Septal hypertrophy and cell cycle re-entry in AD

Using MRI, we recently demonstrated enlargement of basal forebrain septal nuclei in healthy, cognitively-intact subjects destined to develop Alzheimer’s Disease (AD) in an average of approximately three years [1]. Others have shown enlargement/thickening of medial temporal lobe gray matter structures including the hippocampi in subjects with AD pathology but without cognitive impairment [2]. Septal nuclei and hippocampi are structurally and functionally closely connected via the fimbria/fornix and together are critical for memory performance. Enlargement of these structures in association with risk of AD is counterintuitive, as AD is a neurodegenerative disease associated with loss of gray matter volume