scholarly journals Fatigue-incduced modulation of human soleus Hoffmann reflex under conditions of homosynaptic postactivation depression due to pair tibial nerve stimulation

Author(s):  
O. Kolosova

The purpose of our work was to investigate in detail the influence of pair stimulation of tibial nerve (n.tibialis) on human soleus H-reflex amplitude at rest and after long-lasting voluntary contraction of calf muscle (m.m. gastrocnemius-soleus), which caused the fatigue of soleus muscle. The method of H-reflex of soleus muscle was used. Test and conditioned responses (by pair stimulation of n. tibialis) were registered. Homosynaptic postactivation depression led to inhibition of H-reflex at rest. After fatiguing voluntary static contraction the amplitudes of test and conditioned soleus H-reflex were significantly reduced. Then both H-reflex amplitudes subsequently recovered. Soleus H-reflex inhibition might be due to the activation of the groups III and IV afferent nerves under the influence of mechanical and metabolic changes in the muscle.

Author(s):  
O. Kolosova

Monosynaptic reflex indices peculiarities, concerned with adaptative reactions to the long-term physical exercise, might add new data about mechanisms of human nervous system plasticity. The objective of the research was to investigate the influence of fatigue on human soleus H (Hoffmann) reflex in conditions of pair stimulation of tibial nerve with inter stimulus interval 500 m sin tenun trained people (age: M = 25,3, SE = 1,6 years) and ten trained athletes (age: M = 20,5, SE = 0,5 years). H-reflex study was performed using neurodiagnostic complex Nicolet Biomedical Viking Select (Viasys Health care, USA) at rest: before and after long-lasting isometric voluntary contraction of calf muscle, which caused the soleus muscle fatigue; the muscle force was equal to 75 % of maximal voluntary contraction. Test and conditioned responses (by means of stimulation with first and second impulses from pair) were registered. Homosynaptic postactivation depression (HPAD), associated with pair stimulation of tibial nerve, led to 56 % and 51 % inhibition of H-reflex in untrained and trained people at rest, respectively (p < 0,05). After fatiguing voluntary contraction the amplitudes of test and conditioned soleus H-reflex were both reduced approximately in half. Then both H-reflex amplitudes subsequently recovered, more rapidly in trained people. Soleus H-reflex inhibition might be due to the activation of the groups III and IV afferent nerves under the influence of mechanical and metabolic changes in the muscle. It was also found that HPAD H-reflex inhibition intensity increased by 20 % in untrained people and by 15 % in trained ones at 90 s after fatiguing voluntary contraction (p < 0,05). It is assumed that complex influence of fatigue and homosynaptic postactivation depression was more pronounced in untrained people in comparison with trained ones. It can be ascribed to athletes adaptation to the long-term physical exercise.


2019 ◽  
Vol 12 (2) ◽  
pp. 50-64
Author(s):  
George Elesnitsalis ◽  
Ioannis Amiridis ◽  
Dimitrios Patikas ◽  
Ioanna Vekili ◽  
Maria Vourvou

Introduction: Polyneuromyopathy constitutes a common complication in critically ill patients of the Intensive Care Unit (ICU) and in the last few years it appears to be identified as a syndrome detectable in the limbs and respiratory muscles. It is associated with the difficulties during weaning from mechanical ventilation. Aim: The present study investigates the reflective reaction of the soleus muscle following an electrical stimulation of the tibial nerve in intubated critically ill patients hospitalized in ICU with no medical history prior to their admission. Methods: Thirteen (13) patients who had been hospitalized for more than five (5) days and had a high APACHE II score (>15) and 13 age-matched control subjects were asked to participate in the present study on a volunteer basis. During the study, as reflective response parameters the range of the H-reflex and M-wave of the soleus muscle, as well as the conduction velocity of the tibial nerve, after electro-stimulation of the tibial nerve at the popliteal-fossa level, were assessed Results: Statistical analysis revealed significantly lower values in the ICU patients compared to healthy controls in both H-reflex range (p<0,049) and the M-wave range (p<0,041), as well as conduction velocity (p<0,001) of the tibial nerve. Conclusions: It is concluded that the reflective response of the soleus muscle as well as the tibial nerve’s conduction velocity are affected in critically ill patients hospitalized in ICU. The study of the above neurological parameters can provide further insights into the establishment and progress of polyneuromyopathy of critically ill patients in ICUs.


2009 ◽  
Vol 102 (6) ◽  
pp. 3596-3605 ◽  
Author(s):  
Peter W. Stubbs ◽  
Natalie Mrachacz-Kersting

Even though interlimb coordination is critical in bipedal locomotion, the role of muscle afferent mediated feedback is unknown. The aim of this study was to establish if ipsilateral muscle generated afferent feedback can influence contralateral muscle activation patterns in the human lower limb and to elucidate the mechanisms involved. The effect of ipsilateral tibial nerve stimulation on contralateral soleus (cSOL) responses were quantified. Three interventions were investigated, 1) electrical stimulation applied to the tibial nerve at stimulation intensities from 0 to 100% of maximal M-wave (M-max) with the cSOL contracted from 5 to 15% of maximal voluntary contraction (MVC) and 15 to 30% MVC, 2) ispsilateral tibial nerve stimulation at 75% M-max prior to, during, and following the application of ischemia to the ipsilateral thigh. 3) Electrical stimulation applied to the ipsilateral sural (SuN) and medial plantar nerves at stimulation intensities from 1 to 3 times perceptual threshold. A short-latency depression in the cSOL electromyogram (EMG; onset: 37–41 ms) was observed following ipsilateral tibial nerve stimulation. The magnitude of this depression increased ( P = 0.0005 and P = 0.000001) with increasing stimulus intensities. Ischemia delayed the time of the minimum of the cSOL depression ( P = 0.04). SuN and medial plantar nerve stimulation evoked a longer latency depression [average; 91.2 ms (SuN); 142 ms (medial plantar nerve)] and therefore do not contribute to the response. This is the first study to demonstrate a short-latency depression in the cSOL following ipsilateral tibial nerve stimulation. Due to its short latency, the response is spinally mediated. The involvement of crossed spinal interneurons receiving input from low-threshold muscle afferents is discussed.


2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Joanna Mazur–Różycka ◽  
Jan Gajewski ◽  
Krzysztof Buśko ◽  
Radosław Michalski ◽  
Patrycja Łach

Summary Study aim: to evaluate the differences in H-reflex parameters in lying and standing positions in canoeists. Material and methods: twenty seven male canoeists (age 17.2 ± 1.6 year, body mass 73.7 ± 7.6 kg, height 180.9 ± 6.1 cm, training experience 6.5 ± 3.6 years) participated in the study. None of the subjects had any history of neuromuscular disorders. The soleus H-reflex was examined in each subject twice: in lying and standing position. H-reflex was elicited by one-millisecond electrical stimulation of a posterior tibial nerve in the popliteal fossa. A recruitment curve for each subject was obtained by gradually increasing the stimulus intensity. Results: the results obtained in the present study showed statistically significant differences of the variables characterising effects of stimulations performed in lying and standing positions (F4,23 = 8.063; p < 0.001). H/M ratio was 0.50 ± 0.25 and 0.64 ± 0.27 for lying and standing positions, respectively. Our results support previous findings. Conclusions: the lying position is recommended for measurements as more comfortable for subjects and providing a greater level of the elicited H-reflex.


2002 ◽  
Vol 93 (1) ◽  
pp. 92-98 ◽  
Author(s):  
Alexandr M. Degtyarenko ◽  
Marc P. Kaufman

In decerebrate paralyzed cats, we examined the responses of 18 spinoreticular neurons to electrical stimulation of the mesencephalic locomotor region. The activity of each of the spinoreticular neurons was recorded extracellularly from laminae IV through VI of the L7 and S1 spinal cord. In addition, each of the 18 spinoreticular neurons received group III afferent input from the tibial nerve. Spinoreticular projections were established for each of 18 neurons by antidromic invasion of the ventro lateral medulla at the P11 though P14 levels. The onset latencies and current thresholds for antidromic invasion from the ventro lateral medulla averaged 15.0 ± 3.8 ms and 117 ± 11 μA, respectively. Electrical stimulation of the mesencephalic locomotor region attenuated the spontaneous activity or the responses of each of the spinoreticular neurons to tibial nerve stimulation at currents that recruited group III afferents. Our data support the notion that thin-fiber muscle afferent input to the ventrolateral medulla is gated by a central command to exercise.


2011 ◽  
Vol 300 (2) ◽  
pp. H652-H663 ◽  
Author(s):  
Hirotsugu Tsuchimochi ◽  
Jennifer L. McCord ◽  
Anna K. Leal ◽  
Marc P. Kaufman

We investigated the contribution of tetrodotoxin (TTX)-resistant sodium channels to the augmented exercise pressor reflex observed in decerebrated rats with femoral artery ligation. The pressor responses to static contraction, to tendon stretch, and to electrical stimulation of the tibial nerve were compared before and after blocking TTX-sensitive sodium channels on the L3-L6 dorsal roots of rats whose hindlimbs were freely perfused and rats whose femoral arteries were ligated 72 h before the start of the experiment. In the freely perfused group ( n = 9), pressor (Δ22 ± 4 mmHg) and cardioaccelerator (Δ32 ± 6 beats/min) responses to contraction were attenuated by 1 μM TTX (Δ4 ± 1 mmHg, P < 0.05 and Δ17 ± 4 beats/min, P < 0.05, respectively). In the 72 h ligated group ( n = 9), the augmented pressor response to contraction (32 ± 4 mmHg) was also attenuated by 1 μM TTX (Δ8 ± 2 mmHg, P < 0.05). The cardioaccelerator response to contraction was not significantly attenuated in these rats. In addition, TTX suppressed the pressor response to tendon stretch in both groups of rats. Electrical stimulation of the tibial nerve evoked similar pressor responses between the two groups (freely perfused: Δ74 ± 9 mmHg and 72 h ligated: Δ78 ± 5 mmHg). TTX attenuated the pressor response to the tibial nerve stimulation by about one-half in both groups. Application of the TTX-resistant sodium channel blocker A-803467 (1 μM) with TTX (1 μM) did not block the pressor response to tibial nerve stimulation to any greater extent than did application of TTX (1 μM) alone. Although the contribution of TTX-resistant sodium channels to the augmented exercise pressor reflex may be slightly increased in rats with chronic femoral artery ligation, TTX-resistant sodium channels on dorsal roots do not play a major role in the augmented exercise pressor reflex.


2000 ◽  
Vol 83 (4) ◽  
pp. 2063-2070 ◽  
Author(s):  
Yoshiyuki Takada ◽  
Takao Miyahara ◽  
Tatsuya Tanaka ◽  
Takashi Ohyama ◽  
Yoshio Nakamura

A previous study has demonstrated that the soleus H reflex is facilitated in association with voluntary teeth clenching in proportion with biting force in humans. The present study tried to elucidate the functional significance of this facilitation of the soleus H reflex, by examining 1) whether the facilitation of the H reflex is reciprocal or nonreciprocal between the ankle extensors and flexors and 2) whether the reciprocal Ia inhibition of crural muscles is facilitated or depressed in association with voluntary teeth clenching. The H reflex of the pretibial muscles was evoked by stimulation of the common peroneal nerve in seven healthy subjects with no oral dysfunction. The pretibial H reflex was facilitated in association with voluntary teeth clenching in a force-dependent manner. The facilitation started preceding the onset of electromyographic activity of the masseter muscle. Stimulation of the common peroneal nerve at low intensities subthreshold for evoking the M wave of the pretibial muscles inhibited the soleus H reflex after a short latency corresponding with a disynaptic inhibition, indicating that the reciprocal Ia inhibition was depressed in association with voluntary teeth clenching. Thus, the present study has shown that voluntary teeth clenching evokes a nonreciprocal facilitation of ankle extensor and flexor muscles and attenuated reciprocal Ia inhibition from the pretibial muscles to the soleus muscle. It is concluded that voluntary teeth clenching contributes to improve stability of stance rather than smoothness of movements.


1997 ◽  
Vol 272 (4) ◽  
pp. R1020-R1027 ◽  
Author(s):  
A. Ally ◽  
D. Caringi ◽  
D. M. Koester ◽  
T. Kobayashi ◽  
D. J. Mokler

The effects of administering 8-hydroxy-2-(di-n-propylamine) tetralin [8-OH-DPAT, a serotonin 1A (5-HT1A) receptor agonist] into the rostral ventrolateral medulla (RVLM) on cardiovascular responses during tibial nerve stimulation-evoked muscle contraction were investigated using anesthetized rats. Stimulation of the tibial nerve (3 times motor threshold, 0.1 ms, 40 Hz) for 30 s increased mean arterial pressure (MAP), heart rate (HR), and muscle tension by 25 +/- 3 mmHg, 24 +/- 4 beats/min, and 299 +/- 35 g, respectively. Bilateral microdialysis of 8-OH-DPAT (10 mM) for 30 min attenuated the stimulation-evoked increases in MAP (8 +/- 2 mmHg) and HR (11 +/- 5 beats/min), without a change in muscle tension (292 +/- 30 g). However, administration of 1 mM 8-OH-DPAT had no effect on the cardiovascular responses. Thirty minutes of microdialysis of 8-OH-DPAT (10 mM) into the caudal ventrolateral medulla produced no effect on cardiovascular responses during muscle contraction. Prior administration of 10 mM 1-[2-methoxyphenyl]-4-[4-(2-phthalimido)-butyl]piperazine (NAN-190), a 5-HT1A receptor antagonist, for 30 min into the RVLM blocked the attenuating effects of subsequent microdialysis of 8-OH-DPAT (10 mM). Results suggest that activation of 5-HT1A receptors within the RVLM inhibit cardiovascular responses elicited during static muscle contraction.


Author(s):  
Ivan G. Milanov

ABSTRACT:The purpose of this investigation was to compare three methods of assessing the excitability of lower motoneurones—TA-reflex, H-reflex and F-wave—in 120 patients with spastic hemiparesis following a stroke. The H-reflex was recorded from the soleus muscle after submaximal electrostimulation of the tibial nerve. The T-Achilles (TA) reflex was recorded from the soleus muscle after percussion of the Achilles tendon. The F-wave was recorded in the distal limb muscles after supramaximal electrostimulation of the median, ulnar, fibular and tibial nerves. The patient’s healthy side was used as a control. The TA-reflex, H-reflex and F-wave showed increased amplitudes on the spastic side. All amplitude ratios: TA/M, H/M, Fmax/M and Fmean/M were increased. The H-reflex thresholds were decreased. The F-wave duration, persistence and number of phases were also increased on the spastic side. Despite clinically decreased muscle tone, there were no changes in TA or H-reflex parameters after treatment. On the other hand, F-wave parameters tended to normalize after treatment in all groups. In conclusion, the F-wave is a more sensitive method than the TA and H-reflexes in assessing the excitability of the lower motoneurone.


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