neuronal circuitries underlying the reflex responses remain unclear due to the problem of determining the exact reflex latencies. We present a novel cumulated average method to determine the reflex latency during high rate stimulation of the nervous system which was proven to be significantly more accurate than the classical method. The classical method, cumulant density analysis, reveals the relationship between the two synchronously recorded signals as a function of the lag between the signals. The comparison of new method with the classical technique and their relative accuracy was tested using a computer simulation. In the simulated signals the EMG response latency was constructed to be exactly 40 ms. The new method accurately indicated the value of the simulated reflex latency (40 ms. However, the classical method showed that the lag time between the simulated triggers and the simulated signals was 49 ms. Simulation results illustrated that the cumulated average method is a reliable and more accurate method compared with the classical method. We therefore suggest that the new cumulated average method is able to determine the high rate stimulation induced reflex latencies more accurately than the classical method.

  4. Periodic modulation of repetitively elicited monosynaptic reflexes of the human lumbosacral spinal cord

    Science.gov (United States)

    Danner, Simon M.; Freundl, Brigitta; Binder, Heinrich; Mayr, Winfried; Rattay, Frank; Minassian, Karen

    2015-01-01

    In individuals with motor-complete spinal cord injury, epidural stimulation of the lumbosacral spinal cord at 2 Hz evokes unmodulated reflexes in the lower limbs, while stimulation at 22–60 Hz can generate rhythmic burstlike activity. Here we elaborated on an output pattern emerging at transitional stimulation frequencies with consecutively elicited reflexes alternating between large and small. We analyzed responses concomitantly elicited in thigh and leg muscle groups bilaterally by epidural stimulation in eight motor-complete spinal cord-injured individuals. Periodic amplitude modulation of at least 20 successive responses occurred in 31.4% of all available data sets with stimulation frequency set at 5–26 Hz, with highest prevalence at 16 Hz. It could be evoked in a single muscle group only but was more strongly expressed and consistent when occurring in pairs of antagonists or in the same muscle group bilaterally. Latencies and waveforms of the modulated reflexes corresponded to those of the unmodulated, monosynaptic responses to 2-Hz stimulation. We suggest that the cyclical changes of reflex excitability resulted from the interaction of facilitatory and inhibitory mechanisms emerging after specific delays and with distinct durations, including postactivation depression, recurrent inhibition and facilitation, as well as reafferent feedback activation. The emergence of large responses within the patterns at a rate of 5.5/s or 8/s may further suggest the entrainment of spinal mechanisms as involved in clonus. The study demonstrates that the human lumbosacral spinal cord can organize a simple form of rhythmicity through the repetitive activation of spinal reflex circuits. PMID:25904708

  5. Abnormal reflex activation of hamstring muscles in dogs with cranial cruciate ligament rupture.

    Science.gov (United States)

    Hayes, Graham M; Granger, Nicolas; Langley-Hobbs, Sorrel J; Jeffery, Nick D

    2013-06-01

    The mechanisms underlying cranial cruciate ligament rupture (CCLR) in dogs are poorly understood. In this study hamstring muscle reflexes in response to cranial tibial translation were analysed to determine whether these active stabilisers of the stifle joint are differently activated in dogs with CCLR compared to control dogs. In a prospective clinical study reflex muscle activity from the lateral and medial hamstring muscles (biceps femoris and semimembranosus) was recorded using surface electrodes in control dogs (n=21) and dogs with CCLR (n=22). These electromyographic recordings were analysed using an algorithm previously validated in humans. The hamstring reflex was reliably and reproducibly recorded in normal dogs. Both a short latency response (SLR, 17.6±2.1ms) and a medium latency response (MLR, 37.7±2.7ms) could be identified. In dogs with unilateral CCLR, the SLR and MLR were not significantly different between the affected and the unaffected limbs, but the MLR latency of both affected and unaffected limbs in CCLR dogs were significantly prolonged compared to controls. In conclusion, the hamstring reflex can be recorded in dogs and the MLR is prolonged in dogs with CCLR. Since both affected and unaffected limbs exhibit prolonged MLR, it is possible that abnormal hamstring reflex activation is a mechanism by which progressive CCL damage may occur. The methodology allows for further investigation of the relationship between neuromuscular imbalance and CCLR or limitations in functional recovery following surgical intervention. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Modulation of defensive reflex conditioning in snails by serotonin

    Science.gov (United States)

    Andrianov, Vyatcheslav V.; Bogodvid, Tatiana K.; Deryabina, Irina B.; Golovchenko, Aleksandra N.; Muranova, Lyudmila N.; Tagirova, Roza R.; Vinarskaya, Aliya K.; Gainutdinov, Khalil L.

    2015-01-01

    Highlights Daily injection of serotonin before a training session accelerated defensive reflex conditioning in snails.Daily injection of 5-hydroxytryptophan before a training session in snails with a deficiency of serotonin induced by the “neurotoxic” analog of serotonin 5,7-dihydroxytryptamine, restored the ability of snails to learn.After injection of the “neurotoxic” analogs of serotonin 5,6- and 5,7-dihydroxytryptamine as well as serotonin, depolarization of the membrane and decrease of the threshold potential of premotor interneurons was observed. We studied the role of serotonin in the mechanisms of learning in terrestrial snails. To produce a serotonin deficit, the “neurotoxic” analogs of serotonin, 5,6- or 5,7-dihydroxytryptamine (5,6/5,7-DHT) were used. Injection of 5,6/5,7-DHT was found to disrupt defensive reflex conditioning. Within 2 weeks of neurotoxin application, the ability to learn had recovered. Daily injection of serotonin before a training session accelerated defensive reflex conditioning and daily injections of 5-HTP in snails with a deficiency of serotonin induced by 5,7-DHT restored the snail's ability to learn. We discovered that injections of the neurotoxins 5,6/5,7-DHT as well as serotonin, caused a decrease in the resting and threshold potentials of the premotor interneurons LPa3 and RPa3. PMID:26557063

  7. From globalist to cosmopolitan learning: on the reflexive modernization of teacher education

    Directory of Open Access Journals (Sweden)

    Niclas Rönnström

    2013-01-01

    Full Text Available In this article, I discuss teacher education reform and the work of teachers in light of globalization and reflexive modernization. Increasing globalization has meant changed conditions for national education traditionally geared toward nation building and to the nationalizing of lifeworlds. It is assumed that the global economy has made knowledge and lifelong learning essential to economic growth, and governments have considered their citizens, teachers, and schools to be poorly trained for the demands of knowledge economies. Consequently, nation-states have invested massively in teacher education because of the vital role effective high-quality teachers are expected to play in preparation for working on global markets and for the competitive edge of nations. However, recent teacher education reform can be criticized for a one-sided orientation toward principles of economic growth, effectiveness, and competitiveness at the expense of other important educational aims, such as the development of reflective and communicative capacities and education for cosmopolitan citizenship. Moreover, recent teacher education reform in various nation-states seems to neglect how processes of reflexive modernization profoundly change schools, society, and the teaching situation, and undermine the principles that marked earlier phases of nation-centered modernization. I discuss teacher education and the work of teachers as reflexive modern practices and phenomena within the framework of critical social theory, and I mainly use Ulrich Beck's theory of reflexive modernization. I argue that increased reflexivity, institutionalized individualization, and cosmopolitization constitute reasons for the re-contextualization of teacher education away from the uncritical influence of the primacy of the economy, instrumental rationalization, and other principles of modernization that are now running dry. In the final part, I discuss the importance of moving from a mainly

  8. Modification of Otolith Reflex Asymmetries Following Space Flight

    Science.gov (United States)

    Clarke, Andrew H.; Schoenfeld, Uwe; Wood, Scott J.

    2011-01-01

    We hypothesize that changes in otolith-mediated reflexes adapted for microgravity contribute to perceptual, gaze and postural disturbances upon return to Earth s gravity. Our goal was to determine pre- versus post-fight differences in unilateral otolith reflexes that reflect these adaptive changes. This study represents the first comprehensive examination of unilateral otolith function following space flight. Ten astronauts participated in unilateral otolith function tests three times pre-flight and up to four times after Shuttle flights from landing day through the subsequent 10 days. During unilateral centrifugation (UC, +/- 3.5cm at 400deg/s), utricular function was examined by the perceptual changes reflected by the subjective visual vertical (SVV) and by video-oculographic measurement of the otolith-mediated ocular counter-roll (OOR). Unilateral saccular reflexes were recorded by measurement of collic Vestibular Evoked Myogenic Potential (cVEMP). Although data from a few subjects were not obtained early post-flight, a general increase in asymmetry of otolith responses was observed on landing day relative to pre-flight baseline, with a subsequent reversal in asymmetry within 2-3 days. Recovery to baseline levels was achieved within 10 days. This fluctuation in the asymmetry measures appeared strongest for SVV, in a consistent direction for OOR, and in an opposite direction for cVEMP. These results are consistent with our hypothesis that space flight results in adaptive changes in central nervous system processing of otolith input. Adaptation to microgravity may reveal asymmetries in otolith function upon to return to Earth that were not detected prior to the flight due to compensatory mechanisms.

  9. Medial Olivocochlear Reflex Interneurons Are Located in the Posteroventral Cochlear Nucleus: A Kainic Acid Lesion Study in Guinea Pigs

    OpenAIRE

    De VENECIA, RONALD K.; LIBERMAN, M. CHARLES; GUINAN, JOHN J.; BROWN, M. CHRISTIAN

    2005-01-01

    The medial olivocochlear (MOC) reflex arc is probably a three-neuron pathway consisting of type I spiral ganglion neurons, reflex interneurons in the cochlear nucleus, and MOC neurons that project to the outer hair cells of the cochlea. We investigated the identity of MOC reflex interneurons in the cochlear nucleus by assaying their regional distribution using focal injections of kainic acid. Our reflex metric was the amount of change in the distortion product otoacoustic emission (at 2f1–f2)...

  10. Modification of Spastic Stretch Reflexes at the Elbow by Flexion Synergy Expression in Individuals With Chronic Hemiparetic Stroke.

    Science.gov (United States)

    McPherson, Jacob G; Stienen, Arno H; Drogos, Justin M; Dewald, Julius P

    2018-03-01

    To systematically characterize the effect of flexion synergy expression on the manifestation of elbow flexor stretch reflexes poststroke, and to relate these findings to elbow flexor stretch reflexes in individuals without neurologic injury. Controlled cohort study. Academic medical center. Participants (N=20) included individuals with chronic hemiparetic stroke (n=10) and a convenience sample of individuals without neurologic or musculoskeletal injury (n=10). Participants with stroke were interfaced with a robotic device that precisely manipulated flexion synergy expression (by regulating shoulder abduction loading) while delivering controlled elbow extension perturbations over a wide range of velocities. This device was also used to elicit elbow flexor stretch reflexes during volitional elbow flexor activation, both in the cohort of individuals with stroke and in a control cohort. In both cases, the amplitude of volitional elbow flexor preactivation was matched to that generated involuntarily during flexion synergy expression. The amplitude of short- and long-latency stretch reflexes in the biceps brachii, assessed by electromyography, and expressed as a function of background muscle activation and stretch velocity. Increased shoulder abduction loading potentiated elbow flexor stretch reflexes via flexion synergy expression in the paretic arm. Compared with stretch reflexes in individuals without neurologic injury, paretic reflexes were larger at rest but were approximately equal to control muscles at matched levels of preactivation. Because flexion synergy expression modifies stretch reflexes in involved muscles, interventions that reduce flexion synergy expression may confer the added benefit of reducing spasticity during functional use of the arm. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  11. Asynchronous recruitment of low-threshold motor units during repetitive, low-current stimulation of the human tibial nerve.

    Science.gov (United States)

    Dean, Jesse C; Clair-Auger, Joanna M; Lagerquist, Olle; Collins, David F

    2014-01-01

    Motoneurons receive a barrage of inputs from descending and reflex pathways. Much of our understanding about how these inputs are transformed into motor output in humans has come from recordings of single motor units during voluntary contractions. This approach, however, is limited because the input is ill-defined. Herein, we quantify the discharge of soleus motor units in response to well-defined trains of afferent input delivered at physiologically-relevant frequencies. Constant frequency stimulation of the tibial nerve (10-100 Hz for 30 s), below threshold for eliciting M-waves or H-reflexes with a single pulse, recruited motor units in 7/9 subjects. All 25 motor units recruited during stimulation were also recruited during weak (recruited more units (n = 3/25 at 10 Hz; n = 25/25 at 100 Hz) at shorter latencies (19.4 ± 9.4 s at 10 Hz; 4.1 ± 4.0 s at 100 Hz) than lower frequencies. When a second unit was recruited, the discharge of the already active unit did not change, suggesting that recruitment was not due to increased synaptic drive. After recruitment, mean discharge rate during stimulation at 20 Hz (7.8 Hz) was lower than during 30 Hz (8.6 Hz) and 40 Hz (8.4 Hz) stimulation. Discharge was largely asynchronous from the stimulus pulses with "time-locked" discharge occurring at an H-reflex latency with only a 24% probability. Motor units continued to discharge after cessation of the stimulation in 89% of trials, although at a lower rate (5.8 Hz) than during the stimulation (7.9 Hz). This work supports the idea that the afferent volley evoked by repetitive stimulation recruits motor units through the integration of synaptic drive and intrinsic properties of motoneurons, resulting in "physiological" recruitment which adheres to Henneman's size principle and results in relatively low discharge rates and asynchronous firing.

  12. RefleX: X-ray absorption and reflection in active galactic nuclei for arbitrary geometries

    Science.gov (United States)

    Paltani, S.; Ricci, C.

    2017-11-01

    Reprocessed X-ray radiation carries important information about the structure and physical characteristics of the material surrounding the supermassive black hole (SMBH) in active galactic nuclei (AGN). We report here on a newly developed simulation platform, RefleX, which allows to reproduce absorption and reflection by quasi-arbitrary geometries. We show here the reliability of our approach by comparing the results of our simulations with existing spectral models such as pexrav, MYTorus and BNTorus. RefleX implements both Compton scattering on free electrons and Rayleigh scattering and Compton scattering on bound electrons. We show the effect of bound-electron corrections on a torus geometry simulated like in MYTorus. We release with this paper the RefleX executable, as well as RXTorus, a model that assumes absorption and reflection from a torus with a varying ratio of the minor to major axis of the torus. To allow major flexibility RXTorus is also distributed in three components: absorbed primary emission, scattered radiation and fluorescent lines. RXTorus is provided for different values of the abundance, and with (atomic configuration) or without (free-electron configuration) taking into account Rayleigh scattering and bound electrons. We apply the RXTorus model in both configurations on the XMM-Newton and NuSTAR spectrum of the Compton-thick AGN NGC 424 and find that the models are able to reproduce very well the observations, but that the assumption on the bound or free state of the electrons has significant consequences on the fit parameters. RefleX executable, user manual and example models are available at http://www.astro.unige.ch/reflex. A copy of the RefleX executable is also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/607/A31

  13. ESO Reflex: A Graphical Workflow Engine for Data Reduction

    Science.gov (United States)

    Hook, R.; Romaniello, M.; Péron, M.; Ballester, P.; Gabasch, A.; Izzo, C.; Ullgrén, M.; Maisala, S.; Oittinen, T.; Solin, O.; Savolainen, V.; Järveläinen, P.; Tyynelä, J.

    2008-08-01

    Sampo {http://www.eso.org/sampo} (Hook et al. 2005) is a project led by ESO and conducted by a software development team from Finland as an in-kind contribution to joining ESO. The goal is to assess the needs of the ESO community in the area of data reduction environments and to create pilot software products that illustrate critical steps along the road to a new system. Those prototypes will not only be used to validate concepts and understand requirements but will also be tools of immediate value for the community. Most of the raw data produced by ESO instruments can be reduced using CPL {http://www.eso.org/cpl} recipes: compiled C programs following an ESO standard and utilizing routines provided by the Common Pipeline Library. Currently reduction recipes are run in batch mode as part of the data flow system to generate the input to the ESO VLT/VLTI quality control process and are also made public for external users. Sampo has developed a prototype application called ESO Reflex {http://www.eso.org/sampo/reflex/} that integrates a graphical user interface and existing data reduction algorithms. ESO Reflex can invoke CPL-based recipes in a flexible way through a dedicated interface. ESO Reflex is based on the graphical workflow engine Taverna {http://taverna.sourceforge.net} that was originally developed by the UK eScience community, mostly for work in the life sciences. Workflows have been created so far for three VLT/VLTI instrument modes ( VIMOS/IFU {http://www.eso.org/instruments/vimos/}, FORS spectroscopy {http://www.eso.org/instruments/fors/} and AMBER {http://www.eso.org/instruments/amber/}), and the easy-to-use GUI allows the user to make changes to these or create workflows of their own. Python scripts and IDL procedures can be easily brought into workflows and a variety of visualisation and display options, including custom product inspection and validation steps, are available.

  14. Teacher education and the challenges of the reflexive practice

    Directory of Open Access Journals (Sweden)

    Maria Regina Peres

    2013-06-01

    Full Text Available This article approaches the importance of teacher practice and their initial and continuing education in the light of the challenges offered by the critical reflexive proposal. The aims of this study were to investigate the underlying assumptions regarding teachers’ current education and practice, to research and analyze the major difficulties found in the development of teaching practice, to comprehend and analyze the complexity inherent to the teacher’s performance in the initial years of elementary school. A bibliographic research and a qualitative research with elementary school teachers were therefore developed. The results indicate that although teachers believe the learning process to be continuous, they do not invest in this type of education. Furthermore it was found that teachers’ critical reflexive attitudes are blended with eproductivist attitudes.

  15. Explicating Positionality: A Journey of Dialogical and Reflexive Storytelling

    Directory of Open Access Journals (Sweden)

    Celina Carter MN

    2014-02-01

    Full Text Available Qualitative researchers must be aware of and explicit about their social background as well as political and ideological assumptions. To facilitate this awareness, we believe that researchers need to begin with their own story as they seek to understand the stories of others. Taking into account the vulnerable act of storytelling, it is salient to consider how to share personal narratives in an authentic way within academic settings. In this article, we share our process and reflections of engaging in reflexive and dialogical storytelling. The focus of the article is the re-storying of one researcher's experience as she and her research team explore her emotions and positionality prior to conducting research on First Nations men's narratives of identity. We integrate a series of methodological lessons concerning reflexivity throughout the re-storying.

  16. Role of the cerebellum and the vestibular apparatus in regulation of orthostatic reflexes in the cat

    Science.gov (United States)

    Doba, N.; Reis, D. J.

    1974-01-01

    The contribution of the fastigial nucleus and the vestibular nerves (eighth cranial nerves) to the orthostatic reflexes in anesthetized, paralyzed cats was studied. Bilateral lesions of the rostral fastigial nucleus resulted in impairment of the reflex changes in blood pressure, femoral arterial flow, and resistance evoked by head-up tilting to 30 deg or 60 deg. The rostral fastigial nucleus, which might be triggered by the vestibular apparatus, appears to participate in concert with the baroreceptors in the initiation and possibly the maintenance of the orthostatic reflexes.

  17. Review: Franz Breuer with Assistance of Barbara Dieris and Antje Lettau (2009. Reflexive Grounded Theory. Eine Einführung für die Forschungspraxis [Reflexive Grounded Theory: An Introduction to Research Praxis

    Directory of Open Access Journals (Sweden)

    Sandra Da Rin

    2010-03-01

    Full Text Available This textbook by Franz BREUER, produced with the assistance of Barbara DIERIS and Antje LETTAU, is of interest more for the introduction it provides to reflexive research praxis than to grounded theory methodology. This means the subjectivity of the researcher is included in the research process as a decisive source of cognition. Reflexive grounded theory methodology is characterized by three elements that also structure the textbook. In the present review, I focus on two of these in detail: the approach to the research field based on ethnography, particular its epistemological prerequisites, and the inclusion of (self- reflexivity. The latter points to questions that are addressed at the end of this review. URN: urn:nbn:de:0114-fqs1002140

  18. Cough reflex sensitivity does not correlate with the esophageal sensitivity to acid in patients with gastroesophageal reflux disease.

    Science.gov (United States)

    Duricek, Martin; Nosakova, Lenka; Zatko, Tomas; Pecova, Renata; Hyrdel, Rudolf; Banovcin, Peter

    2018-03-27

    The sensitization of cough reflex observed in patients with gastroesophageal reflux disease (GERD) is attributed to activation of vagal C-fibers innervating the esophagus by acid, while the heartburn in GERD is mediated by esophageal acid sensitive C-fibers derived from (dorsal root ganglia) DRG. Here we explored the relationship between cough reflex sensitivity (CRS) and esophageal sensitivity to acid. We evaluated CRS to capsaicin inhalation and esophageal sensitivity to acid (intensity of heartburn evoked by esophageal infusions of acid pH = 3, 2 and 1) in patients with GERD and chronic heartburn before and 3 months after proton pump inhibitor (PPI) treatment. There was no correlation between CRS and esophageal sensitivity to acid at any pH tested. PPI treatment substantially reduced esophageal sensitivity to acid but did not affect CRS. We conclude that a simple direct relationship between CRS and esophageal sensitivity to acid is unlikely. The results indicate that spinal and vagal afferent pathways from the esophagus are probably influenced separately in subjects with GERD. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. The visual rooting reflex in individuals with autism spectrum disorders and co-occurring intellectual disability

    NARCIS (Netherlands)

    de Bildt, Annelies; Mulder, Erik J.; Van Lang, Natasja D. J.; de With, S. A. Jytte; Minderaa, Ruud B.; Stahl, Sherin S.; Anderson, George M.

    The rooting reflex has long been studied by neurologists and developmentalists and is defined as an orientation toward tactile stimulation in the perioral region or visual stimulation near the face. Nearly, all previous reports of the visual rooting reflex (VRR) concern its presence in adults with

  20. A cost minimisation and Bayesian inference model predicts startle reflex modulation across species

    OpenAIRE

    Bach, Dominik R

    2015-01-01

    In many species, rapid defensive reflexes are paramount to escaping acute danger. These reflexes are modulated by the state of the environment. This is exemplified in fear-potentiated startle, a more vigorous startle response during conditioned anticipation of an unrelated threatening event. Extant explanations of this phenomenon build on descriptive models of underlying psychological states, or neural processes. Yet, they fail to predict invigorated startle during reward anticipation and ins...