The neurotransmitter, serotonin, is thought to play a role in various cognitive and behavioral functions. This isoform (A) is the predominant isoform in spleen, caudate and hippocampus. 5-HT7 isoform B is expressed at lower levels. 5-HT7 belongs to the superfamily of G protein-coupled receptors and the gene is a candidate locus for involvement in autistic disorder and other neuropsychiatric disorders. Pharmacological and genetic tools targeting 5-HT7 in preclinical animal models have implicated this receptor in diverse (patho)physiological processes of the central nervous system (CNS).