Figure 6.
Synaptic release in striatal neuronal cultures. A, Representative traces of evoked IPSC in both WT and synaptotagmin-2 KO. AP, Action potential. Pooled data for both amplitude (B) and charge transfer over a time period of 1.5 s (C). D, Normalized average charge integration as a function of time over 1.5 s. WT, n = 16; KO, n = 17. The integrated charge transfer can be well fitted by a double exponential function (black solid line superimposed on to the integrated lines). The fitting gave out a fast decay (τfast) and slow decay (τslow). E, F, Pooled data indicate both τfast and τslow increased in synaptotagmin-2 KO striatal synapses. G, The fraction of the slow constituent (Aslow) increased in KO synapses, and fast constituent (Afast) decreased accordingly. Numbers of neurons recorded are indicated by numbers within each bar. H, Representative traces of sIPSCs in both WT and synaptotagmin-2 KO mice. There are no significant differences in average sIPSC amplitudes (I), 20–80% rise time (J), and 80–20% decay time (K). Events with amplitudes >150 pA, possibly attributable to spontaneous firing of presynaptic neurons, are excluded from analyses. Error bars indicate SEM. *p < 0.05; **p < 0.01.