Catechol-O-methyltransferase (COMT) genotype affects age-related changes in plasticity in working memory: a pilot study.
OBJECTIVE
Recent work suggests that a genetic variation associated with increased dopamine metabolism in the prefrontal cortex (catechol-O-methyltransferase Val158Met; COMT) amplifies age-related changes in working memory performance. Research on younger adults indicates that the influence of dopamine-related genetic polymorphisms on working memory performance increases when testing the cognitive limits through training. To date, this has not been studied in older adults.


METHODS
Here we investigate the effect of COMT genotype on plasticity in working memory in a sample of 14 younger (aged 24-30 years) and 25 older (aged 60-75 years) healthy adults. Participants underwent adaptive training in the n-back working memory task over 12 sessions under increasing difficulty conditions.


RESULTS
Both younger and older adults exhibited sizeable behavioral plasticity through training (P < .001), which was larger in younger as compared to older adults (P < .001). Age-related differences were qualified by an interaction with COMT genotype (P < .001), and this interaction was due to decreased behavioral plasticity in older adults carrying the Val/Val genotype, while there was no effect of genotype in younger adults.


CONCLUSIONS
Our findings indicate that age-related changes in plasticity in working memory are critically affected by genetic variation in prefrontal dopamine metabolism.
Department of Psychology, Humboldt-Universität zu Berlin, Rudower Chaussee 18, 12489 Berlin, Germany ; Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany ; Social and Preventive Medicine, University of Potsdam, Am Neuen Palais 10, 14469 Potsdam, Germany.
Stephan
0000-0003-2325-900X
S
Heinzel
Department of Psychology, Humboldt-Universität zu Berlin, Rudower Chaussee 18, 12489 Berlin, Germany ; Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
Thomas G
TG
Riemer
Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
Stefanie
S
Schulte
Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
Johanna
J
Onken
Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany ; Cluster of Excellence NeuroCure, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
Andreas
A
Heinz
Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany ; Social and Preventive Medicine, University of Potsdam, Am Neuen Palais 10, 14469 Potsdam, Germany ; Cluster of Excellence NeuroCure, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
Michael A
MA
Rapp
D000328:Adult; D000368:Aged; D002394:Catechol O-Methyltransferase / Q000235:genetics* / Q000378:metabolism; D004298:Dopamine / Q000235:genetics / Q000378:metabolism; D005260:Female; D056726:Genetic Association Studies; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000235:genetics* / Q000473:pathology; D008570:Memory, Short-Term; D008875:Middle Aged; D009473:Neuronal Plasticity / Q000235:genetics*; D010865:Pilot Projects; D017397:Prefrontal Cortex / Q000378:metabolism / Q000473:pathology
C588010:COMT protein, human; D002394:Catechol O-Methyltransferase; D004298:Dopamine