Adrenergic stimulation of the rat diencephalon and its effect on food intake and hoarding activity

The diencephalic area most sensitive to microinjections of noradrenaline lay outside the area of the lateral hypothalamus in which feeding can be produced by electrical stimulation. Injection of either area, including injections that caused increased feeding, failed to have any effect on hoarding activity. Since hoarding can be elicited both by food deprivation and by electrical stimulation of the lateral hypothalamus, these findings indicate biochemical, anatomical and motivational differences between the central feeding mechanism sensitive to adrenergic stimulation, and that responding to electrical stimulation or nutritional depletion. The former mechanism may be disinhibitory; the latter, excitatory.