SEXUAL MOTIVATION IN MALE-MICE INDUCED BY FEMALE EXPOSURE

Receptive female mouse placed in a cage behind a partition which preve nted physical contacts but allowed the female to be smelt and seen pro duced in CBA and A/He males an elevation of plasma testosterone level and increase in time spent near the partition (TSNP) in attempts to re ach the female. Both in CBA and A/He males the TSNP was much higher th an in controls with empty ajacent compartment or with a male in it, Th e number of approaches to the partition was also increased but not sex -dependend reflecting the general motor excitement of animals. A 3-4-f old increase in the TSNP preceding blood testosterone elevation was fo und within the first 10 min of female exposure, It was suggested that sexual motivation in males induced by female exposure was not caused b y testosterone increase. The TSNP in male mice produced by female expo sure can be used as an adequate index of sexual motivation.