Taurine restores the exploratory behavior following alcohol withdrawal and decreases BDNF mRNA expression in the frontal cortex of chronic alcohol-treated rats

Highlights

• Alcohol withdrawal decreases rearing in rats and taurine treatment reestablishes it.

• Taurine presents an anxiolytic-like effect in control rats.

• Taurine does not affect behaviors in chronically alcohol treated rats.

• Chronic alcohol or withdrawal does not change GABA_AR α2 mRNA in the frontal cortex of rats.

• Alcohol withdrawal does not change BDNF mRNA in the frontal cortex of rats.

Abstract

Alcohol use disorder is an alarming health problem, and the withdrawal symptoms increase the risk of relapse. We have hypothesized that taurine, a multitarget substance acting as a gamma-aminobutyric acid A receptor (GABA_AR) positive modulator and a partial inhibitor of N-methyl-d-aspartate (NMDA) glutamate receptors, may reduce the withdrawal symptoms or modify behaviors when combined with alcohol. Therefore, we investigated the effects of taurine on behavior in the open field test (OFT), the GABA_AR α₂ subunit and BDNF mRNA expression in the frontal cortex of rats after chronic alcohol treatment or upon withdrawal. Rats received alcohol 2 g/kg (alcohol and withdrawal groups) or water (control group) twice daily by oral gavage for 28 days. On day 29, the withdrawal rats received water instead of alcohol, and all groups were reallocated to receive 100 mg/kg taurine or vehicle intraperitoneally, once a day for 5 days. On day 33, the rats were exposed to OFT; 18 h later, they were euthanized, and the frontal cortex was dissected for GABA_AR α₂ subunit detection and BDNF mRNA expression determination by real-time quantitative PCR. Taurine administration restored rearing behavior to the control levels in the withdrawal rats. Taurine also showed anxiolytic-like effects in control rats and did not change the behaviors in the chronic alcohol group. Chronic alcohol treatment or withdrawal did not change the GABA_AR α₂ subunit or BDNF mRNA expression in the frontal cortex, but taurine decreased the α₂ subunit level in control rats and to the BDNF levels in the alcohol rat group. We conclude that taurine restored exploratory behavior after alcohol withdrawal but that this effect was not related to the GABA_AR α₂ subunit or BDNF mRNA expression in the frontal cortex of the rats.