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BACKGROUND: Current models suggest that a variation in the promoter region of the serotonin transporter gene (5-HTTLPR) is associated with altered amygdala reactivity not only towards negative but also towards positive stimuli, which has been neglected in the past. This association may possibly convey an elevated vulnerability for psychopathology like abuse, craving, and relapses. Since appetitive conditioning is a crucial mechanism in the pathogenesis of these psychiatric disorders, the identification of specific factors contributing to interindividual variation is important. METHODS: In the present study (N = 86), an appetitive conditioning paradigm was conducted, in which a neutral stimulus (CS+) was associated with appetitive stimuli, while a second stimulus (CS-) predicted their absence. Subjects were genotyped according to the 5-HTTLPR genotype. RESULTS: As the main result, we report a significant association between the 5-HTTLPR genotype and hemodynamic responses. Individuals with the s-allele displayed elevated conditioned bilateral amygdala activity in contrast to l/l-allele carriers. Further, increased hemodynamic responses in s-allele carriers were also found in the extended emotional network including the orbitofrontal cortex, the thalamus, and the ventral striatum. CONCLUSION: The present findings indicate an association of the 5-HTTLPR and altered conditioned responses in appetitive conditioning. Further, the findings contribute to the ongoing debate on 5-HTTLPR dependent hemodynamic response patterns by emphasizing that s-allele carriers are not exclusively biased towards fearful, but also towards positive stimuli. In conclusion, our results imply that s-allele carriers might be better described as hyper-reactive towards salient stimuli, which may convey vulnerability for the development of psychiatric disorders.
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Converging lines of research suggest that exaggerated disgust responses play a crucial role in the development and maintenance of certain anxiety disorders. One strategy that might effectively alter disgust responses is counterconditioning. In this study, we used functional magnetic resonance imaging (fMRI) to examine if the neuronal bases of disgust responses are altered through a counterconditioning procedure. One disgust picture (conditioned stimulus: CS+disg) announced a monetary reward, while a second disgust picture (CS-disg) was never paired with the reward. Two neutral control pictures (CS+con/CS-con) were conditioned in the same manner. Analyses of evaluative conditioning showed that both CS+ were rated significantly more positive after conditioning as compared to the corresponding CS-. Thereby, the CS+disg and the CS+con received an equal increase in valence ratings. Regarding the fMRI data, ANOVA results showed main effects of the conditioning procedure (i.e., CS+ vs. CS-) in the dorsal anterior cingulate cortex. Further, main effects of the picture category (disgust vs. control) were found in the bilateral insula and the orbitofrontal cortex. No interaction effects were detected. In conclusion, the results imply that learning and anticipation of reward was not significantly influenced by the disgust content of the CS pictures. This suggests that the affect induced by the disgust pictures and the affect created by the anticipation of reward may not influence the processing of each other.
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Team
- Vaitl (2)
Eintragsart
Sprache
Thema
- classical conditioning
- 5-HTTLPR (1)
- Adult (1)
- Alleles (1)
- amygdala (1)
- Amygdala/physiology (1)
- Appetitive Behavior/*physiology (1)
- *Brain Mapping (1)
- Cerebral Cortex/physiology (1)
- *Cerebrovascular Circulation (1)
- Conditioning, Operant/physiology (1)
- Corpus Striatum/physiology (1)
- counterconditioning (1)
- disgust (1)
- *Echo-Planar Imaging (1)
- Erotica (1)
- evaluative conditioning (1)
- Female (1)
- fMRI (2)
- Frontal Lobe/physiology (1)
- Galvanic Skin Response (1)
- Genotype (1)
- Gyrus Cinguli/physiology (1)
- Hemodynamics (1)
- Humans (1)
- imaging genetics (1)
- *INDEL Mutation (1)
- Male (1)
- positive emotion (1)
- reward learning (1)
- Serotonin Plasma Membrane Transport Proteins/genetics/*physiology (1)
- Sexual Behavior/*physiology (1)
- Thalamus/physiology (1)
- Young Adult (1)