Temporal Cortex Synaptophysin mRNA Is Reduced in Alzheimer's Disease and Is Negatively Correlated with the Severity of Dementia

We measured synaptophysin mRNA in neocortical tissue from 7 prospectively assessed, pathologically verified normal individuals, 17 subjects with Alzheimer's disease (AD), and 13 subjects with a non-AD dementia. In temporal cortex (Brodmann area 21), synaptophysin mRNA was decreased in AD and non-AD dementia groups compared to controls. The loss was also present relative to polyadenylated mRNA content. Synaptophysin mRNA signal correlated negatively with the degree of dementia and negatively with the pathological severity of AD. In occipital cortex (Brodmann area 17) there were no differences between groups nor clinicopathological correlations. These data extend the evidence for a regional synaptic pathology in AD which affects synaptic protein gene expression by temporal cortex neurons.