Effects of amphetamine, morphine and dizocilpine (MK-801) on spontaneous alternation in the 8-arm radial maze.
The induction of psychomotor activation, behavioural sensitization and of perseverative behaviours, resulting in reduced behavioural variability, have been proposed to be common properties of drugs of abuse. The present investigation tested whether these drug effects could be measured using spontaneous alternation in an 8-arm radial maze. Behavioural effects of repeated treatment with amphetamine (2 and 4 mg/kg, i.p.), morphine (1.25 and 10 mg/kg, i.p.) and the non-competitive NMDA receptor antagonist, MK-801 (0.1 and 0.2 mg/kg, i.p.), on spontaneous alternation were evaluated in this paradigm. All drugs induced psychomotor activation. Sensitized as well as reduced locomotor activity could be observed after repeated treatment depending on drug and dose. Analysis of the sequences of arm entries revealed that all drugs induced perseverative locomotor patterns, but the pattern induced by amphetamine and morphine differed qualitatively from the pattern induced by MK-801.
Hölter
S M
SM
Department of Neuropharmacology, University of Tübingen, Germany. hoelter@mpipsykl.mpg.de
Tzschentke
T M
TM
Schmidt
W J
WJ
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D000697:Central Nervous System Stimulants / Q000494:pharmacology*; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*; D009294:Narcotics / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013268:Stimulation, Chemical
D000697:Central Nervous System Stimulants; D018691:Excitatory Amino Acid Antagonists; D009294:Narcotics; D016291:Dizocilpine Maleate; D009020:Morphine; D000661:Amphetamine