Glutamate-mediated transmission, alcohol, and alcoholism

Hepatic encephalophathy: management and diagnostic therapeutic assistance path of Ligurian Local Health Company 3 (ASL3)

Hepatic encephalophathy (HE) is a neuropsychiatric syndrome with a prevalence in the cirrhotic population ranging from 20 to 80%. HE is a cause of inappropriate hospitalization, caregiver burdening and increased social costs. There is need to create dedicated care pathways to better manage patients and support family caregivers. The data used for the preparation of this diagnostic therapeutic assistance path (DTAP) are based on a detailed analysis of the scientific literature published before June 30, 2022 (PubMed, Web of Science, Scopus, Google Scholar). Furthermore, in the process of developing this work, we consulted in particular the guidelines/ position papers of International Society for Hepatic Encephalopathy and Nitrogen Metabolism (ISHEN), Italian Association for the Study of the Liver (AISF), European Association for the Study of the Liver (EASL), American Association for the Study of Liver Diseases (AASLD), Italian Society on Alcohol (Società Italiana di Alcologia [SIA]) and other relevant papers. DTAP was created based on the most recent recommendations of the international scientific literature. The present DTAP highlight the need for a multidisciplinary activity integrated with territorial medicine in close connection with caregivers. This guarantees improved therapeutic adherence, hospital readmission reduction, improved quality of life for patients and caregivers and a significant reduction in costs.

Neutrophil-lymphocyte ratio as a predictor of delirium tremens in hospitalized patients with alcohol withdrawal

Delirium Tremens (DT) is a severe form of alcohol withdrawal that can be fatal if not recognized early and treated appropriately. In our study, we aimed to determine the role of Neutrophil-Lymphocyte ratio (NLR), a marker of systemic inflammation, in predicting the development of DT. This retrospective study was conducted in an alcohol and drug treatment center between March 2017 and March 2020. A total of 212 patients with a diagnosis of alcohol use disorder who were admitted to a special care unit after alcohol withdrawal were included. Blood tests were collected within 24 hours of the patients' admission. Comparisons were made according to whether the patients developed DT during the hospitalization. DT was diagnosed in 24.1% of the patients. It was determined that higher NLR level (odds ratio [OR]: 4.38, 95%CI: 2.58-7.43) and history of DT (OR: 1.33, 95%CI: 1.23-11.73) are independent risk factors for the development of DT in the logistic regression analysis. The optimal cut-off value of NLR in predicting DT was 2.67 (sensitivity: 82.4%, specificity: 88.8%). The ROC curve of NLR showed a larger area under the curve (AUC) than the curves of other systemic inflammation markers. NLR is a simple, practical and inexpensive marker that can predict the development of DT in patients with alcohol withdrawal syndrome.

Repeated Restraint Stress and Binge Alcohol during Adolescence Induce Long-Term Effects on Anxiety-like Behavior and the Expression of the Endocannabinoid System in Male Rats

(1) Background: Negative experiences during adolescence increase the vulnerability to develop mental disorders later in life. A better understanding of the mechanisms underlying these long-term alterations could help to identify better therapeutic interventions. (2) Methods: Adolescent male Wistar rats were used to explore the effects of repeated stress and alcohol exposure on anxiety-like behaviors, plasma corticosterone levels and the gene expression of the endocannabinoid system (ECS) and other relevant signaling systems (glutamatergic, corticotropin-releasing hormone (CRH) and neuropeptide Y (NPY)) in the amygdala and the medial prefrontal cortex (mPFC). (3) Results: Overall, both stress and alcohol induced anxiety-like behaviors, but only the alcohol-exposed rats displayed increased plasma levels of corticosterone. In the amygdala, there was a general deficit in the gene expression of the ECS and increases in the mRNA levels of certain subunits of glutamate receptors. Interestingly, there were significant interaction effects between stress and alcohol on the expression of the NMDA receptor subunits. In addition, increased mRNA levels of the CRH receptor were observed in alcohol-exposed rats. In the mPFC, alcohol exposure was associated with an increase in the gene expression of the ECS. By contrast, the combination of stress and alcohol produced opposite effects. (4) Conclusions: In summary, early stress and alcohol exposure induced long-term anxiety-like behavior in male rats but different mechanisms are involved in these maladaptive changes in the brain.

FACTORS CONTRIBUTING TO THE ESCALATION OF ALCOHOL CONSUMPTION

Understanding factors that contribute to the escalation of alcohol consumption is key to understanding how an individual transitions from non/social drinking to AUD and to providing better treatment. In this review, we discuss how the way ethanol is consumed as well as individual and environmental factors contribute to the escalation of ethanol consumption from intermittent low levels to consistently high levels. Moreover, we discuss how these factors are modelled in animals. It is clear a vast array of complex, interacting factors influence changes in alcohol consumption. Some of these factors act early in the acquisition of ethanol consumption and initial escalation, while others contribute to escalation of ethanol consumption at a later stage and are involved in the development of alcohol dependence. There is considerable need for more studies examining escalation associated with the formation of dependence and other hallmark features of AUD, especially studies examining mechanisms, as it is of considerable relevance to understanding and treating AUD.

Melatonin Blocks Morphine-Induced Place Preference: Involvement of GLT-1, NF-κB, BDNF, and CREB in the Nucleus Accumbens

Opioid addiction remains a widespread issue despite continuous attempts by the FDA to help maintain abstinence. Melatonin is a neurohormone considered to be involved only in the neuroendocrine and reproductive systems; however, recent reports have demonstrated its potential to attenuate drug addiction and dependence. Cumulative studies have suggested that melatonin can attenuate the rewarding effects of several drugs of abuse, including opioids. This study aimed to investigate the effect of melatonin (50 mg/kg) on morphine (5 mg/kg) to produce place preference. We also investigated the effect of melatonin and morphine on the expression of GLT-1, BDNF, NF-κB, and CREB within the nucleus accumbens. Male Wistar rats were divided into control, morphine, melatonin, and the morphine + melatonin groups. The study involved a two-phase habituation phase from day 1 to day 3 and an acquisition phase from day 5 to day 14. The conditioned place preference (CPP) score, distance traveled, resting time, ambulatory count, and total activity count were measured for all animals. Rats that received morphine showed a significant increase in CPP score compared to those in the control group. Morphine treatment reduced the mRNA expression of GLT-1, BDNF, and CREB and increased that of NF-κB. However, melatonin treatment administered 30 min before morphine treatment attenuated morphine place preference and reversed GLT-1, BDNF, NF-κB, and CREB expression levels. In conclusion, the study results indicate, for the first time, the new potential targets of melatonin in modulating morphine-induced CPP.

Caudate nucleus volume mediates the link between glutamatergic neurotransmission and problematic smartphone use in youth

BACKGROUND AND AIMS

Problematic smartphone use (PSU) is growing rapidly among teens. It has similar presentations as other behavioral addictions in terms of excessive use, impulse control problems, and negative consequences. However, the underlying neurobiological mechanisms remain undiscovered. We hypothesized that structural changes in the striatum might serve as an important link between alteration in glutamate signaling and development of PSU.

METHODS

Among 88 participants, twenty (F:M, 12:8; age 16.2 ± 1.1) reported high scores in the smartphone addiction proneness scale (SAPS) with a cut-off score of 42; the other 68 (F:M, 19:49; age 15.3 ± 1.7) comprised the control group. Sociodemographic data and depression, anxiety, and impulsivity traits were measured. Striatal volumes (caudate, putamen, and nucleus accumbens) were estimated from T1 imaging data. Serum glutamate levels were estimated from peripheral blood samples. Group comparisons of each data were performed after controlling for age and gender. Mediation analyses were conducted to test the indirect effects of glutamate level alteration on PSU through striatal volumetric alteration.

RESULTS

The PSU group showed a decrease in both caudate volumes than the control group. Left caudate volume was positively correlated with serum glutamate level, and negatively with impulsivity traits and SAPS scores. The mediation model revealed a significant indirect effect of serum glutamate on SAS scores through the reduced left caudate volume.

DISCUSSION AND CONCLUSIONS

This study suggests that altered glutamatergic neurotransmission may be associated with PSU among teens, possibly through reduced left caudate volume. Current findings might support neural mechanisms of smartphone addiction.

Adolescent intermittent ethanol exposure does not alter responsiveness to ifenprodil or expression of vesicular GABA and glutamate transporters

Adolescent intermittent ethanol (AIE) exposure in the rat results in a retention of adolescent-like responsiveness to ethanol into adulthood characterized by enhanced sensitivity to socially facilitating and decreased sensitivity to socially suppressing and aversive effects. Similar pattern of responsiveness to social and aversive effects of the selective glutamate NMDA NR2B receptor antagonist ifenprodil is evident in adolescent rats, suggesting that AIE would also retain this pattern of ifenprodil sensitivity into adulthood. Social (Experiment 1) and aversive (measured via conditioned taste aversion; Experiment 2) effects of ifenprodil were assessed in adult male and female rats following AIE exposure. Sensitivity to the social and aversive effects of ifenprodil was not affected by AIE exposure. Experiment 3 assessed protein expression of vesicular transporters of GABA (vGAT) and glutamate (vGlut2) within the prelimbic cortex and nucleus accumbens in adolescents versus adults and in AIE adults versus controls. vGlut2 expression was higher in adolescents relative to adults within the PrL, but lower in the NAc. AIE adults did not retain these adolescent-typical ratios. These findings suggest that AIE is not associated with the retention of adolescent-typical sensitivity to NR2B receptor antagonism, along with no AIE-induced shift in vGlut2 to vGAT ratios.

Circadian rhythms and substance use disorders: A bidirectional relationship

The circadian system organizes circadian rhythms (biological cycles that occur around 24 h) that couple environmental cues (zeitgebers) with internal functions of the organism. The misalignment between circadian rhythms and external cues is known as chronodisruption and contributes to the development of mental, metabolic and other disorders, including cancer, cardiovascular diseases and addictive disorders. Drug addiction represents a global public health concern and affects the health and well-being of individuals, families and communities. In this manuscript, we reviewed evidence indicating a bidirectional relationship between the circadian system and the development of addictive disorders. We provide information on the interaction between the circadian system and drug addiction for each drug or drug class (alcohol, cannabis, hallucinogens, psychostimulants and opioids). We also describe evidence showing that drug use follows a circadian pattern, which changes with the progression of addiction. Furthermore, clock gene expression is also altered during the development of drug addiction in many brain areas related to drug reward, drug seeking and relapse. The regulation of the glutamatergic and dopaminergic neurocircuitry by clock genes is postulated to be the main circadian mechanism underlying the escalation of drug addiction. The bidirectional interaction between the circadian system and drug addiction seems to be mediated by the effects caused by each drug or class of drugs of abuse. These studies provide new insights on the development of successful strategies aimed at restoring/stabilizing circadian rhythms to reduce the risk for addiction development and relapse.

Alcohol use disorders and the brain

A diagnosis of alcohol use disorder is associated with a higher risk of dementia, but a dose-response relationship between alcohol intake consumption and cognitive impairment remains unclear. Alcohol is associated with a range of effects on the central nervous system at different doses and acts on a number of receptors. Acute disorders include Wernicke's encephalopathy (WE), traumatic brain injury, blackouts, seizures, stroke and hepatic encephalopathy. The most common manifestations of chronic alcohol consumption are Korsakoff's syndrome (KS) and alcohol-related dementia (ARD). There is limited evidence for benefit from memantine in the treatment of ARD, but stronger evidence for the use of high-dose parenteral thiamine in the progression of neuropsychiatric symptoms for WE. Accumulating evidence exists for pharmacological treatment in the prevention of hepatic encephalopathy. Rehabilitation of people with ARD may take several years, and requires an approach that addresses physical and psychosocial factors.

GLAST (GLutamate and ASpartate Transporter) in human prefrontal cortex; interactome in healthy brains and the expression of GLAST in brains of chronic alcoholics

We have analysed post-mortem samples of prefrontal cortex from control and alcoholic human brains by the technique of Western blotting to estimate and compare the expressions of glutamate transporter GLAST (Excitatory Amino Acid Transporter One; EAAT1). Furthermore, using the non-alcoholic prefrontal cortex and custom-made GLAST (EAAT1) antibody we determined GLAST (EAAT1) "interactome" i.e. the set of proteins selectively bound by GLAST (EAAT1). We found that GLAST (EAAT1) was significantly more abundant (about 1.6-fold) in the cortical tissue from alcoholic brains compared to that from non-alcoholic controls. The greatest increase in the level of GLAST (EAAT1) was found in plasma membrane fraction (2.2-fold). Additionally, using the prefrontal cortical tissue from control brains, we identified 38 proteins specifically interacting with GLAST (EAAT1). These can be classified as contributing to the cell structure (6 proteins; 16%), energy and general metabolism (18 proteins; 47%), neurotransmitter metabolism (three proteins; 8%), signalling (6 proteins: 16%), neurotransmitter storage/release at synapses (three proteins; 8%) and calcium buffering (two proteins; 5%). We discuss possible consequences of the increased expression of GLAST (EAAT1) in alcoholic brain tissue and whether or how this could disturb the function of the proteins potentially interacting with GLAST (EAAT1) in vivo. The data represent an extension of our previous proteomic and metabolomic studies of human alcoholism revealing another aspect of the complexity of changes imposed on brain by chronic long-term consumption of ethanol.

Delirium Tremens: Assessment and Management

Delirium Tremens (DT) falls in the most severe spectrum of alcohol withdrawal, which could potentially result in death, unless managed promptly and adequately. The prevalence of DT in general population is <1% and nearly 2% in patients with alcohol dependence. DT presents with a combination of severe alcohol withdrawal symptoms and symptoms of delirium with agitation and sometimes hallucination. Clinical and laboratory parameters which predict DT have been discussed. Assessment of DT includes assessment of severity of alcohol withdrawal, evaluation of delirium, and screening for underlying medical co-morbidities. Liver disease as a co-morbidity is very common in patients with DT and that could complicate the clinical presentation, determine the treatment choice, and influence the outcome. Benzodiazepines are the mainstay of treatment for DT. Diazepam and lorazepam are preferred benzodiazepine, depending upon the treatment regime and clinical context. In benzodiazepine refractory cases, Phenobarbital, propofol, and dexmedetomidine could be used.

Decreased Serum Glutamate Levels in Male Adults with Internet Gaming Disorder: A Pilot Study

Objective

Alteration in glutamatergic neurotransmission and dopaminergic dysfunction has been implicated in both the initiation and expression of addiction related behaviors. This pilot study was aimed to investigate the serum levels of glutamate and dopamine in adults with internet gaming disorder (IGD).

Methods

We measured serum levels of glutamate and dopamine in male participants with IGD (n=26) and age-matched healthy controls (n=25). Clinical interviews were performed to identify IGD and to rule out psychiatric comorbidities. Serum levels of glutamate and dopamine were examined by enzyme immunoassays using ELISA Kits.

Results

Serum levels of glutamate were lower among IGD than control (IGD: 24.184±12.303 μg/ml; control: 33.676±12.413μg/ml; t=2.742, p=0.008), while levels of dopamine did not differ between. Serum glutamate and dopamine levels did not correlate with gaming hours and exposure to game in the IGD group. But serum glutamate levels were positively correlated with the dopamine levels (r=0.360, p=0.013).

Conclusion

Our results suggest that altered glutamatergic neurotransmission may contribute to the pathophysiology of IGD.

Baclofen for alcohol withdrawal

BACKGROUND

Baclofen shows potential for rapidly reducing symptoms of severe alcohol withdrawal syndrome (AWS) in people with alcoholism. Treatment with baclofen is easy to manage and rarely produces euphoria or other pleasant effects, or craving for the drug. This is an updated version of the original Cochrane Review published in 2015, Issue 4.

OBJECTIVES

To assess the efficacy and safety of baclofen for people with AWS.

SEARCH METHODS

We updated our searches of the following databases to March 2017: the Cochrane Drugs and Alcohol Group Specialised Register, CENTRAL, PubMed, Embase, and CINAHL. We also searched registers of ongoing trials. We handsearched the references quoted in the identified trials, and sought information from researchers, pharmaceutical companies, and relevant trial authors about unpublished or uncompleted trials. We placed no restrictions on language.

SELECTION CRITERIA

We included all randomised controlled clinical trials (RCTs) evaluating baclofen versus placebo or any other treatment for people with AWS. We excluded uncontrolled, non-randomised, or quasi-randomised trials. We included both parallel group and cross-over studies.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included three RCTs with 141 randomised participants. We did not perform meta-analyses due to the different control interventions. For the comparison of baclofen and placebo (1 study, 31 participants), there was no significant difference in Clinical Institute Withdrawal Assessment of Alcohol Scale, Revised (CIWA-Ar) scores (very low quality evidence). For the comparison of baclofen and diazepam (1 study, 37 participants), there was no significant difference in CIWA-Ar scores (very low quality evidence), adverse events (risk difference (RD) 0.00, 95% confidence interval (CI) -0.10 to 0.10; very low quality evidence), dropouts (RD 0.00, 95% CI -0.10 to 0.10; very low quality evidence), and dropouts due to adverse events (RD 0.00, 95% CI -0.10 to 0.10; very low quality evidence). For the comparison of baclofen and chlordiazepoxide (1 study, 60 participants), there was no significant difference in CIWA-Ar scores (mean difference (MD) 1.00, 95% CI 0.70 to 1.30; very low quality evidence), global improvement (MD 0.10, 95% CI -0.03 to 0.23; very low quality evidence), adverse events (RD 2.50, 95% CI 0.88 to 7.10; very low quality of evidence), dropouts (RD 0.00, 95% CI -0.06 to 0.06; very low quality evidence), and dropouts due to adverse events (RD 0.00, 95% CI -0.06 to 0.06; very low quality evidence).

AUTHORS' CONCLUSIONS

No conclusions can be drawn about the efficacy and safety of baclofen for the management of alcohol withdrawal because we found insufficient and very low quality evidence.

The safety and efficacy of baclofen to reduce alcohol use in veterans with chronic hepatitis C: a randomized controlled trial

BACKGROUND AND AIMS

Alcohol use disorders (AUDs) are common among people with chronic hepatitis C (HCV) and accelerate the development of fibrosis and cirrhosis caused by HCV. Baclofen, a gamma-aminobutyric acid (GABA) beta-receptor agonist, differs from medications for AUDs currently approved by the United States Food and Drug Administration (FDA), as it is metabolized primarily through the kidneys. The primary outcome of this study was to compare baclofen with a placebo in the percentage of days abstinent from alcohol.

DESIGN

A double-blind, placebo-controlled randomized trial.

SETTING

Hepatology clinics in four separate US Veteran Affairs Medical Centers in the United States.

PARTICIPANTS

One hundred and eighty Veteran men and women older than 18 years with chronic HCV, a comorbid AUD and current alcohol use.

INTERVENTION AND COMPARATOR

Oral baclofen was given at dosages of 0 (placebo) or 30 mg/day over 12 weeks with concomitant manual-guided counseling.

MEASUREMENTS

The primary measurement was percentage of days abstinent during the 12-week study period between the baclofen and placebo groups [measured by time-line follow-back (TLFB)]. Secondary measurements were the percentage of Veterans who achieved complete abstinence, the percentage of Veterans who achieved no heavy drinking between weeks 4 and 12 of the study, alcohol craving, anxiety, depression and post-traumatic stress disorder (PTSD).

FINDINGS

Primary outcome: compared with placebo, baclofen did not improve the percentage of days abstinent. For all subjects there were significant reductions from baseline to 12 weeks in percentage of days abstinent from 37.0% [standard error (SE) = 2.7] to 68.6% (SE = 2.8, F_(1151.1)  = 66.1, P < 0.001). However, there was no statistically significant difference between groups for change in percentage of days abstinent over the 12-week study period [absolute difference 1.3% (-9.1 to 1.7%), F_(1152.6)  = 0.005, P = 0.95].

SECONDARY OUTCOMES

Of subjects who completed the first 4 weeks of the study, 8.9% (15 of 168) achieved complete abstinence; 10.1% (nine of 89) in the placebo group and 7.6% (six of 79) in the baclofen group [χ²₍₁₎  = 0.33, odds ratio (OR) = 0.73 (0.24-2.15)]. The percentage of no heavy drinking for all subjects between weeks 4 and 12 was 20.2% (34 of 168), but no statistically significant differences were found between placebo 15.7% (14 of 89) and baclofen 25.3% (20 of 79) [χ²₍₁₎  = 2.38, OR = 1.82 (0.85-3.90)]. There were significant reductions for all subjects in all other secondary variables over the course of the study, but no differences between groups. Measures of various biomarkers of alcohol use did not change significantly throughout the course of the study for either the baclofen or placebo groups.

CONCLUSIONS

Baclofen administered at 30 mg/day does not appear to be superior to placebo in increasing abstinence or in reducing alcohol use, cravings for alcohol or anxiety among people with alcohol use disorder.

Medications development for the treatment of alcohol use disorder: insights into the predictive value of animal and human laboratory models

Development of effective treatments for alcohol use disorder (AUD) represents an important public health goal. This review provides a summary of completed preclinical and clinical studies testing pharmacotherapies for the treatment of AUD. We discuss opportunities for improving the translation from preclinical findings to clinical trial outcomes, focusing on the validity and predictive value of animal and human laboratory models of AUD. Specifically, while preclinical studies of medications development have offered important insights into the neurobiology of the disorder and alcohol's molecular targets, limitations include the lack of standardized methods and streamlined processes whereby animal studies can readily inform human studies. Behavioral pharmacology studies provide a less expensive and valuable opportunity to assess the feasibility of a pharmacotherapy prior to initiating larger scale clinical trials by providing insights into the mechanism of the drug, which can then inform recruitment, analyses, and assessments. Summary tables are provided to illustrate the wide range of preclinical, human laboratory, and clinical studies of medications development for alcoholism. Taken together, this review highlights the challenges associated with animal paradigms, human laboratory studies, and clinical trials with the overarching goal of advancing treatment development and highlighting opportunities to bridge the gap between preclinical and clinical research.

Binge ethanol in adulthood exacerbates negative outcomes following juvenile traumatic brain injury

Traumatic brain injuries (TBI) are a major public health problem with enormous costs in terms of health care dollars, lost productivity, and reduced quality of life. Alcohol is bidirectionally linked to TBI as many TBI patients are intoxicated at the time of their injury and we recently reported that, in accordance with human epidemiological data, animals injured during juvenile development self-administered significantly more alcohol as adults than did sham injured mice. There are also clinical data that drinking after TBI significantly reduces the efficacy of rehabilitation and leads to poorer long-term outcomes. In order to determine whether juvenile traumatic brain injury also increased the vulnerability of the brain to the toxic effects of high dose alcohol, mice were injured at 21days of age and then seven weeks later treated daily with binge-like levels of alcohol 5g/kg (by oral gavage) for ten days. Binge-like alcohol produced a greater degree of neuronal damage and neuroinflammation in mice that sustained a TBI. Further, mice that sustained a juvenile TBI exhibited mild learning and memory impairments in adulthood following binge alcohol and express a significant increase in hippocampal ectopic localization of newborn neurons. Taken together, these data provide strong evidence that a mild brain injury occurring early in life renders the brain highly vulnerable to the consequences of binge-like alcohol consumption.

From genetic studies to precision medicine in alcohol dependence

Genetic factors contribute to more than 50% of the variation in the vulnerability to alcohol dependence (AD). Although significant advances have been made in medications for AD, these medications do not work for all people. Precise tailoring of medicinal strategies for individual alcoholic patients is needed to achieve optimal outcomes. This review updates the most promising information on genetic variants in AD, which may be useful for improving diagnostic, therapeutic, and monitoring strategies. We describe genetic candidates of various neurotransmitter and enzyme systems. In addition to biological and allelic associations with AD, genetic effects on AD-related phenotypes and treatment responses have also been described. Gene-gene and gene-environment interactions have been considered. Potential applications of genomewide and epigenetic approaches for identifying genetic biomarkers of AD have been discussed. Overall, the application of genetic findings in precision medicine for AD will likely involve an integrated approach that distinguishes effect sizes of specific genetic predictors with regard to sex, pharmacotherapy, ethnicity, and AD-related aspects and considers gene-gene and gene-environment interactions. Our work may pave the way toward more precise treatment for AD that could ultimately improve clinical management and interventions.

Salvia miltiorrhiza Bunge Blocks Ethanol-Induced Synaptic Dysfunction through Regulation of NMDA Receptor-Dependent Synaptic Transmission

Consumption of high doses of ethanol can lead to amnesia, which often manifests as a blackout. These blackouts experienced by ethanol consumers may be a major cause of the social problems associated with excess ethanol consumption. However, there is currently no established treatment for preventing these ethanol-induced blackouts. In this study, we tested the ethanol extract of the roots of Salvia miltiorrhiza (SM) for its ability to mitigate ethanol-induced behavioral and synaptic deficits. To test behavioral deficits, an object recognition test was conducted in mouse. In this test, ethanol (1 g/kg, i.p.) impaired object recognition memory, but SM (200 mg/kg) prevented this impairment. To evaluate synaptic deficits, NMDA receptor-mediated excitatory postsynaptic potential (EPSP) and long-term potentiation (LTP) in the mouse hippocampal slices were tested, as they are known to be vulnerable to ethanol and are associated with ethanol-induced amnesia. SM (10 and 100 μg/ml) significantly ameliorated ethanol-induced long-term potentiation and NMDA receptor-mediated EPSP deficits in the hippocampal slices. Therefore, these results suggest that SM prevents ethanol-induced amnesia by protecting the hippocampus from NMDA receptor-mediated synaptic transmission and synaptic plasticity deficits induced by ethanol.

Selective alterations of NMDAR function and plasticity in D1 and D2 medium spiny neurons in the nucleus accumbens shell following chronic intermittent ethanol exposure

A major mouse model widely adopted in recent years to induce pronounced ethanol intake is the ethanol vapor model known as "CIE" or "Chronic Intermittent Ethanol." One critical question concerning this model is whether the rapid induction of high blood ethanol levels for such short time periods is sufficient to induce alterations in N-methyl-d-aspartate receptor (NMDAR) function which may contribute to excessive ethanol intake. In this study, we determined whether such short term intermittent ethanol exposure modulates NMDAR function as well as other prominent electrophysiological properties and the expression of plasticity in both D1 (D1+) and D2 (D1-) dopamine receptor expressing medium spiny neurons (MSNs) in the nucleus accumbens (NAc) shell. To distinguish between the two subtypes of MSNs in the NAc we treated Drd1a-TdTomato transgenic mice with CIE vapor and electrophysiological recordings were conducted 24 h after the last vapor exposure. To investigate CIE induced alterations in plasticity, long-term depression (LTD) was induced by pairing low frequency stimulation (LFS) with post synaptic depolarization. In ethanol naïve mice, LFS induced synaptic depression (LTD) was apparent exclusively in D1+ MSNs. Whereas in slices prepared from CIE treated mice, LFS induced synaptic potentiation (LTP) in D1+ MSNs. Furthermore, following CIE exposure, LFS now produced LTD in D1- MSNs. We found that CIE exposure induced an increase in excitability in D1+ MSNs with no change in D1- MSNs. After CIE, we found a significant increase in spontaneous EPSCs (sEPSCs) frequency in D1+ but not D1- MSNs suggesting alterations in baseline α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) mediated signaling. CIE induced changes in NMDAR function were measured using the NMDA/AMPA ratio and input-output curves of isolated NMDAR currents. We observed a significant increase in NMDAR function in D1+ MSNs and a decrease in D1- MSNs after ethanol vapor exposure. The reversal of NMDAR function may account for the CIE induced alterations in the expression of plasticity. The cell type specific alterations in excitatory signaling in the NAc shell may constitute an important neuroadaptation necessary for the expression of increased ethanol consumption induced by intermittent ethanol vapor exposure. This article is part of the Special Issue entitled 'Ionotropic glutamate receptors'.

Alcohol Withdrawal Syndrome: Benzodiazepines and Beyond

Alcohol dependence is an increasing and pervasive problem. Alcohol withdrawal symptoms are a part of alcohol dependence syndrome and are commonly encountered in general hospital settings, in most of the departments. Alcohol withdrawal syndrome ranges from mild to severe. The severe complicated alcohol withdrawal may present with hallucinations, seizures or delirium tremens. Benzodiazepines have the largest and the best evidence base in the treatment of alcohol withdrawal, and are considered the gold standard. Others, such as anticonvulsants, barbiturates, adrenergic drugs, and GABA agonists have been tried and have evidence. Supportive care and use of vitamins is essential in the management. Symptom triggered regime is favoured over fixed tapering dose regime, although monitoring through scales is cumbersome. This article aims to review the evidence base for appropriate clinical management of the alcohol withdrawal syndrome. We searched Pubmed for articles published in English on 'Alcohol withdrawal syndrome' in humans during the last 10 years. A total of 1182 articles came up. Articles not relevant to clinical utility and management were excluded based on the titles and abstract available. Full text articles, meta-analyses, systematic reviews and randomized controlled trials were obtained from this list and were considered for review.

Memantine reduces alcohol drinking but not relapse in alcohol-dependent rats

Alcoholism is a chronic relapsing disorder with consequences on health and that requires more effective treatments. Among alternative therapies, the therapeutic potential of the non-competitive N-methyl-D-aspartate receptor antagonist memantine has been suggested. Despite promising results, its efficiency in the treatment of alcoholism remains controversial. Currently, there is no pre-clinical data regarding its effects on the motivation for ethanol in post-dependent (PD) animals exposed to intermittent ethanol vapor, a validated model of alcoholism. Thus, the objectives of this study were to evaluate the effects of acute injections of memantine (0, 12.5, 25 and 50 mg/kg) on operant ethanol self-administration in non-dependent (ND) and PD rats tested either during acute withdrawal or relapse after protracted abstinence. Our results showed that memantine (25 mg/kg) abolished ethanol self-administration in ND rats and reduced by half the one of PD rats during acute withdrawal. While this effect was observed only 6 hours after treatment in ND rats, it was long lasting in PD rats (at least 30 hours after injection). Furthermore, our results indicated that memantine did not modify the breaking point for ethanol. This suggests that memantine probably act by potentiating the pharmacological effect of ethanol but not by reducing motivation for ethanol. Finally, memantine was also ineffective in reducing relapse after protracted abstinence. Altogether, our pre-clinical results highlighted a potential therapeutic use of memantine that may be used as a replacement therapy drug but not as relapse-preventing drug.

Assessing ethanol's actions in the suprachiasmatic circadian clock using in vivo and in vitro approaches

Research over the past decade has demonstrated substantial interactions between the circadian system and the processes through which alcohol affects behavior and physiology. Here we summarize the results of our collaborative efforts focused on this intersection. Using a combination of in vivo and in vitro approaches, we have shown that ethanol affects many aspects of the mammalian circadian system, both acutely as well as after chronic administration. Conversely, we have shown circadian influences on ethanol consumption. Importantly, we are beginning to delve into the cellular mechanisms associated with these effects. We are also starting to form a picture of the neuroanatomical bases for many of these actions. Finally, we put our current findings into perspective by suggesting new avenues of inquiry for our future efforts.

Alteration of glutamate/GABA balance during acute alcohol intoxication in rats: effect of Xingnaojing injection

ETHNOPHARMACOLOGICAL RELEVANCE

Xingnaojing Injection (XNJI) is a modern Chinese formula came from famous Chinese medicine An Gong Niu Huang Pill. XNJI has been used for treatment of cerebral diseases and stroke in China, and is approved by the State Food and Drug Administration of China for the treatment of acute alcohol intoxication (AAI). XNJI belongs to the ethnopharmacological family of medicines. In this study, we investigated the mechanisms of the XNJI effect on AAI.

AIM OF THE STUDY

To investigate the effects of XNJI on glutamate, gamma-aminobutyric acid (GABA) and related receptor in lateral hypothalamic area (LHA) of AAI rat.

MATERIAL AND METHODS

Adult male Sprague-Dawley rats were implanted with microdialysis probes in LHA. Rats were randomly divided into control, model, 1.36mg/kg XNJI, 0.68mg/kg XNJI and 0.34mg/kg XNJI groups. During microdialysis, baseline samples were collected from 1h to 2.5h; thereafter, the rats were given an intraperitoneal injection of 52% ethanol, 5.2g/kg, or saline for control group. Twenty minutes later, three doses of XNJI was given by unilateral injection respectively, while saline for control and model groups, and samples were collected for the next 4h. The extracellular glutamate and GABA levels were measured in the LHA by a high performance liquid chromatography coupled with fluorescence detector (HPLC-FLU). The expression levels of related receptors N-methyl-d-aspartate receptor (NR) subunit NR2A, NR2B and GABAA were analyzed by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Ethanol (5.2g/kg) significantly decreased the extracellular levels of glutamate and increased extracellular GABA in LHA. On the other hand ethanol significantly decreased NR2A and NR2B mRNAs expression, and increase GABAA mRNA expression. XNJI could increase the extracellular level of glutamate and decrease that of GABA; moreover, induced an increase in NR2A and NR2B mRNA expression, and a decrease in GABAA mRNA expression in LHA.

CONCLUSIONS

The current changes in glutamate, GABA and mRNA expressions of related receptors in LHA after injection of XNJI suggest that changes in these neurotransmitters and receptors as a potential mechanism of action for AAI.

Baclofen for alcohol withdrawal

BACKGROUND

The treatment baclofen shows potential for rapidly reducing symptoms of severe alcohol withdrawal syndrome (AWS) in people with alcoholism. Treatment with baclofen is easy to manage and rarely produces euphoria or other pleasant effects, or craving for the drug. This is an updated version of the original Cochrane review published in Issue 2, 2013.

OBJECTIVES

To assess the efficacy and safety of baclofen for people with AWS.

SEARCH METHODS

We searched the Cochrane Drugs and Alcohol Group Specialised Register (searched 13 January 2015), the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 1), MEDLINE (1966 to January 2015), EMBASE (1980 to January 2015), and CINAHL (1982 to January 2015). We also searched registers of ongoing trials, including ClinicalTrials.gov, the ISRCTN registry, and the European Clinical Trials Database. At the same time, we handsearched the references quoted in the identified trials, and sought information from researchers, pharmaceutical companies, and relevant trial authors about unpublished or uncompleted trials. We placed no restrictions on language.

SELECTION CRITERIA

We included all randomised controlled clinical trials (RCTs) evaluating baclofen versus placebo or any other treatment for people with AWS. We excluded uncontrolled, non-randomised, or quasi-randomised trials. We included both parallel group and cross-over studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed references retrieved for possible inclusion. Any disagreements were resolved by an independent party. We contacted study authors for additional information where needed. We collected adverse effects information from the trials.

MAIN RESULTS

Two RCTs with a total of 81 participants were eligible according to the inclusion criteria. One study suggested that both baclofen and diazepam significantly decreased the Clinical Institute Withdrawal Assessment of Alcohol Scale, Revised (CIWA-Ar) score, without any significant difference between the two interventions. The other study showed no significant difference in CIWA-Ar score between baclofen and placebo, but a significantly decreased dependence on high-dose benzodiazepines with baclofen compared to placebo. Only one study reported on the safety of baclofen, without any side effects.

AUTHORS' CONCLUSIONS

The evidence for recommending baclofen for AWS is insufficient. We therefore need more well-designed RCTs to prove its efficacy and safety.

Neurotoxicity of solvents

Worldwide, several hundred million tons of organic solvents are used annually in household, industry, and other occupational settings. Millions of workers are regularly exposed to organic solvents considered neurotoxic. Acute neurotoxicity due to high exposure of solvent is usually evident, but the nature of long-term effects, such as chronic solvent encephalopathy (CSE), has raised uncertainty even among experts. Earlier studies were criticized for their methodology, mainly epidemiologic studies or investigations of exposed groups with many possible confounders and inadequate exposure assessment. However, an increasing number of studies have been performed since, also on workers with defined CSE based on differential diagnostics. During the last decade, evidence has emerged to enable identification of CSE, a necessity for the early recognition and prevention of progression of dysfunction and disability. Selected chemicals are presented here due to their widespread use, neurotoxic potential, and ability to cause solvent encephalopathy. Constant introduction of new chemicals may introduce new hazardous chemicals or known chemicals may reveal new health effects. It is important to keep an open mind for new findings of solvent-related neurobehavioral effects.

Topiramate for the treatment of epilepsy and other nervous system disorders

Initially synthesized as an oral hypoglycemic agent, topiramate was approved for use as an anticonvulsant in 1996. Its broad spectrum efficacy in epilepsy, including as monotherapy and in children, is well established. Topiramate has also been used in the management of nonepileptic neurologic and psychiatric conditions, including migraine prophylaxis (with firmly established efficacy), obesity (with some evidence of long-term maintenance of weight loss), substance dependence, bipolar disorder and neuropathic pain, and it has been investigated as a possible neuroprotective agent. Paresthesias and cognitive side effects are the most common troublesome adverse effects. Recent trends towards lower doses may help achieve the best combination of efficacy and tolerability.

Alcohol withdrawal delirium - diagnosis, course and treatment

OBJECTIVE

Delirium tremens represents the most severe complication of alcohol withdrawal syndrome and, in its complications, significantly increases the morbidity and mortality of patients. Alcohol withdrawal delirium is characterized by features of alcohol withdrawal itself (tremor, sweating, hypertension, tachycardia etc.) together with general delirious symptoms such as clouded consciousness, disorientation, disturbed circadian rhythms, thought processe and sensory disturbances, all of them fluctuating in time. The treatment combines a supportive and symptomatic approach. Benzodiazepines in supramaximal doses are usually used as drugs of choice but in some countries such as the Czech Republic or Germany, clomethiazole is frequently used as well.

METHOD

A computer search of the all the literature published between 1966 and December 2012 was accomplished on MEDLINE and Web of Science with the key words "delirium tremens", "alcohol withdrawal", "treatment" and "pharmacotherapy". There were no language or time limits applied.

CONCLUSIONS

When not early recognized and treated adequately, delirium tremens may result in death due to malignant arrhythmia, respiratory arrest, sepsis, severe electrolyte disturbance or prolonged seizures and subsequent trauma. Owing to these possible fatalities and other severe unexpected complications, delirium tremens should be managed at an ICU or wards ensuring vital signs monitoring. In symptomatic treatment, high doses of benzodiazepines, especially lorazepam, diazepam and oxazepam are considered the gold standard drugs. Supportive therapy is also of great importance.

Neuropathogenesis of delirium: review of current etiologic theories and common pathways

Delirium is a neurobehavioral syndrome caused by dysregulation of neuronal activity secondary to systemic disturbances. Over time, a number of theories have been proposed in an attempt to explain the processes leading to the development of delirium. Each proposed theory has focused on a specific mechanism or pathologic process (e.g., dopamine excess or acetylcholine deficiency theories), observational and experiential evidence (e.g., sleep deprivation, aging), or empirical data (e.g., specific pharmacologic agents' association with postoperative delirium, intraoperative hypoxia). This article represents a review of published literature and summarizes the top seven proposed theories and their interrelation. This review includes the "neuroinflammatory," "neuronal aging," "oxidative stress," "neurotransmitter deficiency," "neuroendocrine," "diurnal dysregulation," and "network disconnectivity" hypotheses. Most of these theories are complementary, rather than competing, with many areas of intersection and reciprocal influence. The literature suggests that many factors or mechanisms included in these theories lead to a final common outcome associated with an alteration in neurotransmitter synthesis, function, and/or availability that mediates the complex behavioral and cognitive changes observed in delirium. In general, the most commonly described neurotransmitter changes associated with delirium include deficiencies in acetylcholine and/or melatonin availability; excess in dopamine, norepinephrine, and/or glutamate release; and variable alterations (e.g., either a decreased or increased activity, depending on delirium presentation and cause) in serotonin, histamine, and/or γ-aminobutyric acid. In the end, it is unlikely that any one of these theories is fully capable of explaining the etiology or phenomenologic manifestations of delirium but rather that two or more of these, if not all, act together to lead to the biochemical derangement and, ultimately, to the complex cognitive and behavioral changes characteristic of delirium.

The efficacy of a low dose combination of topiramate and naltrexone on ethanol reinforcement and consumption in rat models

RATIONALE

Combined medication approaches, by targeting multiple neurotransmitter systems involved in alcohol use disorders (AUDs), may be more efficacious than single-medication approaches.

OBJECTIVES

We examined, in animal models of consumption and reinforcement, the combined effects of naltrexone (an opioid antagonist) and topiramate (a GABA/glutamate modulator), two medications that have shown promise for treating AUDs, hypothesizing that their combination would be more efficacious than either alone.

METHODS

The effects of naltrexone and topiramate on ethanol consumption were examined in alcohol preferring (P) rats (N=10) and in rats from their background strain (Wistar, N=9) using conditions that induce high levels of consumption (24-h, 3-bottle, free-choice procedure). Low doses of each medication (1mg/kg, naltrexone; 10mg/kg, topiramate) were selected in an attempt to maximize their combined efficacy while minimizing potential side-effects. Their effects on ethanol reinforcement were assessed under a progressive-ratio schedule in additional groups of (N=22) P rats. A moderate dose of topiramate (20mg/kg) was also included to verify topiramate's efficacy on its own.

RESULTS

In P rats, but not in Wistar rats, the combination effectively and persistently reduced consumption; whereas, neither dose alone was effective. The combination and naltrexone alone were equally effective at reducing ethanol reinforcement; however, with the combination, but not naltrexone alone, this effect was selective for ethanol. All treatments produced a similar decrease in home-cage food consumption. The 20mg/kg dose of topiramate also effectively reduced ethanol consumption and reinforcement.

CONCLUSIONS

With greater efficacy and fewer side-effects, the combination shows promise as a treatment for AUDs.

Cold-inducible RNA-binding protein is an important mediator of alcohol-induced brain inflammation

Binge drinking has been associated with cerebral dysfunction. Ethanol induced microglial activation initiates an inflammatory process that causes upregulation of proinflammatory cytokines which in turn creates neuronal inflammation and damage. However, the molecular mechanism is not fully understood. We postulate that cold-inducible RNA-binding protein (CIRP), a novel proinflammatory molecule, can contribute to alcohol-induced neuroinflammation. To test this theory male wild-type (WT) mice were exposed to alcohol at concentrations consistent to binge drinking and blood and brain tissues were collected. At 5 h after alcohol, a significant increase of 53% in the brain of CIRP mRNA was observed and its expression remained elevated at 10 h and 15 h. Brain CIRP protein levels were increased by 184% at 10 h and remained high at 15 h. We then exposed male WT and CIRP knockout (CIRP^−/−) mice to alcohol, and blood and brain tissues were collected at 15 h post-alcohol infusion. Serum levels of tissue injury markers (AST, ALT and LDH) were significantly elevated in alcohol-exposed WT mice while they were less increased in the CIRP^−/− mice. Brain TNF-α mRNA and protein expressions along with IL-1β protein levels were significantly increased in WT mice, which was not seen in the CIRP^−/− mice. In cultured BV2 cells (mouse microglia), ethanol at 100 mM showed an increase of CIRP mRNA by 274% and 408% at 24 h and 48 h respectively. Corresponding increases in TNF-α and IL-1β were also observed. CIRP protein levels were markedly increased in the medium, suggesting that CIRP was secreted by the BV2 cells. From this we conclude that alcohol exposure activates microglia to produce and secrete CIRP and possibly induce pro-inflammatory response and thereby causing neuroinflammation. CIRP could be a novel mediator of alcohol-induced brain inflammation.

The effectiveness of pharmacological approaches in the treatment of alcohol withdrawal syndrome (AWS): a literature review

Mortality statistics for excessive alcohol consumption show no signs of abatement, with a report published in 2011 from the World Health Organization (WHO) estimating that 2.5 million people worldwide died because of their alcohol consumption. Serious physiological, psychological, social and legal problems are thought to affect many more. Alcohol withdrawal syndrome (AWS) is a potentially life-threatening condition that often occurs in those individuals who significantly reduce or stop their intake after a prolonged and excessive period of drinking. Pharmacological treatment of the AWS has traditionally been undertaken by the use of the benzodiazepines, but recent years have witnessed the emergence of several alternatives. The aim of this paper was (1) to review the evidence base supporting the use of various pharmacological agents currently employed to treat AWS, and (2) to consider the efficacy and safety of the emerging alternatives to the benzodiazepines. The Cochrane Database of Systematic Reviews, CINAHL, Embase, PsycINFO, MEDLINE and BNI databases were extensively searched in order to retrieve the maximum number of relevant articles. Reference lists from relevant literature were also used to identify other potential studies for inclusion. All studies concerned with measuring the efficacy and safety of the various pharmacological treatment options for AWS were considered and a total of 63 trials were included in this review. Findings support the use of benzodiazepines as the recommended drug of choice for the treatment of AWS in the absence of adequate evidence to support the use of alternative agents. There is a lack of evidence of a superior pharmacological agent to the benzodiazepines for the treatment of AWS. There are several studies that have shown that there are pharmacological alternatives that could compete or act as an adjunct with the benzodiazepines in terms of high efficacy and safety in the treatment of AWS, but there is a need for further quality research to be carried out before definitive conclusions can be drawn.

Prenatal stress increased Snk Polo-like kinase 2, SCF β-TrCP ubiquitin ligase and ubiquitination of SPAR in the hippocampus of the offspring at adulthood

Exposure to excessive glucocorticoids during fetal development period contributes to later life psychopathology. Prenatal stress decreases dendritic spine density and impair LTP in the hippocampus of rat pups, however, the mechanisms regulating these changes are still unclear. Glutamate receptors are localized in the postsynaptic density. PSD-95 is a postsynaptic scaffolding protein that plays a role in synaptic maturation and regulation of the synaptic strength and plasticity. PSD-95 interacts with other proteins to form the protein networks that promote dendritic spine formation. The present study investigated the effect of prenatal stress on the levels of scaffolding proteins of NMDA receptor in the hippocampus in order to explain how prenatal stress alters the amount of NMDA receptor in the pups' brain. Pregnant rats were randomly assigned to either the prenatal stress (PS) or the control group (C). The pregnant rats in the PS group were restrained in a plexiglas restrainer for 4h/day during the GD 14-21. Control rats were left undisturbed for the duration of their pregnancies. The amount of PSD-95, SPAR, NR2A and NR2B, as well as the levels of Snk Polo-like kinase 2 and the SCF β-TrCP ubiquitin ligase were measured in the hippocampus of the offspring. The results show that prenatal stress induces a reduction in the amount of NR2B and NR2A subunits in the hippocampus of rat pups, parallel to the decrease in PSD-95 and SPAR at P40 and P60. Moreover, prenatal stress increases Snk and β-TrCP in the hippocampus of rat pups, and the timing correlates with the decrease of SPAR and PSD-95. Prenatal stress also induces a significantly increases in the level of ubiquitinated SPAR in the hippocampus of rat pups at adulthood. The results suggest that degradation of SPAR via UPS system may contribute to the loss of PSD-95 and NMDA receptor subunits in the hippocampus of rat pups at adulthood. In conclusion, the present work demonstrates that the developing brain is critically influenced by glucocorticoids, especially during pre- and early postnatal period, which can have long-term effects on brain development. In addition, an involvement of the UPS system in the prenatal stress model has led to a greater understanding of the effects of prenatal stress later on in life.

Baclofen for alcohol withdrawal

BACKGROUND

The treatment baclofen can rapidly reduce symptoms of severe alcohol withdrawal syndrome (AWS) in alcoholic patients, with a significant reduction in the cost. Baclofen is easy to manage, and rare euphoria, craving and other pleasant effects are reported by patients treated with baclofen.

OBJECTIVES

To assess the efficacy and safety of baclofen for patients with AWS.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (October 2012), MEDLINE (1966 to October 2012), EMBASE (1980 to October 2012) and CINAHL (1982 to October 2012). We also searched registers of ongoing trials, for example ClinicalTrials.gov, Controlled-trials.com, EUDRACT, etc. At the same time, we handsearched the references quoted in the identified trials, and contacted researchers, pharmaceutical companies and relevant trial authors seeking information about unpublished or uncompleted trials. All searches included the non-English language literature.

SELECTION CRITERIA

All randomized controlled clinical trials (RCTs) evaluating baclofen versus placebo or any other treatment for patients with AWS. Uncontrolled, non-randomized or quasi-randomized trials were excluded. Both parallel group and cross-over design were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed references retrieved for possible inclusion. All disagreements were resolved by an independent party. Study authors were contacted for additional information. Adverse effects information was collected from the trials.

MAIN RESULTS

We identified a total of 113 references from all electronic databases searched excluding duplicates. After screening of titles and abstracts, full papers of 10 studies were obtained and assessed for eligibility. Finally, two RCTs with 81 participants were eligible according to the inclusion criteria. Regarding the efficacy, one study suggested that both baclofen and diazepam significantly decreased the Clinical Institute Withdrawal Assessment of Alcohol Scale Revised (CIWA-Ar) score, without any significant difference between the two interventions. The other study showed no significant difference in CIWA-Ar score between baclofen and placebo but a significantly decreased dependence on high-dose benzodiazepines with baclofen compared to placebo. Meanwhile, only one study reported the safety outcomes and there were no side effects in either the baclofen or diazepam groups.

AUTHORS' CONCLUSIONS

The evidence for recommending baclofen for AWS is insufficient. More well designed RCTs are needed to prove its efficacy and safety.

Improving the inhibitory activity of arylidenaminoguanidine compounds at the N-methyl-D-aspartate receptor complex from a recursive computational-experimental structure-activity relationship study

Using a combination of both the partial least squares (PLS) and back-propagation artificial neural network (ANN) pattern recognition methods, several models have been developed to predict the activity of a series of arylidenaminoguanidine analogs as inhibitory modulators of the N-methyl-D-aspartate receptor complex. This was done by correlating structural and physicochemical descriptors obtained from computation software with the experimentally observed [(3)H]MK-801 displacement ability of a small library of synthesized and in vitro screened arylidenaminoguanidines. Results for the generated PLS model were r(2)=0.814, rmsd=0.208, rCV(2)=0.714, loormsd=0.261. The ANN model was created utilizing the eleven descriptors from the PLS model for comparison. The quality of the ANN model (r(2)=0.828, rmsd=0.200, rCV(2)=0.721, loormsd=0.257) is similar to the PLS model, and indicates that the feature between the inputs and the output is majorly linear. These computational models were able to predict inhibition of the NMDA receptor complex by this series of compounds in silico, affording a predictive structure-based 'pre-screening' paradigm for the arylideneaminoguanidine analogs.

Alcohol withdrawal

Alcohol withdrawal is a common clinical condition that has a variety of complications and morbidities. The manifestations can range from mild agitation to withdrawal seizures and delirium tremens. The treatments for alcohol withdrawal include benzodiazepines, anticonvulsants, beta-blockers and antihypertensives. Although benzodiazepines are presently a first-line therapy, there is controversy regarding the efficacies of these medications compared with others. Treatment protocols often involve one of two contrasting approaches: symptom-triggered versus fixed-schedule dosing of benzodiazepines. We describe these protocols in our review and examine the data supporting symptom-triggered dosing as the preferred method for most patients in withdrawal.The Clinical Institute Withdrawal Assessment for Alcohol scoring system for alcohol withdrawal streamlines care, optimizes patient management, and is the best scale available for withdrawal assessment. Quality improvement implications for inpatient management of alcohol withdrawal include increasing training for signs of withdrawal and symptom recognition, adding new hospital protocols to employee curricula, and ensuring manageable patient-to-physician and patient-to-nurse ratios.

Influence of chronic ethanol intake on mouse synaptosomal aspartyl aminopeptidase and aminopeptidase A: relationship with oxidative stress indicators

Aminopeptidase A (APA) and aspartyl aminopeptidase (ASAP) not only act as neuromodulators in the regional brain renin-angiotensin system, but also release N-terminal acidic amino acids (glutamate and aspartate). The hyperexcitability of amino acid neurotransmitters is responsible for several neurodegenerative processes affecting the central nervous system. The purpose of the present work was to study the influence of chronic ethanol intake, a well known neurotoxic compound, on APA and ASAP activity under resting and K(+)-stimulated conditions at the synapse level. APA and ASAP activity were determined against glutamate- and aspartate-β-naphthylamide respectively in mouse frontal cortex synaptosomes and in their incubation supernatant in a Ca(2+)-containing or Ca(2+)-free artificial cerebrospinal fluid. The neurotoxic effects were analyzed by determining free radical generation, peroxidation of membrane lipids and the oxidation of synaptosomal proteins. In addition, the bioenergetic behavior of synaptosomes was analyzed under different experimental protocols. We obtained several modifications in oxidative stress parameters and a preferential inhibitor effect of chronic ethanol intake on APA and ASAP activities. Although previous in vitro studies failed to show signs of neurodegeneration, these in vivo modifications in oxidative stress parameters do not seem to be related to changes in APA and ASAP, invalidating the idea that an excess of free acidic amino acids released by APA and ASAP induces neurodegeneration.

Genetic variability in the NMDA-dependent AMPA trafficking cascade is associated with alcohol dependence

Model studies in mice indicate that the severity of alcohol withdrawal is associated with polymorphic variation and expression of the MPDZ gene. Current knowledge about variation in the human MPDZ gene is limited; however, our data indicate its potential association with alcohol dependence. The multi-PDZ protein is an important part of the N-methyl-D-aspartate (NMDA)-dependent α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor trafficking cascade that controls glutamate-related excitatory neurotransmission. To investigate association of variation in the NMDA-dependent AMPA trafficking cascade with alcohol dependence, we performed a gene-set (pathway) analysis using single nucleotide polymorphism (SNP) data from the Study of Addiction: Genetic and Environment. Rather than testing for association with each SNP individually, which typically has low power to detect small effects of multiple SNPs, gene-set analysis applies a single statistical test to evaluate whether variation in a set of genes is associated with the phenotype of interest. Gene-set analysis of 988 SNPs in 13 genes in the pathway demonstrated a significant association with alcohol dependence, with P < 0.01 for the global effect of variation in this pathway. The statistically significant association of alcohol dependence with genetic variation in the NMDA-dependent AMPA receptor trafficking cascade indicates a need for further investigation of the role of this pathway in alcohol dependence.

Ethanol up-regulates nucleus accumbens neuronal activity dependent pentraxin (Narp): implications for alcohol-induced behavioral plasticity

Neuronal activity dependent pentraxin (Narp) interacts with α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) glutamate receptors to facilitate excitatory synapse formation by aggregating them at established synapses. Alcohol is well-characterized to influence central glutamatergic transmission, including AMPA receptor function. Herein, we examined the influence of injected and ingested alcohol upon Narp protein expression, as well as basal Narp expression in mouse lines selectively bred for high blood alcohol concentrations under limited access conditions. Alcohol up-regulated accumbens Narp levels, concomitant with increases in levels of the GluR1 AMPA receptor subunit. However, accumbens Narp or GluR1 levels did not vary as a function of selectively bred genotype. We next employed a Narp knock-out (KO) strategy to begin to understand the behavioral relevance of alcohol-induced changes in protein expression in several assays of alcohol reward. Compared to wild-type mice, Narp KO animals: fail to escalate daily intake of high alcohol concentrations under free-access conditions; shift their preference away from high alcohol concentrations with repeated alcohol experience; exhibit a conditioned place-aversion in response to the repeated pairing of 3 g/kg alcohol with a distinct environment and fail to exhibit alcohol-induced locomotor hyperactivity following repeated alcohol treatment. Narp deletion did not influence the daily intake of either food or water, nor did it alter any aspect of spontaneous or alcohol-induced motor activity, including the development of tolerance to its motor-impairing effects with repeated treatment. Taken together, these data indicate that Narp induction, and presumably subsequent aggregation of AMPA receptors, may be important for neuroplasticity within limbic subcircuits mediating or maintaining the rewarding properties of alcohol.

Pilot study of iPS-derived neural cells to examine biologic effects of alcohol on human neurons in vitro

BACKGROUND

Studies of the effects of alcohol on N-methyl-d-aspartate (NMDA) receptor function and gene expression have depended on rodent or postmortem human brain models. Ideally, the effects of alcohol might better be examined in living neural tissue derived from human subjects. In this study, we used new technologies to reprogram human subject-specific tissue into pluripotent cell colonies and generate human neural cultures as a model system to examine the molecular actions of alcohol.

METHODS

Induced pluripotent stem (iPS) cells were generated from skin biopsies taken from 7 individuals, 4 alcohol-dependent subjects, and 3 social drinkers. We differentiated the iPS cells into neural cultures and characterized them by immunocytochemistry using antibodies for the neuronal marker beta-III tubulin, glial marker s100β, and synaptic marker synpasin-1. Electrophysiology was performed to characterize the iPS-derived neurons and to measure the effects of acute alcohol exposure on the NMDA receptor response in chronically alcohol exposed and nonexposed neural cultures from 1 nonalcoholic. Finally, we examined changes in mRNA expression of the NMDA receptor subunit genes GRIN1, GRIN2A, GRIN2B, and GRIN2D after 7 days of alcohol exposure and after 24-hour withdrawal from chronic alcohol exposure.

RESULTS

Immunocytochemistry revealed positive staining for neuronal, glial, and synaptic markers. iPS-derived neurons displayed spontaneous electrical properties and functional ionotropic receptors. Acute alcohol exposure significantly attenuated the NMDA response, an effect that was not observed after 7 days of chronic alcohol exposure. After 7 days of chronic alcohol exposure, there were significant increases in mRNA expression of GRIN1, GRIN2A, and GRIN2D in cultures derived from alcoholic subjects but not in cultures derived from nonalcoholics.

CONCLUSIONS

These findings support the potential utility of human iPS-derived neural cultures as in vitro models to examine the molecular actions of alcohol on human neural cells.

Pharmacological modulation of mGluR7 with AMN082 and MMPIP exerts specific influences on alcohol consumption and preference in rats

Growing evidence supports a role for the central nervous system (CNS) neurotransmitter L-glutamate and its metabotropic receptors (mGluRs) in drug addiction in general and alcohol-use disorders in particular. Alcohol dependence, for instance, has a genetic component, and the recent discovery that variations in the gene coding for mGluR7 modulate alcohol consumption further validates involvement of the L-glutamate system. Consequently, increasing interest emerges in developing L-glutamatergic therapies for the treatment of alcohol abuse and dependence. To this end, we performed a detailed behavioral pharmacology study to investigate the regulation of alcohol consumption and preference following administration of the mGluR7-selective drugs N,N'-dibenzyhydryl-ethane-1,2-diamine dihydrochloride (AMN082) and 6-(4-Methoxyphenyl)-5-methyl-3-(4-pyridinyl)-isoxazolo[4,5-c]pyridin-4(5H)-one hydrochloride (MMPIP). Upon administration of the allosteric agonist AMN082 (10 mg/kg, i.p.) in rats, there was a significant decrease in ethanol consumption and preference, without affecting ethanol blood metabolism. In contrast, mGluR7 blockade with MMPIP (10 mg/kg, i.p.) showed an increase in alcohol intake and reversed AMN082's effect on ethanol consumption and preference. Both mGluR7-directed pharmacological tools had no effect on total fluid intake, taste preference, or on spontaneous locomotor activity. In conclusion, these findings support a specific regulatory role for mGluR7 on alcohol drinking and preference and provide evidence for the use of AMN082-type drugs as potential new treatments for alcohol-use disorders in man.

Circadian and acamprosate modulation of elevated ethanol drinking in mPer2 clock gene mutant mice

The PER2 clock gene modulates ethanol consumption, such that mutant mice not expressing functional mPer2 have altered circadian behavior that promotes higher ethanol intake and preference. Experiments were undertaken to characterize circadian-related behavioral effects of mPer2 deletion on ethanol intake and to explore how acamprosate (used to reduce alcohol dependence) alters diurnal patterns of ethanol intake. Male mPer2 mutant and WT (wild-type) mice were entrained to a 12:12 h light-dark (12L:12D) photocycle, and their locomotor and drinking activities were recorded. Circadian locomotor measurements confirmed that mPer2 mutants had an advanced onset of nocturnal activity of about 2 h relative to WTs, and an increased duration of nocturnal activity (p < .01). Also, mPer2 mutants preferred and consumed more ethanol and had more daily ethanol drinking episodes vs. WTs. Measurements of systemic ethanol using subcutaneous microdialysis confirmed the advanced rise in ethanol intake in the mPer2 mutants, with 24-h averages being ∼60 vs. ∼25 mM for WTs (p < .01). A 6-day regimen of single intraperitoneal (i.p.) acamprosate injections (300 mg/kg) at zeitgeber time (ZT) 10 did not alter the earlier onset of nocturnal ethanol drinking in the mPer2 mutants, but reduced the overall amplitude of drinking and preference (both p < .01). Acamprosate also reduced these parameters in WTs. These results suggest that elevated ethanol intake in mPer2 mutants may be a partial consequence of an earlier nighttime activity onset and increase in nocturnal drinking activity. The suppressive action of acamprosate on ethanol intake is not due to an altered diurnal pattern of drinking, but rather a decrease in the number of daily drinking bouts and amount of drinking per bout.

Acamprosate-responsive brain sites for suppression of ethanol intake and preference

Acamprosate suppresses alcohol intake and craving in recovering alcoholics; however, the central sites of its action are unclear. To approach this question, brain regions responsive to acamprosate were mapped using acamprosate microimplants targeted to brain reward and circadian areas implicated in alcohol dependence. mPer2 mutant mice with nonfunctional mPer2, a circadian clock gene that gates endogenous timekeeping, were included, owing to their high levels of ethanol intake and preference. Male wild-type (WT) and mPer2 mutant mice received free-choice (15%) ethanol/water for 3 wk. The ethanol was withdrawn for 3 wk and then reintroduced to facilitate relapse. Four days before ethanol reintroduction, mice received bilateral blank or acamprosate-containing microimplants releasing ∼50 ng/day into reward [ventral tegmental (VTA), peduculopontine tegmentum (PPT), and nucleus accumbens (NA)] and circadian [intergeniculate leaflet (IGL) and suprachiasmatic nucleus (SCN)] areas. The hippocampus was also targeted. Circadian locomotor activity was measured throughout. Ethanol intake and preference were greater in mPer2 mutants than in wild-type (WT) mice (27 g·kg(-1)·day(-1) vs. 13 g·kg(-1)·day(-1) and 70% vs. 50%, respectively; both, P < 0.05). In WTs, acamprosate in all areas, except hippocampus, suppressed ethanol intake and preference (by 40-60%) during ethanol reintroduction. In mPer2 mutants, acamprosate in the VTA, PPT, and SCN suppressed ethanol intake and preference by 20-30%. These data are evidence that acamprosate's suppression of ethanol intake and preference are manifest through actions within major reward and circadian sites.

Efficacy and safety of pharmacological interventions for the treatment of the Alcohol Withdrawal Syndrome

BACKGROUND

Alcohol abuse and dependence represents a very serious health problem worldwide with major social, interpersonal and legal interpolations. Pharmacological treatments presently used are of uncertain effectiveness and there is even more doubt on the comparative effects and value for money.

OBJECTIVES

To summarize Cochrane reviews that assess the effectiveness and safety of pharmacological interventions in the treatment of alcohol withdrawal.

METHODS

We searched the Cochrane Database of Systematic Reviews (30 November 2010). Two authors independently screened, extracted data, summarised key characteristics of the included reviews and assessed their quality using AMSTAR; the quality of the evidence was summarised according to the GRADE methodology.

MAIN RESULTS

Five reviews, 114 studies, 7333 participants, satisfied criteria for inclusions. The outcomes considered were alcohol withdrawal seizures, adverse events and dropouts. Comparing the five treatments with placebo, benzodiazepines performed better for seizures, three studies, 324 participants, RR 0.16 (95% CI 0.04 to 0.69), moderate quality of evidence. Comparing each of the five treatments versus specific class of drugs, benzodiazepines performed better than antipsychotics for seizures, 4 studies, 633 participants, RR 0.24 (95% CI 0.07 to 0.88) high quality of the evidence. Comparing different benzodiazepines and anticonvulsants among themselves, 28 comparisons, results never reached statistical significance but chlordiazepoxide performed better. The quality of evidence was high for 3% of the results, moderate for 28%, low for 48% and very low for 20%.

AUTHORS' CONCLUSIONS

Among the treatments considered, benzodiazepines showed a protective benefit against seizures, when compared to placebo and a potentially protective benefit for many outcomes when compared with antipsychotics. Nevertheless, no definite conclusions about the effectiveness and safety of benzodiazepines were possible, because of the heterogeneity of the trials both in interventions and in the assessment of outcomes. Data on potential harms are sparse and fragmented. Results do not provide sufficient evidence in favour of anticonvulsants for the treatment of AWS, but anticonvulsants seem to have limited side effects. There is also not enough evidence of effectiveness and safety of baclofen, because only one study consider this treatment and of GHB for which no strong differences were observed in the comparisons with placebo, benzodiazepines and anticonvulsants.