Regional differences in the expression of DNA topoisomerase IIbeta in the pyramidal neurons of the rat hippocampus.
A detailed analysis of the differential expression of a nuclear enzyme, DNA topoisomerase (topo) IIbeta, was performed in the rat hippocampal pyramidal layer. Three-dimensional (3-D) reconstruction from serial sections immunostained with anti-topo IIbeta antibody showed that the immunoreactivity was apparently weak in the entire CA3 region. Almost all CA1 pyramidal cells showed similar immunoreactivity to that seen in the dentate granular cells, the subicular neurons, and the cerebral neocortical neurons. In addition, immunoblotting analysis in the adult dorsal hippocampus showed that the expression level of topo IIbeta in the CA3 was significantly lower than that in the CA1 region. The dissociation in the expression level between CA1 and CA3 occurred in postnatal days 4 (P4) through P6. The present finding suggests that the enzyme is possibly involved in activities of the hippocampal pyramidal neurons.
Maeda
Y
Y
Third Department of Anatomy, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama, Japan.
Tsutsui
K
K
Tokunaga
A
A
D000818:Animals; D000831:Animals, Newborn; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004268:DNA-Binding Proteins; D006624:Hippocampus / Q000166:cytology / Q000201:enzymology*; D007150:Immunohistochemistry; D008297:Male; D017966:Pyramidal Cells / Q000166:cytology / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar
D004268:DNA-Binding Proteins; D004250:DNA Topoisomerases, Type II