TY  - JOUR
A1  - Neufang, S.
A1  - Akhrif, A.
A1  - Herrmann, C.G.
A1  - Drepper, C.
A1  - Homola, G.A.
A1  - Nowak, J.
A1  - Waider, J.
A1  - Schmitt, A.G.
A1  - Lesch, K.-P.
A1  - Romanos, M.
T1  - Serotonergic modulation of 'waiting impulsivity' is mediated by the impulsivity phenotype in humans
JF  - Translational Psychiatry
N2  - In rodents, the five-choice serial reaction time task (5-CSRTT) has been established as a reliable measure of waiting impulsivity being defined as the ability to regulate a response in anticipation of reinforcement. Key brain structures are the nucleus accumbens (NAcc) and prefrontal regions (for example, pre- and infralimbic cortex), which are, together with other transmitters, modulated by serotonin. In this functional magnetic resonance imaging study, we examined 103 healthy males while performing the 5-CSRTT measuring brain activation in humans by means of a paradigm that has been widely applied in rodents. Subjects were genotyped for the tryptophan hydroxylase-2 (TPH2; G-703T; rs4570625) variant, an enzyme specific for brain serotonin synthesis. We addressed neural activation patterns of waiting impulsivity and the interaction between the NAcc and the ventromedial prefrontal cortex (vmPFC) using dynamic causal modeling. Genetic influence was examined via interaction analyses between the TPH2 genotype (GG homozygotes vs T allele carriers) and the degree of impulsivity as measured by the 5-CSRTT. We found that the driving input of the vmPFC was reduced in highly impulsive T allele carriers (reflecting a reduced top-down control) in combination with an enhanced response in the NAcc after correct target processing (reflecting an augmented response to monetary reward). Taken together, we found a high overlap of our findings with reports from animal studies in regard to the underlying cognitive processes, the brain regions associated with waiting impulsivity and the neural interplay between the NAcc and vmPFC. Therefore, we conclude that the 5-CSRTT is a promising tool for translational studies.
KW  - Clinical Genetics
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164418
IS  - 6
ER  - 
TY  - JOUR
A1  - Ziegler, C.
A1  - Richter, J.
A1  - Mahr, M.
A1  - Gajewska, A.
A1  - Schiele, M.A.
A1  - Gehrmann, A.
A1  - Schmidt, B.
A1  - Lesch, K.-P.
A1  - Lang, T.
A1  - Helbig-Lang, S.
A1  - Pauli, P.
A1  - Kircher, T.
A1  - Reif, A.
A1  - Rief, W.
A1  - Vossbeck-Elsebusch, A.N.
A1  - Arolt, V.
A1  - Wittchen, H.-U.
A1  - Hamm, A.O.
A1  - Deckert, J.
A1  - Domschke, K.
T1  - MAOA gene hypomethylation in panic disorder-reversibility of an epigenetic risk pattern by psychotherapy
JF  - Translational Psychiatry
N2  - Epigenetic signatures such as methylation of the monoamine oxidase A (MAOA) gene have been found to be altered in panic disorder (PD). Hypothesizing temporal plasticity of epigenetic processes as a mechanism of successful fear extinction, the present psychotherapy-epigenetic study for we believe the first time investigated MAOA methylation changes during the course of exposure-based cognitive behavioral therapy (CBT) in PD. MAOA methylation was compared between N=28 female Caucasian PD patients (discovery sample) and N=28 age- and sex-matched healthy controls via direct sequencing of sodium bisulfite-treated DNA extracted from blood cells. MAOA methylation was furthermore analyzed at baseline (T0) and after a 6-week CBT (T1) in the discovery sample parallelized by a waiting time in healthy controls, as well as in an independent sample of female PD patients (N=20). Patients exhibited lower MAOA methylation than healthy controls (P<0.001), and baseline PD severity correlated negatively with MAOA methylation (P=0.01). In the discovery sample, MAOA methylation increased up to the level of healthy controls along with CBT response (number of panic attacks; T0-T1: +3.37±2.17%), while non-responders further decreased in methylation (-2.00±1.28%; P=0.001). In the replication sample, increases in MAOA methylation correlated with agoraphobic symptom reduction after CBT (P=0.02-0.03). The present results support previous evidence for MAOA hypomethylation as a PD risk marker and suggest reversibility of MAOA hypomethylation as a potential epigenetic correlate of response to CBT. The emerging notion of epigenetic signatures as a mechanism of action of psychotherapeutic interventions may promote epigenetic patterns as biomarkers of lasting extinction effects.
KW  - Adult
KW  - Case-Control Studies
KW  - Cognitive Therapy
KW  - DNA Methylation
KW  - Epigenesis
KW  - Genetic
KW  - Female
KW  - Humans
KW  - Monoamine Oxidase/genetics
KW  - Panic Disorder/genetics
KW  - Panic Disorder/therapy
KW  - Sequence Analysis
KW  - DNA
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-164422
IS  - 6
ER  -