Cytoskeletal alterations in the aged human neurohypophysis

The hypophyses of 24 individuals, aged 79-89 years (mean age 83.5+/-3.3 years), were investigated for cytoskeletal changes associated with abnormally phosphorylated tau protein using the monoclonal antibodies AT8, PHF-1 and Alz-50. A previously unreported pattern of cytoskeletal changes was identified in the neurohypophysis consisting of axon-like fibers and large swellings resembling Herring bodies. The density of the cytoskeletal lesions was subject to notable variation among individuals. Marked neurohypophyseal alterations were also noted in cases even devoid of Alzheimer's disease-related cytoskeletal pathology in neocortical areas. Fully developed Alzheimer's disease is thus not a prerequisite for the presence of advanced neurohypophyseal alterations. In conclusion, the aged human neurohypophysis is revealed as a potential focus of abnormal cytoskeletal changes which may impair the neuroendocrine function of the hypothalamo-neurohypophyseal system.