title: Haloperidol produces within-session increments in operant response duration in rats.
abstract: On the basis of previously reported observations that haloperidol induces within-session decrements in operant response rate in rats, it was suspected that other measures of operant behavior may also display within-session changes after treatment with this neuroleptic. Accordingly, haloperidol (0.02, 0.04, 0.08, 0.16 mg/kg) was administered to six rats trained on a fixed-ratio 20 schedule of liquid food reinforcement, and response duration was recorded as a measure of drug effects independent of response rate. Significant within-session decrements in response rate and increments in response duration were observed as responding ensued. At the 0.08 mg/kg dose, 300% increases in response duration were seen during the last third of the responses made in a session. The progressive slowing of individual motor acts were interpreted as neuroleptic-induced Parkinsonism in the rat, and within-session decrements in response rate were likewise seen as a manifestation of the same pharmacological effects that increased response duration.
authors.affiliation: Department of Psychology, University of Mississippi 38677.
authors.forename: R M
authors.initials: RM
authors.lastname: Liao
authors.forename: S C
authors.initials: SC
authors.lastname: Fowler
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D006220:Haloperidol / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012054:Reinforcement, Psychology; D013997:Time Factors
chemical_list: D006220:Haloperidol