AJP - Regulatory, Integrative and Comparative Physiology, Vol 244, Issue 1 114-R118, Copyright © 1983 by American Physiological Society
Cessation of thermoregulation during REM sleep in the pocket mouse
J. M. Walker, L. E. Walker, D. V. Harris and R. J. Berger
Electrophysiological sleep patterns, respiration frequency, brain
temperature (Tbr), and ear temperature (Tear) were recorded from five
pocket mice (Perognathus longimembris) exposed to ambient temperatures (Ta)
of 22.5, 27.5, 32.5, and 35.0 degrees C. Thermoregulation was curtailed
during rapid-eye-movement (REM) sleep, since Tbr declined following REM
onsets at Ta's below thermoneutrality and increased at Ta's above
thermoneutrality. Tbr subsequently returned to pre-REM levels following the
termination of each REM episode. Respiratory frequency was inversely
related to Ta but not as strongly during REM sleep as during slow-wave
sleep (SWS). These results confirm previous reports of loss of
thermoregulatory ability during REM sleep. Mean duration and proportions of
wakefulness, SWS, and REM sleep were unaffected by Ta, consistent with
earlier findings on ground squirrels, but differing from reports of
decreased REM sleep in nonhibernators. Hibernators may have lower
peripheral thermosensitivities than nonhibernators, facilitating sleep at
low ambient temperatures and during entrance into hibernation.
