DECREASED TESTOSTERONE LEVELS AND ACCELERATED EXTINCTION OF A CONDITIONED TASTE-AVERSION IN FLUID-DEPRIVED MALE-RATS

The hypothesis that fluid deprivation accelerates extinction of a cond itioned taste aversion in male Sprague-Dawley-derived rats by reducing serum testosterone levels was tested. Serum testosterone levels were found to be lower in fluid-deprived males than in nondeprived males (E xperiments 1 and 2). Exogenous testosterone treatment that results in high physiological levels of serum testosterone slowed the extinction of fluid-deprived gonadectomized males to rates comparable with those of nondeprived sham males (Experiment 3). It was noted, however, that testosterone treatment was less effective in slowing extinction in flu id-deprived gonadectomized males than in nondeprived gonadectomized ma les even though the serum testosterone levels were the same (Experimen ts 3 and 4). These results provide strong support for the original hyp othesis, but they suggest that fluid deprivation also reduces sensitiv ity to testosterone.