[Effect of isolation of the mediobasal hypothalamus on the predatory aggressiveness of rats].

A study was made of the influence of isolation of the medio-basal hypothalamus area on the predatory aggression of albino male rats, which was measured by the test of mouse-killing. In three weeks after the operation the aggressiveness of rats increased eightfold. Partial isolations--anterior, long-posterior and posterior--did not change the killing aggression of the rats. Extension of dimensions of complete isolation up to the lateral hypothalamic area did not lead to the appearance of "mice killers" among the experimental rats. A conclusion has been drawn that the medio-basal hypothalamus has an inhibitory effect on the predatory aggression, which is achieved in multiple ways and is directed at the lateral hypothalamus.