Authors: Simin Khavandgar Houman Homayoun Mohammad Reza Zarrindast
Publish Date: 2003/03/28
Volume: 167, Issue: 3, Pages: 291-296
Abstract
To examine the effect of the NO synthase NOS inhibitor NGnitrolarginine methyl ester lNAME and NOS substrate larginine on morphineinduced impairment of memory formation and the statedependent retrieval of a passive avoidance task learned under morphine influenceAll drugs were administered intraperitoneally and a onetrial stepdown paradigm was used for the assessment of memory in adult male NMRI mice Morphine was administered 30 min before training to induce impairment of memory formation and 30 min before test to induce statedependent retrieval of the memory acquired under pretraining morphine influence lNAME or larginine was administered either 5 min after training or 45 min before the testPretraining morphine induced impairment of memory formation that was reversible by pretest morphine but not saline Posttraining administration of larginine 200 mg/kg and lNAME 3 10 and 30 mg/kg respectively facilitated and impaired the memory consolidation but their pretest injections did not affect retention However posttraining larginine at per se noneffective doses of 20 mg/kg and 60 mg/kg reversed the morphineinduced impairment of memory formation Pretest administration of lNAME 3 mg/kg and 10 mg/kg could restore the memory impairment induced by pretraining morphine and this effect was blocked by concomitant pretest larginine 60 mg/kg Concomitant administration of low doses of lNAME 1 mg/kg and morphine 05 mg/kg pretest also revealed an additive effect in restoring the morphine state of memory
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