736 research outputs found
Cigarette smoking history is associated with poorer recovery in multiple neurocognitive domains following treatment for an alcohol use disorder.
Cigarette smoking is associated with neurocognitive dysfunction in various populations, including those seeking treatment for an alcohol use disorder (AUD). This study compared the rate and extent of recovery on measures of processing speed, executive functions, general intelligence, visuospatial skills and working memory in treatment-seeking alcohol dependent individuals (ALC) who were never-smokers (nvsALC), former-smoker (fsALC), and active smokers (asALC), over approximately 8 months of abstinence from alcohol. Methods: ALC participants were evaluated at approximately 1 month of abstinence (AP1; n = 132) and reassessed after 8 months of sobriety (AP2; n = 54). Never-smoking controls (CON; n = 33) completed a baseline and follow-up (n = 19) assessment approximately 9 months later. Domains evaluated were executive functions, general intelligence, processing speed, visuospatial skills and working memory; a domain composite was formed from the arithmetic average of the foregoing domains. nvsALC showed greater improvement than fsALC, asALC and CON on most domains over the AP1-AP2 interval. fsALC demonstrated greater recovery than asALC on all domains except visuospatial skills; fsALC also showed greater improvements than CON on general intelligence, working memory and domain composite. asALC did not show significant improvement on any domain over the AP1-AP2 interval. At 8 months of abstinence, asALC were inferior to CON and nvsALC on multiple domains, fsALC performed worse than nvsALC on several domains, but nvsALC were not different from CON on any domain. Our results provide robust evidence that smoking status influenced the rate and extent of neurocognitive recovery between 1 and 8 months of abstinence in this ALC cohort. Chronic smoking in AUD likely contributes to the considerable heterogeneity observed in neurocognitive recovery during extended abstinence. The findings provide additional strong support for the benefits of smoking cessation and the increasing clinical movement to offer smoking cessation resources concurrent with treatment for AUD
Changes of frontal cortical subregion volumes in alcohol dependent individuals during early abstinence: associations with treatment outcome.
We previously reported that at 1-and-4Â weeks of sobriety, those who relapsed after treatment demonstrated significantly smaller total frontal cortical volume than individuals who maintained abstinence for at least 12Â months post treatment. The segmentation method employed did not permit examination of frontal subregions that serve as nodes of the executive, salience and emotional regulation networks; structural abnormalities in these circuits are associated with relapse in those seeking treatment for alcohol use disorders (AUD). The primary goal of this study was to determine if frontal cortical subregion volume recovery during early abstinence is associated with long-term abstinence from alcohol. We compared bilateral components of the dorsal prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex and insula volumes, at 1 and 4Â weeks of abstinence, between individuals who resumed drinking within 12Â months of treatment (Relapsers) those who showed sustained abstinence over 12Â months following treatment (Abstainers) and healthy Controls. At 1 and 4Â weeks of sobriety, Relapsers demonstrated significantly smaller volumes than Controls in 15 of 20 regions of interest, while Abstainers only had smaller volumes than Controls in 5 of 20 regions. In Relapsers, increasing volumes over 1Â month in multiple frontal subregions and the insula were associated with longer duration of abstinence after treatment. The persistent bilateral frontal and insula volume deficits in Relapsers over 4Â weeks from last alcohol use may have implications for neurostimulation methods targeting anterior frontal/insula regions, and represent an endophenotype that differentiates those who respond more favorably to available psychosocial and pharmacological interventions
Cigarette smoking is associated with amplified age-related volume loss in subcortical brain regions
BACKGROUND:
Magnetic resonance imaging studies of cigarette smoking-related effects on human brain structure have primarily employed voxel-based morphometry, and the most consistently reported finding was smaller volumes or lower density in anterior frontal regions and the insula. Much less is known about the effects of smoking on subcortical regions. We compared smokers and non-smokers on regional subcortical volumes, and predicted that smokers demonstrate greater age-related volume loss across subcortical regions than non-smokers.
METHODS:
Non-smokers (n=43) and smokers (n=40), 22-70 years of age, completed a 4T MRI study. Bilateral total subcortical lobar white matter (WM) and subcortical nuclei volumes were quantitated via FreeSurfer. In smokers, associations between smoking severity measures and subcortical volumes were examined.
RESULTS:
Smokers demonstrated greater age-related volume loss than non-smokers in the bilateral subcortical lobar WM, thalamus, and cerebellar cortex, as well as in the corpus callosum and subdivisions. In smokers, higher pack-years were associated with smaller volumes of the bilateral amygdala, nucleus accumbens, total corpus callosum and subcortical WM.
CONCLUSIONS:
Results provide novel evidence that chronic smoking in adults is associated with accelerated age-related volume loss in subcortical WM and GM nuclei. Greater cigarette quantity/exposure was related to smaller volumes in regions that also showed greater age-related volume loss in smokers. Findings suggest smoking adversely affected the structural integrity of subcortical brain regions with increasing age and exposure. The greater age-related volume loss in smokers may have implications for cortical-subcortical structural and/or functional connectivity, and response to available smoking cessation interventions
Brain GABA and Glutamate Concentrations Following Chronic Gabapentin Administration: A Convenience Sample Studied During Early Abstinence From Alcohol.
Gabapentin (GBP), a GABA analog that may also affect glutamate (Glu) production, can normalize GABA and Glu tone during early abstinence from alcohol, effectively treating withdrawal symptoms and facilitating recovery. Using in vivo magnetic resonance spectroscopy, we tested the degree to which daily GBP alters regional brain GABA and Glu levels in short-term abstinent alcohol-dependent individuals. Regional metabolite levels were compared between 13 recently abstinent alcohol-dependent individuals who had received daily GBP for at least 1 week (GBP+) and 25 matched alcohol-dependent individuals who had not received GBP (GBP-). Magnetic resonance spectra from up to five different brain regions were analyzed to yield absolute GABA and Glu concentrations. GABA and Glu concentrations in the parieto-occipital cortex were not different between GBP- and GBP+. Glu levels in anterior cingulate cortex, dorsolateral prefrontal cortex, and basal ganglia did not differ between GBP- and GBP+. However, in a subgroup of individuals matched on age, sex, and abstinence duration, GBP+ had markedly lower Glu in the frontal white matter (WM) than GBP-, comparable to concentrations found in light/non-drinking controls. Furthermore, lower frontal WM Glu in GBP+ correlated with a higher daily GBP dose. Daily GBP treatment at an average of 1,600 mg/day for at least 1 week was not associated with altered cortical GABA and Glu concentrations during short-term abstinence from alcohol, but with lower Glu in frontal WM. GBP for the treatment of alcohol dependence may work through reducing Glu in WM rather than increasing cortical GABA
Frontal Metabolite Concentration Deficits in Opiate Dependence Relate to Substance Use, Cognition, and Self-Regulation.
ObjectiveProton magnetic resonance spectroscopy (1H MRS) in opiate dependence showed abnormalities in neuronal viability and glutamate concentration in the anterior cingulate cortex (ACC). Metabolite levels in dorsolateral prefrontal cortex (DLPFC) or orbitofrontal cortex (OFC) and their neuropsychological correlates have not been investigated in opiate dependence.MethodsSingle-volume proton MRS at 4 Tesla and neuropsychological testing were conducted in 21 opiate-dependent individuals (OD) on buprenorphine maintenance therapy. Results were compared to 28 controls (CON) and 35 alcohol-dependent individuals (ALC), commonly investigated treatment-seekers providing context for OD evaluation. Metabolite concentrations were measured from ACC, DLPFC, OFC and parieto-occipital cortical (POC) regions.ResultsCompared to CON, OD had lower concentrations of N-acetylaspartate (NAA), glutamate (Glu), creatine +phosphocreatine (Cr) and myo-Inositol (mI) in the DLPFC and lower NAA, Cr, and mI in the ACC. OD, ALC, and CON were equivalent on metabolite levels in the POC and γ-aminobutyric acid (GABA) concentration did not differ between groups in any region. In OD, prefrontal metabolite deficits in ACC Glu as well as DLPFC NAA and choline containing metabolites (Cho) correlated with poorer working memory, executive and visuospatial functioning; metabolite deficits in DLPFC Glu and ACC GABA and Cr correlated with substance use measures. In the OFC of OD, Glu and choline-containing metabolites were elevated and lower Cr concentration related to higher nonplanning impulsivity. Compared to 3 week abstinent ALC, OD had significant DLPFC metabolite deficits.ConclusionThe anterior frontal metabolite profile of OD differed significantly from that of CON and ALC. The frontal lobe metabolite abnormalities in OD and their neuropsychological correlates may play a role in treatment outcome and could be explored as specific targets for improved OD treatment
The influence of tDCS on perceived bouncing/streaming
Processing ambiguous situations is a constant challenge in everyday life and sensory input from different modalities needs to be integrated to form a coherent mental representation on the environment. The bouncing/streaming illusion can be studied to provide insights into the ambiguous perception and processing of multi-modal environments. In short, the likelihood of reporting bouncing rather than streaming impressions increases when a sound coincides with the moment of overlap between two moving disks. Neuroimaging studies revealed that the right posterior parietal cortex is crucial in cross-modal integration and is active during the bouncing/streaming illusion. Consequently, in the present study, we used transcranial direct current stimulation to stimulate this brain area. In the active stimulation conditions, a 9 cm2 electrode was positioned over the P4-EEG position and the 35 cm2 reference positioned over the left upper arm. The stimulation lasted 15 min. Each participant did the bouncing/streaming task three times: before, during and after anodal or sham stimulation. In a sample of N = 60 healthy, young adults, we found no influence of anodal tDCS. Bayesian analysis showed strong evidence against tDCS effects. There are two possible explanations for the finding that anodal tDCS over perceptual areas did not modulate multimodal integration. First, upregulation of multimodal integration is not possible using tDCS over the PPC as the integration process already functions at maximum capacity. Second, prefrontal decision-making areas may have overruled any modulated input from the PPC as it may not have matched their decision-making criterion and compensated for the modulation
Distance and Regional Effects on the Value of Wild Bee Conservation
Many wild bee species are threatened across Europe, and with them the pollination function they provide. While numerous studies have assessed the value of bees as pollinators of crops, little is known about the non-marked value of bees. Using a choice modelling experiment, we examine these non-market values in Germany by identifying citizens’ willingness to pay (WTP) for wild bee conservation initiatives in four states. Effects of distance, state and regional affiliation are scrutinised, as previous research found these to affect respondents’ choices. Random parameter logit and latent class models are used to capture preference heterogeneity. Overall, we find strong support of wild bee conservation and a clear preference for improvement relative to the status quo, particularly in natural areas and for rare or endangered species. The yearly WTP for conservation initiatives ranges from 227 to 447€ per household. Our results show distance and regional effects on WTP. Initiatives in respondents’ home states are preferred, and increasing distance to initiatives in other states result in a slightly reduced WTP. Additionally, we observe regional preferences within an eastern and a western home region. These preferences are not explainable by socio-demographic characteristics, home state or distance and probably linked to social and cultural affiliations. We conclude that for widespread support in society and effective conservation initiatives, policy proposals must address this spatial heterogeneity from distance and regional effects. © 2022, The Author(s), under exclusive licence to Springer Nature B.V.The authors thank the anonymous reviewers for their extensive and valuable comments on this manuscript. The authors would further like to thank Julian Sagebiel from the Swedish University of Agricultural Sciences for his support in the analysis of the survey data. They thank Alice Rogowski, Bennet Bergmann, Helena Leinweber, Jan Peters, Jean Paul Moreaux, Thomas Prossliner, as well as the focus groups participants for their valuable comments on the early version of the questionnaire. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. C.M., B.D. and C.R. thank the Danish National Research Foundation for its support of the Center for Macroecology, Evolution and Climate (Grant No. DNRF96)
Synthesis, characterization, and controlled nitric oxide release from S -nitrosothiol-derivatized fumed silica polymer filler particles
A new type of nitric oxide (NO)-releasing material is described that utilizes S -nitrosothiols anchored to tiny fumed silica (FS) particles as the NO donor system. The synthetic procedures suitable for tethering three different thiol species (cysteine, N -acetylcysteine, and N -acetylpenicillamine) to the surface of FS polymer filler particles are detailed. The thiol-derivatized particles are converted to their corresponding S -nitrosothiols by reaction with t -butylnitrite. The total NO loading on the resulting particles range from 21–138 nmol/mg for the three different thiol-derivatized materials [ S -nitrosocysteine-(NO-Cys)-FS, S -nitroso- N -acetylcysteine (SNAC)-FS, and S -nitroso- N -acetylpenicillamine (SNAP)-FS], with SNAP-FS yielding the highest NO loading. NO can be generated from these particles when suspended in solution via the addition of copper(II) ions, ascorbate, or irradiation with visible light. The SNAC-FS and SNAP-FS particles can be blended in polyurethane and silicone rubber matrixes to create films that release NO at controlled rates. Polyurethane films containing SNAC-FS submerged in phosphate-buffered saline (pH 7.4) generate NO surface fluxes ∼0.1–0.7 × 10 −10 mol cm −2 min −1 and SNAP-FS films generate NO fluxes of ∼0–7.5 × 10 −10 mol cm −2 min −1 upon addition of increasing amounts of copper ions. Silicone rubber films containing SNAC-FS or SNAP-FS do not liberate NO upon exposure to copper ions or ascorbate in phosphate-buffered saline solution. However, such films are shown to release NO at rates proportional to increasing intensities of visible light impinging on the films. Such photoinitiated NO release from these composite materials offers the first NO-releasing hydrophobic polymers with an external on/off trigger to control NO generation. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 72A: 409–419, 2005Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35301/1/30275_ftp.pd
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