| pubmed-article:7700956 | pubmed:abstractText | The effect of aging on three different parameters possibly relevant for cognition was investigated in female Naval Medical Research Institute mice: a) N-methyl-D-aspartate (NMDA) receptor density, as determined by the specific binding of [3H]MK-801 to forebrain membranes, decreased by 22% in aged (23 mo) and by 19% in middle-aged (12 mo) animals compared with young (3 mo) animals. b) In a passive avoidance acquisition task, the 24-h latency decreased significantly with age; the middle-aged mice also tended to show impairment in this task. c) The fluidity of the forebrain membranes also decreased significantly with age. Again, there was a significant reduction in the middle-aged group. A comparison of these parameters revealed significant correlations between NMDA receptor density and 24-h latency (r = 0.52, p < 0.003) over all three age groups, as well as significant correlations between membrane fluidity and either NMDA receptor density or 24-h latency. These findings do not prove a causal relationship, but are compatible with the hypothesis that changes of membrane fluidity, by decreasing the number of NMDA receptors, affect passive avoidance performance. | lld:pubmed |
