Memory improvement after spreading depression by NMDA blocker as memory destructor

Abstract

Spreading depression (SD) is transient neural hyperexitablity followed by depolarization wave, which propagates/INS; through the brain and modulate electrical gradient and synaptic activity. Data have shown that SD wave distributes/INS; coincidence between neural activity and behavioral activity/INS;. Neural activity and electrical potential effect on memory retrieval have been demonstrated. Inhibitory effect of NMDA receptors in SD procedure can control memory impairment caused by SD. However, the /INS;negative effect of NMDA receptor blockage on memory has/INS; been proven in previous studies. In the present study the /INS;effect of NMDA receptors blockage (MK801) used to evaluate its efficiency in subsiding of SD negative influence on memory. /INS;Wistar rats/INS; (60–/INS;80 g/INS;) were /INS;randomly chosen in 6 groups and (NMDA blocker0.63–/INS;1 mg/kg) were administrated after 3 mol/L KCl injection for induction of repetitive/INS; SD in rat. The groups were evaluated by T-maze test and SD groups /INS;were compared with control groups, including (NMDA blocker 1–/INS;0.63 mg/kg /INS;controls) and sham group. T-maze data have showed that repeated SD could significantly alter memory/INS; retrieval performance. However, in the second week memory enhancement was/INS; induced by SD induction. Repeated SD induction during other weeks indicated/INS; impairment in memory. Application of NMDA blocker showed significantly enhanced /INS;memory retrieval and/INS; could /INS;potentially control memory impairment after SD. /INS;The studies indicated that NMDA blocker may decrease memory performance/INS;, on the other hand the /INS;effect of MK801 on inhibition of SD propagation may somehow weaken memory improvement due to its memory destruction effects.