Effect of clonidine and phentolamine on self-stimulation behavior in the dorsal and ventral regions of the lateral hypothalamus in mice.
The effects of IP injections of increasing doses of clonidine and phentolamine on self-stimulation behavior (ICSS) in the dorsal and ventral regions of the lateral hypothalamus were studied in C57BL/6 mice. Clonidine specifically stimulates alpha-noradernergic receptors and has two distinct effects on ICSS. Ventral hypothalamic ICSS is immediately depressed at low doses (5 microgram/kg) whereas dorsal ICSS exhibits a discrete increase. At higher doses, ICSS is perturbed at both sites. Phentolamine is a specific blocking agent of alpha-noradrenergic receptors and depresses dorsal ICSS more than that of the ventral region. These observations clearly indicate a noradrenergic influence in the dorsal region of the hypothalamus.
D000818:Animals; D003000:Clonidine / Q000494:pharmacology*; D003864:Depression, Chemical; D007031:Hypothalamus / Q000502:physiology*; D051379:Mice; D010646:Phentolamine / Q000494:pharmacology*; D012653:Self Stimulation / Q000187:drug effects*
D003000:Clonidine; D010646:Phentolamine