当前位置： SCI文献检索 > JOURNAL OF NEUROPHYSIOLOGY期刊下所有文献 > Plantar cutaneous afferents normalize the reflex modulation patterns during stepping in chronic human spinal cord injury.

Plantar cutaneous afferents normalize the reflex modulation patterns during stepping in chronic human spinal cord injury.

Abstract：

:Plantar cutaneous afferent transmission is critical for recovery of locomotion in spinalized animals, whereas a phase-dependent reflex modulation is apparent during fictive or real locomotion. In nine people with a chronic spinal cord injury (SCI) the effects of foot sole stimulation on the soleus H-reflex and tibialis anterior (TA) flexion reflex modulation patterns during assisted stepping were established on different days. The soleus H-reflex was elicited by posterior tibial nerve stimulation followed by a supramaximal stimulus 100 ms after the test H-reflex to control for movement of recording electrodes. The flexion reflex was evoked by sural nerve stimulation with a 30-ms pulse train, recorded from the ipsilateral TA muscle, and elicited at 1.2- to twofold the reflex threshold. During assisted stepping, spinal reflexes were conditioned by percutaneous stimulation of the ipsilateral metatarsals at threefold perceptual threshold with a 20-ms pulse train delivered at 9- to 11-ms conditioning-test intervals. Stimuli were randomly dispersed across the step cycle, which was divided into 16 equal bins. The conditioned soleus H-reflex was significantly facilitated at midstance and depressed during midswing when compared with the unconditioned soleus H-reflex recorded during stepping. Foot sole stimulation induced a significant facilitation of the long-latency TA flexion reflex before, during, and after stance-to-swing transition when compared with the unconditioned long-latency TA flexion reflex during stepping. This study provides evidence that plantar cutaneous afferents remarkably influence the soleus H-reflex and TA flexion reflex modulation patterns during stepping and support that actions of plantar cutaneous afferents onto spinal interneuronal circuits engaged in locomotion are manifested in a phase-dependent manner in chronic SCI subjects.

journal_name

J Neurophysiol

journal_title

Journal of neurophysiology

authors

Knikou M

doi

10.1152/jn.00880.2009

subject

Has Abstract

pub_date

2010-03-01 00:00:00

pages

1304-14

issue

eissn

0022-3077

issn

1522-1598

pii

00880.2009

journal_volume

103

pub_type

杂志文章

在线工具

Plantar cutaneous afferents normalize the reflex modulation patterns during stepping in chronic human spinal cord injury.