[Changes in the distribution of negatively charged sites of the synaptosomal membrane in adult rats].

Changes in the distribution of Anionic sites on the synaptosomal membrane of old rats were investigated by means of cationized ferritin. Synaptosomal fraction was isolated from the cerebral cortex of two groups of rats: a control group-rats aged 2 months and second group-rats aged 14 months. Some diminishing of density was established on anionic sites as well grouping in larger or smaller aggregates of the same sites on the membrane of some synaptosomes of old rats.