Serotonin Affects Movement Gain Control in the Spinal Cord

• DOI: 10.1523/jneurosci.1855-14.2014
• Publication Date: 2014-09-17T17:39:00Z
• Authors: K. Wei; J. I. Glaser; L. Deng; C. K. Thompson; I. H. Stevenson; Q. Wang; T. G. Hornby; C. J. Heckman; K. P. Kording
• Keywords: Motor System; Motor Control

A fundamental challenge for the nervous system is to encode signals spanning many orders of magnitude with neurons limited bandwidth. To meet this challenge, perceptual systems use gain control. However, whether motor uses an analogous mechanism essentially unknown. Neuromodulators, such as serotonin, are prime candidates control during force production. Serotonergic project diffusely pools, and, therefore, production by one muscle should change others. Here we present behavioral and pharmaceutical evidence that serotonin modulates input–output motoneurons in humans. By selectively changing efficacy drugs, systematically modulated amplitude spinal reflexes. More importantly, different limbs interacts systematically, predicted a mechanism. Psychophysics pharmacology suggest adopts mechanisms, primary driver their implementation