Affect-modulated startle reflex and dopamine D4 receptor gene variation


  • P. Pauli and A. Conzelmann contributed equally. Research was supported by the “Deutsche Forschungsgemeinschaft” (KFO 125/1, TP 7). We gratefully thank A. Boreatti, M. Heine, and J. Romanos for their help in the diagnostical screening of participants and R. Gerhard for her help in data preprocessing. The authors also thank N. Steigerwald and N. Döring for excellent technical assistance in DNA sample processing and genotyping.

Address reprint requests to: Prof. Dr. Paul Pauli, University of Würzburg, Department of Psychology, Biological Psychology, Clinical Psychology, and Psychotherapy, Marcusstr. 9-11, 97070 Würzburg, Germany. E-mail:


The affect-modulated acoustic startle response (ASR) might be a promising indicator for emotional reactivity as an endophenotype (an intermediate level between genetics and phenotypes), which we expected to be associated with the DRD4 polymorphism. Therefore, the affect-modulated ASR was examined in 114 healthy volunteers, 74 lacking the DRD4 7R allele (7R-absent group) and 41 with at least one DRD4 7R allele (7R group). Results revealed the well-known affect–modulated ASR in the 7R-absent group. The 7R group, however, was characterized by a blunted affect-modulated ASR, especially by a reduced startle potentiation toward unpleasant pictures. Associations between the exploratory assessed 5-HTT, COMT, and DAT polymorphisms and affect-modulated ASR were not found. Results speak for the importance of the DRD4 polymorphism in modulating emotional responses and also for the usefulness of the affect-modulated ASR as an endophenotype.