Persistence of meal-entrained circadian rhythms following area postrema lesions in the rat.
Rats anticipate daily meals with increased approaches to a feeder and an increase in core body temperature. Food-anticipatory activity (FAA) is thought to be under the control of a feeding-entrained circadian oscillator (FEO). Ibotenic acid and electrolytic lesions in the region of the parabrachial nuclei (PBN) in the rat severely disrupt FAA (feeder approaches) and temperature rhythms. The PBN receive dense input from the area postrema (AP), which lacks a blood-brain barrier and thus has access to humoral factors in the systemic circulation. The present study assesses development and maintenance of FAA in rats with cautery lesions of the AP. The results demonstrate that AP lesions do not alter FAA. This experiment does not support the hypothesis that the AP in the caudal brainstem detects and relays circulating signals from the periphery that trigger FAA.
Davidson
A J
AJ
Department of Psychology, Florida State University, Tallahassee, FL 32306-1270, USA.
Aragona
B J
BJ
Houpt
T A
TA
Stephan
F K
FK
D000818:Animals; D001143:Arousal / Q000502:physiology*; D001362:Avoidance Learning / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology; D001931:Brain Mapping; D002940:Circadian Rhythm / Q000502:physiology*; D003214:Conditioning, Classical / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology*; D018021:Lithium Chloride / Q000633:toxicity; D008297:Male; D011939:Mental Recall / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012249:Rhombencephalon / Q000502:physiology*; D013649:Taste / Q000502:physiology
D018021:Lithium Chloride