The use of quantitative brain oscillations as endophenotypes provides the power to more easily localize and characterize disease susceptibility genes than diagnostic categories. The recent identification of genetic loci associated with human brain oscillations indicates that they are under genetic control and are modulated by genes controlling neurotransmitters in the brain. Several receptor genes have emerged from the genetic studies of event-related oscillations as endophenotypes, that are involved in variation in brain oscillations and hence their cognitive correlates; specifically, theta EROs have been associated with the cholinergic muscarinic receptor (CHRM2), metabotropic glutamate receptor (GRM8), and serotonin receptor (HTR7) genes. Although no functional variant affecting the electrophysiological characteristics has yet been identified at the molecular level, a large body of pharmacological evidence attests to the relevance of these receptors to aspects of cognitive function. The advent of genomics and proteomics and a fuller understanding of gene regulation will open new horizons on the critical electrical events so essential for human brain function. This approach has the unprecedented potential to unravel the complex interplay of various neural subsystems relevant to the generation of brain oscillations elicited under different cognitive conditions and in the disease states.
