AJP - Regulatory, Integrative and Comparative Physiology, Vol 269, Issue 5 1250-R1257, Copyright © 1995 by American Physiological Society
Preoptic/anterior hypothalamic neurons: thermosensitivity in rapid eye movement sleep
M. N. Alam, D. McGinty and R. Szymusiak
Department of Psychology, University of California, Los Angeles 90024, USA.
The thermosensitivity of 15 warm-sensitive neurons (WSNs) and 19
cold-sensitive neurons (CSNs) from the medial preoptic/anterior
hypothalamus (POAH) was tested during wakefulness, non-rapid eye movement
(NREM) sleep and rapid eye movement (REM) sleep by local POAH warming and
cooling in freely moving cats. Thermosensitivity was quantified by three
criteria, Q10, impulses per second per degree Celsius, and percent change
per degree Celsius. Irrespective of the criterion used, WSNs did not
exhibit a significant change in thermosensitivity during REM sleep compared
with wakefulness and NREM sleep. In contrast, CSNs exhibited decreased mean
thermosensitivity during REM sleep compared with wakefulness. CSNs as a
group did not retain significant thermosensitivity in REM sleep. These
findings are consistent with evidence that thermoeffector responses to
cooling are lost in REM sleep, whereas some responses to warming are
preserved.
