Comparison of gene expression profiles in drug-withdrawn rats

The aim of the present study was to compare gene expression profiles in animals treated with abusable drugs. Wistar rats were treated with saline, morphine, chloral hydrate, or pentobarbital twice daily for 14 days. To induce neurotoxicity, a group of rats was treated with kainic acid. 24 hr after withdrawal, and a genome-wide DNA microarray analysis was conducted with the striata. A total of 57 gene expression patterns were altered in the three test groups; 35 of the 157 genes were selected when compared with the kainic acid treated group. Twenty-two of the 24 genes were functionally described in the gene library, and many were involved in long-term potentiation (LTP) and cell adhesion. The results were confirmed by quantitative reverse transcription-polymerase chain reaction analysis. Taken together, the selected genes may subserve identification of physical dependence biomarkers and contribute to determining the molecular mechanisms underlying physical dependence.