Role Of Alcohol Drinking Research Articles

Neuroimmune interactions with binge alcohol drinking in the cerebellum of IL-6 transgenic mice

The neuroimmune system of the brain, which is comprised primarily of astrocytes and microglia, regulates a variety of homeostatic mechanisms that underlie normal brain function. Numerous conditions, including alcohol consumption, can disrupt this regulatory process by altering brain levels of neuroimmune factors. Alcohol and neuroimmune factors, such as proinflammatory cytokines IL-6 and TNF-alpha, act at similar targets in the brain, including excitatory and inhibitory synaptic transmission. Thus, alcohol-induced production of IL-6 and/or TNF-alpha could be important contributing factors to the effects of alcohol on the brain. Recent studies indicate that IL-6 plays a role in alcohol drinking and the effects of alcohol on the brain activity following the cessation of alcohol consumption (post-alcohol period), however information on these topics is limited. Here we used homozygous and heterozygous female and male transgenic mice with increased astrocyte expression of IL-6 to examined further the interactions between alcohol and IL-6 with respect to voluntary alcohol drinking, brain activity during the post-alcohol period, IL-6 signal transduction, and expression of synaptic proteins. Wildtype littermates (WT) served as controls. The transgenic mice model brain neuroimmune status with respect to IL-6 in subjects with a history of persistent alcohol use. Results showed a genotype dependent reduction in voluntary alcohol consumption in the Drinking in the Dark protocol and in frequency-dependent relationships between brain activity in EEG recordings during the post-alcohol period and alcohol consumption. IL-6, TNF-alpha, IL-6 signal transduction partners pSTAT3 and c/EBP beta, and synaptic proteins were shown to play a role in these genotypic effects.

FGF2 is an endogenous regulator of alcohol reward and consumption.

Alcohol use disorder (AUD) is a chronic, relapsing disorder, characterized by escalating alcohol drinking and loss of control, with very limited available treatments. We recently reported that the expression of fibroblast growth factor 2 (Fgf2) is increased in the striatum of rodents following long-term excessive alcohol drinking and that the systemic or intra-striatal administration of recombinant FGF2 increases alcohol consumption. Here, we set out to determine whether the endogenous FGF2 plays a role in alcohol drinking and reward, by testing the behavioural phenotype of Fgf2 knockout mice. We found that Fgf2 deficiency resulted in decreased alcohol consumption when tested in two-bottle choice procedures with various alcohol concentrations. Importantly, these effects were specific for alcohol, as a natural reward (sucrose) or water consumption was not affected by Fgf2 deficiency. In addition, Fgf2 knockout mice failed to show alcohol-conditioned place preference (CPP) but showed normal fear conditioning, suggesting that deletion of the growth factor reduces alcohol's rewarding properties. Finally, Fgf2 knockout mice took longer to recover from the loss of righting reflex and showed higher blood alcohol concentrations when challenged with an intoxicating alcohol dose, suggesting that their ethanol metabolism might be affected. Together, our results show that the endogenous FGF2 plays a critical role in alcohol drinking and reward and indicate that FGF2 is a positive regulator of alcohol-drinking behaviours. Our findings suggest that FGF2 is a potential biomarker for problem alcohol drinking and is a potential target for pharmacotherapy development for AUD.

Alcohol drinking as a mediator of the influence of smoking prevalence on second-hand smoke exposure in workplaces: a mediation analysis

ObjectiveBoth alcohol drinking and second-hand smoke (SHS) exposure have shown a strong association with smoking behaviour. This study uses mediation analysis to clarify the process underlying the relationship between smoking prevalence and SHS exposure and the extent to which this relationship is mediated by alcohol use in the workplace.MethodA total of 14,195 employees from 81 companies in China participated in this survey. Mediation analysis was used to establish the mediation effect of alcohol drinking. Structural equation modelling (SEM) was used to evaluate the role of alcohol drinking when a smoke-free (SF) workplace policy was imposed.ResultsFor males, approximately 6.3% of the effects on SHS exposure were mediated through the channel of alcohol use. For females, this channel mediated 14.1% of the total effects. SF policy was negatively associated with smoking prevalence and SHS exposure. The indirect effect of the SF policy on reducing SHS exposure by controlling smoking behaviour was significant. For smokers, worksite smoking bans were negatively associated with the smoking amount and drinking behaviour, and the indirect effect of this policy on promoting smokers’ intention to quit by reducing the smoking amount and controlling drinking behaviour was significant.ConclusionThis study confirmed that alcohol drinking is among the channels that mediate the association between smoking prevalence and SHS exposure in workplaces. Our results also find a spillover effect of SF workplace policy and call for effective interventions for alcohol use, which may influence the outcomes of SF policy implementation.

Role of Alcohol Drinking in Alzheimer's Disease, Parkinson's Disease, and Amyotrophic Lateral Sclerosis.

Neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD) and amyotrophic lateral sclerosis (ALS), increase as the population ages around the world. Environmental factors also play an important role in most cases. Alcohol consumption exists extensively and it acts as one of the environmental factors that promotes these neurodegenerative diseases. The brain is a major target for the actions of alcohol, and heavy alcohol consumption has long been associated with brain damage. Chronic alcohol intake leads to elevated glutamate-induced excitotoxicity, oxidative stress and permanent neuronal damage associated with malnutrition. The relationship and contributing mechanisms of alcohol with these three diseases are different. Epidemiological studies have reported a reduction in the prevalence of Alzheimer’s disease in individuals who drink low amounts of alcohol; low or moderate concentrations of ethanol protect against β-amyloid (Aβ) toxicity in hippocampal neurons; and excessive amounts of ethanol increase accumulation of Aβ and Tau phosphorylation. Alcohol has been suggested to be either protective of, or not associated with, PD. However, experimental animal studies indicate that chronic heavy alcohol consumption may have dopamine neurotoxic effects through the induction of Cytochrome P450 2E1 (CYP2E1) and an increase in the amount of α-Synuclein (αSYN) relevant to PD. The findings on the association between alcohol consumption and ALS are inconsistent; a recent population-based study suggests that alcohol drinking seems to not influence the risk of developing ALS. Additional research is needed to clarify the potential etiological involvement of alcohol intake in causing or resulting in major neurodegenerative diseases, which will eventually lead to potential therapeutics against these alcoholic neurodegenerative diseases.

The mineralocorticoid receptor antagonist spironolactone reduces alcohol self-administration in female and male rats

Cortisol/corticosterone and the hypothalamic-pituitary-adrenal (HPA) axis serve an important role in modulating alcohol drinking behaviors. To date most alcohol research has focused on the functional involvement of corticosterone and the glucocorticoid receptor (GR), the primary receptor for corticosterone. Recent studies have indicated that the related mineralocorticoid receptor (MR), which binds both corticosterone and aldosterone, may also play a role in alcohol drinking. Therefore, the purpose of the present study was to test the functional role of MR signaling in alcohol self-administration via pharmacological antagonism of the MR with spironolactone. Male and female Long-Evans rats were trained to self-administer a sweetened alcohol solution (15% (v/v) alcohol +2% (w/v) sucrose). The effects of spironolactone (0, 10, 25, 50 mg/kg; IP) were tested on alcohol self-administration and under “probe extinction” conditions to measure the persistence of responding in the absence of the alcohol reinforcer. Parallel experiments in sucrose self-administration trained rats were used to confirm the specificity of spironolactone effects to an alcohol reinforcer. In female rats spironolactone (50 mg/kg) reduced alcohol self-administration and persistence of alcohol responding. In male rats spironolactone (25 and 50 mg/kg) reduced alcohol self-administration, but not persistence of alcohol responding. Spironolactone reduced sucrose intake in female rats only, and locomotion in male and female rats during sucrose self-administration. There was no effect of spironolactone on persistence of sucrose responding. These studies add to growing evidence that the MR is involved in alcohol drinking, while underscoring the importance of studying both male and female animals.

Targeting Opioid and Neurokinin-1 Receptors to Treat Alcoholism

Alcoholism is a multifarious and ongoing disease tightly related to the amount of alcohol ingested, the drinking pattern, the history of alcohol drinking and the individual features, such as some genetic traits. Worldwide alcohol is the necessary cause of approximately 60 diseases and causes circa 2.5 million deaths every year. Studies show that alcohol interacts with brain neurotransmission in a complex manner. Dopaminergic, GABAergic, serotonergic, cholinergic and glutamatergic systems are all key participants in the action of ethanol on the brain. Furthermore, several neuropeptides, such as endogenous opioid peptides, substance P, corticotropin-releasing hormone, or the appetite-regulating peptides (eg., neuropeptide Y, ghrelin or orexin) also play a role in alcohol drinking. Treatment of alcohol use disorders (AUD) is based on the application of combined approaches, including pharmacological intervention directed to different molecular targets. Results, however, are variable, not always satisfactory, and not applicable to all stages and pathologies or to all patients. New strategies focused on the control of neuropeptide performance in the brain are being explored and may be an advance in the therapy of alcoholism. The application of treatments ad personam represents a challenge that currently stimulates research in different realms, including epidemiology, psychology, chemistry, biochemistry, cell biology and pharmacology. In this review the potential value and application of ligands that modulate the function of opioid and neurokinin-1 receptors in alcoholism therapy is analyzed.

Erratum: The Decreased Cyclic-AMP Dependent-Protein Kinase A Function in the Nucleus Accumbens: A Role in Alcohol Drinking but not in Anxiety-Like Behaviors in Rats

The nucleus accumbens (NAc) brain structures have been implicated in the reward and reinforcing properties of ethanol. The present study investigated the role of nucleus accumbal cyclic AMP (cAMP)-dependent protein kinase A (PKA) signaling in alcohol drinking and anxiety-like behaviors of rats. It was found that infusion of PKA inhibitor (Rp-cAMP) into the NAc shell significantly increased the alcohol but not the sucrose intake, without modulating the anxiety-like behaviors, as measured by elevated plus maze test in rats. PKA inhibitor infusion into the NAc shell significantly decreased the protein levels of alpha-catalytic subunit of PKA (PKA-Calpha) and phosphorylated cAMP response element-binding protein (p-CREB) as well as decreased the protein levels of neuropeptide Y (NPY) in the shell but not in the NAc core of rats. On the other hand, infusion of PKA activator (Sp-cAMP) or NPY alone into the NAc shell did not produce any changes in alcohol intake; however, when these agents were coinfused with PKA inhibitor, they significantly attenuated the increases in alcohol preference induced by pharmacological inhibition of PKA. Interestingly, PKA activator coinfusion with PKA inhibitor into the NAc shell significantly normalized the PKA inhibitor-induced decreases in the protein levels of PKA-Calpha and p-CREB as well as of NPY in the NAc shell of rats. Taken together, these results provide the first evidence that decreased PKA function in the NAc shell is involved in alcohol drinking but not in anxiety-like behaviors of rats. Furthermore, decreased function of PKA may regulate alcohol drinking behaviors via CREB-mediated decreased expression of NPY in the NAc shell of rats.

Tobacco smoking, alcohol drinking, and the risk of different histological types of nasopharyngeal cancer in a low-risk population

Nasopharyngeal carcinoma (NPC) is rare in western Countries. Tobacco smoking is a well-recognised risk factor, whereas the role of alcohol drinking is still in debate. We conducted a hospital-based case-control study in Italy on 150, histologically-confirmed, NPC cases of Caucasian ethnicity, aged 18-76years, including 118 undifferentiated NPCs and 22 differentiated squamous-cell NPC. Controls were 450 Caucasian cancer-free patients admitted to general hospitals for acute conditions. Cases and controls were matched according to sex, age, and place of residence. Logistic regression was used to estimate odds ratios (OR) and the corresponding 95% confidence intervals (CI) while adjusting for known confounders. No significant association emerged between tobacco smoking and all NPCs (OR for current vs. never smokers=1.52; 95% CI: 0.89-2.60). Conversely, for differentiated NPC only, statistically significant elevated OR were associated with increasing smoking intensity (OR for ⩾15cigarettes/day=5.40; 95% CI: 1.34-21.76) and duration of the habit (OR for ⩾32years=4.48; 95% CI: 1.11-18.04). Although alcohol drinking was not, per se, significantly associated to NPC risk, the combination of tobacco smoking and alcohol drinking accounted for 57% of differentiated NPCs, whereas it accounted for only 14% of undifferentiated carcinomas. Our findings suggest that, in western populations, NPC includes two separate entities: the differentiated NPC, associated with tobacco smoking like other cancers of head and neck, and the undifferentiated NPC, upon which tobacco smoking has little or no influence.

Erratum: The Decreased Cyclic-AMP Dependent-Protein Kinase A Function in the Nucleus Accumbens: A Role in Alcohol Drinking but not in Anxiety-Like Behaviors in Rats

Erratum: The Decreased Cyclic-AMP Dependent-Protein Kinase A Function in the Nucleus Accumbens: A Role in Alcohol Drinking but not in Anxiety-Like Behaviors in Rats

Erratum: The Decreased Cyclic-AMP-Dependent Protein Kinase A Function in the Nucleus Accumbens: A Role in Alcohol Drinking but not in Anxiety-Like Behaviors in Rats

Erratum: The Decreased Cyclic-AMP-Dependent Protein Kinase A Function in the Nucleus Accumbens: A Role in Alcohol Drinking but not in Anxiety-Like Behaviors in Rats

Central and Medial Amygdaloid Brain-Derived Neurotrophic Factor Signaling Plays a Critical Role in Alcohol-Drinking and Anxiety-Like Behaviors

Brain-derived neurotrophic factor (BDNF) is a member of the nerve growth factor family of neurotrophins and plays a vital role in synaptic plasticity. This study investigated the involvement of the amygdaloid BDNF system in molecular mechanisms underlying anxiety and alcohol-drinking behaviors. Male Sprague Dawley rats were cannulated targeting central amygdala (CeA), medial amygdala (MeA), or basolateral amygdala (BLA), and BDNF expression was manipulated using an antisense oligodeoxynucleotide (ODN) strategy. Anxiety-like and alcohol-drinking behaviors were measured after infusion of BDNF sense and antisense ODNs with or without BDNF coinfusion, using the elevated plus-maze test and two-bottle free-choice paradigm, respectively. Here we report that BDNF antisense ODN infusions into the CeA and MeA, but not BLA, provoked anxiety-like behaviors in rats, which were rescued by BDNF coinfusion. The levels of BDNF, p-ERK1/2 (phosphorylated extracellular signal-regulated kinases 1/2), and p-CREB (phosphorylated cAMP responsive-element binding protein) were decreased by BDNF antisense, but not by sense, ODN infusions, which were restored to normal after BDNF coinfusions. Furthermore, BDNF antisense ODN infusions into the CeA or MeA, but not into BLA, increased alcohol intake, which was attenuated by BDNF coinfusions. These novel results suggest that decreased BDNF levels in the CeA and MeA, but not in the BLA, are crucial in regulating alcohol-drinking and anxiety-like behaviors in rats.

The Decreased Cyclic-AMP Dependent-Protein Kinase A Function in the Nucleus Accumbens: A Role in Alcohol Drinking but not in Anxiety-Like Behaviors in Rats

The nucleus accumbens (NAc) brain structures have been implicated in the reward and reinforcing properties of ethanol. The present study investigated the role of nucleus accumbal cyclic AMP (cAMP)-dependent protein kinase A (PKA) signaling in alcohol drinking and anxiety-like behaviors of rats. It was found that infusion of PKA inhibitor (Rp-cAMP) into the NAc shell significantly increased the alcohol but not the sucrose intake, without modulating the anxiety-like behaviors, as measured by elevated plus maze test in rats. PKA inhibitor infusion into the NAc shell significantly decreased the protein levels of alpha-catalytic subunit of PKA (PKA-Calpha) and phosphorylated cAMP response element-binding protein (p-CREB) as well as decreased the protein levels of neuropeptide Y (NPY) in the shell but not in the NAc core of rats. On the other hand, infusion of PKA activator (Sp-cAMP) or NPY alone into the NAc shell did not produce any changes in alcohol intake; however, when these agents were coinfused with PKA inhibitor, they significantly attenuated the increases in alcohol preference induced by pharmacological inhibition of PKA. Interestingly, PKA activator coinfusion with PKA inhibitor into the NAc shell significantly normalized the PKA inhibitor-induced decreases in the protein levels of PKA-Calpha and p-CREB as well as of NPY in the NAc shell of rats. Taken together, these results provide the first evidence that decreased PKA function in the NAc shell is involved in alcohol drinking but not in anxiety-like behaviors of rats. Furthermore, decreased function of PKA may regulate alcohol drinking behaviors via CREB-mediated decreased expression of NPY in the NAc shell of rats.

Dopamine Release During Ethanol Drinking in AA Rats

The dopamine overflow in the nucleus accumbens of rats from the high alcohol drinking AA line was measured by microdialysis before, during, and after one-half hour sessions of cued drinking of ethanol flavored with saccharin and peppermint or, as a control, saccharin-peppermint drinking. The animals had had extensive previous experience with ethanol drinking. Self-administration of the ethanol solution did not raise the dopamine level substantially: there was a small (17%) but significant increase only during the first 10 min after the onset of drinking. Giving the rats a cue for ethanol, which was part of their daily routine drinking regime, did not raise the dopamine level before ethanol was presented to the rats (i.e., during "anticipation"). The results are consistent with our previous studies showing a lack of a large ethanol-induced dopamine response in rats with previous experience of drinking ethanol and with the idea that although dopamine may play some role in alcohol drinking, it is not the central substrate producing the reinforcement from ethanol in AA rats.