Noradrenaline and “Chemical Coding” of Hypothalamic Neurones

Abstract

FIRING rates of single neurones in the “feeding system”—the perifornical and ventromedial areas of the hypothalamus—are altered by the systemic administration of an anorexigenic agent, such as amphetamine or glucose^1–4. Using the micro-iontophoretic technique which involves releasing chemicals directly on individual neurones, Oomura et al. confirmed that glucose can alter the spontaneous firing rates of some neurones in the hypothalamus of the rat⁵. We wish to report that micro-iontophoretic applications of glucose, amphetamine, and noradrenaline to hypothalamic neurones yield a pattern of results not readily reconcilable with the current views of the role of adrenergic substances as “transmitters” in the regulation of hypothalamic feeding function.