Contrasting effects of flexor group II afferents during fictive locomotion

This study examined the reflex actions of hindlimb flexor muscle nerves on fictive locomotion produced by stimulating the midbrain locomotor region in decerebrate, paralysed, adult cats. Electrical stimulation (typically 100-200 ms trains of 10-20 shocks) of flexor nerves was delivered at particula...

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Main Author: Stecina, Katinka
Language:en_US
Published: 2007
Online Access:http://hdl.handle.net/1993/2314
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spelling ndltd-MANITOBA-oai-mspace.lib.umanitoba.ca-1993-23142014-01-31T03:31:15Z Contrasting effects of flexor group II afferents during fictive locomotion Stecina, Katinka This study examined the reflex actions of hindlimb flexor muscle nerves on fictive locomotion produced by stimulating the midbrain locomotor region in decerebrate, paralysed, adult cats. Electrical stimulation (typically 100-200 ms trains of 10-20 shocks) of flexor nerves was delivered at particular times during the step cycle and the effects on motoneuron activity recorded in electroneurograms from selected hindlimb nerves were examined. The effects of flexor nerve stimulation depended on the nerve being stimulated. Thus stimulation of the 'tibialis anterior' (TA) nerve at 5 times threshold (5T) terminated ongoing flexor activity and reset the locomotor rhythm to extension. In the same preparation, similar stimulation of the ' extensor digitorum longus' (EDL) nerve prolonged the flexion phase and enhanced the activity of hip knee and ankle flexor motoneurons. Enhancement of ongoing flexor motoneuron activity by EDL nerve stimulation was not seen with less than 2T stimulation intensity. When stimulation wasdelivered during extension, the effects of TA and EDL nerve stimulation were weak and variable. There was also some variability in the effects of 5T TA and EDL stimulation delivered during flexi n. The opposite effects of TA and EDL group II stimulation suggest that the reflex effects of flexor group II afferents differentiate into (at least) two classes during fictive locomotion; one promoting extension and another promoting flexion. (Abstract shortened by UMI.) 2007-06-01T19:20:49Z 2007-06-01T19:20:49Z 2000-07-01T00:00:00Z http://hdl.handle.net/1993/2314 en_US
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language en_US
sources NDLTD
description This study examined the reflex actions of hindlimb flexor muscle nerves on fictive locomotion produced by stimulating the midbrain locomotor region in decerebrate, paralysed, adult cats. Electrical stimulation (typically 100-200 ms trains of 10-20 shocks) of flexor nerves was delivered at particular times during the step cycle and the effects on motoneuron activity recorded in electroneurograms from selected hindlimb nerves were examined. The effects of flexor nerve stimulation depended on the nerve being stimulated. Thus stimulation of the 'tibialis anterior' (TA) nerve at 5 times threshold (5T) terminated ongoing flexor activity and reset the locomotor rhythm to extension. In the same preparation, similar stimulation of the ' extensor digitorum longus' (EDL) nerve prolonged the flexion phase and enhanced the activity of hip knee and ankle flexor motoneurons. Enhancement of ongoing flexor motoneuron activity by EDL nerve stimulation was not seen with less than 2T stimulation intensity. When stimulation wasdelivered during extension, the effects of TA and EDL nerve stimulation were weak and variable. There was also some variability in the effects of 5T TA and EDL stimulation delivered during flexi n. The opposite effects of TA and EDL group II stimulation suggest that the reflex effects of flexor group II afferents differentiate into (at least) two classes during fictive locomotion; one promoting extension and another promoting flexion. (Abstract shortened by UMI.)
author Stecina, Katinka
spellingShingle Stecina, Katinka
Contrasting effects of flexor group II afferents during fictive locomotion
author_facet Stecina, Katinka
author_sort Stecina, Katinka
title Contrasting effects of flexor group II afferents during fictive locomotion
title_short Contrasting effects of flexor group II afferents during fictive locomotion
title_full Contrasting effects of flexor group II afferents during fictive locomotion
title_fullStr Contrasting effects of flexor group II afferents during fictive locomotion
title_full_unstemmed Contrasting effects of flexor group II afferents during fictive locomotion
title_sort contrasting effects of flexor group ii afferents during fictive locomotion
publishDate 2007
url http://hdl.handle.net/1993/2314
work_keys_str_mv AT stecinakatinka contrastingeffectsofflexorgroupiiafferentsduringfictivelocomotion
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