In the present study, we investigated the potential associations between single nucleotide polymorphisms (SNPs) in glutamate receptor genes and the quantitative trait of event-related theta band energy during processing of target visual signals. GRM8 was selected because it maps at chromosome 7q31.3–q32.1 within the peak region where we previously identified a significant linkage (peak LOD=3.5, Figure 1) using a genome-wide linkage scan of the same phenotype (theta for the target stimuli) (Jones and others 2006; Jones and others 2004). The findings presented here are the first report to link GRM8 with theta band oscillations underlying the P3 wave using genetic analyses. It is also the first report identifying a positive association between the GRM8 and alcohol dependence.
