On the relevance of the NPY2-receptor variation for modes of action cascading processes.

Every day, we encounter situations in which we have to deal with multiple response options. In order not to overstrain response selection resources, we need to cascade the associated task goals. Yet, the neurobiological foundations of these action cascading processes are largely unknown. Aiming at determining the possible relevance of the neuropeptide Y Y2 receptor for action cascading processes, this study investigates a functional promoter variation (rs2234759) in the neuropeptide Y Y2 receptor gene (NPY2R). 176 healthy subjects completed a stop-change paradigm. Applying mathematical constraints to the obtained behavioral data allowed for a classification of the action cascading processing mode on a serial to parallel continuum. Neurophysiological data (EEG) were analyzed along this mathematical constraint. The behavioral data show that the Y2-receptor high expression G allele is associated with a less efficient mode of action cascading where different task goals are activated in parallel. The neurophysiological data indicate that this effect is based on modulations at the response selection stage but not on changes in the preceding attentional selection processes. Analyses show that the interrelation between behavioral and neurophysiological data is mediated by genotype effects. At the level of response selection, genotype effects are associated with activity changes in the anterior cingulate cortex (ACC). Changes in the reliability of neural synchronization processes in the theta frequency band are also related to these effects. Possibly, these Y2-receptor-related effects emerge from the receptor's strong interrelation with the dopamine system.