Essential role for neuronal nitric oxide synthase in acute ethanol-induced motor impairment.

The cerebellum is widely known as a motor structure because it regulates and controls motor learning, coordination, and balance. However, it is also critical for non-motor functions such as cognitive processing, sensory discrimination, addictive behaviors and mental disorders. The cerebellum has the highest relative abundance of neuronal nitric oxide synthase (nNos) and is sensitive to ethanol. Although it has been demonstrated that the interaction of γ-aminobutyric acid (GABA) and nitric oxide (NO) might play an important role in the regulation of ethanol-induced cerebellar ataxia, the molecular mechanisms through which ethanol regulates nNos function to elicit this behavioral effect have not been studied extensively. Here, we investigated the dose-dependent effects of acute ethanol treatment on motor impairment using the rotarod behavioral paradigm and the alterations of nNos mRNA expression in cerebellum, frontal cortex (FC), hippocampus and striatum. We also examined the link between acute ethanol-induced motor impairment and nNos by pharmacological manipulation of nNos function. We found that acute ethanol induced a dose-dependent elevation of ethanol blood levels which was associated with the impairment of motor coordination performance and decreased expression of cerebellar nNos. In contrast, acute ethanol increased nNos expression in FC but did not to change the expression for this enzyme in striatum and hippocampus. The effects of acute ethanol were attenuated by l-arginine, a precursor for NO and potentiated by 7-nitroindazole (7-NI), a selective inhibitor of nNos. Our data suggests that differential regulation of nNos mRNA expression in cerebellum and frontal cortex might be involved in acute ethanol-induced motor impairment.

Assessment of alcohol withdrawal in Native American patients utilizing the Clinical Institute Withdrawal Assessment of Alcohol Revised Scale.

BACKGROUND: The Clinical Institute Withdrawal Assessment of Alcohol Revised (CIWA-Ar) is a commonly used scale for assessing the severity of alcohol withdrawal syndrome in the acute setting. Despite validation of this scale in the general population, the effect of ethnicity on CIWA-Ar scoring does not appear in the literature. The purpose of our study was to investigate the validity of the CIWA-Ar scale among Native American patients evaluated for acute alcohol detoxification. METHODS: A case series of all patients seen for alcohol withdrawal at an Acute Drug and Alcohol Detoxification facility was conducted from June 1, 2011, until April 1, 2012. The CIWA-Ar scores were recorded by trained nursing staff on presentation to Triage Department and every 2 hours thereafter. At our institution, a score of 10 or greater indicates the need for inpatient hospital admission and treatment. Ethnicity was self-reported. Age, sex, blood alcohol concentration, blood pressure, and pulse were recorded on presentation and vital signs repeated every 2 hours. Patients were excluded from the study if other drug use was noted by history or initial urine drug screen. A multivariate logistic regression model was utilized to identify statistically significant variables associated with admission to the inpatient unit and treatment. The relationship of CIWA-Ar scores and ethnicity was compared using analysis of variance. RESULTS: A total of 115 whites, 45 Hispanics, and 47 Native Americans were included in the analysis. Native Americans had consistently lower CIWA-Ar scores at 0, 2, 4, and 6 hours than the other 2 ethnic groups (P = 0.002). In addition, Native Americans were admitted to the hospital less often than the other 2 groups for withdrawal (P < 0.001). CONCLUSIONS: The CIWA-Ar scale may underestimate the severity of alcohol withdrawal syndrome in certain ethnic group such as Native Americans. Further prospective studies should be undertaken to determine the validity of the CIWA-Ar scale in assessing alcohol withdrawal across different ethnic populations.

Effects of long-term moderate ethanol and cholesterol on cognition, cholinergic neurons, inflammation, and vascular impairment in rats.

There is strong evidence that vascular risk factors play a role in the development of Alzheimer's disease (AD) or vascular dementia (vaD). Ethanol (EtOH) and cholesterol are such vascular risk factors, and we recently showed that hypercholesterolemia causes pathologies similar to AD [Ullrich et al. (2010) Mol Cell Neurosci 45, 408-417]. The aim of this study was to investigate the effects of long-term (12 months) EtOH treatment (20% v/v in drinking water) alone or long-term 5% cholesterol diet alone or a combination (mix) in adult Sprague-Dawley rats. Long-term EtOH treatment (plasma EtOH levels 58±23 mg/dl) caused significant impairment of spatial memory, reduced the number of choline acetyltransferase- and p75 neurotrophin receptor-positive nucleus basalis of Meynert neurons, decreased cortical acetylcholine, elevated cortical monocyte chemoattractant protein-1 and tissue-type plasminogen activator, enhanced microglia, and markedly induced anti-rat immunoglobulin G-positive blood-brain barrier leakage. The effect of long-term hypercholesterolemia was similar. Combined long-term treatment of rats with 20% EtOH and 5% cholesterol (mix) did not potentiate treatment with EtOH alone, but instead counteracted some of the EtOH-associated effects. In conclusion, our data show that vascular risk factors EtOH and cholesterol play a role in cognitive impairment and possibly vaD.

Cluster headache is associated with the alcohol dehydrogenase 4 (ADH4) gene.

BACKGROUND/OBJECTIVES: Alcohol is a well-known trigger factor for cluster headache attacks during the active phases of the disease. The alcohol dehydrogenase (ADH) pathway, which converts alcohol to the toxic substance acetaldehyde, is responsible for most of the alcohol breakdown in the liver. Humans have 7 ADH genes, tightly clustered on chromosome 4q21-q25, that encode different ADH isoforms. The ADH4 gene encodes the class II ADH4 pi subunit, which contributes, in addition to alcohol, to the metabolization of a wide variety of substrates, including retinol, other aliphatic alcohols, hydroxysteroids, and biogenic amines. The purpose of this study was to investigate the association of genetic variants within the ADH4 gene with cluster headache susceptibility and phenotype. METHODS: A total of 110 consecutive unrelated cluster headache patients and 203 age- and sex-matched healthy controls of Caucasian origin were involved in the study. Patients and controls were genotyped for 2 bi-allelic single nucleotide polymorphisms (SNPs) of the ADH4 gene: SNP1 - rs1800759 and SNP2 - rs1126671. Allele, genotype, and haplotype frequencies of the examined polymorphisms were compared between cases and controls. RESULTS: Genotype frequencies of the rs1126671 polymorphism resulted significantly different between cluster headache patients and controls (chi(2) = 10.269, P = .006). The carriage of the AA genotype, in comparison with remaining genotypes, was associated with a significantly increased disease risk (OR = 2.33, 95% CI: 1.25-4.37). Haplotype analysis confirmed the association between the ADH4 gene and the disease. No association between different clinical characteristics of cluster headache and the examined polymorphisms was found. CONCLUSION: Our data suggest that cluster headache is associated with the ADH4 gene or a linked locus. Additional studies are warranted to elucidate the role of this gene in the etiopathogenesis of the disease.

Intolerancia al alcohol con rubor facial transitorio por tratamiento tópico con pimecrolimus / Alcohol Intolerance With Facial Flushing Due to Topical Pimecrolimus Treatment

No disponible

No disponible

Ethanol-related increases in degenerating bodies in the Purkinje neuron dendrites of aging rats.

Chronic ethanol consumption in aging rats results in regression of Purkinje neuron (PN) dendritic arbors ([Pentney, 1995 Measurements of dendritic pathlengths provide evidence that ethanol-induced lengthening of terminal dendritic segments may result from dendritic regression. Alcohol Alcohol. 30, 87-96]), loss of synapses (Dlugos and Pentney, 1997), dilation of the smooth endoplasmic reticulum (SER), and the formation of degenerating bodies within PN dendrites ([Dlugos, C.A., 2006a. Ethanol-Related Smooth Endoplasmic Reticulum Dilation in Purkinje Dendrites of Aging Rats. Alcohol., Clin. Exp. Res. 30, 883-891,Dlugos, C.A., 2006b. Smooth endoplasmic reticulum dilation and degeneration in Purkinje neuron dendrites of aging ethanol-fed female rats. Cerebellum. 5, 155-162]). Dilation of the SER and the formation of degenerating bodies may be a predictor of dendritic regression. Ethanol-induced effects on mitochondria may be involved as mitochondria cooperate with the SER to maintain calcium homeostasis. The purpose of this study was to determine whether degenerating body number and mitochondrial density and structure are altered by chronic ethanol treatment in PN dendrites. Male, Fischer 344 rats, 12 months of age, were fed an ethanol or pair-fed liquid diet, or rat chow for a period of 10, 20, or 40 weeks (15 rats/treatment; 45 rats/treatment duration). Ethanol-fed rats received 35% of their calories as ethanol. At the end of treatment, all animals were euthanized, perfused, and tissue prepared for electron microscopy. The densities of degenerating bodies and mitochondria, mitochondrial areas, and the distance between the SER and the mitochondria were measured. Results showed that there was an ethanol-related increase in degenerating bodies compared to controls at 40 weeks. Ethanol-induced alterations to mitochondria were absent. Correlation of the present results with those of previous studies suggest that degenerating bodies may be formed from membrane reabsorption during dendritic regression or from degenerating SER whose function has been compromised by dilation.

Changed accumbal responsiveness to alcohol in rats pre-treated with nicotine or the cannabinoid receptor agonist WIN 55,212-2.

Alcohol, nicotine, and cannabinoid acutely increase the activity of the mesolimbic dopamine (DA) pathway. Although polysubstance consumption is a common pattern of abuse in humans, little is known about dopamine release following pre-exposure to these drugs. The purpose of this study was to test whether alcohol-induced dopamine release into the nucleus accumbens (NAc) shell is modified by different pre-treatments: water (i.g.), alcohol (1 g/kg, i.g.), nicotine (0.4 mg/kg, s.c.), and WIN 55,212-2 (1 mg/kg, s.c.). Male Wistar rats were treated (i.g.) for 14 days with either water or alcohol. In the following 5 days rats were injected (s.c.) with vehicle, nicotine, or WIN 55,212-2. Finally, a cannula was surgically implanted into the NAc shell and alcohol-induced extracellular dopamine release was monitored in freely moving rats. Alcohol (1 g/kg; i.g.) only increased the release of dopamine when animals were previously treated with water. This DA increase was markedly inhibited by (subchronic) treatment (5 days) with nicotine or WIN 55-212-2 as well as by previous (chronic) exposure to alcohol (14 days). These data demonstrate that pre-treatment with nicotine and the cannabinoid agonist WIN 55,212-2 is able to change the sensitivity of the NAc shell in response to a moderate dose of alcohol. Therefore, cannabinoid and nicotine exposure may have important implications on the rewarding effects of alcohol, because these drugs lead to long-lasting changes in accumbal dopamine transmission.

Efeitos da exposição pré-natal e pós-natal ao etanol no córtex cerebral de ratos: um estudo do neurópilo / Effects of prenatal and postnatal ethanol exposure in the cerebral cortex of rats: a study of neuropil

INTRODUÇÃO: Exposição pré-natal ao etanol é freqüentemente associada a microcefalia e atraso na migração celular. O mecanismo pelo qual o etanol induz seus efeitos no desenvolvimento do sistema nervoso não é muito bem entendido. OBJETIVOS: Avaliar o efeito da exposição crônica ao etanol sobre o córtex visual de ratos durante seu desenvolvimento. MATERIAL E MÉTODO: Ratos Wistar provenientes do acasalamento de 30 fêmeas, divididos nos grupos etanol (n = 10) - 3 g/kg/dia - e controle (n = 10), foram utilizados nesse experimento. Os ratos foram perfundidos e o encéfalo, dividido em três partes: anterior, médio e posterior. Os cortes obtidos do fragmento posterior foram expostos à rotina histológica e submetidos a diferentes técnicas de coloração. Na análise estatística foi utilizado o teste t para comparar os pesos encefálicos e corporais. Considerou-se como nível de rejeição de hipótese nula um valor de p < 0,05. RESULTADO: Houve redução de peso cerebral em diferentes períodos analisados, além de ectopia e heterotopia neuronal. Não se observou deposição de fibras. DISCUSSÃO/CONCLUSÃO: O etanol atua de maneira negativa no desenvolvimento dos ratos, incluindo alterações na migração neuronal e microcefalia. Essas alterações podem ajudar a explicar as disfunções relatadas na síndrome do alcoolismo fetal (SAF).

BACKGROUND: Prenatal exposure to ethanol is frequently associated with microencephaly and delayed cell migration. The mechanism by which ethanol affects the development of the nervous system is still not fully understood. OBJECTIVE: To evaluate the effect of chronic exposure to ethanol on the visual cortex of rats during their development. MATERIAL AND METHOD: Wistar rats, born from the mating of 30 females, were divided into two groups: those exposed to ethanol (n = 10) - 3 g/kg/day - and a control group (n = 10). The rats were perfused and brain was divided into three parts: anterior, middle and posterior. Slices taken from the posterior fragment were subjected to histological analysis routine and different staining techniques. A statistical analysis was carried out using t test to compare brain and body weight. A value < 0,05 was considered a rejection of null hypothesis. RESULTS: There was a reduction of brain weight in different analyzed periods. There were no fiber deposits. Ectopia and neuronal heterotopia were observed. DISCUSSION/CONCLUSION: Ethanol has a negative effect on the development of rats, including alterations in neuronal migration and microencephaly. These alterations may help to explain some of the dysfunctions reported in patients with fetal alcohol syndrome (FAS).

Cannabinoids enhance susceptibility of immature brain to ethanol neurotoxicity.

OBJECTIVE: Marijuana and alcohol are most widely abused drugs among women of reproductive age. Neurocognitive deficits have been reported in children whose mothers used marijuana during pregnancy. Maternal consumption of ethanol is known to cause serious developmental deficits METHODS: Infant rats and mice received systemic injections of Delta(9)-tetrahydrocannabinol (THC; 1-10mg/kg) or the synthetic cannabinoid WIN 55,212-2 (1-10mg/kg), alone or in combination with subtoxic and toxic ethanol doses, and apoptotic neurodegeneration was studied in the brains RESULTS: Acute administration of THC (1-10mg/kg), the principal psychoactive cannabinoid of marijuana, markedly enhanced proapoptotic properties of ethanol in the neonatal rat brain. THC did not induce neurodegeneration when administered alone. Neuronal degeneration became disseminated and severe when THC was combined with a mildly intoxicating ethanol dose (3gm/kg), with the effect of this drug combination resembling the massive apoptotic death observed when administering ethanol alone at much higher doses. The detrimental effect of THC was mimicked by the synthetic cannabinoid WIN 55,212-2 (1-10mg/kg) and counteracted by the CB(1) receptor antagonist SR141716A (0.4mg/kg). THC enhanced the proapoptotic effect of the GABA(A) agonist phenobarbital and the N-methyl-D-aspartate receptor antagonist dizocilpine. Interestingly, infant CB(1) receptor knock-out mice were less susceptible to the neurotoxic effect of ethanol. Furthermore, the CB(1) receptor antagonist SR141716A ameliorated neurotoxicity of ethanol INTERPRETATION: These observations indicate that CB(1) receptor activation modulates GABAergic and glutamatergic neurotransmission and primes the developing brain to suffer apoptotic neuronal death.

Ocular deficits associated with alcohol exposure during zebrafish development.

Approximately 90% of fetal alcohol syndrome cases are accompanied by ocular abnormalities. The zebrafish (Danio rerio) is a well-known developmental model that provides an opportunity for better understanding the histological and cytological effects of developmental exposure to ethanol on the vertebrate eye. The purpose of the present study was to determine the gross, microscopic, and ultrastructual effects of developmental exposure to ethanol in the zebrafish model. Eggs were obtained from WT outbred zebrafish and exposed to 0%, 0.1%, 0.2%, 0.4%, 0.5%, or 1.0% (v/v) ethanol to assess viability and the effect of dose and duration of exposure on eye size. Light and electron microscopy were performed on ethanol-treated and control larvae. Results showed that ethanol treatment decreased viability by about 20% at concentrations of 0.1-0.5% ethanol and by 50% at 1.0% ethanol. Ethanol-related decreases in eye size were recorded at 6 days postfertilization (dpf) and were dose dependent. There were significant decreases in the volumes of the photoreceptor, inner nuclear, and ganglionic layers and in the lens of 9 dpf ethanol-exposed compared with control larvae. Ultrastructural examination showed signs of developmental lags in the ethanol-treated fish as well as abnormal retinal apoptosis in the 6 dpf ethanol-treated larvae compared with their controls. These results demonstrate that the developing zebrafish eye is sensitive to perturbation with ethanol and displays some of the eye deficits present in fetal alcohol syndrome.

The CB1 cannabinoid receptor antagonist rimonabant chronically prevents the nicotine-induced relapse to alcohol.

Preclinical and clinical research shows that the cannabinoid brain receptor type 1 (CB(1)) modulates alcohol- and nicotine-related behaviors. Throughout the nicotine-induced relapse to alcohol, the rats were pre-treated for 10 days with the CB(1) cannabinoid receptor antagonist rimonabant (0, 0.03, 0.3 and 3.0 mg/kg i.p.). In this condition, a long-lasting nicotine-induced relapse to alcohol was observed, and this effect was reversed in a dose-dependent manner with rimonabant. Surprisingly, rats that were not exposed to nicotine developed tolerance to the effects of rimonabant from the sixth day. Also, 3.0 mg/kg of rimonabant reduced the responses for sucrose. Evaluation in the Elevated Plus-Maze after nicotine treatment did not reveal anxiogenic effects. Finally, at the conclusion of rimonabant treatment, a rapid reinstatement of alcohol consumption was detected. These results suggest that rimonabant can prevent the relapse to alcohol, even when an interaction with nicotine exists-the most frequent situation in human alcohol abuse.

Oligodendrocyte myelin glycoprotein (OMgp) in rat hippocampus is depleted by chronic ethanol consumption.

The hippocampal formation has been shown to be particularly vulnerable to the neurotoxic effects of chronic ethanol consumption. It was hypothesized that this damage was due to the disruption of the expression of neurotrophic factors and certain other proteins within the hippocampus. By using real-time reverse transcription-polymerase chain reaction (RT-PCR) techniques, this study aimed to determine whether chronic ethanol consumption could alter the mRNA expression level of brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), and oligodendrocyte myelin glycoprotein (OMgp) in the hippocampus. Wistar male rats received an unrestricted access to a liquid diet containing 5% (v/v) ethanol as the sole source of fluid from 10 to 29 weeks of age. Control rats had unlimited access to a liquid diet containing an isocaloric amount of sucrose. We found that chronic ethanol consumption did not cause significant changes in the levels of mRNA for BDNF and GDNF. However, OMgp mRNA showed a significant deficit in ethanol-treated animals. It is suggested that this deficit may be related to the demyelination that is commonly observed in human alcoholics and that this may contribute to the functional and cognitive deficits.

Ethanol-induced neuroapoptosis in the developing rodent cerebellum and related brain stem structures.

For three decades since the fetal alcohol syndrome (FAS) was first described, researchers have been keenly interested in understanding the mechanism(s) by which ethanol damages or disrupts development of the human fetal brain. It has been reported repeatedly that exposure of infant rats to ethanol causes a reduction in brain mass and loss of cerebellar Purkinje cells, but the mechanisms underlying these effects have remained elusive. In a recent series of studies, we have demonstrated that exposure of infant rats or mice to ethanol on a single occasion during the synaptogenesis period of development causes neurons in many regions of the developing central nervous system to commit suicide (die by apoptosis), but the cerebellum was not among the brain regions focused upon in these studies. Here we show in infant rats and mice that one-time exposure to ethanol triggers acute neurodegeneration of Purkinje cells and other neurons in the cerebellar cortex, deep cerebellar nuclei, and two related brainstem nuclei (nucleus pontis, inferior olivary complex). We also describe the time course of neurodegeneration and window of vulnerability for each of these neuronal cell types and demonstrate that the cell death process in each case is unequivocally apoptotic. We conclude that exposure of infant rats or mice to ethanol on a single occasion during synaptogenesis can kill Purkinje cells, and many other neuronal populations at all levels of the developing neuraxis, and in each case the mechanism of cell death is apoptosis.

Effects of 4-methylpyrazole on ethanol neurobehavioral toxicity in CD-1 mice.

OBJECTIVES: 4-Methylpyrazole (4-MP), an alcohol dehydrogenase (ADH) antagonist, is used for the treatment of ethylene glycol and methanol ingestions. However, ethanol is frequently co-ingested by those who ingest these more toxic alcohols. Several in vitro and in vivo studies have shown a decrease in the elimination rate of ethanol after the administration of 4-MP, but none has evaluated the effects of 4-MP administration on the neurobehavioral toxicity of ethanol. This was a study to determine whether ADH blockade with 4-MP prolongs ethanol neurobehavioral toxicity in a murine model. METHODS: D-1 mice were pretreated with 4-MP, with observation of its effect on ethanol dose-response curves. 4-MP (25 mg/kg) or an equal volume of saline was administered intraperitoneally. Ten minutes later, incremental ethanol doses of 1-5 g/kg were administered intraperitoneally. Pretreated and control groups were composed of ten mice each for each dose of ethanol tested. Outcomes for assessing ethanol neurobehavioral toxicity were successful performance on the rotarod test and presence of the righting reflex, two established and validated outcome measures for ethanol-induced neurobehavioral toxicity in mice. RESULTS: The dose of ethanol at which 50% of the animals failed a particular outcome test (toxic dose 50 [TD(50)]) was decreased with 4-MP administration for both the rotarod test and the righting reflex. The TD(50) intergroup differences (control vs. 4-MP) were statistically significant at 60, 120, and 180 minutes (p < 0.05). CONCLUSIONS: Pretreatment with 4-MP significantly prolonged ethanol neurobehavioral toxicity in CD-1 mice, presumably by inhibiting its metabolism by ADH. Further investigation is warranted to evaluate this interaction.

Chronic ethanol consumption impairs the circadian rhythm of pro-opiomelanocortin and period genes mRNA expression in the hypothalamus of the male rat.

Certain psychiatric disorders are known to alter the body's biological rhythms. However, currently, very little information is known about the effect of chronic ethanol administration on the circadian clock or the rhythm of beta-endorphin-containing neurons that participate in the control of the reward and reinforcement of alcohol drinking. Here, we report that administration of ethanol, via a liquid diet paradigm for a period of 2 weeks, abolishes the circadian rhythm of pro-opiomelanocortin mRNA expression of beta-endorphin neurons in the arcuate nucleus of the hypothalamus. The circadian expression of the clock governing rat period genes (rPeriod1 mRNA and rPeriod2 mRNA) in the arcuate nucleus was significantly altered, suggesting that ethanol administration disrupted the internal clock. Moreover, ethanol consumption altered the circadian rhythms of rPeriod2 and rPeriod3 mRNA levels in the suprachiasmatic nucleus, suggesting that ethanol also affected the function of the central pacemaker. Our findings identified the vulnerability of the body's clock machinery and its opioidergic system to chronic alcohol drinking.

Administration schedule for an ethanol-containing diet in pregnancy affects types of offspring brain malformations.

In the present study, we administered liquid diets containing ethanol to pregnant rats on different schedules, and examined the cerebral cortex of their pups on gestational day (GD) 21 by immunohistochemistry. The first group of pregnant rats was fed a liquid diet containing 5% (w/v) ethanol during GDs 10-21(5% Et). The second group was fed a liquid diet containing 2.5% (w/v) ethanol on GDs 10-12, a diet containing 4% (w/v) ethanol on GDs 13-15, and a diet containing 5% (w/v) ethanol on GDs 16-21 (2.5-5% Et). Pups of 5% Et dams had leptomeningeal heterotopias mainly in the parietal cortex. In 2.5-5% Et pups, other types of malformations such as grooves, microgyri, stacked-up cortices, and defects of layer I were found. The diet intake and body weight gain of 2.5-5% Et dams were significantly higher than those of 5% Et dams during GDs 11-16. There was no difference in total ethanol consumption during GDs 10-21 between the two groups. However, ethanol consumption on GD 15 in 2.5% Et was higher than in 5% Et. A different schedule for administration of an ethanol-containing diet in pregnancy might induce different types of cerebral malformations in rat fetuses.

Irreversible spinal cord injury as a complication of subarachnoid ethanol neurolysis.

Subarachnoid neurolysis using ethanol to destroy selectively the posterior roots of the spinal cord is a method for providing pain relief in patients with advanced cancer. Weakness of the extremities is a complication of the procedure that has been attributed to spread of the neurolytic agent to the anterior roots. The authors provide evidence of spinal cord injury as a cause of lower extremity weakness in a patient after subarachnoid ethanol neurolysis.