Mystixin-7 Peptide Protects Ionotropic Glutamatergic Mechanisms against Glutamate-Induced Excitotoxicity In Vitro

Figure 3

Neuroprotective effects pretreatment of slices by MTX at concentration 50 mg/mL on AMPARs (a) and NMDARs (b) activities at the action of L-glutamate in toxic concentration (20 mM). The left parts of the schedule (in (a) and (b)) show changes in the averaged amplitudes of AMPA and NMDA EPSP under the action MTX in concentration 50 mg/mL. Black columns indicate the beginning and the termination of L-glutamate action. Duration of L-glutamate action was 20 min. This time range has been used by us because according to the data presented in Figure 1(b) the maximum activating effects of glutamate in a toxic concentration of 20 mM on both NMDA and AMPA EPSP were at this duration of agonist exposure. “Wash, 20 min”: washing slices by aCSF during 20 min. Horizontal dotted line (in (a) and (b)) means the control values of the NMDA and AMPA EPSP amplitudes (without MTX and glutamate) before MTX application, and on the -axis it is marked for “C, control” and the subsequent action of L-glutamate as well as at washing process. The data are presented as percentage of control condition and represent means ± SEM of five independent experiments performed in different slices and analyzed statistically by -test, Wilcoxon-Mann-Whitney matched pairs signed-rank test. , number of slices per time point. , significantly different from control. Note that suppression of hyperactivation of AMPARs and NMDARs induced L-glutamate at pretreatment of slices with this peptide. Recovery of the AMPARs and NMDARs activities at washout reached the control level.

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