POSTERIOR HYPOTHALAMIC ACTIVITY AND CORTICAL CONTROL DURING THE PGE(1) HYPERTHERMIA

THE firing rate of the posterior hypothalamic neurones and interscapul ar brown adipose tissue and colonic temperatures (T-IBAT and T-C) were monitored in 36 urethane-anaesthetized male Sprague-Dawley rats befor e and after an intracerebroventricular (i.c.v.) injection of 400 ng pr ostaglandin E(1) (PGE(1)) or saline. The i.c.v. injection was preceded by functional decortication in half of each group. The results show a n increase of firing rate, T-IBAT and T-C after PGE(1) injection in th e rats without decortication. Functional decortication significantly r educed these enhancements. These findings demonstrate that the posteri or hypothalamus plays a significant role in the hyperthermia induced b y PGE(1) and that the cerebral cortex is involved in the control of po sterior hypothalamic activity.