Single neurone activity of hypothalamic feeding centres: effect of local heating

Abstract

Unit activity from neurones of hypothalamic feeding and satiety centres, from other hypothalamic regions, and from some other brain regions was recorded in anaesthetized cats using a stereotaxic method for placing the recording electrode. Local heating of the order of 0.5 to 1.5' was produced through small heating coils, and registered through a thermocouple both guided stereotaxically into hypothalamic regions, and the effects of heating on the spontaneously firing units were observed. The units from the satiety and feeding centres did not respond in any way to local heating. Most of the units from the other hypothalamic regions, as well as all the units from other brain regions, again did not respond to heating. Five units from preoptic and rostral hypothalamic regions, and two units from the posterior hypothalamic area, responded by changed frequency of spikes during the heating interval. It is concluded that small changes in temperature do not in any way directly influence the activity of the satiety and feeding centres and thus change food intake. Whatever changes in food intake are produced by changes in body temperature are possibly mediated through anterior hypothalamic regions.