Alcohol Affects the Brain's Resting-State Network in Social Drinkers

Previous neuroscientific findings have linked Alzheimer's Disease (AD) with less efficient information processing and brain network disorganization. However, pathological alterations of the brain networks during the preclinical phase of amnestic Mild Cognitive Impairment (aMCI) remain largely unknown. The present study aimed at comparing patterns of the detection of functional disorganization in MCI relative to Mild Dementia (MD). Participants consisted of 23 cognitively healthy adults, 17 aMCI and 24 mild AD patients who underwent electroencephalographic (EEG) data acquisition during a resting-state condition. Synchronization analysis through the Orthogonal Discrete Wavelet Transform (ODWT), and directional brain network analysis were applied on the EEG data. This computational model was performed for networks that have the same number of edges (N = 500, 600, 700, 800 edges) across all participants and groups (fixed density values). All groups exhibited a small-world (SW) brain architecture. However, we found a significant reduction in the SW brain architecture in both aMCI and MD patients relative to the group of Healthy controls. This functional disorganization was also correlated with the participant's generic cognitive status. The deterioration of the network's organization was caused mainly by deficient local information processing as quantified by the mean cluster coefficient value. Functional hubs were identified through the normalized betweenness centrality metric. Analysis of the local characteristics showed relative hub preservation even with statistically significant reduced strength. Compensatory phenomena were also evident through the formation of additional hubs on left frontal and parietal regions. Our results indicate a declined functional network organization even during the prodromal phase. Degeneration is evident even in the preclinical phase and coexists with transient network reorganization due to compensation.

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“…Finally, the mean cluster coefficient is computed as the mean value of all cluster coefficient values (Lithari et al, 2012). …”

Section: Methodsmentioning

confidence: 99%

Functional disorganization of small-world brain networks in mild Alzheimer's Disease and amnestic Mild Cognitive Impairment: an EEG study using Relative Wavelet Entropy (RWE)

Frantzidιs

Vivas²,

Tsolaki

et al. 2014

Front. Aging Neurosci.

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“…That is, consumption of drugs or EtOH can facilitate the amount and quality of positive social interaction among men (Kirchner et al, 2006). In part, facilitation of social behavior may reflect EtOH-induced loss of social inhibitions (Lithari et al, 2012). This can promote social support (discussion of mental health, showing concern for others) among male friends who drink together (Emslie et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Ethanol Induces Conditioned Social Preference in Male Mice

Kent

Butler

Wood

2014

Alcoholism Clin & Exp Res

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Background Affiliative social interactions promote alcohol consumption, and alcohol also promotes affiliative behavior. Furthermore, for most species, moderate doses of ethanol (EtOH) and social affiliation are each rewarding. However, animal studies of drug and EtOH reward typically test individuals in isolation. To address social dimensions of EtOH reward, the present study tested EtOH-induced conditioned social preference in male C57BL/6 mice with (ORCHX+T) and without (ORCHX) testosterone. Methods ORCHX+T males received EtOH (0, 1, 2 or 3g/kg) ip and were paired 4x for 30 min each with 1 of 2 stimulus males: with the CS-stimulus male after saline injection, and with the CS+ male following EtOH. After pairing, time spent with CS+ and CS− males was measured in a 10 min test. Results ORCHX+T test males showed conditioned preference for the CS+ male in response to 3 g/kg EtOH (change in preference: +71.3±30.0 sec/10 min, p<0.05), but not for 0, 1 or 2g/kg. By contrast, ORCHX males did not demonstrate conditioned preference for 3g/kg EtOH (+16.0±24.3 sec/10 min, p>0.05). In separate groups of mice, stimulus males (IS+) received EtOH during pairing to determine if test mice prefer another intoxicated mouse. Both ORCHX+T and ORCHX test mice showed an increase in preference score for the IS+ mouse (ORCHX+T: +68.1±24.0 sec, ORCHX: +58.9±19.6 sec, p<0.05). Conclusions These data demonstrate that EtOH promotes social preference in male mice, as it does in females. Testosterone enhances this effect.

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“…Some studies show that shortterm alcohol exposure increases the inhibitory effect of GAB-A A Rs; however, many factors determine whether GABA A Rs respond to short-term alcohol exposure [33] . Alcohol can act as a depressant by increasing inhibitory neurotransmission, by decreasing excitatory neurotransmission, or through a combination of both [13,34] . Commonly, alcohol consumption can induce decreases in attention, alterations in memory, reductions in executive decision-making, changes in mood, and drowsiness.…”

Section: Underlying Mechanisms Of Audmentioning

confidence: 99%

Alcohol use disorders and current pharmacological therapies: the role of GABAA receptors

2014

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Alcohol use disorders (AUD) are defined as alcohol abuse and alcohol dependence, which create large problems both for society and for the drinkers themselves. To date, no therapeutic can effectively solve these problems. Understanding the underlying mechanisms leading to AUD is critically important for developing effective and safe pharmacological therapies. Benzodiazepines (BZs) are used to reduce the symptoms of alcohol withdrawal syndrome. However, frequent use of BZs causes cross-tolerance, dependence, and crossaddiction to alcohol. The FDA-approved naltrexone and acamprosate have shown mixed results in clinical trials. Naltrexone is effective to treat alcohol dependence (decreased length and frequency of drinking bouts), but its severe side effects, including withdrawal symptoms, are difficult to overcome. Acamprosate showed efficacy for treating alcohol dependence in European trials, but two large US trials have failed to confirm the efficacy. Another FDA-approved medication, disulfiram, does not diminish craving, and it causes a peripheral neuropathy. Kudzu is the only natural medication mentioned by the National Institute on Alcohol Abuse and Alcoholism, but its mechanisms of action are not yet established. It has been recently shown that dihydromyricetin, a flavonoid purified from Hovenia, has unique effects on GABA A receptors and blocks ethanol intoxication and withdrawal in alcoholic animal models. In this article, we review the role of GABA A receptors in the treatment of AUD and currently available and potentially novel pharmacological agents.

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Alcohol Affects the Brain's Resting-State Network in Social Drinkers

Cited by 32 publications

References 84 publications

Functional disorganization of small-world brain networks in mild Alzheimer's Disease and amnestic Mild Cognitive Impairment: an EEG study using Relative Wavelet Entropy (RWE)

Functional disorganization of small-world brain networks in mild Alzheimer's Disease and amnestic Mild Cognitive Impairment: an EEG study using Relative Wavelet Entropy (RWE)

Ethanol Induces Conditioned Social Preference in Male Mice

Alcohol use disorders and current pharmacological therapies: the role of GABAA receptors

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