| 1. |
- Melke, Jonas, 1971, et al.
(författare)
-
A polymorphism in the serotonin receptor 3A (HTR3A) gene and its association with harm avoidance in women.
- 2003
-
Ingår i: Archives of general psychiatry. - : American Medical Association (AMA). - 0003-990X. ; 60:10, s. 1017-23
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The brain neurotransmitter serotonin is known to affect various aspects of human behavior, including personality traits. Serotonin receptor type 3 is a ligand-gated channel encoded by 2 different subunit genes, HTR3A and HTR3B. A polymorphism (C178T) in the 5' region of the HTR3A gene has recently been identified and suggested to be of functional importance. OBJECTIVE: To elucidate the possible association between the C178T polymorphism in the HTR3A gene and personality traits in women. DESIGN: Two independent samples of 35- to 45-year-old Swedish women were recruited using the population register. Sample 1 (n = 195) was assessed via the Karolinska Scales of Personality and the Temperament and Character Inventory; sample 2 (n = 175) was assessed using the latter only. Both samples were genotyped with respect to the C178T polymorphism in the HTR3A gene. The A1596G polymorphism in the same gene was also investigated. RESULTS: A significant association between C178T genotype and the Temperament and Character Inventory factor harm avoidance was observed in sample 1 (corrected for multiple comparisons P =.04); this finding was subsequently replicated in sample 2 (P =.004) (pooled populations: P<.001). In the pooled sample, all harm avoidance subscales were found to be significantly associated with the C178T polymorphism: anticipatory worry (P =.001), fear of uncertainty (P<.001), shyness (P<.001), and fatigability and asthenia (P =.008). In addition, a significant association was found in sample 1 between the C178T polymorphism and the Karolinska Scales of Personality nonconformity factor (corrected P =.002), including the subscales of social desirability (P<.001), indirect aggression (P =.002), verbal aggression (P =.05), and irritability (P<.001). Participants homozygous for the less common T allele (<4%) differed from the remaining women by displaying lower ratings on harm avoidance and nonconformity. CONCLUSION: The C178T polymorphism in the HTR3A gene may affect the personality trait of harm avoidance in women.
|
|
| 2. |
- de Frias, Cindy M, et al.
(författare)
-
Catechol O-methyltransferase Val158Met polymorphism is associated with cognitive performance in nondemented adults.
- 2005
-
Ingår i: Journal of cognitive neuroscience. - Cambridge : MIT Press - Journals. - 0898-929X .- 1530-8898. ; 17:7, s. 1018-25
-
Tidskriftsartikel (refereegranskat)abstract
- The catechol O-methyltransferase (COMT) gene is essential in the metabolic degradation of dopamine in the prefrontal cortex. In the present study, we examined the effect of a Val158Met polymorphism in the COMT gene on individual differences and changes in cognition (executive functions and visuospatial ability) in adulthood and old age. The participants were 292 nondemented men (initially aged 35-85 years) from a random sample of the population (i.e., the Betula study) tested at two occasions with a 5-year interval. Confirmatory factor analyses were used to test the underlying structure of three indicators of executive functions (verbal fluency, working memory, and Tower of Hanoi). Associations between COMT, age, executive functioning, and visuospatial (block design) tasks were examined using repeated-measures analyses of variance. Carriers of the Val allele (with higher enzyme activity) compared with carriers of the Met/Met genotype (with low enzyme activity) performed worse on executive functioning and visuospatial tasks. Individuals with the Val/Val genotype declined in executive functioning over the 5-year period, whereas carriers of the Met allele remained stable in performance. An Age x COMT interaction for visuospatial ability located the effect for middle-aged men only. This COMT polymorphism is a plausible candidate gene for executive functioning and fluid intelligence in nondemented middle-aged and older adults.
|
|
| 3. |
- de Frias, Cindy M., et al.
(författare)
-
Influence of COMT Gene Polymorphism on fMRI-assessed Sustained and Transient Activity during a Working Memory Task
- 2010
-
Ingår i: Journal of cognitive neuroscience. - Cambridge, Mass. : MIT Press. - 0898-929X .- 1530-8898. ; 22:7, s. 1614-1622
-
Tidskriftsartikel (refereegranskat)abstract
- The catechol O-methyltransferase (COMT) gene-encoding an enzyme that is essential for the degradation of dopamine (DA) in prefrontal cortex (PFC)-contains a single nucleotide polymorphism (val/met) important for cognition. According to the tonic-phasic hypothesis, individuals carrying the low-enzyme- activity allele (met) are characterized by enhanced tonic DA activity in PFC, promoting sustained cognitive representations in working memory. Val carriers have reduced tonic but enhanced phasic dopaminergic activity in subcortical regions, enhancing cognitive flexibility. We tested the tonic-phasic DA hypothesis by dissociating sustained and transient brain activity during performance on a 2-back working memory test using mixed blocked/event-related functional magnetic resonance imaging. Participants were men recruited from a random sample of the population (the Betula study) and consisted of 11 met/met and 11 val/val carriers aged 50 to 65 years, matched on age, education, and cognitive performance. There were no differences in 2-back performance between genotype groups. Met carriers displayed a greater transient medial temporal lobe response in the updating phase of working memory, whereas val carriers showed a greater sustained PFC activation in the maintenance phase. These results support the tonic-phasic theory of DA function in elucidating the specific phenotypic influence of the COMT val(158)met polymorphism on different components of working memory.
|
|
| 4. |
- Athanasiu, L., et al.
(författare)
-
A genetic association study of CSMD1 and CSMD2 with cognitive function
- 2017
-
Ingår i: Brain Behavior and Immunity. - : Elsevier BV. - 0889-1591 .- 1090-2139. ; 61, s. 209-216
-
Tidskriftsartikel (refereegranskat)abstract
- The complement cascade plays a role in synaptic pruning and synaptic plasticity, which seem to be involved in cognitive functions and psychiatric disorders. Genetic variants in the closely related CSMD1 and CSMD2 genes, which are implicated in complement regulation, are associated with schizophrenia. Since patients with schizophrenia often show cognitive impairments, we tested whether variants in CSMD1 and CSMD2 are also associated with cognitive functions per se. We took a discovery-replication approach, using well-characterized Scandinavian cohorts. A total of 1637 SNPs in CSMD1 and 206 SNPs in CSMD2 were tested for association with cognitive functions in the NCNG sample (Norwegian Cognitive NeuroGenetics; n = 670). Replication testing of SNPs with p-value < 0.001 (7 in CSMD1 and 3 in CSMD2) was carried out in the TOP sample (Thematically Organized Psychosis; n =1025) and the BETULA sample (Betula Longitudinal Study on aging, memory and dementia; n = 1742). Finally, we conducted a meta-analysis of these SNPs using all three samples. The previously identified schizophrenia marker in CSMD1 (SNP rs10503253) was also included. The strongest association was observed between the CSMDI SNP rs2740931 and performance in immediate episodic memory (p-value = 5 Chi 10(-6), minor allele A, MAF 0.48-0.49, negative direction of effect). This association reached the study-wide significance level (p <= 1.2 Chi 10(-5)). SNP rs10503253 was not significantly associated with cognitive functions in our samples. In conclusion, we studied n = 3437 individuals and found evidence that a variant in CSMD1 is associated with cognitive function. Additional studies of larger samples with cognitive phenotypes will be needed to further clarify the role of CSMD1 in cognitive phenotypes in health and disease. (C) 2016 The Authors. Published by Elsevier Inc.
|
|
| 5. |
- Bergman, Olle, 1978, et al.
(författare)
-
Preliminary evidence that polymorphisms in dopamine-related transcription factors LMX1A, LMX1B and PITX3 are associated with schizophrenia
- 2010
-
Ingår i: Progress in Neuro-psychopharmacology and Biological Psychiatry. - : Elsevier. - 0278-5846 .- 1878-4216. ; 34:6, s. 1094-1097
-
Tidskriftsartikel (refereegranskat)abstract
- The early development of dopaminergic pathways has been attributed importance for the aetiology of schizophrenia. Several transcription factors are involved in the survival and maturation of dopamine neurons, including LMX1A, LMX1B and PITX3. The possibility that polymorphisms in these genes may influence the development and/or the maintenance of dopaminergic neurons prompted us to investigate if five single nucleotide polymorphisms (SNPs) previously linked to Parkinson's disease are associated with this disorder. Preliminary evidence that genetic variation in LMX1A (rs6668493, rs4657411), LMX1B (rs10987386) and PITX3 (rs4919621) may increase the risk of developing schizophrenia is presented.
|
|
| 6. |
- de Frias, Cindy M, et al.
(författare)
-
COMT gene polymorphism is associated with declarative memory in adulthood and old age.
- 2004
-
Ingår i: Behavior genetics. - New York : Kluwer Academic Publishers. - 0001-8244 .- 1573-3297. ; 34:5, s. 533-9
-
Tidskriftsartikel (refereegranskat)abstract
- Variation in memory performance is to a large extent explained by genes. In the prefrontal cortex, the catechol O-methyltransferase (COMT) gene is essential in the metabolic degradation of dopamine, a neurotransmitter implicated in cognitive functions. The present study examined the effect of a polymorphism in the COMT gene on individual differences and changes in memory in adulthood and old age. Tests assessing episodic and semantic memory were administered to 286 men (initially aged 35-85 years) from a random sample of the population (i.e., the Betula prospective cohort study) at two occasions followed over a 5-year period. Carriers of the Met/Met genotype (with low enzyme activity) performed better on episodic and semantic memory, as compared to carriers of the Val allele (with higher enzyme activity). Division of episodic memory into its recall and recognition components showed that the difference was specific to episodic recall, not recognition tasks; an effect that was observed across three age groups (middle-age, young-old, and old-old adults) and over a 5-year period. The COMT gene is a plausible candidate gene for memory functioning in adulthood and old age.
|
|
| 7. |
- Hedner, Margareta, et al.
(författare)
-
Age-Related Olfactory Decline is Associated with the BDNF Val66met Polymorphism : Evidence from a Population-Based Study
- 2010
-
Ingår i: Frontiers in Aging Neuroscience. - : Frontiers Media SA. - 1663-4365. ; 2:7, s. 24-
-
Tidskriftsartikel (refereegranskat)abstract
- The present study investigates the effect of the brain-derived neurotrophic factor (BDNF) val66met polymorphism on change in olfactory function in a large scale, longitudinal population-based sample (n = 836). The subjects were tested on a 13 item force-choice odor identification test on two test occasions over a 5-year-interval. Sex, education, health-related factors, and semantic ability were controlled for in the statistical analyses. Results showed an interaction effect of age and BDNF val66met on olfactory change, such that the magnitude of olfactory decline in the older age cohort (70–90years old at baseline) was larger for the val homozygote carriers than for the met carriers. The older met carriers did not display larger age-related decline in olfactory function compared to the younger group. The BDNF val66met polymorphism did not affect the rate of decline in the younger age cohort (45–65years). The findings are discussed in the light of the proposed roles of BDNF in neural development and maintenance.
|
|
| 8. |
- Kauppi, Karolina, 1985-, et al.
(författare)
-
Decreased medial temporal lobe activation in BDNF 66Met allele carriers during memory encoding
- 2013
-
Ingår i: Neuropsychologia. - : Elsevier. - 0028-3932 .- 1873-3514. ; 51:12, s. 2462-2468
-
Tidskriftsartikel (refereegranskat)abstract
- The Met allele of the Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism has been associated with impaired activity-dependent secretion of BDNF protein and decreased memory performance. Results from imaging studies relating Val66Met to brain activation during memory processing have been inconsistent, with reports of both increased and decreased activation in the Medial Temporal Lobe (MTL) in Met carriers relative to Val homozygotes. Here, we extensively studied BDNF Val66Met in relation to brain activation and white matter integrity as well as memory performance in a large imaging (n=194) and behavioral (n=2229) sample, respectively. Functional magnetic resonance imaging (fMRI) was used to investigate MTL activation in healthy participants in the age of 55–75 years during a face-name episodic encoding and retrieval task. White matter integrity was measured using diffusion tensor imaging.BDNF Met allele carriers had significantly decreased activation in the MTL during encoding processes, but not during retrieval processes. In contrast to previous proposals, the effect was not modulated by age and the polymorphism was not related to white matter integrity. Met carriers had lower memory performance than Val homozygotes, but differences were subtle and not significant. In conclusion, the BDNF Met allele has a negative influence on MTL functioning, preferentially during encoding processes, which might translate into impaired episodic memory function.
|
|
| 9. |
- Kauppi, Karolina, et al.
(författare)
-
KIBRA polymorphism is related to enhanced memory and elevated hippocampal processing.
- 2011
-
Ingår i: The Journal of neuroscience : the official journal of the Society for Neuroscience. - : Society for Neuroscience. - 1529-2401 .- 0270-6474. ; 31:40, s. 14218-22
-
Tidskriftsartikel (refereegranskat)abstract
- Several studies have linked the KIBRA rs17070145 T polymorphism to superior episodic memory in healthy humans. One study investigated the effect of KIBRA on brain activation patterns (Papassotiropoulos et al., 2006) and observed increased hippocampal activation in noncarriers of the T allele during retrieval. Noncarriers were interpreted to need more hippocampal activation to reach the same performance level as T carriers. Using large behavioral (N = 2230) and fMRI (N = 83) samples, we replicated the KIBRA effect on episodic memory performance, but found increased hippocampal activation in T carriers during episodic retrieval. There was no evidence of compensatory brain activation in noncarriers within the hippocampal region. In the main fMRI sample, T carriers performed better than noncarriers during scanning but, importantly, the difference in hippocampus activation remained after post hoc matching according to performance, sex, and age (N = 64). These findings link enhanced memory performance in KIBRA T allele carriers to elevated hippocampal functioning, rather than to neural compensation in noncarriers.
|
|
| 10. |
- Annerbrink, Kristina, 1974, et al.
(författare)
-
Catechol O-methyltransferase val158-met polymorphism is associated with abdominal obesity and blood pressure in men.
- 2008
-
Ingår i: Metabolism. - : Elsevier BV. - 0026-0495 .- 1532-8600. ; 57:5, s. 708-711
-
Tidskriftsartikel (refereegranskat)abstract
- Catechol O-methyltransferase (COMT) degrades catecholamines and estrogens, both of which are of known importance for cardiovascular risk factors such as obesity and hypertension. The gene coding for COMT contains a val158-met polymorphism that exerts a considerable influence on enzymatic activity. We hypothesized that this polymorphism might influence risk factors for cardiovascular disease. Deoxyribonucleic acid samples and data regarding blood pressure and anthropometry were collected from 240 Swedish men, all 51 years old. Subjects homozygous for the low-activity allele (met) displayed higher blood pressure, heart rate, waist-to-hip ratio, and abdominal sagittal diameter as compared with heterozygous subjects, who in turn displayed higher blood pressure, heart rate, waist-to-hip ratio, and abdominal sagittal diameter than subjects homozygous for the high-activity allele (val). All measured variables were significantly correlated; however, the associations between COMT val158-met and cardiovascular variables, and the association between COMT val158-met and anthropometry, respectively, were partly independent of each other, as revealed by multiple linear regression.
|
|
