pretreatment with the serotonin ( 5-ht ) antagonist cyproheptadine ( 1.0 mg/kg ) , which does not block the psychological effects of hallucinogens in humans , selectively blocked dom 's reduction of rearings without altering dom 's reduction of center entries , crossovers , or holepokes .
C0086418
humans
C3539821
dom 's