Intraaccumbens administration of NMDA receptor antagonist (+/-)-CPP prevents locomotor activation conditioned by morphine and amphetamine in rats.
In the present experiments the influence of NMDA receptor antagonist (+/-)-CPP on morphine- and amphetamine-conditioned activation of locomotor activity was studied in rats chronically implanted with bilateral cannulas in the nucleus accumbens septi. Animals were conditioned by pairing subcutaneous injections of morphine (3.0 mg/kg), amphetamine (1.5 mg/kg), or saline with a distinctive environment. Following the five drug-environment pairings, rats displayed significant increase in locomotion when exposed to the drug-paired environment. The expression of this conditioned response was completely prevented by the bilateral intraaccumbens pretreatment with (+/-)-CPP (1.0, but not 0.1 or 0.3 microgram/ microliter/side). These findings suggest that the locomotor hyperactivity conditioned by morphine and amphetamine involves the activation of NMDA receptors within the nucleus accumbens.
Bespalov
A Y
AY
Department of Pharmacology, Pavlov Medical University, St. Petersburg, Russia.
Zvartau
E E
EE
D000661:Amphetamine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000701:Analgesics, Opioid / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D000697:Central Nervous System Stimulants / Q000037:antagonists & inhibitors / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000187:drug effects; D018691:Excitatory Amino Acid Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D007267:Injections; D008297:Male; D009020:Morphine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects*; D009714:Nucleus Accumbens / Q000033:anatomy & histology / Q000502:physiology*; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*
D000701:Analgesics, Opioid; D000697:Central Nervous System Stimulants; D018691:Excitatory Amino Acid Antagonists; D010879:Piperazines; D016194:Receptors, N-Methyl-D-Aspartate; D009020:Morphine; C050592:3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid; D000661:Amphetamine