Arcaine and MK-801 make recall state-dependent in rats
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The polyamines putrescine, spermidine, and spermine are a group of aliphatic amines that may act as physiological modulators of the N-methyl-d-aspartate (NMDA) receptor, a glutamate receptor implicated in memory formation and consolidation. Arcaine is a competitive antagonist of the polyamine binding site at the NMDA receptor, the post-training administration of which impairs memory of various tasks.
In this study, we investigated whether the administration of arcaine and MK-801 alters the memory of the step-down inhibitory avoidance task, and whether the effects of these NMDA antagonists involve state-dependency mechanisms, in adult male Wistar rats.
The administration of arcaine (30 mg/kg, i.p.) or MK-801 (0.03 mg/kg, i.p.) immediately after training impaired inhibitory avoidance performance at testing. Arcaine- and MK-801-induced performance impairment was reversed by the administration of arcaine (30 mg/kg, i.p.) and MK-801 (0.03 mg/kg, i.p.), respectively, 30 min before testing. Response transfer also occurred if arcaine substituted MK-801 at testing, and vice-versa.
These results suggest that arcaine and MK-801 induce state-dependent recall and that, probably due to their ability to decrease NMDA receptor function, one drug can substitute for the other at testing, demonstrating a cross-state dependency between arcaine and MK-801.
KeywordsPolyamines Arcaine NMDA receptor MK-801 Memory State dependence
The authors thank Dr. Juliano Ferreira for the helpful suggestions, and Paulino Aguiar and Rinaldo Moreira for competent technical support. This study was supported by CNPq (475131/04-5, 477836/2007-0). K Camera is recipient of a CAPES fellowship CF Mello and MA Rubin are recipients of CNPq productivity fellowships (500120/2003-0, 500096/2003-1, 301558/2007-8). All the experiments complied with the current laws of Brazil.
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