SEX-DIFFERENCES IN ANXIETY BEHAVIOR IN RATS - ROLE OF GONADAL-HORMONES

These experiments examined the role of gonadal hormones at both the or ganizational and activational time periods on sex differences in plus- maze behavior. In the first experiment, adult female Long-Evans rats w ere found to spend more time on the open arms of the plus maze than ad ult males, indicating less anxious behavior. In the second experiment, male and female subjects received a neonatal treatment (chemical cast ration with flutamide or tamoxifen, vehicle injection, or no injection ) and a prepubertal treatment (gonadectomy, sham surgery, or no surger y). Adult females receiving either neonatal tamoxifen or prepubertal o variectomy spent less time on the open arms than control females, but females who received both treatments were the most defeminized subject s. Males were not affected by the absence of gonadal hormones at eithe r time period. These experiment indicate that female gonadal hormones play an important role both organizationally and activationally in plu s-maze behavior. The role of the GABA receptor complex in mediating th is effect is discussed. Knowledge of sex differences in plus-maze beha vior may help to make this maze a more useful tool in investigating an xiety behavior in rats.