Regional and laminar differences in antigen profiles and spatial distributions of astrocytes in the XXXX hippocampus, with reference to aging.

@entity19 @entity14231 @entity2658 @entity9327
The heterogeneity of astrocytes is of growing interest, because this information is now considered to be crucial for understanding the diverse roles of astrocytes, for example, support and nutrition for neurons, and modulation of synaptic plasticity. In this study, we stereologically estimated the regional and laminar differences in antigen profiles and spatial distributions of astrocytes in the young adult (2-month-old) and middle-aged (10-month-old) @entity19 hippocampus. Here we used two established astrocyte markers, that is, @entity9327 ( @entity9327 ) and @entity2658 , to identify the astrocyte population. In addition, we examined the patterns of expression of @entity14231 ( @entity14231 ) in the hippocampus. The majority of astrocytes expressed @entity14231 , and few regional and laminar differences were observed in the expression ratios of @entity14231 in astrocytes. @entity9327 -negative astrocytes were specifically seen in the strata pyramidale and lucidum of the ventral CA3 region. @entity2658 -negative astrocytes were mainly found in the hilus of the dorsal and ventral dentate gyrus. Antigen profiles of astrocytes defined by @entity14231 , @entity9327 , and @entity2658 were rather constant until middle age. We then estimated the heterogeneity in spatial distributions of astrocytes. The numbers of astrocytes in the stratum lacunosum-molecular of the dorsal part of Ammon's horn were significantly larger in the middle-aged @entity19 than in young adult @entity19 . On the contrary, the astrocyte numbers in the stratum oriens of Ammon's horn showed significant age-dependent decline. Despite such changes, the total number of astrocytes in the whole area of the hippocampus showed no differences between young adult and middle-aged @entity19 . The present data may work as an essential anatomical reference to understand the heterogeneity of astrocytes in the hippocampus.
