Diurnal rhythm in the spinal stretch reflex.
We studied primate spinal stretch reflex (SSR) amplitude as a function of time of day. SSR amplitude was greatest around midnight and smallest around noon. The diurnal rhythm was not simply a function of number of trials, or of the lighting cycle. This rhythm offers an opportunity to study the neuronal and synaptic mechanisms producing a diurnal change in CNS function. Its existence indicates that the CNS response to a given limb disturbance, and thus the CNS activity underlying a given performance, varies with time of day.
D000818:Animals; D002940:Circadian Rhythm; D005260:Female; D005552:Forelimb / Q000294:innervation; D008254:Macaca nemestrina; D008297:Male; D009046:Motor Neurons / Q000502:physiology; D009048:Motor Skills / Q000502:physiology; D012026:Reflex, Stretch; D013116:Spinal Cord / Q000502:physiology*; D013569:Synapses / Q000502:physiology