Selective Sparing of Human Nucleus Accumbens in Aging and Anoxia

OBJECTIVE: To investigate the effects of aging and anoxia on the nucleus accumbens. METHODS: The number of neurons in nucleus accumbens and caudate nucleus in 35 patients over 65 and 35 under 65 years, all without neurological or psychiatric disease were counted. RESULTS: There was no statistically significant difference between the number of neurons in the accumbens in the two groups, but there was a decrease in the number of neurons in the elderly group. There was no reduction in volume of the neuronal nucleoli of the accumbens measured in 12 elderly patients compared to controls. These data suggest a sparing of the accumbens from changes associated with aging. There was relative preservation of the nucleus accumbens in 3 patients with anoxic encephalopathy. CONCLUSIONS: These results show that accumbens was resistant to both aging and anoxia, the mechanism of which is discussed.