The effect of aging on synaptosomal Ca2+ transport in the brain.

The effect of aging on Ca2+ -transport in synaptosomal preparations from rat brains was assessed by measuring the accumulation of radioactive 45Ca within these particles. Four groups of rats at 6, 12 24 and 30 months of age were used for this study. Synaptosomal particles were isolated from the cerebral cortex of each animal and the radioactive 45Ca inside the particles were measured after incubating the particles with media containing an energy source and 45Ca Cl2. Results indicated that the transport of 45Ca was lower in the younger rats than the older groups. A 20% increase was consistent with the old rats (30 mo) as compared with the young ones (6 mo). The increase in Ca2+ -transport across synaptic plasma membranes may be related to the transmitter release and behavioral activity after senescence.