Mediation of descending long spinal reflex activity
Mediation of descending long spinal reflex activity
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DOI：
10.1152/jn.1942.5.6.435
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发表时间：
1942-11-01
影响因子：
2.5
通讯作者：
Lloyd, DPC
中科院分区：
文献类型：
--
作者：
Lloyd, DPC
Transmission of reflex effect from the forelimbs to the hindlimbs of the cat has been examined. Free decussation of activity occurs in the cervical and lumbar enlargements, so that activity arising in one forelimb is transmitted through the propriospinal system bilaterally to cross and recross in the lumbar cord. The lateral columns of the cord subserve unilateral transmission, the ventral columns both unilateral and bilateral transmission. The first effect in the lumbar cord of a brachial plexus volley is inhibition of motoneurons on the ipsilateral side. This is a direct action, for latency allows only of conduction and the necessary single synaptic relay. A facilitation period follows, at the height of which motoneurons discharge. The discharge is variable, but may exceed that of segmental reflexes under favorable conditions. Internuncial activity in the lumbar enlargement is confined to the ventral horn, and is most intense in the nucleus of the anterior commissure. Long spinal reflexes reinforce one another, but long and short spinal reflexes (multincuronal) are mutually antagonistic, frequently to a degree too great to be accounted for by occlusion. When nuclei are activated by diffuse discharges such as those involved in long spinal reflexes, nuclear delay rather than synaptic delay, together with conduction, determines central latency.
