Characterization of the picrotoxin site of GABAA receptors.

This unit describes an in vitro assay for characterization of the picrotoxin site of GABAA receptors in rat brain membranes using various radioligands. Methods and representative data for Scatchard analysis (Kd, Bmax determination), association kinetics, dissociation kinetics, and competition assays (IC50, Ki determination) are included.

The site specific demethylation in the 5'-regulatory area of NMDA receptor 2B subunit gene associated with CIE-induced up-regulation of transcription.

Background: The NMDA receptor represents a particularly important site of ethanol action in the CNS. We recently reported that NMDA receptor 2B (NR2B) gene expression was persistently up-regulated following chronic intermittent ethanol (CIE) treatment. Increasing evidence that epigenetic mechanisms are involved in dynamic and long-lasting regulation of gene expression in multiple neuroadaptive processes prompted us to investigate the role of DNA methylation in mediating CIE-induced up-regulation of NR2B gene transcription.

Characterization and pharmacology of the GHB receptor.

Radioligand binding using [(3)H]NCS-382, an antagonist of the GHB receptor, revealed specific binding sites in the rat cerebrocortical and hippocampal membranes. Scatchard analysis of saturation isotherms revealed two different populations of binding sites. NCS-382 was about 10 times more potent than GHB in inhibiting [(3)H]NCS-382 binding.

Effect of 5-azacytidine on the methylation aspects of NMDA receptor NR2B gene in the cultured cortical neurons of mice.

Our previous study revealed that the exposure of the drug 5-Azacytidine and ethanol to the cultured cortical neurons of mice causes demethylation of cytosine residues in the CpG island of the NMDA receptor NR2B gene (Marutha Ravindran and Ticku, Mol Brain Res 121:19-27, 2004). In the present study, we further analyzed methylation in the CpG island with various concentration frame and time frame of exposure of the cultured cortical neurons with 5-azacytidine to identify whether methylation in the NR2B gene is site specific or region specific. Methylation was studied by digesting the genomic DNA with methylation sensitive HpaII, MspI, AciI or HhaI enzyme following the exposure of cultured cortical neurons of mice with 5-azacytidine by performing PCR and Southern hybridization.

Emerging role of epigenetics in the actions of alcohol.

This review deals with the recent developments on the epigenetic effects of ethanol. A large body of data have come from studies in liver and in neuronal systems and involve post-translational modifications in histones and methylations in DNA. Ethanol causes site selective acetylation, methylation, and phosphorylation in histone.