Kainic acid lesions of the cat's antero-medial hypothalamus and emotional-defensive response evoked by carbachol injection to the same loci.

Injections of carbachol (CCh) through a chronic cannula into the antero-medial hypothalamus (AMH) of the cat induced the emotional-defensive response (EDR) which was evaluated by time duration and number of growls in a 30-min experimental session. That response was examined before and after injection of kainic acid (KA) to the same loci of hypothalamus. None of KA doses employed (3 micrograms/2 microliter and 6 micrograms/2 microliter of vehicle) brought about statistically significant changes in parameters of the vocal response. The results suggest that either the AMH neuronal perikarya responsible for CCh-induced EDR, are resistant to KA, or muscarinic receptors initiating the EDR are not localized on perikarya.