Observed hippocampal electrical activity in relation to behavior elicited by stimulation of the lateral hypothalamus in 30 male hooded rats. Rhythmical slow activity (RSA) was always present during walking, rearing, digging, bar pressing, and other presumably "voluntary" movements, but at low stimulation intensities it was often absent during licking, chewing, face washing, and other presumably "automatic" movements. At higher stimulation intensities, Ss became hyperactive and RSA was almost continually present. No relation was found between RSA and heart rate or licking movements. An ascending hypothalamic system may require hippocampal participation in the control of voluntary movements, but hippocampal participation may not be required for the control of more automatic movements. (30 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)