Changes in Pro-Inflammatory Markers in Detoxifying Chronic Alcohol Abusers, Divided by Lesch Typology, Reflect Cognitive Dysfunction.

AIM: To investigate pro-inflammatory markers in the blood and associate with cognitive impairment. METHODS: Il-6 and ferritin were assayed in the blood of 27 patients, divided according to Lesch typology, at the commencement and after 21 days of detoxification, together with a battery of cognitive tests. RESULTS: A significantly higher mean level of IL-6 was present in the blood of patients with Lesch typology 1 compared to the other typologies 2 and 3 on admission to the Detoxification Ward which did not alter significantly after detoxification. The mean level of IL-6 was initially elevated in Lesch typology 2 alcohol abusers and declined to the reference range after detoxification. Lesch typology 3 alcohol abusers showed normal levels of IL-6 at both time points. Only in Lesch typology 1 were the levels of ferritin and IL-10 significantly elevated at the start of the detoxification process. Cognitive impairment, as ascertained by Stroop test and Brown-Peterson procedure was greater in Lesch typology 1 than the other 2 patient groups. CONCLUSION: Such data might indicate a greater degree of neuroinflammation in Lesch typology 1 alcoholic patients. SHORT SUMMARY: Dividing a heterogeneous group of alcoholic subjects into homogenous groups according to Lesch typology, identifies a greater pro-inflammatory profile in Lesch typology 1 patients who also showed greater cognitive impairment.

Influence of adolescent heavy session drinking on the systemic and brain innate immune system.

AIMS: The aim of the study was to evaluate rat models of intermittent alcohol abuse (heavy session/'heavy session' drinking) in relation to inflammatory changes in specific brain regions as well as in the periphery. Furthermore, the study was aimed to assess whether there are inflammatory changes in the blood of human intermittent alcohol abusers who might be associated with changes in neuronal circuitry in the brain, as assessed by functional magnetic resonance imaging (fMRI), which cause adverse effects on memory and learning. METHODS: Various regimes of intermittent alcohol administration have been used in rat models, which vary with respect to the dose and duration of ethanol administration as well as the time of abstinence. Immunohistological methods were used to identify activated microglia in specific brain regions. The response of isolated alveolar macrophages to in vitro stimuli was assessed by the assay of nitric oxide and the pro-inflammatory cytokines IL-6 and TNFα. Blood samples were collected from university students who had been heavy session drinkers for 2 years to assess whether there was an inflammatory cytokine profile that correlated with cognitive test scores as well as fMRI findings. RESULTS: The extent of microglia activation appears to depend on the doses and duration of ethanol administration. In addition, there is activation of phagocytic cells in the periphery, e.g. alveolar macrophages, in the rat models of heavy session drinking. Changes in the plasma levels of pro- and anti-inflammatory cytokines were present in heavy session drinking students, although no changes were identified in specific cognitive tests (which may be because of compensatory changes in the prefrontal cortex, as identified by fMRI). CONCLUSION: Changes in the cytokine levels induced by intermittent ethanol abuse may provoke inflammatory pathways in specific brain regions, such as hippocampus and prefrontal cortex (particularly during the stage of active neurogenesis in the adolescent brain), which might induce cognitive impairment in susceptible individuals.

Increased cortical activity in binge drinkers during working memory task: a preliminary assessment through a functional magnetic resonance imaging study.

BACKGROUND: Cerebral dysfunction is a common feature of both chronic alcohol abusers and binge drinkers. Here, we aimed to study whether, at equated behavioral performance levels, binge drinkers exhibited increased neural activity while performing simple cognitive tasks. METHODS: Thirty-two participants (16 binge drinkers and 16 matched controls) were scanned using functional magnetic resonance imaging (fMRI) while performing an n-back working memory task. In the control zero-back (N0) condition, subjects were required to press a button with the right hand when the number "2" was displayed. In the two-back (N2) condition, subjects had to press a button when the displayed number was identical to the number shown two trials before. RESULTS: fMRI analyses revealed higher bilateral activity in the pre-supplementary motor area in binge drinkers than matched controls, even though behavioral performances were similar. Moreover, binge drinkers showed specific positive correlations between the number of alcohol doses consumed per occasion and higher activity in the dorsomedial prefrontal cortex, as well as between the number of drinking occasions per week and higher activity in cerebellum, thalamus and insula while performing the N2 memory task. CONCLUSIONS: Binge alcohol consumption leads to possible compensatory cerebral changes in binge drinkers that facilitate normal behavioral performance. These changes in cerebral responses may be considered as vulnerability factors for developing adult substance use disorders.

Binge drinking +/- chronic nicotine administration alters extracellular glutamate and arginine levels in the nucleus accumbens of adult male and female Wistar rats.

AIMS: The effect of 'binge drinking' coupled or not with chronic nicotine administration on nucleus accumbens (NAc) glutamate, arginine, taurine and hydroxyl radical levels has been investigated in these present studies. METHODS AND RESULTS: Ethanol, 2 or 3 g/kg, has been administered to male or female adult rats in a 'binge-type' regime for 3 weeks, +/- nicotine, and changes in glutamate, arginine and taurine content in the NAc, assayed by microdialysis after a further dose of ethanol. The basal concentration of NAc glutamate increased 8-fold in the female adult rats but did not change significantly after further doses of ethanol. In contrast, the male adult rats showed no changes in basal glutamate content but exhibited a dose-dependent increase in NAc glutamate after further doses of ethanol. NAc arginine basal levels decreased significantly in both male and female adult rats after further doses of ethanol. Co-administration of nicotine modified the toxicity of ethanol as exemplified by diminishment of both the basal NAc glutamate release as well as modifying the release of this excitatory amino acid after further ethanol doses, particularly in female rats. In addition, the marked changes in arginine release after further ethanol doses were less evident. There was no evidence for increased hydroxyl radical production in the NAc after 'binge drinking' +/- nicotine. CONCLUSION: There appeared to be a greater vulnerability to ethanol toxicity in female adult rats after 'binge drinking'. It remains unclear whether the increased release of glutamate during the microdialysis evokes activation of inducible nitric oxide synthase (iNOS), which would utilize arginine in the formation of nitric oxide.

Anti-inflammatory actions of a taurine analogue, ethane ß-sultam, in phagocytic cells, in vivo and in vitro.

The ability of a taurine prodrug, ethane ß-sultam, to reduce cellular inflammation has been investigated, in vitro, in primary cultures of alveolar macrophages and an immortilised N9 microglial cell line and in vivo in an animal model of inflammation and control rats. Ethane ß-sultam showed enhanced ability to reduce the inflammatory response in alveolar macrophages, as assayed by the lipopolysaccharide-stimulated-nitric oxide release, (LPS stimulated-NO), in comparison to taurine both in vitro (10 nM, 50 nM) and in vivo (0.15 mmol/kg/day by gavage). In addition, ethane ß-sultam, (50, 100 and 1000 nM) significantly reduced LPS-stimulated glutamate release from N9 microglial cells to a greater extent than taurine. The anti-inflammatory response of taurine was shown to be mediated via stabilisation of IkBα. The use of a taurine prodrug as therapeutic agents, for the treatment of neurological conditions, such as Parkinson's and Alzheimer's disease and alcoholic brain damage, where activated phagocytic cells contribute to the pathogenesis, may be of great potential.

Laboratory models available to study alcohol-induced organ damage and immune variations: choosing the appropriate model.

The morbidity and mortality resulting from alcohol-related diseases globally impose a substantive cost to society. To minimize the financial burden on society and improve the quality of life for individuals suffering from the ill effects of alcohol abuse, substantial research in the alcohol field is focused on understanding the mechanisms by which alcohol-related diseases develop and progress. Since ethical concerns and inherent difficulties limit the amount of alcohol abuse research that can be performed in humans, most studies are performed in laboratory animals. This article summarizes the various laboratory models of alcohol abuse that are currently available and are used to study the mechanisms by which alcohol abuse induces organ damage and immune defects. The strengths and weaknesses of each of the models are discussed. Integrated into the review are the presentations that were made in the symposium "Methods of Ethanol Application in Alcohol Model-How Long is Long Enough" at the joint 2008 Research Society on Alcoholism (RSA) and International Society for Biomedical Research on Alcoholism (ISBRA) meeting, Washington, DC, emphasizing the importance not only of selecting the most appropriate laboratory alcohol model to address the specific goals of a project but also of ensuring that the findings can be extrapolated to alcohol-induced diseases in humans.

Neuro-inflammation induced in the hippocampus of 'binge drinking' rats may be mediated by elevated extracellular glutamate content.

The neuropathological and immune changes induced in the brain by 'binge drinking' have been investigated in a rat model. Evidence of neuro-inflammation was identified in the 'binge drinking' rat model of alcohol abuse after 3 weeks of administration of 2 or 3 g/kg ethanol (EtOH), three times per day for two consecutive days, followed by 5 days of abstinence: Firstly, alveolar macrophages, isolated from these animals, showed significant increases in inducible nitric oxide synthase, as assayed by nitrite release, both before and after lipopolysaccaharide stimulation. Secondly, significant numbers of activated microglia were present in the dentate gyrus region of the hippocampus of the 'binge drinking' model, after major histocompatibility complex class II staining, by comparison with the control. Microdialysis studies in the ventral hippocampus identified a significant increase in the basal extracellular concentration of glutamate, in both the 2 and 3 g/kg administered 'binge drinking' rats. In contrast, no changes in the hippocampal extracellular concentrations, of GABA and taurine, or the dopamine and serotonin metabolites were observed under basal conditions. A further dose of EtOH induced a significant decrease in the concentrations of both 3,4-dihydroxyphenylacetic acid and 5-hydroxyindoleacetic acid, whereas glutamate, taurine and GABA levels were unaffected. There was no evidence that EtOH preference was initiated by the 'binge drinking' regimen. Our results suggest that the possible toxicity associated with 'binge drinking' maybe directed by the elevated glutamate levels, which in turn, activate phagocytic cells to release their inflammatory cytokines and chemokines, ultimately leading to neuro-inflammation.

The influence of chronic nicotine administration on behavioural and neurochemical parameters in male and female rats after repeated binge drinking exposure.

AIMS: The possible interaction between nicotine and 'binge drinking' in eliciting changes in behavioural patterns of 'binge drinking' rats as well as nucleus accumbens (NAc) glutamate levels has been investigated in these present studies. METHODS: Adult or adolescent male and female rats received ethanol, 2 g/kg or 3 g/kg, by gavage in a 'binge drinking' regimen (3 times/day over a 6 h period, for 2 days followed by 5 days of abstinence) combined with or without nicotine, 0.3 g/kg, for either a 5-week (adult) or a 4-week (adolescent) period. Motor activity was then assessed for a period of 60 min after three further doses of ethanol or water. In addition, the NAc glutamate level was assayed in each group for 1 h after the first gavage regimen with ethanol, 2 g/kg or 3 g/kg, or water. RESULTS: Adult female rats showed greater sensitivity to each ethanol dose (2 g/kg and 3 g/kg) than the adult male rats, their motor activity decreasing during the first and third 'binge'. In contrast, in male adult rats, the sedative effects of ethanol were reduced, particularly after the third binge when no significant changes in the locomotor activity were apparent between the ethanol-administered male rats and controls. Adolescent rats did differ in their response to ethanol in comparison with adult rats. It was noteworthy that in young female adolescent rats, given 2 g/kg ethanol, motor activity was enhanced, thereby indicating that adolescent female rats are less sensitive to the sedative effects of ethanol at specific doses. In addition, male and female adolescent rats showed little change in locomotor activity in comparison with controls during the third 'binge administration' possibly indicating that tolerance to such alcohol doses was occurring. Nicotine administration did prevent the decrease in locomotor activity after ethanol administration during the first binge regimen in both male and female adolescents as well as adult female rats. However, after the third binge, such alcohol-induced changes in motor activity were not so well defined in the female adult rats that now showed significant decreases in motor activity. In contrast, adolescent male and female rats still showed similar motor activity to that of the controls. No clear association between the NAc glutamate extracellular content and locomotor activity was discernible in either adult or adolescent rats in these present studies. However, chronic nicotine administration markedly reduced the elevated basal glutamate content in the 'binge drinking female' adult rats. CONCLUSIONS: These studies have shown clear and distinct differences, with respect to both sensitivity and tolerance, in adult and adolescent male and female rats, which could be modified by supplementation with nicotine.

Biochemical and neurotransmitter changes implicated in alcohol-induced brain damage in chronic or 'binge drinking' alcohol abuse.

The brain damage, which occurs after either chronic alcoholization or binge drinking regimes, shows distinct biochemical and neurotransmitter differences. An excessive amount of glutamate is released into specific brain regions during binge drinking (in excess of 4- to 5-fold of the normal basal concentration) that is not evident during periods of excessive alcohol consumption in chronic alcohol abusers. Increases in glutamate release are only observed during the initial stages of withdrawal from chronic alcoholism ( approximately 2- to 3-fold) due to alterations in the sensitivities of the NMDA receptors. Such changes in either density or sensitivity of these receptors are reported to be unaltered by binge drinking. When such excesses of glutamate are released in these two different models of alcohol abuse, a wide range of biochemical changes occur, mediated in part by increased fluxes of calcium ions and/or activation of various G-protein-associated signalling pathways. Cellular studies of alveolar macrophages isolated from these two animal models of alcohol abuse showed enhanced (binge drinking) or reduced (chronic alcoholization) lipopolysaccharide (LPS)-stimulated NO release. Such studies could suggest that neuroadaptation occurs with the development of tolerance to alcohol's effects in both neurotransmitter function and cellular processes during chronic alcoholization that delay the occurrence of brain damage. In contrast, 'binge drinking' induces immediate and toxic effects and there is no evidence of an increased preference for alcohol as seen after withdrawal from chronic alcoholization.

Breath alcohol level and plasma amino acids: a comparison between older and younger chronic alcohol-dependent patients.

AIM: The aim of the present study is to examine the distribution of plasma excitatory and inhibitory amino acids, according to the age and current breath alcohol levels (BrAl+/-), of alcohol-dependent patients. PARTICIPANTS AND METHODS: 78 alcohol-dependent patients (mean age=46.2+/-11 years, men/women=54/24) were clinically tested, including the determination of the major excitatory as well as inhibitory amino acids. The independent variables were gender, age and current alcohol consumption measured with the breath alcohol level (BrAl+/-status). RESULTS: In comparison to BrAl negatives, BrAl positives had higher plasma levels of glutamic acid (P=0.01) and proline (P=0.026), and lower levels of aminobutyric acid (P=0.002), serine (P=0.031) and urea (P=0.01). In the BrAl positives, no age effect was found related to the plasma amino acids. In contrast, the BrAl negatives displayed age-related differences. The older (>or=50 years) BrAl negative patients had higher plasma levels of cystine, tyrosine, citrulline and urea, and lower histidine levels, compared to the younger group (<50 years). In general, differences in plasma levels of certain amino acids were dependent on gender, BrAl status, age and biochemical markers (GGT, MCV) of alcohol abuse. CONCLUSIONS: Abstaining patients (BrAl-/) display age-related differences in AAs' distribution, while active drinking (BrAl+/) seems to even out those differences, underpinning the hypothesis that drinking mimics changes seen with advanced age.

Neurochemical pathways involved in the protective effects of nicotine and ethanol in preventing the development of Parkinson's disease: potential targets for the development of new therapeutic agents.

In this short review, neurochemical targets are identified where nicotine, and possibly ethanol, may interact to prevent the occurrence of Parkinson's disease. These are (a) the nicotinic acetycholine receptors present in the nigrostriatal area or on the surface of microglia, (b) monoamine oxidases and (c) inducible nitric oxide synthase. If such induced changes can be verified in clinical studies, this may help in the design of new therapeutic drugs which may be of relevance to diminish the incidence and perhaps the progression of the debilitating condition of Parkinson's disease.

Nicotine increases ethanol preference but decreases locomotor activity during the initial stages of chronic ethanol withdrawal.

AIM: The ability of nicotine to modify withdrawal symptoms in rats chronically treated with alcohol, with respect to locomotor activity and ethanol or nicotine preference, has been evaluated in these studies. METHODS AND RESULTS: Preliminary studies showed that locomotor activity increased 8-9 h after withdrawal from chronic nicotine intoxication, which was dose specific; it occurred in rats administered 0.15 mg/kg or 0.6 mg/kg but not the 0.3 mg/kg nicotine dose. Administration of nicotine, either acutely (0.3 mg/kg) during ethanol withdrawal, or chronically (0.15, 0.3 or 0.6 mg/kg) during the chronic alcohol treatment procedure, diminished locomotor activity, which increases significantly, approximately 6-7 h after withdrawal, in rats chronically treated with alcohol. Rats which were chronically treated with alcohol alone or in combination with nicotine, 0.3 mg/kg, showed an increase in ethanol intake when the free choice was performed between ethanol 10% and tap water; on the contrary, when the free choice was performed between ethanol 10% versus nicotine, 0.3 mg/kg, results showed a decrease in ethanol preference and a concomitant increase in nicotine preference. CONCLUSION: These studies clearly identified the modulatory effects of nicotine, at specific doses, on both motility and preference in rat chronically co-administered nicotine and ethanol.

Functional characteristics of TauA binding protein from TauABC Escherichia coli system.

Although TauA shares few common characteristics with other known periplasmic binding protein, TauA is a putative periplasmic binding protein, part of tauABCD gene cluster involved in sulfonate transport in sulphate starvation condition. This protein was expressed in E. coli BL 21 and purified before to assess its binding functionalities. Measurement of K (d) value (mean 11.3 nM) by binding/dialysis studies revealed high affinity and specificity with taurine and also indicated that TauA possessed a unique binding site for its ligand. Comparisons with other periplasmic binding proteins suggests TauA plays a major role in ABC transport system and could be ideal candidate to serve as taurine catcher in biological fluids.

SR147778, a CB1 cannabinoid receptor antagonist, suppresses ethanol preference in chronically alcoholized Wistar rats.

This study investigated the effect of the new CB1 cannabinoid receptor antagonist, SR147778, on ethanol preference in chronically alcoholized Wistar rats. In study 1, SR147778, at doses of 0.3, 1, or 10 mg/kg/day (mg/kg/d) intraperitonealy (ip), was administered during chronic pulmonary ethanol intoxication for 30 days. The rats were then exposed to a two-bottle choice (ethanol 10% v/v vs. water) for at least 30 days. Neither 0.3 nor 1 mg/kg/d had any effect on ethanol preference. In contrast, the high dose induced a significant transient increase in ethanol intake between days 6 and 10. In study 2, SR147778, at doses of 0.3, 1, or 10 mg/kg/d ip, was administered during the free-choice period after chronic alcoholization. Both ethanol preference and intake were significantly reduced only for 1 and 10 mg/kg/d. These results reinforce the hypothesis that the cannabinoid CB1 receptor is part of the neural substrate mediating alcohol intake and the motivational properties of alcohol. When these results are compared with those obtained with SR141716 (Rimonabant) on ethanol preference, we observed that (1) coadministration of 10 mg/kg/d SR147778 during chronic alcoholization induced a shorter transient increase of ethanol intake than Rimonabant and (2) SR147778 treatment during the free-choice period at doses of 1 and 10 mg/kg/d decreased ethanol intake more dramatically than SR141716 which, furthermore, continued for the duration of the free choice.

Nicotine-induced changes of glutamate and arginine in naive and chronically alcoholized rats: an in vivo microdialysis study.

The effects of nicotine, when administered either acutely or chronically, at doses of 0.15, 0.3 or 0.6 mg/kg, on the release of glutamate and arginine in the rat nucleus accumbens have been studied in microdialysis experiments. Glutamate release significantly increased after acute nicotine injection, 0.3 mg/kg, which was accentuated if there was a priming regime of saline for the previous 27 days. This is possibly related to the rewarding effects of nicotine. Five hours after cessation of chronic oral nicotine administration, there were significant increases in glutamate content, which was possibly reflective of a withdrawal process. Significant decreases in nucleus accumbens arginine release were evident, between 1 and 2 h, after chronic nicotine administration. When nicotine was co-administered to rats during chronic ethanol intoxication, at either 0.15 mg/kg or 0.3 mg/kg doses, glutamate release did not increase during the first 12 h of withdrawal. However, a decrease in arginine microdialysate content was still observed with all nicotine doses. The nicotine-induced changes in glutamate and arginine release in nucleus accumbens highlights the complex neuropharmacological interactions evoked by this compound and also identified its possible modulating effect on glutamate release during the initial stages of chronic ethanol withdrawal.

Glutamic acid in withdrawal and weaning in patients classified according to Cloninger's and Lesch's typologies.

AIMS: Though glutamic acid is well known as a working excitatory in the CNS, its impact on the modulation of alcohol withdrawal symptoms and withdrawal fits are not yet clear. The study has been undertaken to examine the levels of glutamic acid in chronic alcohol-dependent patients at different stages of alcohol withdrawal and weaning and to examine any existence of any differences according to Cloninger's and Lesch's typologies. PATIENTS AND METHODS: One hundred and fifty-nine alcohol-dependent patients were assessed according to Cloninger's and Lesch's typologies and related to abstinence duration, age, and gender. Blood samples were taken for mean corpuscular volume (MCV), gamma-glutamyltransferase (GGT) and glutamic acid, in order to find primarily any differences in glutamic acid according to the typologies, age, abstinence duration, and liver damage. RESULTS: There was no significant association between Cloninger's and Lesch's typologies. Cloninger's types 1 and 2 had an equal distribution of GGT and duration of abstinence, while Lesch's type I had more patients with high GGT, and more patients who were sober for a maximum of 2 days. Unlike in Lesch's types, glutamic acid levels did not differ according to Cloninger's types, as significantly higher glutamic acid values were found in Lesch's types I and IV. Glutamic acid values did not differ significantly in different age groups. CONCLUSIONS: Our study findings of varying glutamic acid levels seen in Lesch's typology, higher in types I and IV than in types II and III, are of significant clinical value and can be interpreted differently, as in type I high levels of glutamic acid is seen as a kindling phenomenon, while in type IV elevated levels might be related to either compulsivity of frequent repetition of drinking or withdrawal.

Production of reactive oxygen species following acute ethanol or acetaldehyde and its reduction by acamprosate in chronically alcoholized rats.

The salicylate trap method, combined with microdialysis, has been used to validate whether reactive oxygen species, particularly hydroxyl radicals, ((*)OH), are generated in the hippocampus of male Wistar rats after acute intraperitoneal administration of either ethanol, 2 and 3 g/kg, or acetaldehyde, 200 mg, or during the initial stages of ethanol withdrawal after chronic ethanol intoxication. Salicylate (5 mM) was infused into the hippocampus via the microdialysis probe and the products of its metabolism by hydroxyl radical, particularly 2,3-dihydroxybenzoic acid (2,3-DHBA) as well as 2,5-dihydroxybenzoic acid (2,5-DHBA) assayed by HPLC (High Pressure Liquid Chromatography). Acetaldehyde, 200 mg/kg, and the higher acute dose of ethanol, 3 g/kg, induced transitory increases in 2,3-DHBA and 2,5-DHBA microdialysate content. At the cessation of four weeks of chronic ethanol intoxication, (by the vapour inhalation method), the mean blood alcohol level was 1.90 g/l. Significant increases of microdialysate 2,3-DHBA and 2,5-DHBA levels were assayed 3 h after alcohol withdrawal which were sustained for a further 5 and 1 h 40 min respectively. Oral administration of Acamprosate, 400 mg/kg/day, during the chronic ethanol intoxication procedure prevented the increased formation of 2,3- and 2,5-DHBA by comparison to rats chronically ethanol intoxicated alone.

Neuroprotective and abstinence-promoting effects of acamprosate: elucidating the mechanism of action.

Acamprosate is an abstinence-promoting drug widely used in the treatment of alcohol dependence but which has a mechanism of action that has remained obscure for many years. Recently, evidence has emerged that this drug may interact with excitatory glutamatergic neurotransmission in general and as an antagonist of the metabotropic glutamate receptor subtype 5 (mGluR5) in particular. These findings provide, for the first time, a satisfactory, unifying hypothesis that can bring together and explain the diverse neurochemical effects of acamprosate. Glutamic acid is involved in several aspects of alcohol dependence and withdrawal, many of which can be modified by acamprosate. For example, during chronic exposure to alcohol, the glutamatergic system becomes upregulated, leaving the brain exposed to excessive glutamatergic activity when alcohol is abruptly withdrawn. The surge in glutamic acid release that occurs following alcohol withdrawal can be attenuated by acamprosate. The elevated extracellular levels of glutamic acid observed in withdrawal, together with supersensitivity of NMDA receptors, may expose vulnerable neurons to excitotoxicity, possibly contributing to the neuronal loss sometimes observed in chronic alcohol dependence. In vitro studies suggest that the excitotoxicity produced by ethanol can effectively be blocked by acamprosate. Moreover, glutamatergic neurotransmission plays an important role in the acquisition of cue-elicited drinking behaviours, which again can be modulated by acamprosate. In conclusion, the glutamatergic hypothesis of the mechanism of action of acamprosate helps explain many of its effects in human alcohol dependence and points the way to potential new activities, such as neuroprotection, that merit exploration in the clinic.