Neuroimaging in alcoholism: CT and MRI results and clinical correlates

Female rats exposed to stress and alcohol show impaired memory and increased depressive-like behaviors

Exposure to daily life stressors is associated with increases in anxiety, depression, and overall negative affect. Alcohol or other psychoactive drugs are often used to alleviate stress effects. While females are more than twice as likely to develop mood disorders and are more susceptible to dependency than males, they are infrequently examined. In this study, female rats received no stress/no alcohol control (CON), alcohol alone (ALC), stress alone (STR), or stress plus alcohol (STR+ALC). Stress consisted of restraint for 6h/day/7days, and alcohol was administered immediately following restraint via gastric gavage at a dose of 2.0g/kg. Dependent measures included tests utilizing object recognition (OR), Y-maze, elevated plus maze (EPM), forced swim (FST), blood alcohol content, corticosterone levels, and body weights. ALC, STR+ALC, but not stress alone, impaired memory on OR. All treatments impaired spatial memory on the Y-maze. Anxiety was not affected on the EPM, but rats treated with alcohol or in combination with stress showed increased immobility on the FST, suggestive of alcohol-induced depression. Previously, we found alcohol reversed deleterious effects of stress on memory and mood in males, but current results show that females reacted negatively when the two treatments were combined. Thus, responses to alcohol, stress and their combination suggest that sex specific treatments are needed for stress-induced behavioral changes and that self-medicating with alcohol to cope with stress maybe deleterious in females.

Alcohol dependence associated with increased utilitarian moral judgment: a case control study

Recent studies indicate that emotional processes, mediated by the ventromedial prefrontal cortex (VMPC), are of great importance for moral judgment. Neurological patients with VMPC dysfunction have been shown to generate increased utilitarian moral judgments, i.e. are more likely to endorse emotionally aversive actions in order to maximize aggregate welfare, when faced with emotionally salient personal moral dilemmas. Patients with alcohol dependence (AD) also exhibit impairments in functions mediated by the prefrontal cortex, but whether they exhibit increased utilitarian moral reasoning has not previously been investigated. The aim of this study was to investigate moral judgment in AD patients (n = 20) compared to healthy controls (n = 20) matched by sex, age and education years. Each subject responded to a battery of 50 hypothetical dilemmas categorized as non-moral, moral impersonal and moral personal. They also responded to a questionnaire evaluating explicit knowledge of social and moral norms. Results confirmed our hypothesis that AD patients generated increased utilitarian moral judgment compared to controls when faced with moral personal dilemmas. Crucially, there was no difference in their responses to non-moral or impersonal moral dilemmas, nor knowledge of explicit social and moral norms. One possible explanation is that damage to the VMPC, caused by long term repeated exposure to alcohol results in emotional dysfunction, predisposing to utilitarian moral judgment. This work elucidates a novel aspect of the neuropsychological profile of AD patients, namely a tendency to generate utilitarian moral judgment when faced with emotionally salient moral personal dilemmas.

Effects of abstinence on brain morphology in alcoholism: a MRI study

Chronic alcohol abuse leads to morphological changes of the brain. We investigated if these volumetric changes are reversible after a period of abstinence. For this reason 41 male and 15 female alcohol patients underwent MRI-scanning after in-patient detoxification (baseline) entering alcoholism treatment programs, and between 6 and 9 months later (follow-up), in a phase of convalescence. Additionally, 29 male and 16 female control subjects were examined. The MRI-scans were delineated and the resulting regions of interest, volumes of lateral ventricles and prefrontal lobes were expressed relatively to total brain volume. Compared to control subjects alcohol patients showed bilaterally decreased prefrontal lobes (11% reduction) and increased lateral ventricles (up to 42% enlargement). The extent of the ventricular increase was depending on patient's additional psychiatric diagnosis, showing smaller lateral ventricles in patients with additional personality disorder. While at follow-up the size of prefrontal lobes remained unchanged, volumes of the lateral ventricles decreased (5-6% reduction) in alcohol patients with abstinence and improved drinking behavior, especially in patients that underwent only one detoxification. The extent of the ventricular enlargement correlated with the elevation of alcohol related laboratory measures (mean corpuscular volume, gamma-glutamyl transpeptidase). In conclusion this study confirms the hypothesis that alcoholism causes brain damages that are partially reversible. It should be analyzed in further studies with larger sample sizes, if complete brain regeneration is possible maintaining abstinence over a longer period.

Cognitive performance of detoxified alcoholic Korsakoff syndrome patients remains stable over two years

Excessive alcohol consumption is assumed to promote cognitive decline, eventually increasing the risk of dementia. However, little is known about the time course of cognitive functions in patients with chronic alcoholic Korsakoff syndrome (KS). Therefore, we assessed neuropsychological performance in 20 detoxified chronic KS inpatients at time 1 (T1) with a follow-up after two years (T2). The neuropsychological tests assessed verbal and visual short- and long-term memory, working memory, basic executive functions, language, general knowledge, and visual-spatial abilities. Surveys with caregivers and medical records provided information about current and previous disease-related parameters, drinking history, additional pathologies, as well as psychosocial and cognitive therapy within the two-year period. At both sessions, the majority of the KS patients' results were inferior to those of normal subjects. Comparing T1 and T2 revealed no significant decline in any of the investigated functions. Instead, general knowledge, visual long-term memory, and verbal fluency improved slightly after two years, though they still remained within pathological range. Comparing most improved and most deteriorated patients, better outcome occurred more frequently in men than women and was associated with higher premorbid education and fewer detoxifications in the past. In this sample of detoxified KS patients there was no indication of accelerated cognitive decline or onset of dementia-like symptoms over two years.

Social cognition in alcoholism: a link to prefrontal cortex dysfunction?

AIMS

Alcoholism is associated with a range of cognitive deficits. These deficits might be explained by the 'frontal lobe hypothesis' which suggests a specific vulnerability of the prefrontal cortex (PFC) to the neurotoxic effects of alcohol. Social cognition is thought to be processed in the PFC, but so far only few studies have addressed the issue of social cognition deficits in alcoholism. This review aims to evaluate the deficits in social cognition in alcoholic patients. In addition an outline for future perspectives is given.

METHODS

Medline and Psyclit searches were performed for a 30-year period (1977-2007).

RESULTS

Alcoholism is associated clearly with social cognition impairments which include emotional face and prosody perception problems, theory of mind deficits and humour processing difficulties.

CONCLUSIONS

In summary, the social cognition impairments are consistent with the frontal lobe hypothesis of alcoholism. Future studies should focus on (i) the delineation of the basic cognitive processes which underlie social cognition deficits; and (ii) their relevance as predictors of treatment outcome in alcoholism.

SPECT neuroimaging in translational research of CNS disorders

High resolution SPECT imaging is an emerging field and there are only limited studies as yet available in this direction. Still there is continuous effort to achieve better spatial and temporal resolution in order to obtain detailed structural and functional information of different brain regions in small experimental animals. Recently, SPECT imaging system has been used to perform in vivo imaging using specific radioligands to further elucidate the role of dopaminergic, serotonergic, and cholinergic neurotransmission in relation to regional cerebral blood flow in various human CNS disorders and in gene-manipulated mouse models of neurodegeneration. Although in vivo and non-invasive translational research can be performed by high-resolution microPET imaging system, its limited spatial resolution restricts detailed anatomical and functional information of different brain regions involved in disease process. Recently developed NanoSPECT/CT imaging system has a better spatial resolution hence can be used to correlate and confirm microPET imaging data and determine the precise structural and functional anatomy of CNS disorders and their remission. Moreover SPECT imaging system reduces the cost and number of animals and provides detailed information of CNS disorders at the cellular, molecular and genetic level. Furthermore, SPECT system is economical, provides less radiation burden, and can be used to study bio-distribution of newly synthesized radioligands with increased target to non-target ratios, quality control, and clinical applications. It is envisaged that high-resolution SPECT imaging system will further improve in vivo non-invasive translational research on CNS disorders of unknown etiopathogenesis and their treatment in future.

Monitoring the effects of chronic alcohol consumption and abstinence on brain metabolism: a longitudinal proton magnetic resonance spectroscopy study

BACKGROUND

This study focused on metabolic brain alterations in recently detoxified alcohol-dependent patients (S1) and their possible reversibility after 3 (S2) and 6 months (S3) of abstinence.

METHODS

Thirty-three alcohol-dependent patients and 30 healthy control subjects were studied with multislice proton magnetic resonance spectroscopic imaging (echo time = 135 msec at 1.5 T at three time points).

RESULTS

In the patient group, we found that choline-containing compounds (Ch) in three frontal and cerebellar subregions at S1 were significantly below normal, whereas N-acetyl aspartate (NAA) differences did not reach significance but showed a trend toward below-normal values in frontal white matter. Abstinent patients showed a significant increase of Ch in all subregions at S2. At S3, no further significant metabolite changes in abstinent patients compared with S2 could be detected. No significant increase of NAA could be detected at follow-up.

CONCLUSIONS

The increase of the Ch signal in the follow-up measurement after 3 months in abstinent alcohol-dependent patients supports the hypotheses of an alcohol- or alcohol detoxification-induced altered cerebral metabolism of lipids in membranes or myelin, which seems to be reversible with duration of alcohol abstinence.

Identifikation von Risikogenen für Alkoholabhängigkeit

Alcohol dependence is one of the most common addictive diseases and known to be in part genetically transmitted, based on an oligogenic background in which each gene involved contributes only little to the resulting phenotype. Besides influencing other signal transduction mechanisms, alcohol specifically inhibits the NMDA signaling cascade, which mediates the excitatory effects of glutamate in the brain. Target molecules, sensitive to ethanol, include the NMDA receptors as well as downstream molecules of the glutamatergic system, glutamate transporters, and associated regulatory proteins. Adaptive processes of the glutamatergic system during chronic alcohol consumption may play a major role for later development of reward symptoms. Candidate gene studies, including association studies and animal models, are powerful and sensitive for detecting oligogenic effects and thus important to alcoholism research.

Neurocircuitry in alcoholism: a substrate of disruption and repair

The chronic, excessive consumption of alcohol results in significant modification of selective neural systems of the brain structure, physiology, and function. Quantitative MR structural imaging, diffusion tensor imaging (DTI), and functional MRI (fMRI), together with neuropsychological challenges, have enabled rigorous in vivo characterization of the results of alcoholism on the brain in the human condition. Neuroimaging has also enabled longitudinal study for the examination of alcoholism's dynamic course through periods of drinking and sobriety. Controlled studies have revealed compelling evidence for alcohol-related brain structural and functional modification--some longstanding, some transient, and some compensatory. Patterns of circuitry disruption identified through structural and functional MRI studies suggest a central role for degradation of frontocerebellar neuronal nodes and connecting circuitry affecting widespread brain regions and contributing to alcoholism's salient, enduring, and debilitating cognitive and motor deficits--executive dysfunction, visuospatial impairment, and ataxia.

Alcohol Effects on Central Nervous System Gene Expression in Genetic Animal Models

This article summarizes the proceedings of a symposium presented at the 2004 annual meeting of the Research Society on Alcoholism in Vancouver, British Columbia, Canada. The organizers and chairs were William J. McBride and Michael F. Miles. The presentations were (1) Molecular Triangulation on Gene Expression Patterns in Behavioral Responses to Acute Ethanol, by Robnet T. Kerns; (2) Gene Expression in Limbic Regions After Ethanol Self-Infusion Into the Posterior Ventral Tegmental Area, by Zachary A. Rodd; (3) Microarray Analysis of CNS Limbic Regions of Inbred Alcohol-Preferring and -Nonpreferring rats and Effects of Alcohol Drinking, by Wendy N. Strother and Howard J. Edenberg; and (4) Microarray Analysis of Mouse Lines Selected for Chronic Ethanol Withdrawal Severity: The Convergence of Basal, Ethanol Regulated, and Proximity to Ethanol Quantitative Trait Loci to Identify Candidate Genes, by Joel G. Hashimoto and Kristine M. Wiren.

Alcohol abuse and traumatic brain injury: quantitative magnetic resonance imaging and neuropsychological outcome

Prior or concurrent alcohol use at the time of traumatic brain injury (TBI) was examined in terms of post-injury atrophic changes measured by quantitative analysis of magnetic resonance imaging (MRI) and neuropsychological outcome. Two groups of TBI subjects were examined: those with a clinically significant blood alcohol level (BAL) present at the time of injury (TBI + BAL) and those without a significant BAL (TBI-only). To explore the potential impact of both acute and chronic alcohol use, subjects in both groups were further clustered into one of four subgroups (NONE, MILD, MODERATE or HEAVY) based upon available information regarding their pre-injury alcohol use. One-way analysis of covariance (ANCOVA) and multiple analysis of covariance (MANCOVA) were used with subject grouping as the main factor. Age, injury severity as measured by Glasgow Coma Scale (GCS) score, years of education, total intracranial volume (TICV), and the number of days post-injury were included as covariates where appropriate. Increased general atrophy was observed in patients with (a) a positive BAL and/or (b) a history of moderate to heavy pre-injury alcohol use. In addition, performance on neuropsychological outcome variables (WAIS-R and WMS-R Index scores) was generally worse in the subgroups of patients with positive BAL and a history of preinjury alcohol use, as compared to the other TBI groups though not statistically significant. Implications of alcohol use, at the time of brain injury, are discussed.

Positron emission tomography imaging of the serotonin transporter in subjects with a history of alcoholism

BACKGROUND

Our purpose was to investigate the serotonin transporter (SERT) in various brain regions of alcoholics using positron emission tomography and C-11 McN5652.

METHOD

Thirty-two adult subjects were involved, 17 social drinkers as control subjects and 15 subjects who were abstinent or recovering alcoholics. Concomitant psychiatric diseases were ruled out based on DSM-IV criteria. The majority of subjects were men. Radioligand binding in 11 brain areas was expressed as the total distribution volume (DV), distribution volume of specific binding (DV(spec)), and distribution volume ratio (DVR). The cerebellum was used as reference tissue for calculation of DV(spec) and DVR.

RESULTS

In subjects with a history of alcoholism, DV was lower in all brain regions, with significant differences in the midbrain, thalamus, amygdala, pons, cingulate gyrus, frontal cortex, and cerebellum. Additionally, DV(spec) was lower in all brain regions, but differences were only significant in the midbrain; DVR was lower in nine regions but the differences did not reach statistical significance.

CONCLUSIONS

These studies demonstrate lower binding of [(11)C](+)McN5652 to the SERT in the brain of abstinent or recovering alcoholics compared with control subjects. Differences in the radioligand distribution volumes are more significant before than after correction for nonspecific binding of the radioligand.

Expression of hNP22 Is Altered in the Frontal Cortex and Hippocampus of the Alcoholic Human Brain

BACKGROUND

Human neuronal protein (hNP22) is a gene with elevated messenger RNA expression in the prefrontal cortex of the human alcoholic brain. hNP22 has high homology with a rat protein (rNP22). These proteins also share homology with a number of cytoskeleton-interacting proteins.

METHODS

A rabbit polyclonal antibody to an 18-amino acid epitope was produced for use in Western and immunohistochemical analysis. Samples from the human frontal and motor cortices were used for Western blots (n = 10), whereas a different group of frontal cortex and hippocampal samples were obtained for immunohistochemistry (n = 12).

RESULTS

The hNP22 antibody detected a single protein in both rat and human brain. Western blots revealed a significant increase in hNP22 protein levels in the frontal cortex but not the motor cortex of alcoholic cases. Immunohistochemical studies confirmed the increased hNP22 protein expression in all cortical layers. This is consistent with results previously obtained using Northern analysis. Immunohistochemical analysis also revealed a significant increase of hNP22 immunoreactivity in the CA3 and CA4 but not other regions of the hippocampus.

CONCLUSIONS

It is possible that this protein may play a role in the morphological or plastic changes observed after chronic alcohol exposure and withdrawal, either as a cytoskeleton-interacting protein or as a signaling molecule.

Effect of copper overload together with ethanol uptake on hippocampal neurons

Copper is an essential trace element which forms an integral component of many enzymes. While trace amounts of copper are needed to sustain life, excess copper is extremely toxic in the brain. Also, ethanol intake causes morphological changes in the brain. The present study aims to investigate effects of copper overload with ethanol intake in hippocampal neuron numbers of rat brain. Control and experimental group of rats (n = 6 for each group) were fed ad libitum. Experimental group were given ethanol with copper in drinking water each day for ten days. Control group animals were given only drinking water during this period. Afterwards, animals were decapitated and their brains were removed by craniotomy. Frozen brains were cut by a cryostat. Sections collected via systematic random sampling were stained with hematoxylin and eosin. On microscopic images obtained from pyramidal cell layers in hippocampus, total neuron numbers were estimated using the optical fractionator method. We observed that pyramidal neuron numbers in the subdivisions of hippocampus were significantly lower in the experimental group than in the control group. These results suggest that copper overdose with ethanol intake can cause neuronal loss in hippocampus of rat brain.

CSF monoamine metabolites and MRI brain volumes in alcohol dependence

Correlations between cerebrospinal fluid (CSF) concentrations of monoamine metabolites (MAM) and brain structure have been described in schizophrenia, but not in alcoholism. To investigate the relationship between monoaminergic transmission and brain structure in alcoholism, the metabolites of dopamine (homovanillic acid, HVA), norepinephrenine (3-methoxy-4-hydroxyphenylethyleneglycol, MHPG) and serotonin (5-hydroxyindoleacetic acid, 5-HIAA) were measured in lumbar CSF in 54 alcohol-dependent patients and 20 healthy subjects. The volumes of the cerebrum, total grey and white matter, total and ventricular CSF, left and right hippocampus, and corpus callosum area were measured with MRI. MHPG and age were positively correlated in alcoholic women. The MAM concentrations were not significantly correlated with the MRI volumes in the subject categories. There were no differences in MAM across subjects defined by diagnosis and gender, age of onset of alcoholism or comorbidity of psychiatric disorders. Total CSF, cerebrum, and white and grey matter tissue volumes differed between patients and healthy subjects. The greatest difference was the white matter reduction in alcoholic women. In alcoholic women and men, monoaminergic neurotransmission measured by the CSF MAM HVA, MHPG, and 5-HIAA is not significantly correlated with the size of different brain structures.

T-wave response: a sensitive test for latent alcoholic polyneuropathy

To date, the H-reflex is the most sensitive test to measure nerve conduction velocity in alcoholic polyneuropathy. Analogous to the H-reflex, we investigated the T-wave response from the soleus muscle using a hand-held reflex hammer. Twenty-four inpatients suffering from chronic alcoholism and 24 healthy volunteers were recruited. All probands had a careful neurological examination and were graded (PNP-classifications). The T- and H-reflexes were measured. In the clinical examination, only a few patients exhibited symptoms of alcoholic PNP. However, when the autonomic nervous system was also tested, 50% exhibited signs of alcoholic PNP. Both the T- and H-reflex responses were pathologically retarded, indicating latent alcoholic PNP in 60% of the patients. Thus the main finding in our study is the difference between clinical and electrophysiological examinations: only a few of the patients had neurological symptoms for alcoholic PNP but 14 patients (60%) exhibited a so-called latent, subclinical alcoholic PNP by showing delayed reflex latencies. Measuring the T-wave proved to be a simple and painless screening method for diagnosis and monitoring of alcoholic PNP. Among the clinical tests the best indicator for alcoholic PNP was the test for autonomous alcoholic PNP.

Linear CT-scan measurements in alcohol-dependent patients with and without delirium tremens

The aims of the present study were to examine whether chronic alcohol dependence and the development of delirium tremens are characterized by changes in linear CT measurements of brain liquor spaces and intracranial distances indicative of prefrontal atrophy, and frontal (sub)cortical or temporal (sub)cortical atrophy. Toward this end linear measurements were performed in 47 alcohol dependent patients with and without a history of delirium tremens and in 10 healthy volunteers using CT-scanning. The following linear measurements were calculated: (1) the Evans ratio; (2) the cella media index (CMI); (3) the maximum width of the third ventricle; (4) the maximum width of the fourth ventricle; (5) the maximum frontal subarachnoid space (MFSS); (6) the maximum width of the anterior interhemispheric fissure (MIF), and (7) the maximum width of the Sylvian fissure (MSF). The alcoholics were divided into subgroups according to the Münchner Alkoholismus Test (MALT) and the presence of delirium tremens. The MFSS of the alcohol-dependent patients was significantly larger than that of the controls. The MIF and MSF of high MALT scorers were significantly larger than those of low scorers and controls. Alcohol-dependent patients with a known history of delirium tremens had significantly larger MIF and MSF than did patients without delirium tremens and controls. The results suggest that alcohol dependence is characterized by prefrontal atrophy, and that frontal cortical and temporal (sub)cortical atrophy may be related to the development of delirium tremens.

Cognitive impairment and cerebral atrophy in "heavy drinkers"

1. Aim of the work was to verify the following three hypotheses in alcoholics: a) right hemisphere; b) diffuse brain deficit; c) anterior brain deficit, by means of a neuropsychological and a neuroradiological assessment. 2. 15 alcoholic right-hand male subjects and 15 matched controls were enrolled in the study. 3. Specifically designed neuropsychological testing was performed to investigate logical abilities, selective attention and memory. 4. Neurological investigation was performed by a standard CT scan to assess the degree and localization of brain damage. 5. Alcoholics performed worse than controls on some neuropsychological tests, i.e. Attention Matrices Test, Verbal Judgement Test, Forward Digit Span, Story Recall and Remote Memory Test. The analysis of variance adjusted by the attentional score showed no significant differences between alcoholics and controls. 6. Neuroradiological data showed a preeminent and a more frequent atrophy of the frontal region. 7. No correlations emerged between neuropsychological and neuroradiological data. 8. In conclusion, the hypothesis of anterior brain deficit seems to be confirmed by our study.

The cerebral cortex is damaged in chronic alcoholics

There is some controversy in the literature concerning whether chronic alcohol consumption damages the cerebral cortex. While decreased neuronal density in specific cortical regions is well described in chronic alcoholics, a recent study by Badsberg Jensen and Pakkenberg using unbiased stereological methods questions whether neurodegeneration occurs. In order to assess selective neurodegeneration in the cerebral cortex of chronic alcoholics, regional volumes and unbiased estimates of regional neuronal number (including neuronal identification with calcium-binding proteins) were calculated for 14 chronic alcoholics and 21 controls. Cases were carefully screened to exclude any interfering pathologies. Lifetime and maximum daily alcohol consumption was determined, and homogeneous groups were identified (four chronic alcoholics with Wernicke's encephalopathy and Korsakoff's psychosis, four chronic alcoholics with Wernicke's encephalopathy alone, six chronic alcoholics without Wernicke's encephalopathy or Korsakoff's psychosis, and 21 controls). Brain volume analysis revealed that discrete regions were significantly smaller in the chronic alcoholics compared to controls. As previously shown, white matter regions (particularly in the frontal lobe) were the most significantly reduced in volume. Alcoholics with Wernicke's encephalopathy (either alone or in combination with Korsakoff's psychosis) had significantly smaller white matter volumes than controls or alcoholics without these complications. Medial temporal lobe regions and the thalamus were also reduced in volume. Regression analyses revealed that the volume of both the white matter and thalamus negatively correlated with alcohol consumption. Consistent with the interpretation of previous neuronal density studies, selective neuronal loss was found in the superior frontal association cortex of chronic alcoholics, while no loss occurred from the motor cortex. The number of parvalbumin-, calbindin- and calretinin-immunoreactive neurons was found to be unaltered in chronic alcoholics, suggesting that the neurodegeneration is confined to the non-GABAergic pyramidal neurons. As neurodegeneration was observed in all alcoholic groups, damage to the frontal association cortex is not restricted to alcoholics with the amnesia of Korsakoff's psychosis. These results are consistent with the notion that chronic alcohol consumption is associated with selective neuronal vulnerability. The selective frontal neurodegeneration and the frontal focus of white matter atrophy are supported by neuropsychological, regional blood flow, and magnetic resonance imaging studies of frontal lobe dysfunction in chronic alcoholics and may correlate with abnormalities in working memory.

Chronic alcohol consumption does not cause hippocampal neuron loss in humans

High alcohol consumption for long periods of time causes significant hippocampal neurodegeneration in rodents. A single study using neuronal density measures has reported similar findings in humans. The present study aims to substantiate these findings in human alcoholics using unbiased stereological techniques. Both amnesic (n = 5) and nonamnesic (n = 7) chronic alcoholics were selected and compared with nonalcoholic controls (n = 8) and patients with marked memory loss and hippocampal neurodegeneration caused by Alzheimer's disease (n = 4). Hippocampal volume was significantly reduced in the alcoholics and in patients with Alzheimer's disease. However, in alcoholics the volume reduction occurred exclusively in the white matter, whereas both the gray and white matter were reduced in the patients with Alzheimer's disease. Neuron loss occurred exclusively from the CA1 and subiculum subregions of the hippocampus in Alzheimer's disease. No neuron loss occurred from any subregion of the hippocampus in alcoholics. There were no correlations with age and any of the volume or neuron number measures. Hippocampal volume correlated with brain volume and with the regional gray and white matter volumes within the hippocampus. In addition, hippocampal gray matter volume correlated with the number of CA1 pyramidal neurons. These results do not support the theory that chronic alcohol consumption is neurotoxic to hippocampal pyramidal neurons in humans. Further, the present results suggest that changes observed in rodent models of alcoholism do not parallel those observed in humans, questioning the validity of such models.