Fig. 5
DN10 and DN13 enhance DCG-IV effect at mossy fiber terminals in the CA3 hippocampal area. a A schematic view of the hippocampus illustrating the granule neurons of the dentate gyrus (DG) projecting to the pyramidal neurons in the CA3 area via the mossy fibers. b DN10 inhibits the presynaptic calcium transients evoked by electrical stimulation of the mossy fibers (blue arrowhead in a) in the CA3 area (red box in a) and prolonged the inhibitory effect of saturating concentrations of DCG-IV (5 µM) (large inset). In this and all other panels, data are plotted as normalized amplitudes of peak fluorescence transients (∆F/F) evoked by five stimulations of mossy fibers (delivered at 100 Hz). In the inset, data are normalized to the base line to better illustrate the difference in off rate kinetics. c DN13 slows the off rate kinetics of the DCG-IV (5 µM) inhibitory effect. d DN13 potentiates the inhibitory effect of a low concentration of DCG-IV (100 nM) on evoked presynaptic calcium transients. Right inset in d shows the average normalized area corresponding to the depressant effect of DCG-IV alone (black bar, 100 ± 5.4%, n = 10) and in the presence of DN13 (white bar, 578.5 ± 69%, n = 9), P < 0.001. Left inset in c, d and top inset in b display superimposed fluorescence changes in one of these experiments recorded at the indicated times. Each trace in b–d are an average of 10 consecutive trials. Since the variance was different between DCG-IV and DCG-IV + DN13 groups, the Welch test was applied for statistical analysis
