Figure 7.
Silencing of transmitter release reduces α7–nAChR mobility inside presynaptic terminals. The mobility of α7–nAChRs on hippocampal neurons in culture was assessed with QDs as in Figure 1. Mobility on neurons with normal synaptic activity (transfected with Sph–GFP) was compared with those on neurons in which transmitter release was silenced (transfected with TeT/Sph–GFP). A, Median Di ± 25–75% IQR of α7–nAChR–QD complexes in synaptic (Syn) and extrasynaptic (Extra) spaces on neurons transfected with Sph–GFP (Ctrl) or TeT/Sph–GFP (TeT). Silencing of transmitter release significantly decreased the mobility of synaptic receptors specifically inside terminals (n = 50, 55 and 118, 149 for synaptic and extrasynaptic trajectories of Ctrl and TeT conditions, 3 culture sets for each; Mann–Whitney test, ***p < 0.001). B, Synaptic silencing reduces the dwell time of α7–nAChR–QDs inside terminals (n = 12 and 22 QDs from 3 culture sets for Ctrl and TeT, respectively; mean ± SEM; Student's t test, ***p < 0.001).