TY - JOUR
T1 - Facilitation of the soleus stretch reflex induced by electrical excitation of plantar cutaneous afferents located around the heel
AU - Sayenko, Dimitry G.
AU - Vette, Albert H.
AU - Kamibayashi, Kiyotaka
AU - Nakajima, Tsuyoshi
AU - Akai, Masami
AU - Nakazawa, Kimitaka
N1 - Funding Information:
The authors thank Dr. Hirofumi Sekiguchi for assistance in data processing, Drs. Ji-Hee Kim and Makoto Takahashi for their comments on the experimental design, and Dr. Noritaka Kawashima for reviewing the manuscript. This study was supported by the grant and fellowship program of the Japan Society for the Promotion of Science.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2007/3/30
Y1 - 2007/3/30
N2 - Previous studies have demonstrated that plantar cutaneous afferents can adjust motoneuronal excitability, which may contribute significantly to the control of human posture and locomotion. However, the role of plantar cutaneous afferents with respect to their location specificity in modulating the mechanically induced stretch reflex still remains unclear. In the present study, it was hypothesized that electrical stimulation of the ipsilateral heel region of the foot is followed by a modulation of spinal excitability, leading to a facilitation of the soleus motor output. The study was performed to investigate the effect of excitation of plantar cutaneous afferents located around the heel on the soleus stretch reflex. The soleus stretch reflex was evoked by rotating the ankle joint in dorsiflexion direction at two different angular velocities of 50 and 200° s-1. A conditioning pulse train of non-noxious electrical stimulation was delivered to the plantar surface of the heel at different conditioning test intervals ranging from 5 to 100 ms. Excitation of plantar cutaneous afferents around the heel resulted in a pronounced facilitation of the soleus stretch reflex with magnitude and time course comparable for both velocities. This facilitation was manifested by a significant increase of reflex size for conditioning test intervals from 30 to 70 ms. The observed effect implies a potential functional role of cutaneous afferents in balance control conditions where the ankle is naturally disturbed, e.g., during step reactions to external perturbations.
AB - Previous studies have demonstrated that plantar cutaneous afferents can adjust motoneuronal excitability, which may contribute significantly to the control of human posture and locomotion. However, the role of plantar cutaneous afferents with respect to their location specificity in modulating the mechanically induced stretch reflex still remains unclear. In the present study, it was hypothesized that electrical stimulation of the ipsilateral heel region of the foot is followed by a modulation of spinal excitability, leading to a facilitation of the soleus motor output. The study was performed to investigate the effect of excitation of plantar cutaneous afferents located around the heel on the soleus stretch reflex. The soleus stretch reflex was evoked by rotating the ankle joint in dorsiflexion direction at two different angular velocities of 50 and 200° s-1. A conditioning pulse train of non-noxious electrical stimulation was delivered to the plantar surface of the heel at different conditioning test intervals ranging from 5 to 100 ms. Excitation of plantar cutaneous afferents around the heel resulted in a pronounced facilitation of the soleus stretch reflex with magnitude and time course comparable for both velocities. This facilitation was manifested by a significant increase of reflex size for conditioning test intervals from 30 to 70 ms. The observed effect implies a potential functional role of cutaneous afferents in balance control conditions where the ankle is naturally disturbed, e.g., during step reactions to external perturbations.
KW - Cutaneous afferents
KW - Motoneuronal excitability
KW - Reflex conditioning
KW - Sensorimotor integration
KW - Soleus stretch reflex
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U2 - 10.1016/j.neulet.2007.01.037
DO - 10.1016/j.neulet.2007.01.037
M3 - Article
C2 - 17276004
AN - SCOPUS:33947108029
SN - 0304-3940
VL - 415
SP - 294
EP - 298
JO - Neuroscience Letters
JF - Neuroscience Letters
IS - 3
ER -