Interleukin-1 affects the behavioral despair response in rats by an indirect mechanism which requires endogenous CRF.

ABSTRACT

Interleukin-1 (IL-1) administered intracerebroventricularly (i.c.v.) to rats significantly reduces the level of immobility in animals forced to swim in a confined space. Immunoneutralization of endogenous CRF (corticotropin-releasing factor) by i.c.v. administration of CRF-antiserum prevents the IL-1-induced sinking in rats. This shows that the release of cerebral CRF, probably from the hypothalamus, may mediate the behavioral effect promoted by IL-1. Taken together our results suggest the existence of a complex interface between immune, neuroendocrine and behavioral regulation.