| 摘要: | The γ-aminobutyric acidA (GABAA)/benzodiazepine (BZ) receptor is a pentamer composed of subunits belonging to several classes (α1–6, β1–4, γ1–4, δ, and ρ1 and ρ2). In situ hybridization, radioligand autoradiography, and immunocytochemistry were used to examine GABAA/BZ receptor α1, α6, β2, β3, and γ2 subunit expression in murine Purkinje, granule, and deep cerebellar neurons after in vivo ethanol exposure. Chronic ethanol treatment resulted in decreased α1 subunit mRNA expression in each cell type, whereas the expression of α6 and γ2 subunit mRNA levels increased; no changes were observed in the expression of β2 and β3 subunit mRNA. GABA and BZ agonist binding and antibody staining paralleled the changes in mRNA levels. Acute ethanol injection resulted in increased expression of α1 and β3 mRNAs, whereas levels of α6, β2, and γ2 mRNAs remained stable. Our results indicate that, in cerebellar neurons, the expression of specific GABAA/BZ receptor subunit mRNAs, polypeptides, and binding sites is independently regulated by in vivo administration of alcohol. The observed changes were not restricted to any one cerebellar cell type, because subunit expression in Purkinje, granule, and deep cerebellar cells was similarly affected. |
