SB 699551

SB-699551 is a drug which was the first compound developed to act as a selective antagonist for the serotonin receptor 5-HT_5A, with selectivity of around 100x over other serotonin receptor subtypes. The function of the 5-HT_5A receptor remains poorly defined, but SB-699551 was found to modulate serotonin release from neurons, suggesting it acts as a presynaptic inhibitory autoreceptor similar to the 5-HT_1B and 5-HT_1D receptors. Multiple therapeutic roles have been suggested for 5-HT_5A ligands due to the presence of this receptor in several areas of the brain, but research is still at an early stage, with one possible application being the currently difficult to treat negative symptoms of schizophrenia.