Interactions between taurine and ethanol in the central nervous system

This purpose of this review will be to summarize the interactions between the endogenous amino acid taurine and ethyl alcohol (ethanol) in the central nervous system (CNS). Taurine is one of the most abundant amino acids in the CNS and plays an integral role in physiological processes such as osmoregulation, neuroprotection and neuromodulation. Both taurine and ethanol exert positive allosteric modulatory effects on neuronal ligand-gated chloride channels (i.e., GABA_A and glycine receptors) as well as inhibitory effects on other ligand- and voltage-gated cation channels (i.e., NMDA and Ca²⁺ channels). Behavioral evidence suggests that taurine can alter the locomotor stimulatory, sedating, and motivational effects of ethanol in a strongly dose-dependent manner. Microdialysis studies have revealed that ethanol elevates extracellular levels of taurine in numerous brain regions, although the functional consequences of this phenomenon are currently unknown. Finally, taurine and several related molecules including the homotaurine derivative acamprosate (calcium acetylhomotaurinate) can reduce ethanol self-administration and relapse to drinking in both animals and humans. Taken together, these data suggest that the endogenous taurine system may be an important modulator of effects of ethanol on the nervous system, and may represent a novel therapeutic avenue for the development of medications to treat alcohol abuse and alcoholism.