Aphagia and adipsia after preferential destruction of nerve cell bodies in hypothalamus

Microinjections of the excitatory neurotoxin kainic acid into the lateral hypothalamus of rats produced a period of aphagia and adipsia. Kainate-treated rats displayed transient motor effects during the first hours after the injection but did not show the persisting sensory-motor and arousal disturbances typically observed in animals with electrolytic lesions in this part of the hypothalamus. Histological examination revealed a significant reduction in the number of nerve cell bodies in the lateral hypothalamus. Silver-stained material indicated no evidence of damage to fiber systems passing through the affected region. Assays of dopamine in hypothalamus, striatum, and telencephalon did not indicate significant differences between experimental and control animals. These results are in agreement with recent reports of the anatomical and biochemical effects of intracerebral kainic acid injections and suggest that the observed effect on feeding behavior is related to the destruction of neurons in the lateral hypothalamus.