HTR5A and epilepsy: Conversely, drugs that decrease the concentration of 5-HT in the brain promote seizures in animal models of epilepsy (Wenger et al., 1973; Maynert et al., 1975; Lazarova et al., 1983), while knocking-out the gene encoding for 5-HT2C receptors facilitates epileptic seizures (Tecott et al., 1995; Applegate and Tecott, 1998; Upton et al., 1998).