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Background: The aging of the human brain is accompanied by changes in cortical structure as well as functional activity and variable degrees of cognitive decline. One-third of the observable inter-individual differences in cognitive decline are thought to be heritable. SCN1A encodes the sodium channel α subunit and is considered to be a susceptibility gene for several neurological disorders with prominent cognitive deficits. In a recent genome-wide association study the C allele of the SCN1A variant rs10930201 was observed to be significantly associated with poor short-term memory performance. rs10930201 was further observed to be related to differences in neural activity during a working memory task., Methods: The aim of the present study was to explore whether SCN1A modifies the vulnerability to aging processes of the human brain. Therefore we assessed the interacting effects of the SCN1A vulnerability allele rs10930201 and age in terms of brain activity and brain morphology in 62 healthy volunteers between 21 and 82 years of age., Results: In C allele carriers, activity in the right inferior frontal cortex and the posterior cingulate cortex increased with age. Moreover, exploratory analysis revealed regional effects of rs10930201 on brain structure, indicating reduced gray matter densities in the frontal and insular regions in the C allele carriers., Conclusions: Collectively, the present results suggest that the SCN1A polymorphism has modulatory effects on brain morphology and vulnerability to age-related alterations in brain activity of cortical regions that subserve working memory., (Copyright © 2012 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: In alcoholism, excessive glutamatergic neurotransmission has long been implicated in the acute withdrawal syndrome and as a key signal for dependence-related neuroplasticity. Our understanding of this pathophysiological mechanism originates largely from animal studies, but human data are needed for translation into successful medication development., Methods: We measured brain glutamate levels during detoxification in alcohol-dependent patients (n = 47) and in healthy control subjects (n = 57) as well as in a rat model of alcoholism by state-of-the-art ¹H-magnetic magnetic resonance spectroscopy at 3 and 9.4 T, respectively., Results: We found significantly increased glutamate levels during acute alcohol withdrawal in corresponding prefrontocortical regions of treatment-seeking alcoholic patients and alcohol-dependent rats versus respective control subjects. The augmented spectroscopic glutamate signal is likely related to increased glutamatergic neurotransmission because, enabled by the high field strength of the animal scanner, we detected a profoundly elevated glutamate/glutamine ratio in alcohol-dependent rats during acute withdrawal. All dependence-induced metabolic alterations normalize within a few weeks of abstinence in both humans and rats., Conclusions: Our data provide first-time direct support from humans for the glutamate hypothesis of alcoholism, demonstrate the comparability of human and animal magnetic resonance spectroscopy responses, and identify the glutamate/glutamine ratio as potential biomarker for monitoring disease progression., (Copyright © 2012 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: Emotional dysfunction in a frontolimbic network has been implicated in the pathophysiology of borderline personality disorder (BPD). The amygdala is a key region of the limbic system and plays an important role in impulsivity, affect regulation, and emotional information processing and thus is likely related to BPD symptoms. Alterations of the metabolism in the amygdala might be of interest for understanding the pathophysiology of BPD. However, the amygdala is a difficult region from which to acquire magnetic resonance spectra. We implemented a method for proton magnetic resonance spectroscopy ((1)H MRS) at 3.0 T in which we acquire data within only the small amygdala. The purpose of this study was to determine alterations of the metabolism in the amygdala in BPD patients., Methods: Twenty-one unmedicated BPD patients and 20 age-matched healthy control participants underwent (1)H MRS to determine neurometabolite concentrations in the left amygdala. All participants underwent psychometric assessments., Results: Significantly reduced total N-acetylaspartate (tNAA) and total creatine (tCr) concentrations in the left amygdala of patients with BPD were found. BPD patients with comorbid posttraumatic stress disorder (PTSD) showed lower levels of tCr compared with BPD patients without PTSD and healthy control subjects. No significant correlations between neurochemical concentrations and psychometric measures were found., Conclusions: Decreased tNAA and tCr might indicate disturbed affect regulation and emotional information processing in the amygdala of BPD patients. These findings are consistent with many functional and structural neuroimaging studies and may help to explain the greater emotional reactivity of BPD patients., (Copyright 2010 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: Cannabinoids present neurotoxic and neuroprotective properties in in vitro studies, inconsistent alterations in human neuroimaging studies, neuropsychological deficits, and an increased risk for psychotic episodes., Methods: Proton magnetic resonance spectroscopy ((1)H-MRS), neuropsychological testing, and hair analysis for cannabinoids was performed in 13 male nontreatment-seeking recreational cannabis users and 13 male control subjects., Results: A significantly diminished N-acetylaspartate/total creatine (NAA/tCr) ratio in the dorsolateral prefrontal cortex (DLPFC) was observed in cannabis users (p = .0003). The NAA/tCr in the putamen/globus pallidum region correlated significantly with cannabidiol (R(2) = .66, p = .004). Results of the Wisconsin Card Sorting test, Trail making Test, and D2 test for attention were influenced by cannabinoids., Conclusions: Chronic recreational cannabis use is associated with an indication of diminished neuronal and axonal integrity in the DLPFC in this study. As chronic cannabis use is a risk factor for psychosis, these results are interesting because diminished NAA/tCr ratios in the DLPFC and neuropsychological deficits were also reported in schizophrenia. The strong positive correlation of NAA/tCr and cannabidiol in the putamen/globus pallidum is in line with neuroprotective properties of cannabidiol, which were also observed in in vitro model studies of Parkinson's disease.

Background: Although the major principles of dopamine (DA) signaling have been well described previously, its precise modulatory impact on the prefrontal cortex (PFC) in humans is poorly understood. Two major neurophysiological models propose segregated functional circuits on the systems level as well as D(1) and D(2) receptor-dependent processing states on the cellular level (two-state model)., Methods: We examined the predictive validity of these models in 10 healthy male volunteers with a haloperidol challenge (HLP). Cortico-striatal-thalamo-cortical (CSTC) motor loop functions were examined during functional magnetic resonance imaging (fMRI) with a sequential finger opposition task. Neuropsychological implications of the two-state model were evaluated with a test battery of D(1)- or D(2)-sensitive prefrontal measures., Results: Analysis of fMRI data revealed a significant HLP-induced blood oxygen level dependent-signal decrease in the sensorimotor striatum and a lateralized activation loss of ipsilateral higher order motor cortices and contralateral cerebellum. Neuropsychological evaluation demonstrated a preferential impairment of D(2)-sensitive functions, whereas D(1) or non-dopaminergic domains were unaffected., Conclusions: Our data support the hypothesis that mesocortical D(1) and D(2) receptors exert differential influences in the PFC for cognitive function, but the nigrostriatal CSTC network model for the motor domain could not be confirmed.

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.