Figure 1.

Synaptophysin is required to sustain SV fusion events during repetitive stimulation. Primary cultures of synaptophysin knockout hippocampal neurons were transfected with vGLUT1‐pHluorin and either empty mCerulean (KO) vector or synaptophysin‐mCerulean (syp). Neurons were challenged with four trains of 300 action potentials delivered at 10 Hz at 5‐min intervals as shown in (a). (b) Representative traces of the evoked vGLUT1‐pHluorin response (ΔF/F₀ ± SEM) in synaptophysin knockout neurons expressing either mCer (KO, black) or syp (syp, red) are displayed. Traces are normalised to the peak amplitude response during the first‐action potential train. Bar indicates period of stimulation. (c) Bar graph displaying the mean peak amplitudes of the vGLUT1‐pHluorin peak for each of the four trains of stimuli, calculated as a proportion of the first train. Bars indicate SEM (n = 4 KO, n = 5 syp; repeated measures two‐way anova with Sidak’s multiple comparison test, **p < 0.01; train 1 p > 0.9999, train 2 p = 0.9859, train 3 p = 0.0985, train 4 p = 0.0086. n indicates a single field of view from a single coverslip; assays were repeated across two independent cultures from independent animals).