Effects of transient forebrain ischemia on cognitive performance and cell death in the Cornet d'Ammon 1 (CA1) region of the hippocampus in juvenile (2-month-old) and adult (6-month-old) Mongolian gerbils (Meriones unguiculatus).

Working memory tests were performed on days 8-18 after 5-min cerebral ischemia in juvenile (2-month-old) and adult (6-month-old) gerbils, followed by observation of cell death in the hippocampus on postoperative day 19. Both 2- and 6-month-old ischemic gerbils made significantly more working memory errors than age-matched sham-operated ones. After repeated trials, the number of working memory errors in 2-month-old ischemic gerbils reached the level of sham-operated ones earlier than in 6-month-old gerbils. However, no significant differences were seen in the number of hippocampal cell deaths between 2- and 6-month-old ischemic gerbils. This study revealed that juvenile gerbils recovered from cognitive impairment more quickly than adults, although no difference in hippocampal damage was evident after transient forebrain ischemia.