Collinson and Dawson (1997) presented the anxiolytic-like effect of 5-HT1A receptor agonist, 8-OH-DPAT, which was reversed by 5-HT1A receptor antagonist (WAY-100635). Moreover, 5-HT1A knockout mice, lacking 5-HT1A auto- and heteroreceptors, displayed a heightened anxiety-like phenotype in several tests in rodents (Heisler et al., 1998; Parks et al., 1998; Ramboz et al., 1998) and resistance to benzodiazepines (Sibille et al., 2000). Overall, the above findings demonstrate the involvement of 5-HT1A receptors in anxiogenic processes. Here, HTR1A is linked to Anxiety.