Suprachiasmatic nucleus and circadian core temperature rhythm in the rat.
Powell-EW; Halberg-F; Pasley-JN; Lubanovic-W; Ernsberger-P; Scheving-LE
J Therm Biol 1980 Oct; 5(4):189-196
The role of the suprachiasmatic nucleus (SCN) in circadian core temperature rhythms was investigated in rats. Twenty six singly housed adult male inbred Fischer-rats were standardized to light from 0600 to 1800 hours, alternating with darkness. Food and water were freely available. Bilateral electrolytic lesioning of the SCN was carried out on some of the animals, while others were sham operated. A temperature sensor was implanted intraperitoneally. After 16 weeks of the 12:12 light/dark schedule, there was a 6 hour delay in the schedule; after 8 days, a continuous light schedule was imposed for 3 weeks. Rats were then killed, and brains were examined to identify the extent of the lesions. The least squares fit of certain trial periods was used to analyze the telemetered data obtained at 10 minute intervals from each rat for the first 9 days. In the SCN lesioned rats which sustained destruction of both SCN, a circadian population rhythm persisted. The amplitude of the circadian temperature rhythm was attenuated and the rhythm's acrophase advanced from mid dark to a time near the transition from light to darkness. Unilateral lesions of the SCN altered the circadian amplitude but not the phasing.
NIOSH-Publication; NIOSH-Grant; Neurotoxic-effects; Laboratory-animals; Circadian-rhythms; Biological-rhythms;
Author Keywords: Suprachiasmatic nucleus; brain; circadian rhythm; chronobiology; temperature; rat; lesion
Anatomy University of Arkansas 4301 West Markham Little Rock, Ark 72201
Neurotoxic Disorders; Neurotoxic-effects
Journal of Thermal Biology
University of Arkansas Med Scis Ltl Rock, Little Rock, Arkansas