title: Genetic variation in serotonin transporter function affects human fear expression indexed by fear-potentiated startle.
abstract: The serotonin transporter (SERT) plays a crucial role in anxiety. Accordingly, variance in SERT functioning appears to constitute an important pathway to individual differences in anxiety. The current study tested the hypothesis that genetic variation in SERT function is associated with variability in the basic reflex physiology of defense. Healthy subjects (N=82) were presented with clearly instructed cues of shock threat and safety to induce robust anxiety reactions. Subjects carrying at least one short allele for the 5-HTTLPR polymorphism showed stronger fear-potentiated startle compared to long allele homozygotes. However, short allele carriers showed no deficit in the downregulation of fear after the offset of threat. These results suggest that natural variation in SERT function affects the magnitude of defensive reactions while not affecting the capacity for fear regulation.
authors: Department of Experimental Psychology & Psychopharmacology, Utrecht University, Heidelberglaan 2, 3508 TC, Utrecht, The Netherlands. F.Klumpers@uu.nl
authors: Floris
authors: F
authors: Klumpers
authors: Ivo
authors: I
authors: Heitland
authors: Ronald S
authors: RS
authors: Oosting
authors: J Leon
authors: JL
authors: Kenemans
authors: Johanna M P
authors: JM
authors: Baas
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000483:Alleles; D001007:Anxiety / Q000235:genetics; D003463:Cues; D005239:Fear / Q000502:physiology*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D012018:Reflex / Q000235:genetics*; D013216:Reflex, Startle / Q000235:genetics*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*
chemical_list: D050486:Serotonin Plasma Membrane Transport Proteins