The entorhinal cortex (EC) is especially vulnerable in the early stages of Alzheimer’s disease (AD). In particular, cognitive deficits have been linked to alterations in the upper layers of EC. In the present report, we performed light microscopy analysis and 3D ultrastructural analyses of synapses in the EC using Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM) to examine possible alterations related to AD. We analyzed 5000 synaptic junctions that were 3D reconstructed, representing the largest 3D ultrastructural study of synapses in the EC of the human brain from cases with AD performed to date. Structural differences were found in the AD tissue at the light microscope level and at the ultrastructural level. These differences may play a role in the anatomical basis for the impairment of cognitive functions in AD.
bioRxiv Subject Collection: Neuroscience