ISSN:0006-8977    

DOI:10.1159/000125420

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000125421

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

There are a number of discrete electro-physiological responses which can be recorded from the ventral horn. Those which can be related to anatomically defined structures, or at least to positions within the laminae of Rexed, include the responses of α-motoneurons, γ-motoneurons, α-motor axons, Renshaw cells, type A interneurons, and commissural neurons. Recurrent inhibition is best explained by the excitation of Renshaw cells by recurrent collaterals of motor axons; Renshaw cells in turn inhibit motoneurons. The synaptic transmitter released by the recurrent collaterals is acetylcholine. That released by Renshaw cells may be glycine or a related substance. Recurrent facilitation is best explained by the inhibition by Renshaw cells of inhibitory interneurons. Candidate inhibitory interneurons include type A interneurons, which may mediate group I reciprocal inhibition, and other Renshaw cells. There is no good reason to believe that Renshaw cells are actually the terminals of recurrent collaterals or the dendrites of motoneurons rather than interneurons. However, there is also no convincing evidence that Renshaw cells are necessarily short-axoned cel

ISSN:0006-8977    

DOI:10.1159/000125422

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

There are a number of discrete electro-physiological responses which can be recorded from the ventral horn. Those which can be related to anatomically defined structures, or at least to positions within the laminae of Rexed, include the responses of α-motoneurons, γ-motoneurons, α-motor axons, Renshaw cells, type A interneurons, and commissural neurons. Recurrent inhibition is best explained by the excitation of Renshaw cells by recurrent collaterals of motor axons; Renshaw cells in turn inhibit motoneurons. The synaptic transmitter released by the recurrent collaterals is acetylcholine. That released by Renshaw cells may be glycine or a related substance. Recurrent facilitation is best explained by the inhibition by Renshaw cells of inhibitory interneurons. Candidate inhibitory interneurons include type A interneurons, which may mediate group I reciprocal inhibition, and other Renshaw cells. There is no good reason to believe that Renshaw cells are actually the terminals of recurrent collaterals or the dendrites of motoneurons rather than interneurons. However, there is also no convincing evidence that Renshaw cells are necessarily short-axoned cel

ISSN:0006-8977    

DOI:10.1159/000125423

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The phenomenon of antidromic inhibition in the spinal cord is generally considered to depend on a population of intercalated interneurons which are cholinergically activated by motoneuron collaterals and are, in turn, responsible for the powerful IPSP''s generated in adjacent motoneurons and the coincident burst of rapid repetitive neural activity in the immediate surround. Detailed analysis of the structural substrate in the anterior horn using Golgi impregnations and related methods, does not support the circuit arrangements currently postulated to account for this effect. The problems inherent in the present model are considered in detail and an alternative substrate is suggested.

ISSN:0006-8977    

DOI:10.1159/000125424

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The phenomenon of antidromic inhibition in the spinal cord is generally considered to depend on a population of intercalated interneurons which are cholinergically activated by motoneuron collaterals and are, in turn, responsible for the powerful IPSP''s generated in adjacent motoneurons and the coincident burst of rapid repetitive neural activity in the immediate surround. Detailed analysis of the structural substrate in the anterior horn using Golgi impregnations and related methods, does not support the circuit arrangements currently postulated to account for this effect. The problems inherent in the present model are considered in detail and an alternative substrate is suggested.

ISSN:0006-8977    

DOI:10.1159/000125425

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:0006-8977    

DOI:10.1159/000125426

出版商:S. Karger AG    

年代:1971

数据来源: Karger