| Abstract: | Ovarian hormones alter spine density of hippocampal granule and pyramidal cells in young adult and aging female rats. (P. Miranda, C. L. Williams, and G. Einstein, 1999; C. S. Woolley, see record 1998-11866-006). The present study used a delay matching-to-place version of the water maze to investigate a behavioral correlate of these hormone-induced changes in hippocampal connectivity in 3- and 8-mo-old female rats. When primed with 10-mg injections of estradiol 72 and 48 hrs before testing, the memory retention of ovariectomized rats was improved compared with retention after priming with oil. A single injection of progesterone maintained the enhancement if testing occurred within 8 hrs of the progesterone injection but not if testing occurred more than 34 hrs after the progesterone injection. These findings indicate that estradiol and progesterone alter memory retention and suggest that these changes may be the result of hormone-induced increased in hippocampal connectivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
