Figure 5.

Spontaneous alternation and social preference are not altered by global ischemia or chronic estradiol treatment in middle-aged female rats. (A) For spontaneous alternation, rats were placed on the Y-maze for 15 min and the sequence and number of arms entered were recorded. For each consecutive triplet entry, it was determined if the rat exhibited a spontaneous alternation pattern. Data are reported as percentage scores (± S.E.M.) that were computed by dividing the number of alternations made by each rat by the total number of triplets then multiplying that quotient by 100. Because no differences were found between pre-test and post-test scores for either sham-operated or ischemic groups, only post-test data are illustrated. (B) For social preference tests, rats were placed in the start arm of a Y-maze and were allowed to freely explore for 5 min. Enclosed at the end of one arm was a juvenile female rat while at the other end was a small clear bottle. The amount of time exploring either the juvenile animal or clear bottle was recorded (sec). For each animal, a preference score was defined as the time spent exploring the juvenile rat divided by the total time spent exploring the juvenile rat and the object. Data are reported as mean percentage ± S.E.M. Because no significant differences were found between pre- and post-test scores for either sham-operated or ischemic rats, only post-test data are illustrated.