Induction of the neuronal major histocompatibility complex class I and paired immunoglobulin-like receptor B pathway in the hippocampus with aging and cognitive decline

The aim of this study was to identify alterations in hippocampal synaptic mRNA expression with aging and cognitive decline. Transcriptional profiling and subsequent bioinformatic analysis was performed to identify the most highly regulated pathways of genes. Interestingly, the antigen processing and presentation pathway was identified as the most highly regulated pathway with aging. Adult (12 month) and aged (28 month) Fischer 344 x Brown Norway (F1) hybrid rats were assessed for cognitive performance using the Morris water maze task and were divided into Adult (n=5), Aged Cognitively Intact (n=8), and Aged Cognitively Impaired (n=7) groups. One week following testing, all animals were sacrificed, the hippocampi were dissected, and synaptosomes were isolated for subsequent transcriptomic profiling. Only 5 cognitively intact animals were processed on the arrays.