Abstract
Middle-aged (18 month old) and old (24 month old) mice showed poorer retention of footshock active avoidance training (FAAT) than young mice (2 month old). Immediate post-training subcutaneous injection of dehydroepiandrosterone sulfate (DHEAS) improved retention of FAAT in middle-aged and old mice to the high levels observed in young mice. DHEAS, a major naturally occurring adrenal steroid that decreases in blood serum with age, could be rate-limiting in achievement of retention of learning.
