Does the catechol-O-methyltransferase (COMT) Val158Met human polymorphism in influence procrastination?

Genetic studies are enlightening how the expression of several genes influences neuronal activity and all facets of human normal and abnormal behaviour. Among these, a growing body of information shows that a few key genes regulating activity of central neurotransmitters have specific roles in cognitive and/or emotional processes, as ‘procrastination’. We investigated the association of the 5-HTTLPR and COMT Val158Met polymorphisms with students’ procrastination in an academic writing task. Results: showed no relationship between procrastination and the 5-HTT polymorphism but they revealed an association with the COMT Val158Met one. Particularly, the presence of the Met158 allele was found to be significantly associated with the tendency to initiate and complete the assigned task. We hypothesize that the role of central monoamines and of dopamine already identified in impulsive behaviour, extends to procrastination. Since the 158Met allele provides neurons with significantly higher basal dopamine levels when compared to the 158Val allele, our observation suggests that under normal conditions the 158Met allele provides carriers with increased inhibitory control, resulting in an increased tendency to adhere to a planned schedule and therefore reducing procrastination. On the other hand, the Val158 allele may result more effective in increasing carriers’ performances under stress conditions, namely when the schedule deadline is approaching, and dopamine release is increased. This would result in a higher tendency to procrastinate. This hypothesis can readily be tested by applying the experimental approach here employed to various samples of subjects belonging to different categories and extending the analysis to other putative neuron-expressed gene

Brain-Derived Neurotrophic Factor (Val66Met) and Serotonin Transporter (5-HTTLPR) Polymorphisms Modulate Plasticity in Inhibitory Control Performance Over Time but Independent of Inhibitory Control Training

Several studies reported training-induced improvements in executive function tasks and also observed transfer to untrained tasks. However, the results are mixed and there is large interindividual variability within and across studies. Given that training-related performance changes would require modification, growth or differentiation at the cellular and synaptic level in the brain, research on critical moderators of brain plasticity potentially explaining such changes is needed. In the present study, a pre-post-follow-up design (N=122) and a three-weeks training of two response inhibition tasks (Go/NoGo and Stop-Signal) was employed and genetic variation (Val66Met) in the brain-derived neurotrophic factor (BDNF) promoting differentiation and activity-dependent synaptic plasticity was examined. Because Serotonin (5-HT) signaling and the interplay of BDNF and 5-HT are known to critically mediate brain plasticity, genetic variation in the 5-HT transporter (5-HTTLPR) was also addressed. The overall results show that the kind of training (i.e., adaptive vs. non-adaptive) did not evoke genotype-dependent differences. However, in the Go/NoGo task, better inhibition performance (lower commission errors) were observed for BDNF Val/Val genotype carriers compared to Met-allele ones supporting similar findings from other cognitive tasks. Additionally, a gene-gene interaction suggests a more impulsive response pattern (faster responses accompanied by higher commission error rates) in homozygous l-allele carriers relative to those with the s-allele of 5-HTTLPR. This, however, is true only in the presence of the Met-allele of BDNF, while the Val/Val genotype seems to compensate for such non-adaptive responding. Intriguingly, similar results were obtained for the Stop-Signal task. Here, differences emerged at post-testing, while no differences were observed at T1. In sum, although no genotype-dependent differences between the relevant training groups emerged suggesting no changes in the trained inhibition function, the observed genotype-dependent performance changes from pre- to post measurement may reflect rapid learning or memory effects linked to BDNF and 5-HTTLPR. In line with ample evidence on BDNF and BDNF-5-HT system interactions to induce (rapid) plasticity especially in hippocampal regions and in response to environmental demands, the findings may reflect genotype-dependent differences in the acquisition and consolidation of task-relevant information, thereby facilitating a more adaptive responding to task-specific requirements

Association between Neurocognitive Impairment and the Short Allele of 5-HTT Promoter Polymorphism in Depression: A Pilot Study.

Peer reviewe

Association between Neurocognitive Impairment and the Short Allele of 5-HTT Promoter Polymorphism in Depression: A Pilot Study.

Peer reviewe

Impact of the Serotonin Transporter Polymorphism on Emotion Identification in Healthy Older Adults

Older adults exhibit reduced accuracy and efficiency for identifying facial emotion expressions yet it is unclear how genetic or cognitive variables influence these findings. This study examined the impact of serotonin transporter polymorphism 5-HTTLPR on patterns of explicit emotion identification accuracy and reaction time (RT) in healthy older adults. The impact of 5-HTTLPR on measures of processing speed, attention, and executive function as well as correlations between cognitive measures and emotion identification measures were also examined. Methods: Forty-one individuals over the age of 50 were genotyped for bi-allelic and tri-allelic variants of 5-HTTLPR and administered an emotion recognition paradigm and tests of cognitive function. Results: Results indicated that individuals carrying low expressing S alleles were significantly slower when identifying expressions of emotion, particularly fear and disgust. A similar pattern of results for fear and disgust was revealed for low expressing S and LG carriers, but these findings were not held after adjustment for multiple comparisons. RTs for happy and neutral faces were correlated with performance on measures of processing speed, attention, and executive function in low expression groups, but these findings were not held after adjustment for multiple comparisons. Conclusions: Overall, this study suggests that possession of low-expressing genetic variants of 5-HTTLPR is associated with diminished emotion identification RT performance among healthy older adults

Geenid ja alkoholitarvitamine: levinud geenipolümorfismide mõju rahvastikus

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Alkoholi kuritarvitamine on üks peamistest ennetatavate surmade ja terviserikete põhjustajatest. Lähtuvalt sellest, kui palju probleeme tekib tarvitajale endale ja teda ümbritsevatele, on alkohol loetud kõige kahjulikumaks uimastiks1. Kuigi olukord on tasapisi paranemas, paistab Eesti rahvusvahelisel tasandil veel jätkuvalt silma ohtra alkoholitarbimisega2. Mehed tarvitavad alkoholi ning kogevad alkoholiga seotud probleeme enamasti rohkem kui naised. Nii ka meie rahvastikupõhises pikaajalises sünnikohortide uuringus – poisid alustasid alkoholi tarvitamisega varem ning tegelesid sellega sagedamini kui tüdrukud. Nooreks täiskasvanueaks oli selle tulemusena meeste seas tunduvalt rohkem neid, kes alkoholi kuritarvitamisega hädas. Alkoholiprobleemide kogemise tõenäosust tõstsid ka stressirikkad elusündmused ning halvad suhted pereliikmete ja õpetajatega. Kuna alkoholism on krooniline ja ravile raskesti alluv, on selle haiguse tekkimist ennustavate bioloogiliste näitajate uurimine äärmiselt päevakajaline. Analüüsides geenide mõju alkoholitarbimisele, leidsime, et probleemset alkoholitarbimist ennustasid just sellised geneetilised eripärad, mis olid seotud madalama stressitaluvuse ja suurema avatusega keskkondlike mõjude suhtes. Seosed ei olnud aga üleüldised ja sõltusid suures osas sünnikohordist – perioodist, mil inimene sündinud oli. Sotsiaalsed normid ja hoiakud alkoholi tarbimisse koonduvad sünnikohortide kaupa ning mõjutavad otseselt uimastite tarvitamist. 1990. aastatel alguse saanud kiired ühiskondlikud muutused mõjutavad meie siirdeühiskonnas väärtushinnanguid, vaba aja tegevusi, suhteid ja igapäevast toimetulekut. Kultuurilised ja ühiskondlikud muutused vormivad pidevalt inimeste identiteeti ja elustiili ning võivad vahendada ka geeniefekte alkoholitarbimisele. [1 Nutt DJ, King LA, Phillips LD (2010) Drug harms in the UK: a multicriteria decision analysis. Lancet 376:1558-1565. 2 OECD (2015) Tackling harmful alcohol use: Economics and public health policy. OECD Publishing.]Problematic use of alcohol is one of the leading causes of preventable deaths and disability. Based on the harm to the user and others, alcohol has been considered to be the most harmful drug1. Men generally drink more alcohol and have more alcohol-related problems than women. Also in our population-representative longitudinal birth cohort study in Estonia, the boys started consuming alcohol earlier and were more frequent alcohol consumers than girls. By young adulthood, there were significantly more men than women diagnosed with alcohol use disorder. The more frequent was the alcohol consumption during the teenage years, the more problable was the occurrence of alcohol problems by young adulthood. In addition, the more stressful life events, the worse relationships with family members and with teachers the children experienced, the higher was the likelihood of developing alcohol use problems later on in life. The chronic nature of alcoholism is the reason why the search for predictive biomarkers is so urgent. When we analyzed the effects of common genetic variances on alcohol use and abuse, the genotypes associated with higher levels of stress reactivity and openness to environmental influences were the ones also linked to problematic alcohol use. However, the relations were not universal and strongly depended on birth cohort – the time period when one was born. Social norms and attitudes regarding alcohol use cluster in birth cohorts, and this clustering has a direct effect on drug use. The rapid socioeconomic changes that have taken place in Estonia since the beginning of 1990s and are still ongoing affect the values, activities, relationships, leisure time choices and everyday functioning of the people living in this transition society. Cultural transformation processes continuously shape the identities and lifestyles of individuals, and can also moderate the genetic effects on alcohol consumption. [1 Nutt DJ, King LA, Phillips LD (2010) Drug harms in the UK: a multicriteria decision analysis. Lancet 376:1558-1565.

The Influence of Gene Environment Interaction on the Risk of Cognitive Impairment: Reducing Sexual Risk Behaviors and Alcohol Use in HIV-infected Adults

Memory deficits and executive dysfunction are highly prevalent among HIV-infected adults. These conditions can affect their quality of life, antiretroviral adherence, and HIV risk behaviors. Several factors have been suggested including the role of genetics in relation to HIV disease progression. This dissertation aimed to determine whether genetic differences in HIV-infected individuals were correlated with impaired memory, cognitive flexibility and executive function and whether cognitive decline moderated alcohol use and sexual transmission risk behaviors among HIV-infected alcohol abusers participating in an NIH-funded clinical trial comparing the efficacy of the adapted Holistic Health Recovery Program (HHRP-A) intervention to a Health Promotion Control (HPC) condition in reducing risk behaviors. A total of 267 individuals were genotyped for polymorphisms in the dopamine and serotonin gene systems. Results yielded significant associations for TPH2, GALM, DRD2 and DRD4 genetic variants with impaired executive function, cognitive flexibility and memory. SNPs TPH2 rs4570625 and DRD2 rs6277 showed a risk association with executive function (odds ratio = 2.5, p = .02; 3.6, p = .001). GALM rs6741892 was associated with impaired memory (odds ratio = 1.9, p = .006). At the six-month follow-up, HHRP-A participants were less likely to report trading sex for food, drugs and money (20.0%) and unprotected insertive or receptive oral (11.6%) or vaginal and/or anal sex (3.2%) than HPC participants (49.4%,

Genetic influences on emotion/cognition interactions : from synaptic regulation to individual differences in working memory for emotional faces

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Psychologie und Gehirn 2007

Die Fachtagung "Psychologie und Gehirn" ist eine traditionelle Tagung aus dem Bereich psychophysiologischer Grundlagenforschung. 2007 fand diese Veranstaltung, die 33. Jahrestagung der „Deutschen Gesellschaft für Psychophysiologie und ihre Anwendungen (DGPA)“, in Dortmund unter der Schirmherrschaft des Instituts für Arbeitsphysiologie (IfADo) statt. Neben der Grundlagenforschung ist auch die Umsetzung in die Anwendung erklärtes Ziel der DGPA und dieser Tradition folgend wurden Beiträge aus vielen Bereichen moderner Neurowissenschaft (Elektrophysiologie, bildgebende Verfahren, Peripherphysiologie, Neuroendokrinologie, Verhaltensgenetik, u.a.) präsentiert und liegen hier in Kurzform vor