[Synaptic plasticity and the glio-synaptic relationships of the rat hippocampus in age-related memory dysfunction]

Qualitative and quantitative studies of structural changes of synaptic contacts and processes were performed in aged memory-non-impaired an aged memory-impaired rats compared to young rats in the stratum lucidum of the hippocampus. Aged memory-impaired rats (compared with young adults) showed alteration in the ultrastructure of mossy fiber expansions and the loss of axospinous synapses formed by them. These changes were more pronounced than in memory-non-impaired rats. There were no significant differences between aged memory impaired and aged memory non-impaired rats except for a significant decrease in volume density of postsynaptic density in axodendritic synapses formed by mossy fiber expansions in memory impaired animals.