SB 258741 hydrochloride is a potent antagonist of the 5-HT 7 receptor, designed specifically for studying schizophrenia [1].

SB-258741 acts as a partial inverse agonist, with its antagonistic potency, denoted as apparent pK B , measured to be 8.47 [2].

SB 258741, administered subcutaneously at doses ranging from 0.56 to 9.1 mg/kg either once or daily for three days, demonstrates antipsychotic properties in male Wistar rats weighing between 250-300 g for studies involving phencyclidine (PCP)-disrupted prepulse inhibition (PPI) and social interaction (SIT) tests, and 200-250 g for catalepsy, motility, and D-amphetamine-induced hyperactivity studies. The results indicate that SB 258741 effectively reverses hyperactivity caused by D-amphetamine at doses above 0.56 mg/kg and reduces motility at 4.6 and 9.1 mg/kg. It does not counteract the disrupted PPI induced by D-Amphetamine, but it does enhance PPI disrupted by PCP and decreases PCP (2 mg/kg)-induced hyperactivity.