Hippocampal volume is preserved and fails to predict recognition memory impairment in aged rhesus monkeys (Macaca mulatta).

Aged monkeys exhibit deficits in memory mediated by the medial temporal lobe system, similar to the effects of normal aging in humans. The contribution of structural deterioration to age-associated memory loss was explored using magnetic resonance imaging techniques. We quantified hippocampal, cerebral and ventricular volumes in young (n = 6, 9-12 years) and aged (n = 6, 24-29 years) rhesus monkeys.