[Pathogenesis and prevention of Alzheimer's disease: when and in what way does the pathological process begin?].

Abnormal tau lesions (e.g., pretangles, neuropil threads, and neurofibrillary tangles) that develop in a few types of nerve cells in the central nervous system are essential to the pathogenesis of Alzheimer's disease. Pretangles begin to occur in puberty and even during early childhood in the locus coeruleus. Evolutionally speaking, the propensity to develop tau lesions may be related to late developing and maturing nerve cell types in the human brain.