ACQUISITION AND RETENTION EFFECTS OF ETHYLESTRENOL IN A FOOD-SEARCH TASK

Ethylestrenol, a synthetic anabolic steroid, was administered to adult male Long-Evans rats to investigate its role in acquisition and reten tion of a spatial food-search task. The animals were injected i.p. eve ry other day either with 100 mu g of ethylestrenol or with the vehicle alone. Injections began 1 week prior to testing and continued through out the study. A modified hole-board task was used. After modest food deprivation, the animals were required to find a food reward placed in a given hole. Acquisition of the task was measured by the time requir ed to reach the food hole. Eight trials were given per day. Following a 10-day period without deprivation (but with 2 injections on separate days), eight retention trials were given. Following this, the rats we re trained to find the reward at a new location for 2 subsequent days. There were small differences between the groups in performance during acquisition in the original 5-day period but not in the final 2-day ' 'new-hole'' training period. During the retention test, however, the e thylestrenol-treated rats reached the food reward significantly faster than did the vehicle-treated rats. These results indicate that retent ion was substantially enhanced by the synthetic hormone-like agent und er conditions in which there was only limited enhancement of acquisiti on.