Figure 4.

MPP⁺ incubation induced a decrease of BDNF expression after KCl depolarization and this was prevented by pre-application of memantine (M). (A) Scheme of the in vitro experimental procedure. The slices from control mice were incubated with memantine, NMDA receptor antagonist (AP5), calpain inhibitor (CI-III) or AMPA receptor inhibitor (NBQX) for 20 min, and then treated with MPP⁺, NMDA, or 4 mM Ca²⁺ for 2 h. After washing out the drug for about 20 min, the slices were depolarized by KCl for 3 min. One hour later, the slices were collected for protein assay. (B) Upper panel shows representative blots after different drug treatments. Lower panel shows summary data of BDNF expression after different drug treatments. (C) Left panel shows representative blots after different drug treatments. Right panel shows summary data of BDNF expression after different drug treatments. The data presented are means ± SEM (n = 5). ^$P < 0.05 compared with control group after KCl depolarization; two-way anova followed by Bonferroni test. (D) Direct effect of AP5 or memantine on KCl-induced BDNF expression was analysed as shown in the scheme. (E) Direct effect of AP5 or memantine on KCl-induced BDNF expression. Upper panel shows representative blots after different drug treatments. Lower panel shows summary data of BDNF expression after different drug treatments. The data presented are means ± SEM. Three slices from each animal and a total of three animals in each group were used. *P < 0.05 compared with corresponding basal level; ^$P < 0.05 compared with control group after KCl depolarization; two-way anova followed by Bonferroni test.