[en] Several microdialysis studies have investigated the effects of acute ethanol on extracellular amino acids in various rat brain regions, However, these studies led to conflicting results, suggesting that individual differences between rat strains and lines may play an important role. In the present study, high-alcohol sensitive (HAS) and low-alcohol sensitive (LAS) rats were used to investigate the possible relationship between ethanol sensitivity and the concentrations of extracellular amino acids in the nucleus accumbens. Several groups of HAS and LAS rats were injected with either saline or ethanol (1.0, 2.0 or 3.0 g/kg, i.p.) and the concentrations of amino acids in the nucleus accumbens microdialysates were assayed by electrochemical detection. Acute ethanol induced a dose-dependent increase in extracellular taurine concentrations. However, this increase was significantly reduced at 2,0 and 3.0 g,,kg ethanol in HAS rats relative to LAS rats. Since the biological functions of taurine suggest its implication in the reduction of ethanol adverse effects, a higher increase in taurine concentrations may contribute to the lower ethanol sensitivity of LAS rats. Although 2.0 and 3.0 g/kg ethanol did not affect extracellular glutamate concentrations, a significant increase in glutamate was observed after 1.0 g/kg ethanol to HAS rats but not to LAS rats. Such an effect remains unexplained but suggests that discrepancies between the results of previous microdialysate studies may be related to differences in the ethanol sensitivities of various rat strains. (C) 2002 Elsevier Science B.V All rights reserved.
Research center :
Centre de Neurosciences Cognitives et Comportementales - ULiège
Aragon C.M.G., Amit Z. (1993) Taurine and ethanol-induced conditioned taste aversion. Pharmacol. Biochem. Behav. 44:263-266.
Aragon C.M.G., Trudeau L.E., Amit Z. (1992) Effect of taurine on ethanol-induced changes in open-field locomotor activity. Psychopharmacology 107:337-340.
Billard J.M. (1990) Taurine in deep cerebellar nuclei of the rat. In vivo comparison to GABA inhibitory effect. Brain Res. 514:155-158.
Boggan W.O., Medberry C., Hopkins D.H. (1978) Effects of taurine on some pharmacological properties of ethanol. Pharmacol. Biochem. Behav. 9:469-472.
Bureau M.H., Olsen R.W. (1991) Taurine acts on a subclass of GABAa receptors in mammalian brain in vitro. Eur. J. Pharmacol. 207:9-16.
Colombo G., Agabio R., Carai M.A., Lobina C., Pani M., Reali R., Vacca G., Gessa G.L. (2000) Different sensitivity to ethanol in alcohol-preferring sP and -nonpreferring sNP rats. Alcohol., Clin. Exp. Res. 24:1603-1608.
Dahchour A., De Witte P. (2000) Ethanol and amino acids in the central nervous system: Assessment of the pharmacological actions of acamprosate. Prog. Neurobiol. 60:343-362.
Dahchour A., Quertemont E., De Witte P. (1994) Acute ethanol increases taurine but neither glutamate nor GABA in the nucleus accumbens of male rats: A microdialysis study. Alcohol Alcohol. 29:485-487.
Dahchour A., Quertemont E., De Witte P. (1996) Taurine increases in the nucleus accumbens microdialysate after acute ethanol administration to naive and chronically alcoholised rats. Brain Res. 30:9-19.
Dahchour A., Hoffman A., Deitrich R., De Witte P. (2000) Effects of ethanol on extracellular amino acid levels in high- and low-alcohol sensitive rats: A microdialysis study. Alcohol Alcohol. 35:548-553.
Deitrich R.A., Erwin V.G. Pharmacological Effects of Ethanol on the Nervous System, New York: CRC Press; 1996.
Deitrich R.A., Draski L.J., Baker R.C. (1994) Effect of pentobarbital and gaseous anesthetics on rats selectively bred for ethanol sensitivity. Pharmacol. Biochem. Behav. 47:721-725.
Draski L.J., Spuhler K.P., Erwin V.G., Baker R.C., Deitrich R.A. (1992) Selective breeding of rats differing in sensitivity to the effects of acute ethanol administration. Alcohol., Clin. Exp. Res. 16:48-54.
El Idrissi A., Trenkner E. (1999) Growth factors and taurine protect against excitotoxicity by stabilizing calcium homeostasis and energy metabolism. J. Neurosci. 19:9459-9468.
Ferko A.P. (1987) Ethanol-induced sleep time: Interaction with taurine and a taurine antagonist. Pharmacol. Biochem. Behav. 27:235-238.
Grobin A.C., Matthews D.B., Devaud L.L., Morrow A.L. (1998) The role of GABAA receptors in the acute and chronic effects of ethanol. Psychopharmacology 139:2-19.
Hansen C., Spuhler K. (1984) Development of the National Institutes of Health genetically heterogeneous rat stock. Alcohol., Clin. Exp. Res. 8:477-479.
Huxtable R.J. (1989) Taurine in the central nervous system and the mammalian actions of taurine. Prog. Neurobiol. 32:471-533.
Malminen O., Kontro P. (1987) Actions of taurine on the GABA-benzodiazepine receptor complex solubilized from rat brain. Neurochem. Int. 11:113-117.
McBroom M.J., Elkhawad A.O., Dlouha H. (1986) Taurine and ethanol-induced sleeping time in mice: Route and time course effects. Gen. Pharmacol. 17:97-100.
Moghaddam B., Bolinao M.L. (1994) Biphasic effect of ethanol on extracellular accumulation of glutamate in the hippocampus and the nucleus accumbens. Neurosci. Lett. 178:99-102.
Paxinos G., Watson C. The Rat Brain in Stereotaxic Coordinates, New York: Academic Press; 1982.
Quertemont E., De Neuville J., De Witte P. (1998) Changes in the amygdala amino acid microdialysate after conditioning with a cue associated with ethanol. Psychopharmacology 139:71-78.
Quertemont E., Goffaux V., Vlaminck A.M., Wolf C., De Witte P. (1998) Oral taurine supplementation modulates ethanol-conditioned stimulus preference. Alcohol 16:201-206.
Quertemont E., Dahchour A., Ward R.J., De Witte P. (1999) Ethanol induces taurine release in the amygdala: An in vivo microdialysis study. Addict. Biol. 4:47-54.
Quertemont E., Lallemand F., Colombo G., De Witte P. (2000) Taurine and ethanol preference: A microdialysis study using Sardinian alcohol-preferring and non-preferring rats. Eur. Neuropsychopharmacol. 10:377-383.
Quertemont E., Devitgh A., De Witte P. (2001) Ethanol-induced brain extracellular taurine release: An osmoregulatory mechanism?. Alcohol Alcohol. 36:476.
Robinson T.E., Whishaw I.Q. (1988) Normalization of extracellular dopamine in striatum following recovery from a partial unilateral 6-OHDA lesion of the substantia nigra: A microdialysis study in freely moving rats. Brain Res. 450:209-224.
Rozza A., Masoero E., Favalli L., Lanza E., Govoni S., Rizzo V., Montalbetti L. (2000) Influence of different anaesthetics on extracellular amino acids in rat brain. J. Neurosci. Methods 101:165-169.
Selim M., Bradberry C.W. (1996) Effect of ethanol on extracellular 5-HT and glutamate in the nucleus accumbens and prefrontal cortex: Comparison between the Lewis and Fisher 344 rat strains. Brain Res. 716:157-164.
Shimizu K., Matsubara K., Uezono T., Kimura K., Shiono H. (1998) Reduced dorsal hippocampal glutamate release significantly correlates with the spatial memory deficits produced by benzodiazepines and ethanol. Neuroscience 83:701-706.
Solis J.M., Herranz A.S., Herreras O., Lerma J., Martin del Rio R. (1988) Does taurine act as an osmoregulatory substance in the rat brain?. Neurosci. Lett. 15:53-58.
Wang D.S., Xu T.L., Pang Z.P., Li J.S., Akaike N. (1998) Taurine-activated chloride currents in the rat sacral dorsal commissural neurons. Brain Res. 792:41-47.
Woodward J.J. (2000) Ethanol and the NMDA receptor signaling. Crit. Rev. Neurobiol. 14:69-89.
Yan Q.S., Reith M.E., Yan S.G., Jobe P.C. (1998) Effect of systemic ethanol on basal and stimulated glutamate releases in the nucleus accumbens of freely moving Sprague-Dawley rats: A microdialysis study. Neurosci. Lett. 258:29-32.