Who gets afraid in the MRI-scanner? Neurogenetics of state-anxiety changes during an fMRI experiment.

Neurosci Lett. 2014 Sep 16;

Authors: Mutschler I, Wieckhorst B, Meyer AH, Schweizer T, Klarhöfer M, Wilhelm FH, Seifritz E, Ball T

Abstract
Experimental settings using functional magnetic resonance imaging (fMRI) play a fundamental role in affective neuroscience. When placed in an MR scanner, some volunteers feel safe and relaxed in this situation, while others experience uneasiness and fear. Little is known about the basis and consequences of such inter-individually different responses to the general experimental fMRI setting. In this study emotional stimuli were presented during fMRI and subjects' state-anxiety was assessed at the onset and end of the experiment while they were within the scanner. We show that Val/Val but neither Met/Met nor Val/Met carriers of the catechol-O-methyltransferase (COMT) Val(158)Met polymorphism -a prime candidate for anxiety vulnerability-became significantly more anxious during the fMRI experiment (N=97 females: 24 Val/Val, 51 Val/Met, and 22 Met/Met). Met carriers demonstrated brain responses with increased stability in the right parietal cortex over time and significantly better cognitive performances likely mediated by lower levels of anxiety. There was no significant difference in state-anxiety at the beginning of the experiment. The exposure of a control group (N=56 females) to the same experiment outside the scanner did not cause a significant increase in state-anxiety, suggesting that the increase we observe in the fMRI experiment may be specific to the fMRI setting. Our findings reveal that neurogenetic mechanisms play an important role in shaping inter-individual different responses on neuronal, emotional and cognitive levels that may be induced by general experimental fMRI settings.

PMID: 25238960 [PubMed - as supplied by publisher]