Fig. 5.

Stereological estimates of the total number of BrdU-labeled cells (A) and pyknotic cells (B) in the dentate gyrus of sham ovariectomized, ovariectomized, and estrogen-replaced ovariectomized adult female rats. Ovariectomy produced a significant decrease in the numbers of BrdU-labeled cells in the dentate gyrus of adult female rats compared with both sham-operated controls (the majority of which were in proestrus at the time of BrdU injection) and estrogen-replaced, ovariectomized animals. Conversely, ovariectomy doubled the numbers of pyknotic cells in the dentate gyrus of adult female rats compared with both sham-operated controls and estrogen-replaced, ovariectomized animals. Bars represent mean + SEM each obtained from four or five animals. Asterisk indicates significant difference from other means (p < 0.05).