Altered Expression of Cellular Markers in Molecular Brain Aging

The molecular aging of the human brain encompasses pervasive transcriptome changes associated with â normalâ brain aging that occur in local cortical circuits comprised of GABA neurons, pyramidal cells, and astrocytes. Cortical samples obtained from a novel postmortem human cohort were analyzed using RT-qPCR technology to assess changes in the expression of nine markers representative of neuropeptide signalling, synaptic function, calcium regulation, and glial activation within cortical cellular networks that occur in congruence with a pervasive molecular program mediating brain aging. Presynaptic interneuron markers displayed decreases in expression in aged subjects compared to young controls, whilst postsynaptic interneuron marker expression was increased, as was the expression of glial markers. Although changes in extrasynaptic glutamate marker expression were not significantly different, there was a nominal decrease in their expression in aged subjects. Altogether, these results replicate findings of pervasive molecular changes in the aged cortex, and suggest consequences for cortical network function.M.Sc