Alpha-motoneuron excitability at high altitude.

Détails

ID Serval
serval:BIB_8B6459396FF5
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Alpha-motoneuron excitability at high altitude.
Périodique
European Journal of Applied Physiology and Occupational Physiology
Auteur(s)
Kayser B., Bökenkamp R., Binzoni T.
ISSN
1439-6319
ISSN-L
0301-5548
Statut éditorial
Publié
Date de publication
1993
Volume
66
Numéro
1
Pages
1-4
Langue
anglais
Résumé
It has been hypothesized that chronic hypobaric hypoxia could lead to inhibition of the alpha-motoneuron pool, thus limiting the maximal activation of working skeletal muscles. To test this hypothesis six subjects [32 (SEM 2) years] were evaluated in resting conditions, at sea level and after acclimatization at 5,050 m. The recruitment curves of the Hofmann-reflex (H-) and the direct muscle-response. (M-) of the right soleus muscle were obtained by stimulating the posterior tibial nerve with different intensities while recording the electromyogram of the soleus muscle. From the recorded data the net alpha-motoneuron excitability (ratio of maximal H-reflex to M-response Hmax:Mmax ratio), the threshold and gain for both responses, obtained from linear regressions through the rising phase of the recruitment curves of both responses, as well as the latency times of both responses were determined. The latency times and the Hmax:Mmax ratio were unchanged at altitude. The thresholds of both responses and the gain of the M-response were unaltered. The gain of the H-response was significantly higher at altitude when compared to sea level.(ABSTRACT TRUNCATED AT 250 WORDS)
Mots-clé
Adult, Altitude, Cell Hypoxia/physiology, H-Reflex/physiology, Humans, Male, Motor Neurons/physiology, Muscles/physiology, Reaction Time/physiology
Pubmed
Web of science
Création de la notice
19/09/2013 11:27
Dernière modification de la notice
03/03/2018 19:11
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