FIG. 7.

A single 5-min agrin pulse leads to efficient AChR clustering that is not affected by CGP77675 (CGP). In the presence or absence of CGP77675, C2 myotubes were continuously treated with 0.5 nM agrin for 8 h or for 5 or 40 min followed by withdrawal of agrin for 8 h. AChRs were stained with rhodamine-α-BT and were analyzed by fluorescence microscopy. Scale bar, 40 μm. (B) The numbers of AChR clusters per myotube are shown as the percentage of untreated cells (C, control) (means ± SEM of at least five experiments). An asterisk indicates that the result differs significantly from that of the control (P < 0.01) but not from each other (P > 0.09; two-tailed paired t test).