Under the same theta ERO linkage peak on chromosome 7 is a glutamate receptor (GRM8) gene that is another very likely candidate gene for modulating electrophysiological networks, particularly as the glutamatergic system is also involved in theta oscillations and P3 [182]. Family-based association analyses of theta EROs revealed significant associations with several SNPs in the GRM8 gene and theta EROs to target stimuli at frontal, central, and parietal regions [198]. An interesting finding is that several of the same GRM8 SNPs were also significant for diagnosis of alcohol dependence using ICD-10 diagnostic criteria.
