Figure 5.

(A) Wild-type mice cortical synaptosomes preloaded with radioactive tracer were incubated with several stimuli in absence or presence of JGRi1 or sJGRi1, as indicated. The experiment demonstrated that, among the applied stimuli, JGRi1 is able to specifically inhibit only the NMDA-evoked glutamate release in a dose dependent manner, while scramble peptide is not. Means ± s.e.m. n = 3 experiments run in triplicate (three superfusion chambers for each experimental condition), **p < 0.01 vs. basal release; Newman-Keuls’s test. (B) Exocytosis evoked by KCl (8 mM) or NMDA (100 μM) + glycine (1 μM) stimuli has been evaluated in cortical synaptosomes as a measure of FM1-43 destaining in time-lapse image experiments. Pretreatment with JGRi1 at different concentrations given 30 min before the registration specifically reduced NMDA-evoked exocytosis. Average percentage of fluorescence loss has been reported in the histograms. Means ± s.e.m. n = 5, **p < 0.01 vs. control; Newman-Keuls’s test. In each experiment three coverslips for each experimental group were analysed. (C) Histograms show the median values expressed as percentage versus control (100%) of mEPSC amplitude (left) and iei (right) recorded in vehicle, JGRi1 (1-10 μM) or scrambled condition (sJGRi1 10 μM), in response to D-AP5. mEPSCs were detected in the presence of extracellular tetrodotoxin (TTX, 1 μM), picrotoxin (PTX, 100 μM) and MK-801 (10 μM) in the patch-pipette (in order to block NMDA receptors in the cell recorded). Means ± s.e.m. n = 8, **p < 0.01 vs. ctrl, #p < 0.05 vs. JGRi1 (1 μM), t-test).