Vol. 274, Issue 4, R1087-R1093, April 1998
Effects of temperature on sleep in the developing rat
Roger N.
Morrissette1,2 and
H.
Craig
Heller1
1 Department of Biological
Sciences, Stanford University, Stanford 94305;
and 2 Program in Neuroscience,
University of California at Los Angeles, California 90025
In
altricial species, such as humans and rats, much of the development of
autonomic systems occurs postnatally. Consequently, vulnerabilities
exist early in postnatal development when immature autonomic functions
are challenged by external factors such as variations in ambient
temperature (Ta).
Ta profoundly influences sleep/wake state structure in adult animals and humans, and exposure to
excessive warmth has been implicated as a risk factor in sudden infant
death syndrome. To better understand the relationship between temperature and sleep during development, we investigated the effect of
Ta variation on sleep/wake state
structure and sleep intensity in developing rats. In this experiment,
sleep intensity was measured by the intensity of slow-wave activity
during slow-wave sleep. Neonatal Long-Evans hooded rat pups were
surgically prepared for chronic sleep/wake state and brain temperature
(Tbr) recording. Two-hour
recordings of sleep/wake state and
Tbr were obtained from rats on
postnatal day
12 (P12),
P14,
P16,
P18, and
P20 at a
Ta of either 28.0-30.0,
33.0-35.0, or 38.0-40.0°C.
Ta significantly influenced
sleep/wake state structure but had little, if any, effect on sleep
intensity in developing rats.
ontogeny; neonate; slow-wave activity; delta power
