Participation of the red nucleus in motor initiation: unit recording and cooling in cats.
Cats were trained to release (Go) or not to release (No-go) a lever after a brief auditory signal, depending on the presence of an additional tone (No-go cue). Unit recording and cooling were made in the red nucleus (RN) contralateral to the performing limb. Three major results were found: (1) in the Go condition, we observed phasic increases of rubral firing, with a constant latency after the auditory signal and with an amplitude correlated to the latency of motor triggering (i.e. reaction time, RT); the tonic activity preceding the auditory signal could also be correlated to the RTs for some units; (2) in the No-go condition, there was no phasic increase of rubral firing after the auditory signal; the tonic activity during the presentation of the No-go cue was markedly decreased compared to the Go trials; (3) cooling of the RN increased the RTs and could also block the motor triggering. These results suggest that the RN is involved in setting and triggering a conditioned motor response according to sensory cues.
Schmied
A
A
Laboratoire de Neurobiologie et Neuropharmacologie du Développement, C.N.R.S. UA-1121, Université Paris-Sud, Orsay, France.
Amalric
M
M
Dormont
J F
JF
Condé
H
H
Farin
D
D
D000818:Animals; D002415:Cats; D004525:Efferent Pathways / Q000502:physiology; D005071:Evoked Potentials; D009048:Motor Skills / Q000502:physiology*; D009132:Muscles / Q000294:innervation*; D009474:Neurons / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012012:Red Nucleus / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology*