Table 1.

AChR half-life and labeling intensity by Rh-BuTx at ectopic neural agrin-induced AChR aggregates and at normal NMJs

DNA efficiency	Stimulation	Pixel intensity at day 0	Half-life, days	n
Low	No	0.23  ± 0.07	0.86	28–64
Low	Yes		3.75*	14–64
Medium	No	0.27  ± 0.01	3.68	18–65
Medium	Yes		5.39*	17–65
High	No	0.47  ± 0.05	10.25	15–38
High	Yes		9.90	13–34
Original endplates		1.93  ± 0.08	11.10	30

SOL muscles were denervated and injected with neural agrin cDNA of different transfection efficiencies. Eight days later (day 0), Rh-BuTx was injected and mean pixel intensity at agrin-induced AChR aggregates was measured that day. Electrodes were implanted on day 0 and mean pixel intensity measured on subsequent days to determine the AChR half-life in stimulated and unstimulated muscles. Pixel intensity ± SEM; n, number of AChR aggregates examined. 

^*Significant difference (P < 0.05) between values in unstimulated and stimulated muscles.