title: Somatodendritic and postsynaptic serotonin-1A receptors in the attenuation of haloperidol-induced catalepsy.
abstract: The mechanism by which stimulation of somatodendritic and/or postsynaptic 5-hydroxytryptamine (5-HT, serotonin)-1A receptor could attenuate acute Parkinsonian-like effects of typical antipsychotics is investigated by comparing the anticataleptic and neurochemical effects of 8-hydroxy-2-di-n-propylaminotetralin (8-OH-DPAT) and buspirone in rats injected with haloperidol. Cataleptic effects of a submaximal dose (1 mg/kg) of haloperidol were attenuated more by prior administration of 8-OH-DPAT (0.25 mg/kg) than buspirone (1 mg/kg). Striatal 5-HT metabolism decreased more in buspirone- than 8-OH-DPAT-injected animals. Administration of haloperidol did not alter 5-HT metabolism in saline-, 8-OH-DPAT- or buspirone-injected animals. Dopamine decreased and its metabolite homovanillic acid (HVA) increased in the striatum of rats injected with buspirone. Effects of 8-OH-DPAT on dopamine metabolism were not significant. Haloperidol-induced increases of dopamine metabolites were attenuated by prior administration of 8-OH-DPAT, but not buspirone. The mechanism by which stimulation of somatodendritic as well as postsynaptic 5-HT-1A receptors could attenuate haloperidol-induced catalepsy is discussed. The findings have potential implications in the treatment of schizophrenia and motor behavior.
authors.affiliation: Department of Biochemistry, Neurochemistry and Biochemical Neuropharmacology Research laboratory, University of Karachi, Karachi 75270, Pakistan. djh@super.net.pk
authors.forename: Darakhshan Jabeen
authors.initials: DJ
authors.lastname: Haleem
authors.forename: Erum
authors.initials: E
authors.lastname: Shireen
authors.forename: M A
authors.initials: MA
authors.lastname: Haleem
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000818:Animals; D001522:Behavior, Animal; D001923:Brain Chemistry / Q000187:drug effects; D002065:Buspirone; D002375:Catalepsy / Q000139:chemically induced / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003342:Corpus Striatum / Q000187:drug effects*; D004347:Drug Interactions; D004563:Electrochemistry / Q000379:methods; D006220:Haloperidol; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism
chemical_list: D044282:Receptor, Serotonin, 5-HT1A; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D006220:Haloperidol; D002065:Buspirone