Abstract
Two groups of five pigeons each were trained to discriminate morphine 5.6 mg/kg vs cocaine 5.6 mg/kg (High dose cocaine group), and morphine 5.6 mg/kg vs cocaine 3.0 mg/kg (Low dose cocaine group), respectively. Within both groups, cocaine dose generalization gradients were radically flatter in comparison to those obtained when the same cocaine dosages were discriminated from saline, whereas morphine gradients, analogously compared, were only moderately so. Responding to non-drug tests did not deviate significantly from random in either group. After lowering morphine training doses to 3.0 mg/kg in a systematic replication of the experiment, training drugs generalization gradients took symmetrical, flattened, shapes in the High dose cocaine group, whereas in the Low dose cocaine group the previous relation between gradients was enhanced. Responding to non-drug tests in this phase did not deviate significantly from random in the High dose cocaine group, whereas the reverse was true with the Low dose cocaine group. Tests with novel drugs (apomorphine, LSD, pentobarbital and Δ9-THC), did not differentiate between the groups. The roles of generalization gradients, non-drug tests and novel drugs tests as measures of relative stimulus control of training stimuli in drug discrimination experiments are discussed within the framework of a drug discrimination model.
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References
Appel JB, White FJ, Holohean AM (1982) Analyzing mechanism(s) of hallucinogenic drug action with drug discrimination procedures. Neurosci Biobehav Rev 6:529–536
Barry III H, Krimmer EC (1979) Differential stimulus attributes of chlordiazepoxide and pentobarbital. Neuropharmacology 18:991–998
Colpaert FC (1982) The pharmacological specificity of opiate drug discrimination. In: Colpaert FC, Slangen JL (eds) Drug discrimination: applications in CNS pharmacology. Elsevier Biomedical Press, Amsterdam New York Oxford, pp 3–16
Colpaert FC, Janssen PAJ (1981) Factors regulating drug cue sensitivity: the effect of frustrative non-reward in fentanyl-saline discrimination. Arch Int Pharmacodyn Thér 254:241–251
Colpaert FC, Janssen PAJ (1982a) Factors regulating drug cue sensitivity: limits of discriminability and the role of a progressively decreasing training dose in cocaine-saline discrimination. Neuropharmacology 21:1187–1194
Colpaert FC, Janssen PAJ (1982b) Factors regulating drug cue sensitivity: the effects of dose ratio and absolute dose level in the case of fentanyl dose-dose discrimination. Arch Int Pharmacodyn Thér 258:283–299
Colpaert FC, Niemegeers CJE, Janssen PAJ (1980a) Factors regulating drug cue sensitivity: the effect of training dose in fentanyl-saline discrimination. Neuropharmacology 19:705–713
Colpaert FC, Niemegeers CJE, Janssen PAJ (1980b) Factors regulating drug cue sensitivity: limits of discriminability and the role of a progressively decreasing training dose in fentanylsaline discrimination. J Pharmacol Exp Ther 212:474–480
Colpaert FC, Slangen JL (eds) (1982) Drug discrimination: applications in CNS pharmacology. Elsevier Biomedical Press, Amsterdam New York Oxford
Extance K, Goudie AJ (1981) Inter-animal olfactory cues in operant drug discrimination procedures in rats. Psychopharmacology 73:363–371
Hays WL (1970) Statistics. Holt Rinehart and Winston, London
Holohean AM, White FJ, Appel JB (1982) Dopaminergic and serotonergic mediation of the discriminable effects of ergot alkaloids. Eur J Pharmacol 81:595–602
Järbe TUC (1978) Discriminative effects of morphine in the pigeon. Pharmacol, Biochem Behav 9:411–416
Järbe TUC (1981) Cocaine cue in pigeons: time course studies and generalization to structurally related compounds (norcocaine, Win 35,428 and 35,065-2) and (+)-amphetamine. Br J Pharmacol 73:843–852
Järbe TUC (1984) Discriminative stimulus properties of cocaine: effects of apomorphine, haloperidol, procaine and other drugs. Neuropharmacology 23:899–907
Järbe TUC, Loman P, Swedberg MDB (1979) Evidence supporting lack of discriminative stimulus properties of combinations of morphine and naltrexone in gerbils. Pharmacol, Biochem Behav 10:493–497
Järbe TUC, Ohlin GC (1979) Discriminative effects of combinations of Δ9-tetrahydrocannabinol and pentobarbital in pigeons. Psychopharmacology 63:233–239
Järbe TUC, Svensson R, Laaksonen T (1983) Conditioning of a discriminative drug stimulus: overshadowing and blocking like procedures. Scand J Psychol 24:325–330
Järbe TUC, Swedberg MDB (1981) Differences in the stimulus effects of CNS depressant substances as evidenced by drug vs drug discrimination techniques. Acta Pharmacol Toxicol 49: abstract no 45, suppl IV
Järbe TUC, Swedberg MDB (1982) A conceptualization of drug discrimination learning. In: Colpaert FC, Slangen JL (eds) Drug discrimination: applications in CNS pharmacology. Elsevier Biomedical Press, Amsterdam New York Oxford, pp 327–341
Koek W, Slangen JL (1982) The role of fentanyl training dose and of the alternative stimulus condition in drug generalization. Psychopharmacology 76:149–156
Overton DA, Merkle DA, Hayes ML (1983) Are “no drug” cues discriminated during drug discrimination training? Anim Learn Behav 11:295–301
Pieri L, Keller HH, Burkard W, DaPrada M (1978) Effects of lisuride and LSD on cerebral monoamine systems and hallucinosis. Nature 272:278–280
Richards III DV (1978) A functional analysis of the discriminative stimulus properties of amphetamine and pentobarbital. In: Ho BT, Richards III DW, Chute DL (eds) Drug discrimination and state dependent learning. Academic Press, New York San Francisco London, pp 227–247
Sidman M (1960) Tactics of scientific research. Evaluating experimental data in psychology. Basic Books Inc., New York
Siegel S (1956) Nonparametric statistics for the behavioral sciences. McGraw-Hill, New York Toronto London
Sofia RD, Kubena RK, Barry H III (1974) Comparison among four vehicles and four routes for administering Δ9-tetrahydrocannabinol. J Pharm Sci 63:939–941
Swedberg MDB, Järbe TUC (1982) Morphine cue saliency: limits of discriminability and third state perception by pigeons. In: Colpaert FC, Slangen JL (eds) Drug discrimination: applications in CNS pharmacology. Elsevier Biomedical Press, Amsterdam New York Oxford, pp 147–164
Swedberg MDB, Loman P, Järbe TUC (1978) Effects of chlormethiazole (Heminevrin®) on drug discrimination and open-field behavior in gerbils. Psychopharmacology 59:165–170
White FJ, Appel JB (1982) Lysergic acid diethylamide (LSD) and lisuride: differentiation of their neuropharmacological actions. Science 216:535–537
Witkin JM, Carter RB, Dykstra LA (1980) Discriminative stimulus properties of d-amphetamine-pentobarbital combinations. Psychopharmacology 68:269–276
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Swedberg, M.D.B., Järbe, T.U.C. Drug discrimination procedures: Roles of relative stimulus control in two-drug cases. Psychopharmacology 86, 444–451 (1985). https://doi.org/10.1007/BF00427906
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DOI: https://doi.org/10.1007/BF00427906