Comparison of the effect of prostaglandin E1 and norepinephrine injected into the brain on ingestive behavior in the rat

Norepinephrine hydrochloride (NE) in doses of either 5 or 25 μg and prostaglandin E₁ (PGE₁) in doses of either 5 or 50 ng were made directly into the substance of the hypothalamus as well as other limbic structures of the unrestrained, unanesthetized rat. The animals had free access to food and water at all times. NE injected into the perifornical area of the hypothalamus, the hippocampus and the amygdala elicited vigorous eating. PGE₁ did not produce eating which differed from that observed following control injections of a physiological control solution. Drinking was not observed following injections of either NE or PGE₁ at the dose used. These data indicate that PGE₁ does not play a direct role in the hypothalamic and limbic control of ingestive behavior.