Aging with alcohol-related brain damage: Critical brain circuits associated with cognitive dysfunction

Neuropathology of deaths due to acute alcohol toxicity in Australia, 2011-2022

BACKGROUND

A major alcohol-related harm is structural pathology affecting the brain. The study aimed to: 1. Determine the frequency and nature of neuropathology amongst cases of death due to acute alcohol toxicity; 2. Compare diagnoses of brain atrophy with pathology in other organs; 3. Determine the demographic, clinical and organ pathology correlates of brain atrophy.

METHODS

Retrospective study of 500 cases of death attributed to acute alcohol toxicity in Australia, 2011-2022. Data on clinical characteristics, toxicology, neuropathology and other organ pathology were retrieved from police reports, autopsies, toxicology and coronial findings.

RESULTS

Mean age was 49.5 years, 69.4 % were male, with alcohol use problems documented in 70.2 %. Brain atrophy was diagnosed in 60 cases (12.0 %), most commonly in the cerebellum (32 cases, 6.4 %). Atrophy at other sites was present in 37 (7.4 %). The presence of brain atrophy was lower than other major pathologies: cardiomegaly (32.6 %, p<.001), nephro/arteriosclerosis (30.2 %, p<.001), and chronic obstructive pulmonary disease (21.8 %, p<.001) but not hepatic cirrhosis (11.9 % p=1.0). Those diagnosed with atrophy were older (53.4v 49.0 years, p<.001), more likely to have documented alcohol problems (85.0v 68.2 %, Odds ratio: OR 2.53) and seizure history (10.0v 3.0 %, OR 2.92), to have cardiomegaly (43.3v 31.0 %, OR 1.90, COPD (48.3v 18.2 %, 3.57) and nephro/arteriosclerosis (50.0 v 27.4 %, OR 2.27).

CONCLUSIONS

Despite the majority of cases having a history of alcohol problems, the level of neuropathology amongst cases of death due to acute alcohol toxicity was comparatively low.

Alcohol consumption and accelerated biological ageing in middle-aged and older people: A longitudinal study from two cohorts

BACKGROUND AND AIMS

The relationship between alcohol consumption and age-related diseases is inconsistent. Biological age (BA) serves as both a precursor and a predictor of age-related diseases; however, longitudinal associations between alcohol consumption and BA in middle-aged and older people remain unclear. We measured whether there was a longitudinal association between drinking frequency and pure alcohol intake with BA among middle-aged and older people.

DESIGN AND SETTING AND PARTICIPANTS

This study involved two prospective cohort studies, set in Southwestern China and the United Kingdom. A total of 8046 participants from the China Multi-Ethnic Cohort study (CMEC) and 5412 participants from the UK Biobank (UKB), aged 30-79 years, took part, with complete data from two waves of clinical biomarkers.

MEASUREMENTS

BA was calculated by the Klemera Doubal's method. Accelerated BA equalled BA minus chronological age. Drinking frequency and pure alcohol intake were obtained through self-reported questionnaires. Drinking frequency in the past year was classified as current non-drinking, occasional (monthly drinking) and regular (weekly drinking).

FINDINGS

Compared with consistent current non-drinkers, more frequent drinkers [CMEC: β = 0.46, 95% confidence interval (CI) = 0.13-0.80; UKB: β = 0.65, 95% CI = 0.01-1.29)], less frequent drinkers (CMEC: β = 0.62, 95% CI = 0.37-0.87; UKB: β = 0.54, 95% CI = -0.01-1.09), consistent occasional drinkers (CMEC: β = 0.51, 95% CI = 0.23-0.79; UKB: β = 0.63, 95% CI = 0.13-1.13) and consistent regular drinkers (CMEC: β = 0.56, 95% CI = 0.17-0.95; UKB: β = 0.46, 95% CI = 0.00-0.91) exhibited increased accelerated BA. A non-linear relationship between pure alcohol intake and accelerated BA was observed among consistent regular drinkers.

CONCLUSIONS

In middle-aged and older people, any change in drinking frequency and any amount of pure alcohol intake seem to be positively associated with acceleration of biological ageing, compared with maintaining abstinence.

Exercise leads to sex-specific recovery of behavior and pathological AD markers following adolescent ethanol exposure in the TgF344-AD model

Introduction

Human epidemiological studies suggest that heavy alcohol consumption may lead to earlier onset of Alzheimer's Disease (AD), especially in individuals with a genetic predisposition for AD. Alcohol-related brain damage (ARBD) during a critical developmental timepoint, such as adolescence, interacts with AD-related pathologies to accelerate disease progression later in life. The current study investigates if voluntary exercise in mid-adulthood can recover memory deficits caused by the interactions between adolescence ethanol exposure and AD-transgenes.

Methods

Male and female TgF344-AD and wildtype F344 rats were exposed to an intragastric gavage of water (control) or 5 g/kg of 20% ethanol (adolescent intermittent ethanol; AIE) for a 2 day on/off schedule throughout adolescence (PD27-57). At 6 months old, rats either remained in their home cage (stationary) or were placed in a voluntary wheel running apparatus for 4 weeks and then underwent several behavioral tests. The number of cholinergic neurons in the basal forebrain and measure of neurogenesis in the hippocampus were assessed.

Results

Voluntary wheel running recovers spatial working memory deficits selectively in female TgF344-AD rats exposed to AIE and improves pattern separation impairment seen in control TgF344-AD female rats. There were sex-dependent effects on brain pathology: Exercise improves the integration of recently born neurons in AIE-exposed TgF344-AD female rats. Exercise led to a decrease in amyloid burden in the hippocampus and entorhinal cortex, but only in male AIE-exposed TgF344-AD rats. Although the number of basal forebrain cholinergic neurons was not affected by AD-transgenes in either sex, AIE did reduce the number of basal forebrain cholinergic neurons in female rats.

Discussion

These data provide support that even after symptom onset, AIE and AD related cognitive decline and associated neuropathologies can be rescued with exercise in unique sex-specific ways.

Ethanol's impact on the brain: a neurobiological perspective on the mechanisms of memory impairment

Alcohol consumption is known to have detrimental effects on memory function, with various studies implicating ethanol in the impairment of cognitive processes related to memory retention and retrieval. This review aims to elucidate the complex neurobiological mechanisms underlying ethanol-induced memory impairment. Through a thorough search of existing literature using electronic databases, relevant articles focusing on the neurobiological mechanisms of ethanol on memory were identified and critically evaluated. This review focuses on the molecular and neural pathways through which ethanol exerts its effects on memory formation, consolidation, and recall processes. Key findings from the included studies shed light on the impact of ethanol on neurotransmitter systems, synaptic plasticity, and neuroinflammation in relation to memory impairment. This review contributes to a better understanding of the intricate mechanisms by which alcohol impairs memory function, offering insights for future research directions and the development of targeted interventions to alleviate these cognitive impairments.

Dysregulation of neurotrophin expression in prefrontal cortex and nucleus basalis magnocellularis during and after adolescent intermittent ethanol exposure

A preclinical model of human adolescent binge drinking, adolescent intermittent ethanol exposure (AIE) recreates the heavy binge withdrawal consummatory patterns of adolescents and has identified the loss of basal forebrain cholinergic neurons as a pathological hallmark of this model. Cholinergic neurons of the nucleus basalis magnocellularis (NbM) that innervate the prefrontal cortex (PFC) are particularly vulnerable to alcohol related neurodegeneration. Target derived neurotrophins (nerve growth factor [NGF] and brain-derived neurotrophic factor [BDNF]) regulate cholinergic phenotype expression and survival. Evidence from other disease models implicates the role of immature neurotrophin, or proneurotrophins, activity at neurotrophic receptors in promoting cholinergic degeneration; however, it has yet to be explored in adolescent binge drinking. We sought to characterize the pro- and mature neurotrophin expression, alongside their cognate receptors and cholinergic markers in an AIE model. Male and female Sprague Dawley rats underwent 5 g/kg 20% EtOH or water gavage on two-day-on, two-day-off cycles from post-natal day 25-57. Rats were sacrificed 2 h, 24 h, or 3 weeks following the last gavage, and tissue were collected for protein measurement. Western blot analyses revealed that ethanol intoxication reduced the expression of BDNF and vesicular acetylcholine transporter (vAChT) in the PFC, while NGF was lower in the NbM of AIE treated animals. During acute alcohol withdrawal, proNGF in the PFC was increased while proBDNF decreased, and in the NbM proBDNF increased while NGF decreased. During AIE abstinence, the expression of neurotrophins, their receptors, and vAChT did not differ from controls in the PFC. In contrast, in the NbM the expression of both NGF and choline acetyltransferase (ChAT) were reduced long-term following AIE. Taken together these findings suggest that AIE alters the expression of proneurotrophins and neurotrophins during intoxication and withdrawal that favor prodegenerative mechanisms by increasing the expression of proNGF and proBDNF, while also reducing NGF and BDNF.

Modulation of the p75NTR during Adolescent Alcohol Exposure Prevents Cholinergic Neuronal Atrophy and Associated Acetylcholine Activity and Behavioral Dysfunction

Binge alcohol consumption during adolescence can produce lasting deficits in learning and memory while also increasing the susceptibility to substance use disorders. The adolescent intermittent ethanol (AIE) rodent model mimics human adolescent binge drinking and has identified the nucleus basalis magnocellularis (NbM) as a key site of pathology. The NbM is a critical regulator of prefrontal cortical (PFC) cholinergic function and attention. The cholinergic phenotype is controlled pro/mature neurotrophin receptor activation. We sought to determine if p75NTR activity contributes to the loss of cholinergic phenotype in AIE by using a p75NTR modulator (LM11A-31) to inhibit prodegenerative signaling during ethanol exposure. Male and female rats underwent 5 g/kg ethanol (AIE) or water (CON) exposure following 2-day-on 2-day-off cycles from postnatal day 25-57. A subset of these groups also received a protective dose of LM11A-31 (50 mg/kg) during adolescence. Rats were trained on a sustained attention task (SAT) and behaviorally relevant acetylcholine (ACh) activity was recorded in the PFC with a fluorescent indicator (AChGRAB 3.0). AIE produced learning deficits on the SAT, which were spared with LM11A-31. In addition, PFC ACh activity was blunted by AIE, which LM11A-31 corrected. Investigation of NbM ChAT+ and TrkA+ neuronal expression found that AIE led to a reduction of ChAT+TrkA+ neurons, which again LM11A-31 protected. Taken together, these findings demonstrate the p75NTR activity during AIE treatment is a key regulator of cholinergic degeneration.

Huanglian Jiedu decoction alleviates neurobehavioral damage in mice with chronic alcohol exposure through the RAS-RAF-MEK-ERK pathway

Objective

Long-term alcohol consumption can cause organic damage to the brain, resulting in mental and nervous system abnormalities and intellectual impairment. Huanglian Jiedu decoction (HLJDD) is the classic representative of clearing heat and detoxifying. This study aimed to explore the effects and possible mechanisms of HLJDD on brain injury in chronic alcohol-exposed mice.

Methods

The alcohol-exposed mice were treated with different doses of HLJDD to observe behavioral changes, hippocampal Aβ1-42 deposition, number and ultrastructural changes of neurons in the hippocampus and prefrontal cortex, and expressions of synaptic proteins. On this basis, transcriptome sequencing was used to analyze the differentially expressed genes in different treatment groups, and functional enrichment analysis was performed. Then, WB and RT-PCR were used to verify the expression of the pathway.

Results

Chronic alcohol exposure reduced body weight in mice, led to motor cognitive impairment, increased Aβ1-42 in the hippocampus, decreased the number of neurons in the hippocampus and prefrontal cortex, and the expression of PSD95 and SYN in the hippocampus. HLJDD significantly improved the cognitive dysfunction of mice and alleviated the damage of the hippocampus and prefrontal cortex. Transcriptome sequencing results showed that the regulatory effects of HLJDD on chronic alcohol-exposed mice may be related to the RAS pathway. Further experiments confirmed that chronic alcohol exposure caused a significant increase in protein and gene expressions of the RAS-RAF-MEK-ERK pathway in mouse, and this activation was reversed by HLJDD.

Conclusion

HLJDD may ameliorate brain damage caused by chronic alcohol exposure by regulating the RAS-RAF-MEK-ERK pathway.

Modulation of the p75NTR during adolescent alcohol exposure prevents cholinergic neuronal atrophy and associated acetylcholine activity and behavioral dysfunction

Binge alcohol consumption during adolescence produces lasting deficits in learning and memory, while also increasing the susceptibility to substance use disorders. The adolescent intermittent ethanol (AIE) rodent model mimics human adolescent binge drinking and has identified the Nucleus Basalis Magnocellularis (NbM) as a key site of pathology. The NbM is a critical regulator of prefrontal cortical (PFC) cholinergic function and attention. The cholinergic phenotype is controlled pro/mature neurotrophin receptor activation. We sought to determine if p75NTR activity contributes to the loss of cholinergic phenotype in AIE by using a p75NTR modulator (LM11A-31) to inhibit prodegenerative signaling during ethanol exposure. Male and female rats underwent 5g/kg ethanol (AIE) or water (CON) exposure following 2-day-on 2-day-off cycles from PND 25-57. A subset of these groups also received a protective dose of LM11A-31 (50mg/kg) during adolescence. Rats were trained on a sustained attention task (SAT) while recording activity with a fluorescent acetylcholine indicator (AChGRAB 3.0). AIE produced learning deficits on the SAT, which were spared with LM11A-31. In addition, mPFC ACh activity was blunted by AIE, which LM11A-31 corrected. Investigation of NbM ChAT+ and TrkA+ neuronal expression found that AIE led to a reduction of ChAT+TrkA+ neurons, which again LM11A-31 protected. Taken together these findings demonstrate the p75NTR activity during AIE treatment is a key regulator of cholinergic degeneration.

Rare and Common Variants Associated with Alcohol Consumption Identify a Conserved Molecular Network

Genome-wide association studies (GWAS) have identified hundreds of common variants associated with alcohol consumption. In contrast, rare variants have only begun to be studied for their role in alcohol consumption. No studies have examined whether common and rare variants implicate the same genes and molecular networks. To address this knowledge gap, we used publicly available alcohol consumption GWAS summary statistics (GSCAN, N=666,978) and whole exome sequencing data (Genebass, N=393,099) to identify a set of common and rare variants for alcohol consumption. Gene-based analysis of each dataset have implicated 294 (common variants) and 35 (rare variants) genes, including ethanol metabolizing genes ADH1B and ADH1C, which were identified by both analyses, and ANKRD12, GIGYF1, KIF21B, and STK31, which were identified only by rare variant analysis, but have been associated with related psychiatric traits. We then used a network colocalization procedure to propagate the common and rare gene sets onto a shared molecular network, revealing significant overlap. The shared network identified gene families that function in alcohol metabolism, including ADH, ALDH, CYP, and UGT. 74 of the genes in the network were previously implicated in comorbid psychiatric or substance use disorders, but had not previously been identified for alcohol-related behaviors, including EXOC2, EPM2A, CACNB3, and CACNG4. Differential gene expression analysis showed enrichment in the liver and several brain regions supporting the role of network genes in alcohol consumption. Thus, genes implicated by common and rare variants identify shared functions relevant to alcohol consumption, which also underlie psychiatric traits and substance use disorders that are comorbid with alcohol use.

Acute Genetic Damage Induced by Ethanol and Corticosterone Seems to Modulate Hippocampal Astrocyte Signaling

Astrocytes maintain CNS homeostasis but also critically contribute to neurological and psychiatric disorders. Such functional diversity implies an extensive signaling repertoire including extracellular vesicles (EVs) and nanotubes (NTs) that could be involved in protection or damage, as widely shown in various experimental paradigms. However, there is no information associating primary damage to the astrocyte genome, the DNA damage response (DDR), and the EV and NT repertoire. Furthermore, similar studies were not performed on hippocampal astrocytes despite their involvement in memory and learning processes, as well as in the development and maintenance of alcohol addiction. By exposing murine hippocampal astrocytes to 400 mM ethanol (EtOH) and/or 1 μM corticosterone (CTS) for 1 h, we tested whether the induced DNA damage and DDR could elicit significant changes in NTs and surface-attached EVs. Genetic damage and initial DDR were assessed by immunolabeling against the phosphorylated histone variant H2AX (γH2AX), DDR-dependent apoptosis by BAX immunoreactivity, and astrocyte activation by the glial acidic fibrillary protein (GFAP) and phalloidin staining. Surface-attached EVs and NTs were examined via scanning electron microscopy, and labeled proteins were analyzed via confocal microscopy. Relative to controls, astrocytes exposed to EtOH, CTS, or EtOH+CTS showed significant increases in nuclear γlH2AX foci, nuclear and cytoplasmic BAX signals, and EV frequency at the expense of the NT amount, mainly upon EtOH, without detectable signs of morphological reactivity. Furthermore, the largest and most complex EVs originated only in DNA-damaged astrocytes. Obtained results revealed that astrocytes exposed to acute EtOH and/or CTS preserved their typical morphology but presented severe DNA damage, triggered canonical DDR pathways, and early changes in the cell signaling mediated by EVs and NTs. Further deepening of this initial morphological and quantitative analysis is necessary to identify the mechanistic links between genetic damage, DDR, cell-cell communication, and their possible impact on hippocampal neural cells.

Verbal memory and executive components of recall in adolescent binge drinkers

Introduction

Binge drinking (BD) is a common health-risk behavior among young people. Due to the incomplete maturation of the adolescent brain, BD can lead to structural and functional changes that impact neurocognitive processes, particularly executive functioning and verbal memory. This study aimed to investigate the influence of executive components, such as mnemonic strategies and error avoidance, on performance in a verbal memory test and the potential effects of BD on this performance.

Methods

A sample of 160 college students (51.55% female) with a mean age of 18.12 ± 0.32 years completed assessments for alcohol use disorders using the Alcohol Use Disorder Identification Test (AUDIT), as well as psychopathological (Symptom Checklist-90-R) and neuropsychological evaluations (Verbal Learning Test Spain-Complutense and WMS-III Logical Memory). The Intensive Drinking Evaluation Instrument (IECI) was utilized to gather detailed information about binge drinking habits, including the calculation of the highest blood alcohol concentration (BAC) during an episode of intake.

Results

Correlation and clustering analyses revealed a negative association between BAC values and verbal memory performance, as well as the use of memory strategies. The high BAC group (BD) exhibited negative values in verbal memory variables, higher accuracy errors, and less efficient strategy usage, while the low BAC group (No BD) demonstrated better memory test performance, fewer precision errors, and superior use of memory strategies.

Discussion

These findings support the hypothesis that, when solving tests requiring verbal memory, adolescents reporting a BD consumption pattern show fewer executive skills in their resolution and, therefore, achieved poorer performance than non-binge drinkers. Addressing excessive alcohol consumption in young individuals is crucial for safeguarding their cognitive development and overall well-being.

Effect of alcohol on Brain-Derived Neurotrophic Factor (BDNF) blood levels: a systematic review and meta-analysis

Brain-Derived Neurotrophic Factor (BDNF) is a vital protein involved in neuronal development, survival, and plasticity. Alcohol consumption has been implicated in various neurocognitive deficits and neurodegenerative disorders. However, the impact of alcohol on BDNF blood levels remains unclear. This systematic review and meta-analysis aimed to investigate the effect of alcohol consumption on BDNF blood levels. A comprehensive search of electronic databases was conducted to identify relevant studies. Eligible studies were selected based on predefined inclusion criteria. Data extraction was performed, and methodological quality was assessed using appropriate tools. A meta-analysis was conducted to estimate the overall effect size of alcohol consumption on BDNF levels. A total of 25 studies met the inclusion criteria and were included in the final analysis. Alcohol use and BDNF blood levels were significantly correlated, according to the meta-analysis (p = 0.008). Overall, it was discovered that drinking alcohol significantly decreased BDNF levels (SMD: - 0.39; 95% CI: - 0.68 to - 0.10; I2: 93%). There was a non-significant trend suggesting that alcohol withdrawal might increase BDNF levels, with an SMD of 0.26 (95% CI: - 0.09 to 0.62; I2: 86%; p = 0.14). Subgroup analysis based on the source of BDNF demonstrated significant differences between the subgroups (p = 0.0008). No significant publication bias was observed. This study showed that alcohol consumption is associated with a significant decrease in BDNF blood levels. The findings suggest a negative impact of alcohol on BDNF levels regardless of alcohol dosage. Further studies are needed to strengthen the evidence and elucidate the underlying mechanisms.

Relationship between Composite Dietary Antioxidant Index and Aging

BACKGROUND

Numerous studies have demonstrated a close relationship between antioxidant-rich diets and comorbidities as well as mortality. However, the relationship between such diets and aging remains unclear. The purpose of this study was to investigate the association between the Composite Dietary Antioxidant Index (CDAI) and aging.

METHODS

All participants were from the National Health and Nutrition Examination Survey (NHANES) 2001-2010. Phenotypic age was calculated using a formula and subtracted from the chronological age to determine the aging. When the phenotypic age exceeded the chronological age, it was considered as aging. A weighted logistic regression model was employed to explore the relationship between CDAI and aging. Restricted cubic splines (RCSs) were used to examine the potential nonlinear relationship between them. Subgroup analysis and joint analysis were conducted to explore the effect of modifiers in these relationships.

RESULTS

A total of 19,212 participants (weighted: 165,285,442 individuals) were included in this study. The weighted logistic regression model showed a significant correlation between CDAI and the risk of aging (OR = 0.90, 95% CI: 0.84-0.96). RCS analysis revealed an L-shaped dose-response relationship between CDAI and the risk of aging. Subgroup analysis indicated that the association between CDAI and aging was more pronounced in middle-aged individuals and non-smokers. The joint analysis demonstrated that although smoking accelerated aging among participants, a high CDAI diet could still offset these damages.

CONCLUSIONS

The association between high CDAI and reduced risk of aging is particularly significant in young and middle-aged individuals and non-smokers. Consuming foods rich in CDAI components may potentially lower the risk of aging.

Impact of Elevated Brain IL-6 in Transgenic Mice on the Behavioral and Neurochemical Consequences of Chronic Alcohol Exposure

Alcohol consumption activates the neuroimmune system of the brain, a system in which brain astrocytes and microglia play dominant roles. These glial cells normally produce low levels of neuroimmune factors, which are important signaling factors and regulators of brain function. Alcohol activation of the neuroimmune system is known to dysregulate the production of neuroimmune factors, such as the cytokine IL-6, thereby changing the neuroimmune status of the brain, which could impact the actions of alcohol. The consequences of neuroimmune-alcohol interactions are not fully known. In the current studies we investigated this issue in transgenic (TG) mice with altered neuroimmune status relative to IL-6. The TG mice express elevated levels of astrocyte-produced IL-6, a condition known to occur with alcohol exposure. Standard behavioral tests of alcohol drinking and negative affect/emotionality were carried out in homozygous and heterozygous TG mice and control mice to assess the impact of neuroimmune status on the actions of chronic intermittent alcohol (ethanol) (CIE) exposure on these behaviors. The expressions of signal transduction and synaptic proteins were also assessed by Western blot to identify the impact of alcohol-neuroimmune interactions on brain neurochemistry. The results from these studies show that neuroimmune status with respect to IL-6 significantly impacts the effects of alcohol on multiple levels.

A subchronic history of binge-drinking elicits mild, age- and sex-selective, affective, and cognitive anomalies in C57BL/6J mice

Introduction

Alcohol abuse is a risk factor for affective and cognitive disorders, with evidence indicating that adolescent-onset excessive drinking can result in long-term deficiencies in emotional regulation and cognition, with females more susceptible to the negative emotional and cognitive consequences of excessive alcohol consumption. However, our prior examination of the interactions between sex and the age of drinking-onset indicated minimal signs of anxiety-like behavior during alcohol withdrawal, which may have related to the concurrent anxiety testing of male and female subjects.

Methods

The present study addressed this potential confound by assaying for alcohol withdrawal-induced negative affect separately in males and females and expanded our investigation to include measures of spatial and working memory.

Results

Following 14 days of drinking under modified Drinking-in-the-Dark procedures (10, 20, and 40% alcohol v/v; 2 h/day), adolescent and adult binge-drinking mice of both sexes exhibited, respectively, fewer and more signs of negative affect in the light-dark shuttle-box and forced swim tests than their water-drinking counterparts. Adolescent-onset binge-drinking mice also exhibited signs of impaired working memory early during radial arm maze training during early alcohol withdrawal. When tested in late (30 days) withdrawal, only adult female binge-drinking mice buried more marbles than their water-drinking counterparts. However, adolescent-onset binge-drinking mice exhibited poorer spatial memory recall in a Morris water maze.

Discussion

These findings indicate that a subchronic (14-day) binge-drinking history induces mild, age- and sex-selective, changes in negative affect and cognition of potential relevance to understanding individual variability in the etiology and treatment of alcohol abuse and alcohol use disorder.

Chronic ethanol induces a pro-inflammatory switch in interleukin-1β regulation of GABAergic signaling in the medial prefrontal cortex of male mice

Neuroimmune pathways regulate brain function to influence complex behavior and play a role in several neuropsychiatric diseases, including alcohol use disorder (AUD). In particular, the interleukin-1 (IL-1) system has emerged as a key regulator of the brain's response to ethanol (alcohol). Here we investigated the mechanisms underlying ethanol-induced neuroadaptation of IL-1β signaling at GABAergic synapses in the prelimbic region of the medial prefrontal cortex (mPFC), an area responsible for integrating contextual information to mediate conflicting motivational drives. We exposed C57BL/6J male mice to the chronic intermittent ethanol vapor-2 bottle choice paradigm (CIE-2BC) to induce ethanol dependence, and conducted ex vivo electrophysiology and molecular analyses. We found that the IL-1 system regulates basal mPFC function through its actions at inhibitory synapses on prelimbic layer 2/3 pyramidal neurons. IL-1β can selectively recruit either neuroprotective (PI3K/Akt) or pro-inflammatory (MyD88/p38 MAPK) mechanisms to produce opposing synaptic effects. In ethanol naïve conditions, there was a strong PI3K/Akt bias leading to a disinhibition of pyramidal neurons. Ethanol dependence produced opposite IL-1 effects - enhanced local inhibition via a switch in IL-1β signaling to the canonical pro-inflammatory MyD88 pathway. Ethanol dependence also increased cellular IL-1β in the mPFC, while decreasing expression of downstream effectors (Akt, p38 MAPK). Thus, IL-1β may represent a key neural substrate in ethanol-induced cortical dysfunction. As the IL-1 receptor antagonist (kineret) is already FDA-approved for other diseases, this work underscores the high therapeutic potential of IL-1 signaling/neuroimmune-based treatments for AUD.

Coordination and Cognition in Pure Nutritional Wernicke’s Encephalopathy with Cerebellar Degeneration after COVID-19 Infection: A Unique Case Report

Background: Alcoholic cerebellar degeneration is a restricted form of cerebellar degeneration, clinically leading to an ataxia of stance and gait and occurring in the context of alcohol misuse in combination with malnutrition and thiamine depletion. However, a similar degeneration may also develop after non-alcoholic malnutrition, but evidence for a lasting ataxia of stance and gait and lasting abnormalities in the cerebellum is lacking in the few patients described with purely nutritional cerebellar degeneration (NCD). Methods: We present a case of a 46-year-old woman who developed NCD and Wernicke’s encephalopathy (WE) due to COVID-19 and protracted vomiting, resulting in thiamine depletion. We present her clinical course over the first 6 months after the diagnosis of NCD and WE, with thorough neuropsychological and neurological examinations, standardized clinical observations, laboratory investigations, and repeated MRIs. Results: We found a persistent ataxia of stance and gait and evidence for an irreversible restricted cerebellar degeneration. However, the initial cognitive impairments resolved. Conclusions: Our study shows that NCD without involvement of alcohol neurotoxicity and with a characteristic ataxia of stance and gait exists and may be irreversible. We did not find any evidence for lasting cognitive abnormalities or a cerebellar cognitive-affective syndrome (CCAS) in this patient.

Distinct Sleep Alterations in Alcohol Use Disorder Patients with and without Korsakoff's Syndrome: Relationship with Episodic Memory

Alcohol Use Disorder (AUD) results in sleep disturbances that may have deleterious impacts on cognition, especially on memory. However, little is known about the sleep architecture in patients with Korsakoff's syndrome (KS). This study aims at characterizing sleep disturbances in KS compared to AUD without KS and at specifying the relationships with cognitive impairments. Twenty-nine AUD patients (22 without KS and 7 with KS) and 15 healthy controls underwent a neuropsychological assessment and a polysomnography. The severity of sleep-disordered breathing and sleep fragmentation was similar in AUD and KS patients compared to controls. Sleep architecture differed between both patient groups: the proportion of slow-wave sleep was reduced in AUD patients only, while a lower proportion of rapid-eye movement (REM) sleep was specifically observed in KS patients. The proportion of REM sleep correlated with the severity of episodic memory deficits when AUD and KS were examined together. These data provide evidence for both similarities and specificities regarding sleep alterations in AUD patients with and without KS. They also indicate that altered sleep architecture may contribute to the pathophysiology of alcohol-related memory disorders.

Assessment of cognitive functioning using the Mini Mental State Examination in men with Alcohol and Crack Cocaine Use Disorder

INTRODUCTION

Consumption of substances has been associated with cognitive impairment. The Mini Mental State Examination (MMSE) is an easy-to-apply screening tool used to assess cognitive functions.

OBJECTIVES

To evaluate the cognitive performance of individuals with alcohol (AUD) and/or crack cocaine use disorder (CUD) and polysubstance use using the MMSE and to investigate the impact of substance use profile and the moderation effect of educational level on MMSE performance.

METHODS

Cross-sectional study with 508 adult male inpatients diagnosed with substance use disorders (245 with AUD, 85 with CUD, and 178 with polysubstance use). Cognitive performance was assessed using the MMSE scale (total and composite scores).

RESULTS

Individuals with AUD had worse total MMSE scores and scored worse for all three MMSE components compared to individuals with polysubstance use (p < 0.001, oral/written language comprehension, p < 0.001, attention/memory, and p = 0.007, motor functions). MMSE scores were positively correlated with educational level (p < 0.017), but were not associated with age, recent drug use, or years of drug use. Educational level moderated the impact of substance use on MMSE performance, especially total score and composite language comprehension score. Individuals with a low educational level (≤ 8 years) had worse performance than those with a high educational level (≥ 9 years), mainly in individuals with AUD (p < 0.001).

DISCUSSION

Individuals with a low educational level and alcohol use are more prone to present cognitive impairment than crack cocaine users, especially involving language aspects. Better-preserved cognitive function could impact treatment adherence and might guide the decision of therapeutic strategies.

The neuroimmune system - Where aging and excess alcohol intersect

As the percentage of the global population over age 65 grows, and with it a subpopulation of individuals with alcohol use disorder (AUD), understanding the effect of alcohol on the aged brain is of utmost importance. Neuroinflammation is implicated in both natural aging as well as alcohol use, and its role in alterations to brain morphology and function may be exacerbated in aging individuals who drink alcohol to excess. The neuroimmune response to alcohol in aging is complex. The few studies investigating this issue have reported heightened basal activity and either hypo- or hyper-reactivity to an alcohol challenge. This review of preclinical research will first introduce key players of the immune system, then explore changes in neuroimmune function with aging or alcohol alone, with discussion of vulnerable brain regions, changes in cytokines, and varied reactions of microglia and astrocytes. We will then consider different levels of alcohol exposure, relevant animal models of AUD, and neuroimmune activation by alcohol across the lifespan. By identifying key findings, challenges, and targets for future research, we hope to bring more attention and resources to this underexplored area of inquiry.

Alcohol consumption from midlife and risk of disabling dementia in a large population-based cohort study in Japan

OBJECTIVES

The association between alcohol consumption and dementia in Japanese is poorly understood, and use of single-point alcohol assessment may cause measurement error. We explored this association in Japanese using repeated alcohol assessments.

METHODS

Participants in the Japan Public Health Center-based Prospective Study (JPHC Study) since 1990 and who were alive in 2006 were followed from 2006 until 2016 for dementia ascertainment. Disabling dementia was identified through long-term care insurance records. Alcohol consumption was assessed at the 5-year questionnaire survey (1995-1999) and drinking patterns were assessed on repeated follow-up (2000-2003). We performed Cox proportional hazards models with age as the time-scale with adjustment for various lifestyle factors and medical history using light consumption (<75 g ethanol/week, hereinafter "g") as reference. Analysis considering death as a competing risk was also conducted.

RESULTS

Among 42,870 participants aged 54-84 years, 4802 cases of disabling dementia were newly diagnosed. Average years from alcohol assessment until dementia incidence was 14.9 years. Non-drinkers and regular drinkers with ≥450 g at 5 years had adjusted HRs (95% CI) of 1.29 (1.12-1.47) and 1.34 (1.12-1.60). Patterns of long-term abstinence, former drinking, and regular heavy weekly consumption of ≥450 g showed increased adjusted HRs of 1.61 (1.28-2.03), 2.54 (1.93-3.35), and 1.96 (1.49-2.59), respectively. Competing risk analysis yielded similar results.

CONCLUSIONS

In Japanese, non-drinking and regular weekly consumption of ≥450 g from midlife were associated with high risk of disabling dementia compared with light drinking.

Alcohol binge drinking induces downregulation of blood-brain barrier proteins in the rat frontal cortex -but not in the hippocampus- that is not prevented by OEA pretreatment

Alcohol binge drinking promotes neuroinflammation which could be partially mediated by the passage of ABD-induced peripheral inflammatory molecules to the brain parenchyma through the blood-brain barrier. The BBB is sealed by tight junction proteins, which regulate the access of substances to the brain. Whether ABD alters the BBB or not remains controversial. Here, we measured the expression of BBB proteins in frontal cortex and hippocampus after an ABD procedure that was previously shown to induce neuroinflammation in the FC, and checked neuroinflammation in the hippocampus. Oleoylethanolamide is known to inhibit ABD-induced neuroinflammation in rat FC but the mechanisms of action are not clear: whereas OEA protects against alcohol-induced breakdown of the TJ proteins in the gut barrier reducing peripheral inflammation, its effect in the TJ of the BBB remains unknown. Here, we studied whether OEA (5 mg/kg, before each gavage) prevented alcohol-induced BBB dysfunction by measuring the expression of zona-occludens, occludin, and laminin in FC and hippocampus. ABD animals showed reduced laminin and occludin levels in the FC, indicative of BBB dysfunction, which is concordant with previous findings showing ABD-induced neuroinflammation in this brain region. OEA did not prevent ABD-induced changes in the BBB proteins in the FC, suggesting that the OEA main mechanism of action to inhibit neuroinflammation in this brain region is not related to prevention of TJ proteins alteration in the BBB. In the hippocampus, this ABD protocol did not alter BBB protein levels and no markers of neuroinflammation were found elevated.

[Binge drinking in the young population: Lost memory after initial ethanol exposure via neuroinflammation and epigenetic]

Binge drinking (BD) in young adults/adolescents can lead to cognitive deficits in the adult probably through neuroinflammation and epigenetic. However, the mode of action of alcohol during the initial exposure is less known while it may be the origin of the deficits seen in adults. Recent studies in adolescent rat hippocampus revealed that loss of memory occurred since the very first exposure to BD with similar mechanisms than those highlighted for longer alcohol exposure. Thus, initiation to BD in the young is responsible for cognitive deficits that will be probably entertained by repeated BD behavior. These kind of data may serve to reinforce the prevention campaigns towards the young population who practice BD.

Neuropsychiatric Alterations in a Patient Diagnosed with Advanced Korsakoff's Syndrome: Clinical Case of Low Incidence and Prevalence in Colombia

Korsakoff's syndrome (KS) is an insidious and progressive neuropsychiatric disorder that affects specific neurocognitive functioning, especially in tasks that require sustained attention, memory, executive functions, and visuospatial functioning. Usually, this disease generates neuropsychiatric complications that worsen the quality of life (QOL) of patients in the medium term. We present a case of a 63-year-old male who presented with a diagnosis of advanced Korsakoff's syndrome and has a clinical history of recurrent memory loss and a history of alcohol abuse. The patient showed difficulty manipulating immediate information, associated with a possible frontal lobe dysfunction, and inability to remember material given through the auditory pathway. The patient showed a psychiatric clinical picture which is constantly worsening his and his immediate caregiver's QOL. The data obtained demonstrate that the patient presents a progressive cognitive impairment, which in the short term is correlated with Korsakoff-type dementia. It is suggested to carry out functional neurorehabilitation plans aimed at improving the QOL of the patient, his immediate caregiver, and future people with this type of diagnosis.

Sodium Butyrate Supplementation Modulates Neuroinflammatory Response Aggravated by Antibiotic Treatment in a Mouse Model of Binge-like Ethanol Drinking

Growing evidence supports the pivotal role of the bidirectional interplay between the gut microbiota and the central nervous system during the progression of alcohol use disorder (AUD). In our previous study, supplementation with sodium butyrate (SB) in C57BL/6J mice prevented increased ethanol consumption in a binge-like drinking paradigm (DID) as a result of treatment with a non-absorbable antibiotic cocktail (ABX). In this study, we tested the hypothesis that SB protection against enhanced ABX-induced ethanol consumption in mice is partially due to modulation of neuroinflammatory responses. Pro- and anti-inflammatory cytokines, as well as changes in microglia and astrocytes were analyzed in hippocampus tissues from ABX-, SB-, ABX+SB-treated mice subjected to 4-week DID. We found that ethanol without or with ABX treatment increased mRNA levels of key brain cytokines (MCP-1, TNF-α, IL-1β, IL-6 and IL-10) while SB supplementation prevented these changes. Additionally, SB supplementation prevented changes in microglia, i.e., increase in Iba-1 positive cell number and morphology, and in astrocytes, i.e., decrease in GFAP-positive cell number, induced by combination of ethanol and ABX treatments. Our results suggest that gut microbiota metabolites can influence drinking behavior by modulation of neuroinflammation, highlighting the potential for microbiome-targeting strategies for treatment or prevention of AUD.

Lactobacillus plantarum ST-III culture supernatant ameliorates alcohol-induced cognitive dysfunction by reducing endoplasmic reticulum stress and oxidative stress

Background

Long-term alcohol exposure is associated with oxidative stress, endoplasmic reticulum (ER) stress, and neuroinflammation, which may impair cognitive function. Probiotics supplements can significantly improve cognitive function in neurodegenerative diseases such as Alzheimer’s disease. Nevertheless, the effect of Lactobacillus plantarum ST-III culture supernatant (LP-cs) on alcohol-induced cognitive dysfunction remains unclear.

Methods

A mouse model of cognitive dysfunction was established by intraperitoneal injection of alcohol (2 g/kg body weight) for 28 days. Mice were pre-treated with LP-cs, and cognitive function was evaluated using the Morris water maze test. Hippocampal tissues were collected for biochemical and molecular analysis.

Results

LP-cs significantly ameliorated alcohol-induced decline in learning and memory function and hippocampal morphology changes, neuronal apoptosis, and synaptic dysfunction. A mechanistic study showed that alcohol activated protein kinase R-like endoplasmic reticulum kinase (PERK) signaling and suppressed brain derived neurotrophic factor (BDNF) levels via ER stress in the hippocampus, which LP-cs reversed. Alcohol activated oxidative stress and inflammation responses in the hippocampus, which LP-cs reversed.

Conclusion

LP-cs significantly ameliorated alcohol-induced cognitive dysfunction and cellular stress. LP-cs might serve as an effective treatment for alcohol-induced cognitive dysfunction.

Dichrocephala integrifolia Aqueous Extract Antagonises Chronic and Binges Ethanol Feeding-Induced Memory Dysfunctions: Insights into Antioxidant and Anti-Inflammatory Mechanisms

Ethanol consumption is widely accepted despite its addictive properties and its mind-altering effects. This study aimed to assess the effects of Dichrocephala integrifolia against, memory impairment, on a mouse model of chronic and binges ethanol feeding. Mice were divided, into groups of 8 animals each, and received distilled water, Dichrocephala integrifolia aqueous extract (25; 50; 100; or 200 mg/kg) or memantine (200 mg/kg) once a day, while fe, with Lieber-DeCarli control (sham group only) or Lieber-DeCarli ethanol diet ad libitum for 28 days. The Y maze and the novel object recognition (NOR) tests were used to evaluate spatial short-term and recognition memory, respectively. Malondialdehyde, nitric oxide, glutathione levels, and proinflammatory cytokines (Il-1β, TNF-α, and Il-6) were evaluated in brain homogenates following behavioral assessments. The results showed that chronic ethanol administration in mice was associated with a significant (p < 0.001) reduction in the spontaneous alternation percentage and the discrimination index, in the Y maze and the NOR tests, respectively. It significantly (p < 0.01) increased oxidative stress and inflammation markers levels in the brain. Dichrocephala integrifolia (100 and 200 mg/kg) as well as memantine (200 mg/kg) significantly (p < 0.001) increased the percentage of spontaneous alternation and the discrimination index, in the Y maze and NOR tests, respectively. Dichrocephala integrifolia (100 and 200 mg/kg) likewise memantine (200 mg/kg) significantly (p < 0.01) alleviated ethanol-induced increase, in the brain malondialdehyde level, nitric oxide, Il-1β, TNF-α, and Il-6. From these findings, it can be concluded that Dichrocephala integrifolia counteracted memory impairment, oxidative stress, and neuroinflammation induced by chronic ethanol consumption in mice.

Impact of alcohol consumption on treatment outcome of hepatocellular carcinoma patients with viral hepatitis who underwent transarterial chemoembolization

BACKGROUND

Alcohol consumption increases the risk of hepatocellular carcinoma (HCC) in patients with pre-existing liver disease, including viral hepatitis. However, studies on the impact of alcohol consumption on the outcomes of HCC are limited. We hypothesized that alcohol had an additional effect with chronic viral hepatitis infection on treatment outcomes after transarterial chemoembolization (TACE) in patients with intermediate-stage HCC (Barcelona Clinical Liver Cancer [BCLC] -B).

AIM

To evaluate the additional effect of alcohol on treatment outcomes of TACE among HCC patients with viral hepatitis.

METHODS

This study, conducted at Hatyai Hospital in Thailand, included HCC patients over 18 years of age with chronic viral hepatitis. Records of HCC patients with viral hepatitis classified as BCLC-B who underwent TACE as the first treatment modality between 2014 and 2019 were retrospectively reviewed. Patients with chronic viral hepatitis only were categorized under group A, and those with chronic viral hepatitis and concurrent alcohol consumption were categorized under group B. Both groups were compared, and the Cox proportional-hazards model was used to identify the survival-influencing variables.

RESULTS

Of the 69 patients, 53 were categorized in group A and 16 in group B. There were no statistically significant differences in tumor characteristics between the two patient groups. However, Group A had a statistically significantly higher proportion of complete response (24.5% vs 0%, P = 0.030) and a higher median survival rate (26.2 mo vs 8.4 mo; log-rank P = 0.012) compared to group B. Factors associated with decreased survival in the proportional-hazards model included alcohol consumption (hazards ratio [HR], 2.377; 95% confidence interval [CI], 1.109-5.095; P = 0.026), presence of portal hypertension (HR, 2.578; 95%CI, 1.320–5.037; P = 0.006), largest tumor size > 5 cm (HR, 3.558; 95%CI, 1.824-6.939; P < 0.001), and serum alpha-fetoprotein level > 100 ng/mL (HR, 2.536; 95%CI, 1.377-4.670; P = 0.003).

CONCLUSION

In HCC BCLC B patients with chronic viral hepatitis, alcohol consumption is an independent risk factor for increased mortality and decreases the rate of complete response and survival after TACE.

Alcohol-Drinking Under Limited-Access Procedures During Mature Adulthood Accelerates the Onset of Cognitive Impairment in Mice

A history of heavy drinking increases vulnerability to, and the severity of, Alzheimer’s disease (AD) and related dementias, with alcohol use disorder identified as the strongest modifiable risk factor for early-onset dementia. Heavy drinking has increased markedly in women over the past 10 years, particularly in mature adult women during the coronavirus (COVID-19) pandemic. This is concerning as women are more sensitive to many alcohol-related disease states, including AD and related dementias. Herein, we conducted two studies to determine if a 1-month period of binge drinking during mature adulthood (i.e., 5–9 months of age) impairs spatial and working memory to a greater extent in female vs. male C57BL/6J (B6J) mice. The anxiogenic and cognitive-impairing effects of binge drinking were also compared between mature adult and old B6J mice (18 months of age) in a third study. Throughout, females consumed more alcohol than males, indicating that a sex difference in binge drinking persists into old age. Despite the sex difference in intake, we detected no consistent sex difference in our measures of alcohol withdrawal-induced anxiety during a behavioral test battery. Although mature adult females exhibited more cognitive deficits than males, the precise outcome exhibiting a female-selective effect varied across studies. Old mice drank lower amounts of alcohol than mature adult mice, yet their blood ethanol concentrations (BECs) were within error of the 80 mg/dl criterion for binge drinking, indicative of an age-related slowing of alcohol metabolism. As expected, 18-month-old controls exhibited more signs of cognitive impairment than their 6-month-old counterparts, and binge drinking history impaired the Morris water maze performance of mice of both ages. In contrast, binge drinking history impaired the radial arm maze performance of 6-month-old mice only, and the extent of the impairment was comparable to the behavior exhibited by the older mice. We conclude from our studies that: (1) both biological sex and the age of drinking onset are subject factors that impact voluntary alcohol consumption by mice into old age; (2) binge drinking during later life elicits a negative affective state that is relatively sex-independent; (3) binge drinking during both mature adulthood and old age impairs spatial learning and memory; (4) binge drinking during mature adulthood accelerates deficits in working memory; and (5) mature adult females tend to exhibit more alcohol-induced cognitive impairments than males. If relevant to humans, these findings suggest that binge-like drinking by older adult men and women induces a negative affective state and cognitive decline, but that mature adult women, in particular, may be more sensitive to both the immediate and persistent cognitive-impairing effects of heavy drinking.

Alcohol and Nicotine Use among Adolescents: An Observational Study in a Sicilian Cohort of High School Students

In recent years, the mode of alcoholic intake known as binge drinking (BD) has become a common practice, especially among adolescents who, due to socio-environmental motives, tend to reach a rapid state of drunkenness. This drunkeness leads to alterations in brain areas responsible for executive functions and cognitive processes, as well as to the genesis of factors that predispose to lasting addiction. Likewise, nicotine leads to a comparable degree of addiction. On this basis, the aim of this research was to evaluate, on a cohort of 349 high school students (15−17 years old) in the province of Palermo, the following: (I) the drinking model of alcoholic beverages; (II) the use of nicotine and the degree of dependence; (III) the correlation between the consumption of alcoholic beverages and the use of nicotine. We employed the AUDIT-C test and the Fagerström test, two valid and standard instruments, in order to assess alcohol and nicotine use, respectively. Statistical analysis of the data showed that male and female students consumed alcohol prominently in a BD mode (77.2%, audit score (AS) 3.497, confidence interval (CI) 3.206−3.788; 69.6%, AS 2.793, CI 2.412−3.274) and nicotine (41.5%, Fagerström score (FS) 3.882, CI 3.519−4.245; 28%, FS 3.286, CI 2.547−4.024). Furthermore, a positive correlation between alcohol consumption and nicotine use was found for male (r = 0.6798, p < 0.0001) and female (r = 0.6572, p < 0.0001) students. This study provided further insights into the use of legal substances of abuse in adolescents, evidencing the obvious need for the promotion of specific school educational programs aimed at the wellbeing of youth populations.

The Relaxin-3 Receptor, RXFP3, Is a Modulator of Aging-Related Disease

During the aging process our body becomes less well equipped to deal with cellular stress, resulting in an increase in unrepaired damage. This causes varying degrees of impaired functionality and an increased risk of mortality. One of the most effective anti-aging strategies involves interventions that combine simultaneous glucometabolic support with augmented DNA damage protection/repair. Thus, it seems prudent to develop therapeutic strategies that target this combinatorial approach. Studies have shown that the ADP-ribosylation factor (ARF) GTPase activating protein GIT2 (GIT2) acts as a keystone protein in the aging process. GIT2 can control both DNA repair and glucose metabolism. Through in vivo co-regulation analyses it was found that GIT2 forms a close coexpression-based relationship with the relaxin-3 receptor (RXFP3). Cellular RXFP3 expression is directly affected by DNA damage and oxidative stress. Overexpression or stimulation of this receptor, by its endogenous ligand relaxin 3 (RLN3), can regulate the DNA damage response and repair processes. Interestingly, RLN3 is an insulin-like peptide and has been shown to control multiple disease processes linked to aging mechanisms, e.g., anxiety, depression, memory dysfunction, appetite, and anti-apoptotic mechanisms. Here we discuss the molecular mechanisms underlying the various roles of RXFP3/RLN3 signaling in aging and age-related disorders.

Disinhibition-Like Behavior Correlates with Frontal Cortex Damage in an Animal Model of Chronic Alcohol Consumption and Thiamine Deficiency

Wernicke-Korsakoff syndrome (WKS) is induced by thiamine deficiency (TD) and mainly related to alcohol consumption. Frontal cortex dysfunction has been associated with impulsivity and disinhibition in WKS patients. The pathophysiology involves oxidative stress, excitotoxicity and inflammatory responses leading to neuronal death, but the relative contributions of each factor (alcohol and TD, either isolated or in interaction) to these phenomena are still poorly understood. A rat model was used by forced consumption of 20% (w/v) alcohol for 9 months (CA), TD hit (TD diet + pyrithiamine 0.25 mg/kg, i.p. daily injections the last 12 days of experimentation (TDD)), and both combined treatments (CA+TDD). Motor and cognitive performance and cortical damage were examined. CA caused hyperlocomotion as a possible sensitization of ethanol-induced excitatory effects and recognition memory deficits. In addition, CA+TDD animals showed a disinhibited-like behavior which appeared to be dependent on TDD. Additionally, combined treatment led to more pronounced alterations in nitrosative stress, lipid peroxidation, apoptosis and cell damage markers. Correlations between injury signals and disinhibition suggest that CA+TDD disrupts behaviors dependent on the frontal cortex. Our study sheds light on the potential disease-specific mechanisms, reinforcing the need for neuroprotective therapeutic approaches along with preventive treatments for the nutritional deficiency in WKS.

Differential effects of alcohol-drinking patterns on the structure and function of the brain and cognitive performance in young adult drinkers: A pilot study

INTRODUCTION

This study was aimed to determine how different patterns of alcohol consumption drive changes to brain structure and function and their correlation with cognitive impairments in young adult alcohol drinkers.

METHODS

In this study, we enrolled five groups participants and defined as: long-term abstinence from alcohol (LA), binge drinking (BD), long-term low dosage alcohol consumption but exceeding the safety drinking dosage (LD), long-term alcohol consumption of damaging dosage (LDD), and long-term heavy drinking (HD). All participants underwent magnetic resonance imaging (MRI) and functional MRI (fMRI) to acquire data on brain structure and function, including gray matter volume (GMV), fractional amplitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo), functional connectivity (FC), and brain network properties. The cognitive ability was evaluated with the California Verbal Learning Test (CVLT), intelligence quotient (IQ), and short delay free recall (SDFR).

RESULTS

Compared to LA, GMV significantly decreased in the brain regions in VN, SMN, and VAN in the alcohol-drinking groups (BD, LD, LDD, and HD). ReHo was significantly enhanced in the brain regions in VN, SMN, and VAN, while fALFF significantly increased in the brain regions in VN and SMN. The number of intra- and inter-modular connections within networks (VN, SMN, sensory control network [SCN], and VAN) and their connections to other modules were abnormally changed. These changes adversely affected cognition (e.g., IQ, CVLT, SDFR).

CONCLUSION

Despite the small sample size, this study provides new evidence supporting the need for young people to abstain from alcohol to protect their brains. These findings present strong reasoning for updating anti-alcohol slogans and guidelines for young people in the future.

Age modifies the effect of ethanol on behavior: Investigations in adolescent, adult and aged rats

The number of older people is increasing in most if not all countries in the world. In addition, the amount of alcohol consumption in the aged population is increasing and the consumption pattern is often in a binge fashion. However, little is known if the effects of alcohol, either acute or chronic exposure, vary in the older population compared to younger populations. The current mini-review will provide an overview of the effects of acute and chronic ethanol exposure at three different periods of development: adolescent, adult and aged on multiple different commonly studied behaviors. The overall conclusion is that biological age of the subject is a critical factor in understanding the effects of ethanol across the lifespan.

Midline Thalamic Damage Associated with Alcohol-Use Disorders: Disruption of Distinct Thalamocortical Pathways and Function

The thalamus, a significant part of the diencephalon, is a symmetrical and bilateral central brain structure. The thalamus is subdivided into three major groups of nuclei based on their function: sensorimotor nuclei (or principal/relay nuclei), limbic nuclei and nuclei bridging these two domains. Anatomically, nuclei within the thalamus are described by their location, such as anterior, medial, lateral, ventral, and posterior. In this review, we summarize the role of medial and midline thalamus in cognition, ranging from learning and memory to flexible adaptation. We focus on the discoveries in animal models of alcohol-related brain damage, which identify the loss of neurons in the medial and midline thalamus as drivers of cognitive dysfunction associated with alcohol use disorders. Models of developmental ethanol exposure and models of adult alcohol-related brain damage and are compared and contrasted, and it was revealed that there are similar (anterior thalamus) and different (intralaminar [adult exposure] versus ventral midline [developmental exposure]) thalamic pathology, as well as disruptions of thalamo-hippocampal and thalamo-cortical circuits. The final part of the review summarizes approaches to recover alcohol-related brain damage and cognitive and behavioral outcomes. These approaches include pharmacological, nutritional and behavioral interventions that demonstrated the potential to mitigate alcohol-related damage. In summary, the medial/midline thalamus is a significant contributor to cognition function, which is also sensitive to alcohol-related brain damage across the life span, and plays a role in alcohol-related cognitive dysfunction.

The specificity of thalamic alterations in Korsakoff's syndrome: Implications for the study of amnesia

The pathophysiological mechanisms behind amnesia are still unknown. Recent literature, through the study of patients with Alcohol Use Disorder with and without Korsakoff's syndrome, increasingly shows that physiological alterations to the thalamus have an important role in the development of amnesia. This review gives an overview of neuropsychological, neuropathological and neuroimaging contributions to the understanding of Korsakoff's syndrome, highlighting the central role of the thalamus in this amnesia. The thalamus being a multi-nucleus structure, the limitations regarding the loci, nature and alterations to specific nuclei are discussed, along with potential solutions. Finally, future directions for clinical research are laid out to unravel the intricacies inherent to amnesia. They consider the need to evaluate the physiological role of the thalamus, not only as an entity but also as part of a brain circuit through a more integrative approach.

Alcohol-Related Dementia: Rethink How Much You Drink

People have consumed alcohol for centuries. Most clinicians who work with people who have dementia acknowledge that alcohol may cause or exacerbate dementia's symptoms. Alcohol-related dementia (ARD) has been recognized since the 1960s, but clinicians rarely use this diagnosis. Regardless, it is common and develops pursuant to long-term excessive alcohol consumption. It may, in some cases, evolve into Wernicke-Korsakoff syndrome. Diagnosis can be obscured if patients are not truthful about their alcohol consumption. Often, friends or family provide a better picture of the patient's alcohol history than patients do themselves. Thiamine treatment may prevent or improve symptoms. Abstinence from alcohol is critical, but it is difficult for older people with long histories of heavy drinking. Consultant pharmacists can help the heath care team develop nuanced care plans for patients who have ARD.

Effects of an Alcohol-Related Harm Prevention Program among Out-of-School Female Adolescents

This study aimed to evaluate the effects of an alcohol-related harm prevention program on out-of-school adolescent girls. This was a quasi-experimental study employing a randomized controlled non-synchronized design. There were 23 and 22 participants in the experimental and control groups, respectively. The program comprised three sessions aiming to motivate voluntary changes and promote autonomous decision-making. The experimental group showed significantly higher alcohol-related knowledge and substantially lower alcohol outcome expectancy than the control group. No significant differences emerged from drinking refusal, self-efficacy, or alcohol abstinence intention. This program could improve alcohol-related knowledge and reduce out-of-school adolescent girls' positive alcohol outcome expectancy.

Jacobian Mapping Reveals Converging Brain Substrates of Disruption and Repair in Response to Ethanol Exposure and Abstinence in 2 Strains of Rats

BACKGROUND

In a previous study using Jacobian mapping to evaluate the morphological effects on the brain of binge (4-day) intragastric ethanol (EtOH) on wild-type Wistar rats, we reported reversible thalamic shrinkage and lateral ventricular enlargement, but persistent superior and inferior colliculi shrinkage in response to binge EtOH treatment.

METHODS

Herein, we used similar voxel-based comparisons of Magnetic Resonance Images collected in EtOH-exposed relative to control animals to test the hypothesis that regardless of the intoxication protocol or the rat strain, the hippocampi, thalami, and colliculi would be affected.

RESULTS

Two experiments [binge (4-day) intragastric EtOH in Fisher 344 rats and chronic (1-month) vaporized EtOH in Wistar rats] showed similarly affected brain regions including retrosplenial and cingulate cortices, dorsal hippocampi, central and ventroposterior thalami, superior and inferior colliculi, periaqueductal gray, and corpus callosum. While most of these regions showed significant recovery, volumes of the colliculi and periaqueductal gray continued to show response to each proximal EtOH exposure but at diminished levels with repeated cycles.

CONCLUSIONS

Given the high metabolic rate of these enduringly affected regions, the current findings suggest that EtOH per se may affect cellular respiration leading to brain volume deficits. Further, responsivity greatly diminished likely reflecting neuroadaptation to repeated alcohol exposure. In summary, this unbiased, in vivo-based approach demonstrating convergent brain systems responsive to 2 EtOH exposure protocols in 2 rat strains highlights regions that warrant further investigation in both animal models of alcoholism and in humans with alcohol use disorder.

Link Between Perception of Treatment Need and Craving Reports in Addiction

BACKGROUND

Perception of treatment need (PTN), a component of clinical insight, is associated to negative addiction treatment outcomes when low. Our hypothesis was that lower PTN was associated with less craving when reported retrospectively, the most common measure of craving in clinical settings.

OBJECTIVE

To explore the association between PTN and craving among a dataset of subjects with severe substance use disorders.

METHODS

Participants were recruited from outpatient addiction clinic admissions or harm reduction program services. Good and low PTN were based on consistency between severe addiction (at least six DSM-5 criteria) and self-report need for addiction treatment from the Addiction Severity Index. Craving was retrospectively characterized over the past 30 days. Multiple regression analyses were conducted.

RESULTS

Participants with low PTN (n = 97) retrospectively reported less frequent and intense episodes of craving, compared with participants with good PTN (n = 566) after controlling for sociodemographic factors, addiction type, and severity (p < 0.0001).

CONCLUSION

Low perception of treatment need among subjects with severe addictions is associated to less retrospective report of craving, which may contribute to reduced efficiency of treatment. Further studies are needed to explore the mechanisms of the association.

Acute ethanol administration produces larger spatial and nonspatial memory impairments in 29-33 month old rats compared to adult and 18-24 month old rats

The average age of the population in many countries is continuing to increase. Older people continue to consume alcohol, often in a binge like fashion. Previous research has demonstrated that older human subjects and aged animal subjects have an increased sensitivity to the effects of ethanol on a variety of behaviors. However, it has yet to be determined if acute ethanol exposure impairs spatial and/or nonspatial memory to a greater extent in aged rats compared to adult rats. In the current studies we trained male rats ranging in age from young adult (2 months of age) to aged rats (29-33 months of age) in the standard nonspatial task followed by the standard spatial task in the Morris water maze. Only animals deemed "cognitively-spared", that is aged animals that learn as well as young animals, were administered one of two doses of moderate ethanol and had their memory tested 30 min later. Acute ethanol administration produced similar performance impairments in spatial and nonspatial memory in all cognitively-spared animals except for the 29-33 month old animals which showed a significantly greater cognitive impairment in both tasks. In addition, blood ethanol levels were similar across all ages. The present work adds to the growing literature on the selective effects of acute ethanol exposure in aged animals.

Cognitive Impairments in Early-Detoxified Alcohol-Dependent Inpatients and Their Associations with Socio-Demographic, Clinical and Psychological Factors: An Exploratory Study

PURPOSE

Cognitive impairment is common among patients with alcohol use disorder (AUD). However, neuropsychological assessment is not usually included as routine practice in alcohol rehabilitation programs. The aim of this study was to describe qualitatively the cognitive deficits in early-detoxified AUD patients undergoing rehabilitation and to explore relevant associations with socio-demographic, clinical and psychological factors.

PATIENTS AND METHODS

Forty-one patients with a diagnosis of AUD were consecutively recruited from a residential rehabilitation hospital in Northern Italy. Cognitive impairment was assessed using the Brief Neuropsychological Examination 2 (ENB-2). Anxiety, depression and severity of alcohol dependence were also evaluated using validated self-report questionnaires. Alcohol relapse was investigated 1 month after discharge.

RESULTS

Overall, 31.7% of AUD patients showed cognitive impairments according to the global score scale. However, 70.7% had an impaired performance on at least one test of the ENB-2, with particular regard to executive function, visuospatial and memory domains. Age, education and abstinence at admission were the most relevant factors associated with cognitive deficits in this clinical population.

CONCLUSION

The detection of cognitive impairments is essential in order to adapt alcohol rehabilitation treatment to patients with cognitive deficits and enhance clinical outcomes.

Preface: Setting the stage for understanding alcohol effects in late aging: A special issue including both human and rodent studies

It is widely recognized that people worldwide are living longer than in previous decades, with formidable projections regarding the expansion of elderly age groups in the decades to come. Older individuals are also sustaining higher levels of alcohol consumption later in life, and binge drinking remains a prevalent pastime in a significant proportion of aged individuals. Older people are more sensitive to neurobehavioral effects of alcohol, and as individuals age, the cumulative impact of lifetime alcohol intake begins to emerge. This brief review provides a perspective on the emerging field of how alcohol interacts with the aging brain and sets the stage for understanding the relationship between alcohol and overall brain health. In doing so, we introduce a set of articles collected in this book series (all chapters available on PubMed) which spans human epidemiology and clinical outcomes, along with a series of neurobehavioral studies in preclinical (rodent) models. Because both natural aging as well as alcohol use and abuse include tell-tale signs of neuroinflammation (heightened expression of neuroimmune genes, activation of inflammatory signaling pathways, and signs of glial activation), particular emphasis is placed on the role of neuroinflammation in both aging- and alcohol-related alterations in neurobehavioral function, with special emphasis on the spectrum of cognitive dysfunction ranging from mild cognitive impairment to Alzheimer's associated brain pathology.

A comparison of hippocampal microglial responses in aged and young rodents following dependent and non-dependent binge drinking

Alcoholism is a highly visible and prevalent issue in the United States. Although binge-drinking is assumed to be a college-age problem, older adults (ages 65+) consume binge amounts of alcohol and have alcohol use disorders (AUDs). Moreover, individuals with alcohol dependence in their youth often continue to drink as they age. As such, this study tested the hypothesis that the effects of alcohol on hippocampal microglia are exacerbated in aged versus younger rodents in two AUD models. Briefly, adult (2-3 months) and aged (15+ months) Sprague-Dawley rats were administered alcohol or control diet using the Majchrowicz model to study alcohol-induced neurodegeneration. To study the effects of non-dependent binge consumption on microglia, adolescent (6-8 weeks) and aged (18+ months) C57/BL6N were subjected to the Drinking in the Dark paradigm. Microglia number and densitometry were assessed using immunohistochemistry. Hippocampal subregional and model/species-specific effects of alcohol were observed, but overall, aging did not appear to increase the alcohol-induced microglia reactivity as measured by Iba-1 densitometry. However, analysis of microglial counts revealed a significant decrease in the number microglia cells in both the alcohol-induced neurodegeneration and DID model across age groups. In the dentate gyrus, the loss of microglia was exacerbated by aging, particularly in mice after DID, non-dependent model. Using qRT-PCR, the persistence of alcohol and aging effects was assessed following the DID model. Allograft Inflammatory Factor 1 mRNA was increased in both young and aged mice by alcohol exposure; however, only in the aged mice did the alcohol effect persist. Overall, these data imply that the microglial response to alcohol is complex with evidence of depressed numbers of microglia but also increased reactivity with advanced age.