LEVELS OF HYPOTHALAMIC LUTEINIZING HORMONE-RELEASING FACTOR AFTER EXPOSURE TO AGGRESSION (DEFEAT) IN C57BL/6J MICE

Abstract

Aggression, in animals, can be produced by a variety of methods ranging from simple isolation-frustration to more complex behavioural manipulations. For the past 5 yr. aggression and defeat have been studied in this laboratory utilizing the training method of Scott (1946). Thus, we have studied specifically the effects of combative behaviour for measured periods of time, on aggressive mice and on defeated mice and the mode of endocrine adaptation. This investigation was conducted to determine the levels of the hypothalamic luteinizing hormone-releasing factor (LH-RF) in C57BL/6J mice that were trained to be aggressive and in mice defeated repeatedly by the aggressive mice. The experimental design and treatment were identical to those described previously (Eleftheriou & Church, 1967). Groups of 30 male mice each were killed at each of the following periods: 0 (control), 1, 2, 4, 8 and 16 days after daily exposure for two 5 min. periods to trained