Antagonism by neuroleptics of serotonin 5-HT_1A and 5-HT₂ receptors of normal human brain in vitro

Using radioligand binding techniques and human frontal cortex, we determined the equilibrium dissociation constants (K_D^S) of 17 neuroleptics at the serotonin 5-HT_1A and serotonin 5-HT₂ receptors with [³H]WB4101 and [³H]ketanserin, respectively. At the serotonin 5-HT_1A receptor, the most and least potent neuroleptics were chlorprothixene (K_D = 230 nM) and fluphenazine (K_D = 40 μM), respectively. At the serotonin 5-HT₂ receptor, the most and least potent neuroleptics were spiperone (K_D = 0.38 nM)and molindone, (K_D = 5 μM), respectively.