Effects of Estradiol on Radial Arm Maze Performance of Young and Aged Rats
Luine, V.; Rodriguez, M.
Behavioral and Neural Biology 62(3): 230-236
ISSN/ISBN: 0163-1047 PMID: 7857245 DOI: 10.1016/s0163-1047(05)80021-4
Gonadectomized male and female Sprague-Dawley rats, given estradiol (E-2) via sc Silastic capsules that generated proestrus levels of hormones, were tested for spatial memory performance on an 8-arm radial maze. Performance of males, with or without E-2, exceeded that of females, with or without E-2, for choice accuracy parameters over 20 trials. In addition, males reached criterion earlier than females (6 vs 11 trials). There were no significant effects of E-2 on performance of either sex. When a 1-h delay was instituted between the 4th and 5th choices, the performance of males remained better than that of the females, and E-2 administration was associated with a small, but significant, improvement in performance of the males but not the females. E-2 administration to 25-month-old males also did not affect performance in regular trials, but performance was enhanced in trials with delays of 1-3 h after the 4th choice. These results show that estradiol can influence spatial memory performance and suggest that E-2 may be beneficial for age and/or disease-related memory impairments.