Body temperature and sleep in intact and ovariectomized female
rats.
Li, Hua, and Evelyn Satinoff.
University of Illinois at Urbana-Champaign, Champaign, IL 61820,
Department of Psychology, Department of Physiology, 3Neuroscience
Program
APStracts 3:0277R, 1996.
The present study examined intact and ovariectomized adult rats to
assess the effects of removal of sex hormones on body temperature
(Tb) and sleep. Subjects were 12 female rats, aged 5-8 months, half
of which were bilaterally ovariectomized (OVX). Sleep/waking and Tb
were recorded under a 12:12 light:dark cycle. There was a strong
coupling between level of Tb and the three conditions of Waking,
Slow-Wave Sleep (SWS) and Rapid-Eye-Movement Sleep (REMS): Tb was
significantly positively correlated with Waking, and significantly
negatively correlated with SWS and REMS. These correlations were even
higher in OVX rats. In the light, OVX rats had more SWS and stayed
awake less than did the intact rats. OVX rats had more REMS than did
intact rats in both light and dark. Mean Tb and daily Tb amplitude
were the same in both groups. These results suggest that ovariectomy
increases and, by extension, gonadal steroids decrease, the coupling
between Tb and sleep.
Received 18 August 1995; accepted in final form 14 June 1996
APS Manuscript Number R518-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 25 July 1996