Low-dose ethanol ameliorates amnesia induced by a brief seizure model: the role of NMDA signaling

Objective: The present study aimed to evaluate the ameliorative effect of low-dose ethanol (Eth) on amnesia induced by a brief seizure model and the role of N-methyl D-aspartate (NMDA) signaling in this event. Materials and Methods: Four groups of rats (total number = 36; n = 9, each group) were used: control, Eth (0.5 g/kg/i.p.), pentylenetetrazole (PTZ) (60 mg/kg/i.p.), and Eth+PTZ. Eth was administered for 6 days before the single injection of PTZ, at minute dose that cannot induce memory impairment. The consequences of Eth pretreatment, coadministered with PTZ, were studied in an inhibitory avoidance (IA) memory model. The PTZ was injected 30 min prior to the IA memory test. Thereafter, locomotion, liver enzymes, and the Real-time PCR for NR1 subunit of NMDA receptor were studied. The statistical analyses were performed using the parametric/nonparametric ANOVA and the post-hoc tests. Results: Our findings revealed that Eth pretreatment significantly improved the IA memory impairment induced by PTZ (P < 0.001), and indicated no change in locomotion and serum ALT, but significantly differed for AST between the PTZ and PTZ groups (P = < 0.05). The Real-time PCR results indicate the decreased NR1 mRNA expression in Eth and PTZ groups and the increased NR1 mRNA expression in Eth+PTZ group, compared to the control group (P < 0.001); however, the NR1 mRNA expression was increased in the Eth+PTZ group, compared to PTZ group (P < 0.001). Conclusion: The present study provides evidence that the low-dose Eth can improve the amnesia induced by a brief seizure model presumably via NMDA signaling in a rat.