title: Screening hallucinogenic drugs: systematic study of three behavioral tests.
abstract: The effects of several hallucinogenic and non-hallucinogenic drugs have been studied on three behavioral tests proposed as useful indexes of hallucinogenic activity: "head-twitching" in mice, defecation in an open-field, and suppression of responding on a differential reinforcement of low rates (DRL) schedule of reinforcement. According to the original propositions, after administration of hallucinogenic agents the frequency of head-twitches would increase in mice, the defecation of rats in an open field would decrease without consistent change in ambulation, rearing and grooming, and the responding of rats on a DRL schedule would yield a typical cumulative record pattern. It was found that the head-twitch test was sensitive to mescaline and LSD-25, but not to delta9-THC or to myristicin and elemicin. Besides, the data on interobserver agreement suggested there is a high degree of subjectivity involved in assessing this response. In the open-field test, non-hallucinogenic drugs such as chlorpromazine and apomorphine fell into the hallucinogenic pattern proposed. In addition, the post-injection interval selected seemed to critically affect defecation scores. The DRL "hallucinogenic" pattern occurred nonspecifically after administration of hallucinogenic and non-hallucinogenic drugs. It was concluded that the three tests have limited value for screening purposes.
mesh_terms: D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001143:Arousal / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects*; D002746:Chlorpromazine / Q000494:pharmacology; D003975:Diazepam / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical / Q000379:methods* / Q000592:standards; D006120:Grooming; D006213:Hallucinogens / Q000494:pharmacology*; D006257:Head; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects; D009069:Movement Disorders / Q000139:chemically induced; D010424:Pentobarbital / Q000494:pharmacology; D051381:Rats; D012055:Reinforcement Schedule; D012054:Reinforcement, Psychology / Q000187:drug effects; D012107:Research Design
chemical_list: D006213:Hallucinogens; D009020:Morphine; D006916:5-Hydroxytryptophan; D000661:Amphetamine; D010424:Pentobarbital; D001058:Apomorphine; D003975:Diazepam; D002746:Chlorpromazine