A KINEMATIC ANALYSIS OF SEX-TYPICAL MOVEMENT PATTERNS USED DURING EVASIVE DODGING TO PROTECT A FOOD ITEM - THE ROLE OF TESTICULAR HORMONES

Feeding rats dodge laterally away from a conspecific attempting to ste al their food. Dodges by female and male rats differ in their composit ion of movement. Females pivot around a point more posterior on the lo ngitudinal axis than do males, producing a greater amount of movement of the snout in relation to the pelvis. This experiment examined the r ole of testicular hormones on these sex-typical movement patterns. Cas tration at weaning (ZI days) does not affect the male-typical pattern. Neonatal testicular hormone manipulation. however, does alter sex-typ ical patterns of movements. Whereas castration neonatally makes male r ats more female-like, injections of neonatal female rats with testoste rone propionate make them more male-like. These findings suggest that the organization of sex-typical patterns of dodging involves perinatal action of gonadal hormones. Results are discussed in relation to anat omy, neural structure, and tile role of gonadal hormones during develo pment.