Hypothalamic thermosensitivity in capsaicin-desensitized rats

• Published in: The Journal of physiology Vol. 363; no. 1; pp. 227 - 236
• Main Authors: Cormarèche-Leydier, M, Shimada, S G, Stitt, J T
• Format: Journal Article
• Language: English
• Published: Oxford The Physiological Society 01-06-1985; Blackwell
• Subjects: Animals; Biological and medical sciences; Body Temperature - drug effects; Body Temperature Regulation - drug effects; Capsaicin - pharmacology; Cold Temperature; Fundamental and applied biological sciences. Psychology; Hot Temperature; Hypothalamus - physiology; Male; Metabolism; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Rats; Rats, Inbred Strains; Vertebrates: nervous system and sense organs; Vertebrata; Mammalia; Rat; Rodentia; Central nervous system; Nervous center; Thermoregulation; Brain (Vertebrata); Hypothalamus; Diencephalon
• ISSN: 0022-3751; 1469-7793
• DOI: 10.1113/jphysiol.1985.sp015706

In rats, we tested the hypothesis that capsaicin desensitization reduces hypothalamic warm thermosensitivity. We locally heated
and cooled the hypothalamus using water-perfused thermodes while observing thermoregulatory variables. In untreated rats,
a small dose of capsaicin had profound effects on thermoregulation. However, desensitizing rats to capsaicin had no effect
on hypothalamic thermosensitivity for metabolic rate or changes in body temperature due to displacements of hypothalamic temperature.
Contrary to current opinion, we conclude that capsaicin desensitization does not alter hypothalamic thermosensitivity to warm
or cold.