(A,B) a-bungarotoxin-alexa555 labeled post-synaptic endplates from Tuba1aND/+ and Tuba1aND/ND diaphragms reveals synapse patterning defect in Tuba1aND/ND. Scalebar = 200 μm. (C,D) Higher magnification of abungarotoxin-alexa555 labeled post-synaptic endplates from Tuba1aND/+ and Tuba1aND/ND diaphragms. Scalebar = 20 μm. (E,F) Examples of sharp electrode recordings of Tuba1aND/+ and Tuba1aND/ND diaphragms. Endplate potential (EPP) labeled by black arrow. Asynchronous event (asynch event) is labeled with black arrowhead. (G) Quantification of EPP amplitude in Tuba1aND/+ and Tuba1aND/ND diaphragms. Values are the mean from 22 EPPs from 5 Tuba1aND/+ diaphragms, and 26 EPPs from 5 Tuba1aND/ND diaphragms. Asterisks indicate significant difference, by t-test (p < 0.05). (H) Quantification of asynchronous events during a 30 s period after evoked EPP. Values are the mean from 20 measurements from 5 Tuba1aND/+ diaphragms, and 23 measurements from 5 Tuba1aND/ND diaphragms. Asterisks indicate significant difference, by t-test (p < 0.05).