AJP - Regulatory, Integrative and Comparative Physiology, Vol 262, Issue 4 586-R594, Copyright © 1992 by American Physiological Society
Feeding suppression elicited by electrical and chemical stimulations of monkey hypothalamus
A. Takaki, S. Aou, Y. Oomura, E. Okada and T. Hori
Department of Physiology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
The effects of electrical (ES) and chemical stimulations of the
hypothalamus were investigated in monkeys during bar-press feeding. ES
elicited both prolonged and nonprolonged types of suppression of bar-press
feeding in hungry animals. Prolonged type suppression persisted for greater
than 1 min beyond one or more post-ES trials and was found after ES of the
dorsomedial hypothalamus (DMH), the ventromedial hypothalamus (VMH), and
the ventromedial part of the lateral hypothalamic area (LHA). Non-prolonged
type suppression was observed only during ES at some sites of both in
hypothalamic and extrahypothalamic areas. A microinjection of glutamate
into the VMH and the DMH, but not into the LHA, was able to reproduce the
ES-induced prolonged type suppression. In contrast, the ES of the LHA, but
not the VMH and DMH, in a satiated state provoked feeding. The results,
together with the previous findings, suggest that the neuronal inhibitory
mechanism of feeding exists in the VMH and DMH, while both the neuronal
facilitatory and axonal inhibitory mechanisms in the LHA are involved in
the feeding regulation, and these mechanisms of the LHA are affected by the
hunger/satiety state.
