|Budget Amount *help
¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1992 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1991 : ¥1,100,000 (Direct Cost : ¥1,100,000)
In order to understand the mechanisms of synaptic responses of neuronal cells at the level of gene expression, we carried out a gel-shift assay to examine the changes in DNA-binding activities of specific transcriptional factors, which could be occurred with the cerebellar granule cells stimulated via glutamate receptors in primary culture. In this study, we found that exogenous NMDA (N-methyl-D-aspartate) or kainate increased both TRE (TPA responsive element)- and CRE (cAMP responsive element)-binding activities specifically through NMDA or non-NMDA receptors. These increases of both TRE- and CRE-binding activities were mediated by common DNA-binding activities including c-Fos proteins. The activation of protein kinase C caused by the influxes of Ca^<2+> into the cells could be involved in the increases of TRE-binding activities. We have developed a method for preparing nuclear mini-extracts from small brain tissues (approximately 1 mg), and found that intraperitoneal administration of NMDA or kainate to mice caused the increase of TRE-binding activities in the CA1, CA3 and dentate gyrus of the hippocampus.
Direct gene transfer of E. coli beta-galactosidase gene into mouse muscle myofibers revealed a regionally restricted distribution of introduced gene products with a single nucleus in mouse myofibers, suggesting a possible cytoplasmic compartment centered by a nucleus in myofiber where gene products could distribute near the corresponding nucleus.