Forbes EE, Dahl RE, Almeida JR, Ferrell RE, Nimgaonkar VL, Mansour H, Sciarrillo SR, Holm SM, Rodriguez EE, and Phillips ML. Biol Psychiatry. 2012 Mar 1;71(5):451-7.
The purpose of this study of 90 adolescents was to determine the relationship between SNPs in circadian genes and reward mediating brain circuitry. The authors found that carriers of the G allele for the rs2304672 SNP in per2 tended to have less brain activity in the medial prefrontal cortex, an area of the brain associated with self-regulation, as measured by functional magnetic resonance imaging (fMRI).
rs2304672 in per2