Does Myelin Play the Leading Role in Alzheimer’s Disease Pathology?

Alzheimer’s disease (AD) is known for some well-characterized pathological changes including the extracellular accumulation of amyloid plaques, intra-neuronal presence of neurofibrillary tangles, glial hypertrophy and neuronal death [1-3]. Paradoxically, myelin pathology in human AD has not been widely studied, even though it has been more than a century since Alois Alzheimer described myelin disruption in AD in 1911 [4,5]. It is unclear why the phenomenon of myelin impairment has been forgotten for more than 100 years. Classical neuropathological changes in AD, such as amyloid plaque deposition and the presence of neurofibrillary tangles in the brain, are responsible for neuronal damage and synapse loss, but there is also emerging evidence that oligodendroglial degeneration and myelin impairment are present in the brains of AD patients [6-9].