Enhancement by serotonin of tonic vibration and stretch reflexes in the decerebrate cat.

TitleEnhancement by serotonin of tonic vibration and stretch reflexes in the decerebrate cat.
Publication TypeJournal Article
Year of Publication1986
AuthorsCarp, JS, Rymer, WZ
JournalExperimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale
Volume62
Pagination111–122
Date Published03/1986
ISSN0014-4819
Keywordsbistable neuronal behavior, serotonin, Spinal Cord, stretch reflex, tonic vibration reflex
Abstract

The effects of pharmacological manipulation of serotonergic systems on spinal reflexes were determined in the unanesthetized decerebrate cat. The prolonged motor output that continues after cessation of high frequency longitudinal tendon vibration was strongly enhanced by the serotonin reuptake blocker fluoxetine and the serotonin precursor 5-hydroxytryptophan, and was decreased by the serotonin receptor antagonist methysergide. In addition, both dynamic and static stretch reflex stiffness was markedly increased by fluoxetine and 5-hydroxytryptophan, while methysergide produced a decrease in stretch reflex stiffness. These powerful effects on tonic vibration and stretch reflexes could not be explained by drug-induced alterations in muscle spindle primary afferent discharge. In light of other recent results on serotonin-mediated effects on motoneurons, we believe that the effects of these agents result from modification of an intrinsically mediated prolonged depolarization of spinal neurons. However, the possibility that these drugs modify longlasting discharge in associated interneuronal pathways cannot be ruled out.

URLhttp://www.ncbi.nlm.nih.gov/pubmed/3007191
DOI10.1007/BF00237407

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