Effects of chronic ethanol administration on brain protein levels: a proteomic investigation using 2-D DIGE system.

The effects of chronic ethanol treatment on the brain proteome were investigated in the long-fin striped strain of zebrafish Danio rerio. Prolonged exposure to 0.5% (v/v) ethanol resulted in the development of tolerance to the ethanol-induced disruption of normal swimming behavior. This behavioral tolerance was manifested after two weeks of continuous treatment and was maintained for an additional three weeks. After four weeks of ethanol treatment, zebrafish brains were divided into 40,000 g supernatant and pellet fractions, and an Ettan 2-D fluorescence difference gel electrophoresis (DIGE) system was used to detect ethanol-induced alterations in the level of protein expression. Protein identification was carried out using matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and the Mascot and ProFound search engines. In the present study, we have identified some novel protein targets as well as substantiated some putative previous targets of chronic ethanol exposure.