Figure 4.

Polylysine motif mutants have a decreased release probability compared with transgenic controls. EJPs were evoked by 30 s of 10-Hz stimulation in 1.5 mM (A) or 2.0 mM (B) extracellular Ca²⁺. EJP amplitudes were normalized to the amplitude of the EJP evoked by the first pulse and then averaged. After the first nine points, the points plotted are averages of 10 EJPs. Polylysine motif mutants: gray triangles, n = 6 fibers for 1.5 mM Ca²⁺ and n = 9 fibers for 2.0 mM Ca²⁺. Transgenic controls: black circles, n = 6 fibers for 1.5 mM Ca²⁺ and n = 10 fibers for 2.0 mM Ca²⁺. Error bars are SEM.