Abstract
Rats were trained to shuttle between two selected (“ON”) arms of a Y maze, to obtain electrical stimulation of the medial forebrain bundle. Each shuttle response was rewarded with a brief pulse train. Repetitive entries into the same “ON” arm were not rewarded, nor were entries made into the third (“OFF”) arm. Every 67s, stimulation was made available from a different pair of arms. Test sessions lasted for 80 min, beginning immediately after SC injection. Undrugged subjects responded faster, and with a greater proportion of rewarded responses, the higher the stimulation current.
In non-tolerant rats, nicotine (0–0.4 mg/kg) depressed responding and induced ataxia shortly after injection; from 40 min, nicotine increased low rates of responding but decreased high rates. All these effects were dose-dependent. Mecamylamine (2.0 mg/kg) prevented the initial depressant action. With repeated daily injections of nicotine (0.4 mg/kg), a marked stimulant action emerged which replaced the initial depressant action, and this was dose-dependent. However, responding was increased by nicotine even when brain stimulation was not available (“time-out”). In contrast, an additional “rate-free” index based on discrimination showed that nicotine did not augment the rewarding properties of the brain stimulation.
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References
Bennet G, Tyler C, Zaimis E (1957) Mecamylamine and its mode of action. Lancet 2, 218–222
Bignami G, Michalek H (1978) Cholinergic mechanisms and aversively motivated behaviours. Ch. 4 In: Anisman H, Bignami G (eds) Psychopharmacology of aversively motivated behaviour. Plenum, New York, pp 173–256
Clarke PBS, Kumar R (1982) The effects of nicotine on locomotor activity in non-tolerant and tolerant rats. Br J Pharmacol (in press)
Cox DR (1958) Planning of experiments. Wiley, London
De Groot J (1959) The rat forebrain in stereotactic coordinates. Trans R Neth Acad Sci 52:No. 4
Domino EF, Lutz MP (1973) Tolerance to the effects of daily nicotine on rat bar pressing behaviour for water reinforcement. Pharmacol Biochem Behav 1:445–448
Goldberg SR, Spealman RD, Goldberg DM (1981) Persistent high-rate behaviour maintained by intravenous self-administration of nicotine. Science 214 (4250):573–575
Kornetsky C, Esposito RU, McLean S, Jacobson JO (1979) Intracranial self-stimulation thresholds — a model for the hedonic effects of drugs of abuse. Arch Gen Psychiatry 36:289–292
Kuschinksy G, Hotovy R (1943) Über die zentral erregende Wirkung des Nicotins. Klin Wschr 22:649–650
Morrison CF (1967) Effects of nicotine on operant behaviour of rats. Int J Neuropharmacol 6:229–240
Morrison CF, Lee PN (1968) A comparison of the effects of nicotine and physostigmine on a measure of activity in the rat. Psychopharmacology 13:210–221
Morrison CF, Stephenson JA (1972) The occurrence of tolerance to a central depressant effect of nicotine. Br J Pharmacol 46:151–156
Nelson WT, Cox B (1982) Nicotine self-administration in rat. Pharmacol Biochem Behav 15:833
Olds J, Domino EF (1969a) Comparison of muscarinic and nicotinic cholinergic agonists on self-stimulation behaviour. J Pharmacol Exp Ther 166:189–204
Olds J, Domino EF (1969b) Differential effects of cholinergic agonists on intracranial self-stimulation and escape behaviour. J Pharmacol Exp Ther 170:157–167
Pradhan SN (1970) Effects of nicotine on several schedules of behaviour in rats. Arch Int Pharmacodyn Ther 183:127–138
Pradhan SN, Bowling C (1971) Effects of nicotine on self-stimulation in rats. J Pharmacol Exp Ther 176:229–243
Spealman RD, Goldberg SR, Gardner ML (1981) Behavioural effects of nicotine. I. Schedule-controlled responding by squirrel monkeys. J Pharmacol Exp Ther 216:484–491
Stitzer M, Morrison J, Domino EF (1970) Effects of nicotine on fixed interval behaviour and modification by cholinergic antagonists. J Pharmacol Exp Ther 171:165–177
Stone CA, Torchiana ML, Navarro A, Beyer KH (1956) Ganglionic blocking properties of 3-methylaminoisocamphane hydrochloride (mecamylamine): A secondary amine. J Pharmacol Exp Ther 117:169–183
Wanner HU, Bättig K (1966) Wirkung von Nikotin und Amphetamin auf die Selbstreizung bei der Ratte. Helv Physiol Pharmacol Acta 24:C122–124
Winer BJ (1971) Statistical principles in experimental design: Second edition. McGraw-Hill, New York
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Clarke, P.B.S., Kumar, R. Nicotine does not improve discrimination of brain stimulation reward by rats. Psychopharmacology 79, 271–277 (1983). https://doi.org/10.1007/BF00427826
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DOI: https://doi.org/10.1007/BF00427826