| Abstract: | Marked hyperphagia with an increase in the rate of body weight gain was noted in adult female rats 4 days after injections of 2 nmoles of kainic acid into the dorsal and ventral parts of hippocampus. The effect was still present 70 days later. At this time the increase in daily food intake and body weight gain amounted, respectively, to 39% and 93% over the control value. There was no change in water intake. The injection of kainic acid into only one part of the hippocampus--either dorsal or ventral--did not induce hyperphagia. Male rats with kainic acid lesion did not show changes in food intake or body weight gain as compared to vehicle-treated controls. In both sexes the degeneration of hippocampal perikarya induced by kainic acid was associated with a 50-60% decrease in glutamic acid decarboxylase activity and [3H]glutamate uptake, as well as with a small decrease in [3H]glutamate uptake in the hypothalamus, an area that receives glutamatergic fibers from the hippocampus. The results show that the hippocampus appears to play an important role in appetite motivation control by a mechanism which is sex-related. |
