Medial hypothalamic lesions and play fighting in juvenile rats.

The effects of medial preoptic area (MPOA), anterior hypothalamic (AH) and ventromedial hypothalamic (VMH) lesions on play fighting were studied in juvenile rats that were housed and observed in heterosexual groups of 6-8 animals. Overall males engaged in play fighting more frequently than females and none of the lesions reliably affected this measure. Males also initiated more play fights. AH and VMH lesions reduced the frequency of play initiation in both sexes, but MPOA lesions had no reliable effect in either sex.