Fig. 5.

Synapsin injection increases PTP without changing basal ACh release. A, Effects of synapsin I injection on basal release. A representative experiment of a series of six is illustrated. Dephosphorylated synapsin I was injected at an estimated final concentration in the soma of 0.5–1 μm. The experiments and data presentation are as described in Figure 2. ● and ○ denote IPSC amplitude from synapsin I-injected and noninjected neurons, respectively. B, C, The mean amplitude of IPSCs and the mean IPSC rise time evoked from synapsin-injected (black bars; n = 6) and buffer-injected (gray bars;n = 6) neurons after the injection are reported as a percentage of the IPSC amplitude and rise time determined before injection. D–F, Effects of synapsin I injection on PTP. D, Typical PTP recorded 300 min before (top panel) and 320 min after (bottom panel) synapsin injection. Same presentation as in Figure 3A. E, PTP amplitude was followed as a function of time after the injection (arrow) of synapsin. Presentation of data is as in Figure 3B. F, Means (±SEM) of the PTP amplitudes observed after synapsin (black bars) or buffer (gray bars) injection.n = 5 at +300 min and n = 3 at +480 min for synapsin-injected neurons, and n= 3 at both +300 min and +480 min for buffer-injected neurons. Statistical analysis was performed by using two-way ANOVA followed by Tukey–Kramer test. **p = 0.026 versus buffer injection on PTP amplitude. n.s, Not significant.