No clock signal in the discharge of neurons in the deep cerebellar nuclei.
J.G.Keating and W.T.Thach.
Department of Anatomy and Neurobiology, Washington University School of
Medicine, 660 S. Euclid Avenue, St. Louis, MO, 63110.
APStracts 4:002N, 1997.
ABSTRACT
We examined the spike activity of deep cerebellar nuclear cells recorded from
awake, behaving monkeys to determine if there was a tendency for periodic
discharge at or near 10 Hz. Data was obtained from four Rhesus monkeys trained
to perform either targeted flexions and extensions of the wrist in relation to
a visual cue (2 monkeys) or instrumented digit movements and natural reaches
(2 monkeys). We determined the interspike intervals of 274 isolated cells. We
looked for periodicity by autocorrelating the interval data and Fourier
transforming the resulting autocorrelation function. The autocorrelograms and
the Fourier transforms failed to reveal periodicity at or near 10 Hz for any
cell. This lack of oscillatory discharge in deep nuclear cells of the
cerebellum is consistent with our previously reported results (Keating and
Thach 1995) that the complex spike of the Purkinje cell is aperiodic. Our
failure to observe a clock-like timing signal in awake behaving animals in
either the Purkinje cell complex spike or the deep nuclear cell discharge
argues against a popular idea that the inferior olive may act through the
cerebellum as a motor clock.
Received 14 June 1996; accepted in final form 27 December 1996.
APS Manuscript Number J476-6.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 24 January 1997