title: The Role of Dopamine in Anticipatory Pursuit Eye Movements: Insights from Genetic Polymorphisms in Healthy Adults.
abstract: There is a long history of eye movement research in patients with psychiatric diseases for which dysfunctions of neurotransmission are considered to be the major pathologic mechanism. However, neuromodulation of oculomotor control is still hardly understood. We aimed to investigate in particular the impact of dopamine on smooth pursuit eye movements. Systematic variability in dopaminergic transmission due to genetic polymorphisms in healthy subjects offers a noninvasive opportunity to determine functional associations. We measured smooth pursuit in 110 healthy subjects genotyped for two well-documented polymorphisms, the COMT Val158Met polymorphism and the SLC6A3 3'-UTR-VNTR polymorphism. Pursuit paradigms were chosen to particularly assess the ability of the pursuit system to initiate tracking when target motion onset is blanked, reflecting the impact of extraretinal signals. In contrast, when following a fully visible target sensory, retinal signals are available. Our results highlight the crucial functional role of dopamine for anticipatory, but not for sensory-driven, pursuit processes. We found the COMT Val158Met polymorphism specifically associated with anticipatory pursuit parameters, emphasizing the dominant impact of prefrontal dopamine activity on complex oculomotor control. In contrast, modulation of striatal dopamine activity by the SLC6A3 3'-UTR-VNTR polymorphism had no significant functional effect. Though often neglected so far, individual differences in healthy subjects provide a promising approach to uncovering functional mechanisms and can be used as a bridge to understanding deficits in patients.
authors.affiliation: Department of Psychology, Justus-Liebig-Universität , 35394 Giessen, Germany.
authors.forename: Jutta
authors.identifier: 0000-0003-0362-6140
authors.initials: J
authors.lastname: Billino
authors.affiliation: Department of Psychology, Justus-Liebig-Universität , 35394 Giessen, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hennig
authors.affiliation: Department of Psychology, Justus-Liebig-Universität , 35394 Giessen, Germany.
authors.forename: Karl R
authors.identifier: 0000-0001-5390-0684
authors.initials: KR
authors.lastname: Gegenfurtner
mesh_terms: D000293:Adolescent; D000328:Adult; D059031:Anticipation, Psychological / Q000502:physiology*; D019540:Area Under Curve; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D053483:Eye Movement Measurements; D005260:Female; D060005:Genotyping Techniques; D006801:Humans; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D009043:Motor Activity / Q000235:genetics / Q000502:physiology*; D015999:Multivariate Analysis; D011110:Polymorphism, Genetic; D011698:Pursuit, Smooth / Q000235:genetics / Q000502:physiology*; D012372:ROC Curve; D055815:Young Adult
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; C493214:SLC6A3 protein, human; C588010:COMT protein, human; D002394:Catechol O-Methyltransferase; D004298:Dopamine
keywords: COMT; anticipation; dopamine; genetic polymorphisms; individual differences; pursuit system