Neurogenesis occurs in the adult and the aged dentate gyrus (DG), and about 50% of newly generated neurons survive for prolonged periods in the adult DG suggesting that newly formed neurons play roles in learning and memory. Kainic acid (KA) induced hippocampal CA3-lesion, increases DG neurogenesis in the young hippocampus, and maintains DG neurogenesis to the level of age-matched intact hippocampus in the middle-aged and the aged hippocampus (Rao et al., SFN abstracts, 2003). However, it is unknown whether newly generated neurons in the DG of lesioned adult and aged hippocampus are capable of enduring survival. We quantified the long-term survival of new neurons in the DG of adult (4-months-old), middle-aged (12-months-old) and aged (24-months-old) F344 rats generated at early post-KA lesion. Newly generated neurons were labeled using daily injections of 5’-bromodeoxyuridine (BrdU; 100 mg/Kg bw) from 4-15 days post-lesion. At 6-months post-lesion, the survival of DG neurons generated during 4-15 days post...