Objective To study the expression of γ-aminobutyric acid transporter (OAT) mRNA in the brain tissues of rats with hepatic encephalopathy. Methods Twelve male Spragne-Dawley rats were randomized into hepatic encephaiopathy group (n=6) and control group (n=6).In the former group, hepatic encephalopathy was induced by intraperitoneal injection of thioacetamide (TAA, 350 mg/kg), and saline was administered intraperitoneally in the control group. In situ hybridization was used to detect GAT-1 mRNA expression in rat cerebral cortex, basal nuclei, substantia nigra and hippocampus. Results In rats with hepatic encephalopathy, GAT-1 mRNA expression levels were significantly decreased in the basal nuclei, substantia nigra compacta pars, substantia nigra reticularis pars, and hippocampus, but showed no obvious changes in the cerebral cortex. Conclusion The changes in GAT-1 mRNA expression might be involved in the pathogenesis of hepatic encephalopathy.