Temperature sensitivity of sleep homeostasis during hibernation in
the golden-mantled ground squirrel (spermophilus lateralis).
Larkin, J. E., and H. C. Heller.
Department of Biological Sciences, Stanford University, Stanford,
CA 94305
APStracts 2:0296R, 1995.
Brain temperature (Tbr), vigilance state, and electroencephalograph
slow-wave activity (EEG SWA, 1.0-4.0 Hz) were measured during
hibernation and spontaneous arousals to euthermia in seven golden
-mantled ground squirrels (Spermophilus lateralis). Animals were held
at air temperatures (Ta) ranging from 6 to 21 C. SWA was used as a
measure of the intensity of non-rapid-eye-movement (NREM) sleep.
Squirrels that had hibernated at high Tas had lower SWA in NREM sleep
in the hours following arousal than when they hibernated at low Tas.
SWA in NREM sleep during euthermia immediately following arousal was
significantly correlated to minimum Tbr and SWA during hibernation.
The duration of the preceding hibernation bout had no significant
effect on SWA during euthermia. We hypothesize that the restorative
process of sleep, reflected by SWA, is temperature sensitive and is
compromised by the low temperatures in hibernation. The accumulation
of a SWA debt during hibernation may be related to the temperature
-dependant depression of SWA during hibernation.
Received 6 June 1994; accepted in final form 19 October 1995.
APS Manuscript Number R312-4.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 14 November 95