Synaptic density in the hippocampal and parahippocampal subregions and its association with the severity of axonal damage and cognitive decline in Alzheimer’s disease

The entorhinal cortex is vulnerable to synapse degeneration in AD. Moreover, our results confirm the strong relation between (para)hippocampal synaptic loss, axonal damage and cognitive decline in AD, while neuropathological load (Aβ and p-tau) could not explain differences in vulnerability across donors. These results suggest that the synaptic integrity in these regions seem to be important for cognitive function. A better understanding of the selective vulnerability of hippocampal subregions would provide insight into their intricate connections and functions, underpunning their involvement in cognitive decline.