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Renshaw cells are inhibitory interneurons found in the gray matter of the spinal cord, and are associated in two ways with an alpha motor neuron. * They receive an excitatory collateral from the alpha neuron's axon as they emerge from the motor root, and are thus "kept informed" of how vigorously that neuron is firing. * They send an inhibitory axon to synapse with the cell body of the initial alpha neuron and/or an alpha motor neuron of the same motor pool. In this way, Renshaw cell inhibition represents a negative feedback mechanism. A Renshaw cell may be supplied by more than one alpha motor neuron collateral and it may synapse on multiple motor neurons. ==Discovery== The concept of the Renshaw cells was postulated by Birdsey Renshaw (1908–1948),〔Renshaw B. Central effects of centripetal impulses in axons of spinal ventral roots. J Neurophysiol 1946 9:191–204〕 when it was discovered that with antidromic signals from a motor neuron running collaterally back via the ventral root into the spinal cord, there were interneurons firing with a high frequency, resulting in inhibition. Later work by Eccles ''et al.'',〔Eccles JC, Fatt P, Koketsu K. Cholinergic and inhibitory synapses in a pathway from motor-axon collaterals to motoneurones. J Physiol. 1954;126:524–562.〕 provided evidence that these interneurons, which they called “Renshaw Cells,” are stimulated by acetylcholine from motor neurons. Previous work by Renshaw〔Renshaw B. Influence of discharge of motoneurons upon excitation of neighboring motoneurons. J Neurophysiol 1941 4:167〕 and Lloyd〔Lloyd, D. P. C.. Facilitation and inhibition of spinal motoneurons, J.Neurophysiol.,1946, 9,421.〕〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Renshaw cell」の詳細全文を読む スポンサード リンク
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