OBJECTIVES: The abnormal accumulation of tau protein is increasingly recognized as the neuropathological hallmark of a number of @entity221 in which @entity747 occurs. In this paper we examined the age-dependant deposition of tau protein in the frontal and entorhinal neocortices. METHODS: We examined autopsy records from 1997 to 2002 and selected 87 cases (10 in each decade from 0 to 79 years of age, 7 in 80-89 decade) with no history of @entity303 or other @entity179 , and for which @entity179 were excluded neuropathologically. Archival paraffin-embedded frontal and entorhinal cortices were examined by both Gallyas-Braak @entity575 staining and a panel of antibodies recognizing tau protein accumulation. RESULTS: Tau neuronal aggregates were observed in both frontal and entorhinal cortices in the third decade. While the frontal neuronal tau aggregates remained infrequent in the remaining decades, the number and extent ofneuronal tau aggregates in the entorhinal cortex increased such that by the 7th decade the majority of cases showed extensive tau aggregate formation. The most consistent morphological observation was of dense, perikaryal neuronal tau-immunoreactive aggregates, similar to the total tau distribution, firstly presenting in @entity655 and III and subsequently involving in layers IV-VI. Neuropil threads became maximal in the 9th decade in both frontal and entorhinal cortices. Astrocytic tau accumulation was first observed in both frontal and entorhinal cortices in the 6th decade, predominantly in @entity62 , and increased in number with aging. Extraneuronal tau reactive aggregates and coiled bodies were rarely observed in the entorhinal cortex, and when present, were scattered through layer II to VI. CONCLUSIONS: We have observed an age-dependant pattern of neuronal, extraneuronal and @entity66 in the entorhinal cortex in individuals without @entity179 . In contrast, tau @entity6960 is infrequently observed in the frontal cortex as a function of aging.

Tau XXXX in the frontal and entorhinal cortices as a function of aging.

@entity66 :: ('MESH:D004194', 'Disease') :: ['glial tau protein accumulation'] @entity575 :: ('MESH:D012834', 'Chemical') :: ['silver'] @entity303 :: ('MESH:D003704', 'Disease') :: ['dementia'] @entity747 :: ('MESH:D057174', 'Disease') :: ['frontotemporal lobar degeneration'] @entity179 :: ('MESH:D019636', 'Disease') :: ['neurodegenerative diseases'] @entity6960 :: ('MESH:D001796', 'Disease') :: ['protein aggregation'] @entity655 :: ('MESH:C535504', 'Disease') :: ['cortical layers II'] @entity62 :: ('MESH:D056784', 'Disease') :: ['layer I and subcortical white matter'] @entity221 :: ('MESH:D005334', 'Disease') :: ['dementing illness']
@entity6960 :: (MESH:D001796,Disease) :: ['protein aggregation']
