Dopamine and opioid regulation of the memory retrieval recovery in mice.
The reactivation effects of the delta-opioid receptor blockade and D2 dopamine receptor activation on the detention-induced memory deficit in mice were investigated, in order to study possible interactions between opioid and dopamine systems in memory retrieval. Animals were trained in a one-trial passive-avoidance task. Pretesting treatment with ICI 174,864 (1, 3 or 5 mg/kg, i.p.) or quinpirole (0.5, 1 or 2 mg/kg, i.p.) facilitated retrieval of memory trace in saline-pretreated mice. Pretraining injection of the dopamine autoreceptor agonist, (+)-3PPP (2 mg/kg), having no effect alone in learning, prevented the ability of ICI 174,864 to produce the memory-enhancing effect. It is suggested that the normal functioning of the dopamine system was critical for the facilitation of retrieval by delta-antagonist. Quinpirole-induced reactivátion of memory retrieval was enhanced by pretreatment with Leu-enkephalin (0.2 mg/kg), inducing increased retention. We discuss these results in the context of an important interactions between D2 dopamine and delta-opioid receptors.
Dubrovina
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Department of Central Mechanisms of Regulation, Siberian Branch of Russian Academy of Medical Sciences, Novosibirsk, Russia. ROOT@SMPHYS.NSK.SU
Ilyutchenok RYu
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D018491:Dopamine Agonists / Q000494:pharmacology; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009292:Narcotic Antagonists / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D019257:Quinpirole / Q000494:pharmacology; D017448:Receptors, Dopamine D2 / Q000819:agonists / Q000502:physiology*; D017465:Receptors, Opioid, delta / Q000819:agonists / Q000502:physiology*
D018491:Dopamine Agonists; D009292:Narcotic Antagonists; D010880:Piperidines; D017448:Receptors, Dopamine D2; D017465:Receptors, Opioid, delta; D019257:Quinpirole; D004743:Enkephalin, Leucine; C040643:N,N-diallyl-tyrosyl-alpha-aminoisobutyric acid-phenylalanyl-leucine; C026539:preclamol