Renshaw cell

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The Renshaw cells (also Renshaw interneurons ) were named after their first description, the US neurophysiologist Birdsey Renshaw (1911-1948).

These are inhibitory interneurons with the transmitter glycine in the anterior horns of the gray matter of the spinal cord . They are excitedly innervated by collaterals (branches) of the axons of alpha motor neurons (those nerve cells that directly innervate the muscles ), as well as by neurons that descend (project) from the brain into the spinal cord. In turn, the Renshaw cells exert an inhibitory influence on the alpha motor neuron that innervates them. You are thus exerting a negative feedback.

Functionally, these cells are involved in the declining (recurrent) inhibition of an alpha motor neuron. In contrast to the initial inhibition of supraspinal (ie higher, above the spinal cord) inhibitory influences, the inhibition by the Renshaw cells is also referred to as output inhibition . This retrograde inhibition may serve:

  • the self-protection of the muscle. The stronger the innervation of the muscle, the stronger the inhibitory feedback that reduces this innervation.
  • the fine coordination of the distal parts of the extremities , mainly the hands. The force can be modulated by regulating the sensitivity of the Renshaw cells. If these cells are set very sensitively by the brain, very small movements (e.g. fingers) are possible.

See also

Individual evidence

  1. ^ Heinz-Peter Schmiedebach : Renshaw, Birdsey. In: Werner E. Gerabek , Bernhard D. Haage, Gundolf Keil , Wolfgang Wegner (eds.): Enzyklopädie Medizingeschichte. De Gruyter, Berlin / New York 2005, ISBN 3-11-015714-4 , p. 1238.