Abstract
Pigeons were trained to discriminate the IM injection of pentobarbital (5 or 10 mg/kg) from saline in a task in which 20 consecutive pecks on one of two response keys produced access to mixed grain. Pentobarbital (1.0–17.8 mg/kg) produced a dose-related increase in the percentage of the total session responses that occurred on the pentobarbital-appropriate key. The concomitant administration of bemegride (5.6–17.8 mg/kg) antagonized the discriminative control of behavior exerted by the training dose of pentobarbital. Benzodiazepines, diazepam (1.0 mg/kg) and clobazam (3.2 mg/kg), and barbiturates, methohexital (10 mg/kg), phenobarbital (56 mg/kg), and barbital (56 mg/kg), produced responding on the pentobarbital-appropriate key similar to that produced by pentobarbital. In contrast, narcotics such as morphine, ethylketazocine, cyclazocine, and SKF-10,047, at doses up to and including those that markedly suppressed response rates, produced responding predominantly on the saline-appropriate key. Similarly, the anticonvulsants, valproate, phenytoin, and ethosuximide occasioned only saline-appropriate behavior, indicating that not all anticonvulsants share discriminative stimulus effects with pentobarbital. Muscimol, a direct GABA agonist, and baclofen, a structural analogue of GABA, also failed to produce pentobarbital-appropriate responding. Ketamine, dextrorphan, and ethanol (0.3–3.2 g/kg, orally) produced intermediate levels of pentobarbital-appropriate responding, suggesting that the discriminative effects of these drugs may be somewhat like those of pentobarbital.
Similar content being viewed by others
References
Barry H, III (1974) Classification of drugs according to their discriminable effects in rats. Fed Proc 33:1814–1824
Barry H, III, Krimmer EC (1972) Pentobarbital effects perceived by rats as resembling several other depressants but not alcohol. Proc 80th Am Psychol Assoc 7:849–850
Barry H, III, Krimmer EC (1977) Discriminable stimuli produced by alcohol and other CNS depressants. In: Lal H (ed) Discriminative stimulus properties of drugs. Plenum Press, New York, p 73
Barry H, III, Krimmer EC (1978) Similarities and differences in discriminative stimulus effects of chlordiazepoxide, pentobarbital, ethanol, and other sedatives. In: Colpaert FC, Rosecrans JA (eds) Stimulus properties of drugs: Ten years of progress. Elsevier/North Holland Biomedical Press, Amsterdam, p 31
Colpaert FC (1977) Discriminative stimulus properties of benzodiazepines and barbiturates. In: Lal H (ed) Discriminative stimulus properties of drugs. Plenum Press, New York, p 93
Colpaert FC, Desmedt LKC, Janssen PAJ (1976) Discriminative stimulus properties of benzodiazepines, barbiturates, and pharmacologically related drugs; relation to some intrinsic and anticonvulsant effects. Eur J Pharmacol 37:113–123
Enna SJ, Maggi A (1979) Biochemical pharmacology of GABAergic agonists. Life Sci 24:1727–1738
Ferster CB, Skinner BF (1957) Schedules of reinforcement. Appleton-Century-Crofts, New York, p 14
Gilbert PE, Martin WR (1976) The effects of morphine- and nalorphine-like drugs in the nondependent, morphine-dependent and cyclazocine-dependent chronic spinal dog. J Pharmacol Exp Ther 198:66–82
Goodman LS, Grewal MS, Brown WC, Swinyard EA (1953) Comparison of maximal seizures evoked by pentylenetetrazol (Metrazol) and electroshock in mice, and their modification by anticonvulsants. J Pharmacol Exp Ther 108:168–176
Goodman LS, Toman JEP, Swinyard EA (1946) The anticonvulsant properties of Tridione. Am J Med 1:213–228
Hein DW, Herling S, Young AM, Valentino RJ, Woods JH (1980) Qualitative differences between the discriminative stimulus characteristics produced by ethylketazocine in the rhesus monkey and the pigeon. Fed Proc 39:995
Herling S, Coale EH, Jr, Valentino RJ, Hein DW, Woods JH (1980a) Narcotic discrimination in pigeons. J Pharmacol Exp Ther 214: 139–146
Herling S, Winger GD, Coale EH, Hein DW, Woods JH (1980b) Similarity of the discriminative stimulus effects of dextrorphan, ketamine, and cyclazocine in the pigeon. Fed Proc 39:994
Holtzman SG, Shannon HE, Schaefer GJ (1977) Discriminative properties of narcotic antagonists. In: Lal H (ed) Discriminative stimulus properties of drugs. Plenum Press, New York, p 47
Jarbe TUC (1976) Characteristics of pentobarbital discrimination in the gerbil: Transfer and antagonism. Psychopharmacology 49:33–40
Jarbe TUC (1978) Discriminative effects of morphine in the pigeon. Pharmacol Biochem Behav 9:411–416
Jarbe TUC, Ohlin GC (1979) Discriminative effects of combinations of Δ9-tetrahydrocannabinol and pentobarbital in pigeons. Psychopharmacology 63:233–239
Johansson JO, Jarbe TUC (1975) Antagonism of pentobarbital induced discrimination in the gerbil. Psychopharmacologia 41:225–228
Krimmer EC (1974) Drugs as discriminative stimuli. Dissertation Abstr Internal 35:4572-B
Krimmer EC, Barry H, III (1973) Differential stimulus characteristics of alcohol and pentobarbital in rats. Proc Am Psychol Assoc 8:1005–1006
Krimmer EC, Barry H, III (1979) Pentobarbital and chlordiazepoxide differentiated from each other and from nondrug. Comm in Psychopharmacol 3:93–99
Krimmer EC, Barry H, III, Coltrin D (1978) Antagonism of pentobarbital discriminative stimulus by bemegride in immobilized rats. In: Colpaert FC, Rosecrans JA (ed) Stimulus properties of drugs: Ten years of progress. Elsevier/North Holland Biomedical Press, Amsterdam, p 167
Leberer MR, Fowler SC (1977) Drug discrimination and generalization in pigeons. Pharmacol Biochem Behav 7:483–486
Martin WR, Eades CG, Thompson JA, Huppler RE, Gilbert PE (1976) The effects of morphine- and nalorphine-like drugs in the non-dependent and morphine-dependent chronic spinal dog. J Pharmacol Exp Ther 197:517–532
Myslobodsky MS, Ackermann RF, Engel J, Jr (1979) Effects of γ-acetylenic GABA and γ-vinyl GABA on metrazol-activated, and kindled seizures. Pharmacol Biochem Behav 11:265–271
Nemeth MA (1979) Benzomorphan drugs: effects on operant behavior and antagonism by naloxone. Paper presented at the American Psychological Association. New York, NY
Overton DA (1966) State-dependent learning produced by depressant and atropine-like drugs. Psychopharmacologia 10:6–31
Overton DA (1975) A comparison of the discriminable CNS effects of ketamine, phencyclidine, and pentobarbital. Arch Int Pharmacodyn Ther 215:180–189
Overton DA (1977) Comparison of ethanol, pentobarbital, and phenobarbital using drugs vs. drug discrimination training. Psychopharmacology 53:195–199
Schaefer GJ, Holtzman SG (1977) Discriminative effects of morphine in the squirrel monkey. J Pharmacol Exp Ther 201:67–75
Schaefer GJ, Holtzman SG (1978) Dicriminative effects of cyclazocine in the squirrel monkey. J Pharmacol Exp Ther 205:291–301
Shannon HE, Holtzman SG (1976) Evaluation of the discriminative effects of morphine in the rat. J Pharmacol Exp Ther 198:54–65
Shearman G, Lal H (1978) Discriminative stimulus properties of pentylenetetrazol in the rat. In: Colpaert FC, Rosecrans JA (eds) Stimulus properties of drugs: Ten years of Progress. Elsevier/North Holland Biomedical Press, Amsterdam, p 181
Shearman G, Lal H (1979) Discriminative stimulus properties of picrotoxin, bemegride and pentylenetetrazol: A possible relationship between an anxiogenic action and pentylenetetrazol discriminative stimulus. Fed Proc 38:256
Trost JG, Ferraro DP (1974) Discrimination and generalization of drug stimuli in monkeys. In: Singh JM, Lal H (eds) Drug additction, vol 3: Neurobiology and influences on behavior, Stratton, New York, p 223
Valentino RJ, Herling S, Woods JH, Medzihradsky F, Merz H (1980) Comparison between narcotic antagonists and their quaternary derivatives. Fed Proc 39:760
Witkin JM, Carter RB, Dykstra LA (1980) Discriminative stimulus properties of d-amphetamine-pentobarbital combinations. Psychopharmacology 68:269–276
Woods JH, Herling S, Valentino RJ, Hein DW, Coale EH (1979) Narcotic drug discriminations by rhesus monkeys and pigeons. In: Harris LS (ed) Problems of drug dependence 1979: Proceedings of the 41st Annual Scientific Meeting, The Committee on Problems of Drug Dependence, Inc. NIDA Research Monograph 27, US Govt Printing Office, Washington, p 128
York JL (1978) A comparison of the discriminative stimulus effects of ethanol, barbital, and phenobarbital in rats. Psychopharmacology 60:19–23
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Herling, S., Valentino, R.J. & Winger, G.D. Discriminative stimulus effects of pentobarbital in pigeons. Psychopharmacology 71, 21–28 (1980). https://doi.org/10.1007/BF00433247
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00433247