Hippocampal CA1 apical neuropil atrophy and memory performance in Alzheimer's disease

► 7 T microstructural MRI reveals hippocampal subfields and stratal layers in vivo. ► CA1 apical neuropil atrophy correlated with memory deficits in Alzheimer's disease. ► This correlation was stronger in the left hemisphere. ► Entorhinal cortex and CA1 stratum pyramidale thicknesses also correlated with memory. ► CA1 apical neuropil atrophy may be useful as a biomarker to track memory loss in AD.