Figure 6.

Glutamate release in response to KCl is impaired in Gdi1 KO synaptosomes. (A) Synaptosomes purified from adult WT (n = 12) and KO (n = 12) mice were depolarized with either 15 or 50 mm KCl and the stimulus-evoked overflow of glutamate was expressed in pmol of endogenous glutamate/mg protein. Bars are means ± SEM of six independent experiments. *P < 0.05, Student’s t-test KO versus WT synaptosomes. (B) KCl evokes release of glutamate during repetitive stimulation. Synaptosomes were stimulated with three sequential pulses of 15 mm KCl for 90 s administered at interpulse intervals of 9 min and the spontaneous or evoked release of endogenous glutamate was monitored. Glutamate overflow evoked by each pulse, expressed in percent of the release evoked by the first stimulus, is plotted as means ± SEM for WT and KO synaptosomes (n = 6 independent experiments run in triplicate). *P < 0.05; **P < 0.01; unpaired Student’s t-test KO versus the respective release value in WT synaptosomes.