Nb. Chauhan et Gj. Siegel, IN-SITU ANALYSIS OF NA,K-ATPASE ALPHA-1-ISOFORM AND ALPHA-3-ISOFORM MESSENGER-RNAS IN AGING RAT HIPPOCAMPUS, Journal of neurochemistry, 66(4), 1996, pp. 1742-1751
Age-related changes in the expression of Na,K-ATPase alpha 1- and alph
a 3-isoform mRNAs were analyzed by in situ hybridization in the Fische
r-344 rat hippocampus. Quantification of signal density with cRNA prob
es in rat hippocampus at 3 months of age showed (a) alpha 1 content is
1.5 times higher in granule than in pyramidal cell layers, whereas al
pha 3 content shows the opposite ratio and (b) alpha 3 label is found
in large clusters related to messy cells and basket cells and in mediu
m clusters corresponding to interneurons within the dendritic fields o
f CA1-3. In the 24-month-old rats as compared with the young animals,
the alpha 1 signal is increased more than sevenfold in the dendritic f
ields and is not significantly changed in perikaryal layers, The alpha
3 signal is reduced about threefold (p < 0.0001, ANOVA, n = 6) in per
ikaryal layers, is almost completely absent over the interneurons, bas
ket cells, and messy cells, and is not significantly changed in dendri
tic fields, These data indicate age-related, cell- and isoform-specifi
c alterations in pretranslational regulation of Na,K-ATPase alpha isof
orms, The striking changes in the dendritic fields, messy cells, and G
ABAergic basket cells and interneurons may constitute early and sensit
ive markers for age-related alterations in hippocampal function, befor
e cell loss.