AJP - Regulatory, Integrative and Comparative Physiology, Vol 257, Issue 3 605-R612, Copyright © 1989 by American Physiological Society

ARTICLES

Suprachiasmatic nucleus: phase-dependent activation during the hibernation cycle

T. S. Kilduff, C. M. Radeke, T. L. Randall, F. R. Sharp and H. C. Heller
Department of Psychiatry, Stanford University, California.

The suprachiasmatic nucleus (SCN) of the golden-mantled ground squirrel undergoes a phase-dependent change in its accumulation of 2-[14C]deoxy-D-glucose (2-DG) relative to other brain structures during the hibernation cycle. The greatest relative 2-DG uptake (R2DGU) is observed in the SCN during entrance into and during deep hibernation. A circadian fluctuation in R2DGU of the SCN is not evident in the euthermic ground squirrel but can be increased during the subjective day by photic stimulation. An increase in R2DGU by the paraventricular nucleus (PVN) correlates with the increase in R2DGU by the SCN during entrance to hibernation but not with the increase in SCN R2DGU evoked by photic stimulation during euthermia. The periventricular nuclei of the hypothalamus (PEV) also have high levels of R2DGU during the latter phase of the entrance. These observations support the hypothesis that the SCN, PEV, and PVN may play important roles in hibernation and suggest progressive activation of synaptic input to and within the SCN during entrance into this state.

This article has been cited by other articles:

				N. F. Ruby, J. Dark, D. E. Burns, H. C. Heller, and I. Zucker The Suprachiasmatic Nucleus Is Essential for Circadian Body Temperature Rhythms in Hibernating Ground Squirrels J. Neurosci., January 1, 2002; 22(1): 357 - 364. [Abstract] [Full Text] [PDF]

				A. M. Strijkstra and S. Daan Dissimilarity of slow-wave activity enhancement by torpor and sleep deprivation in a hibernator Am J Physiol Regulatory Integrative Comp Physiol, October 1, 1998; 275(4): R1110 - R1117. [Abstract] [Full Text] [PDF]