Fig. 6. Denervation increases the removal rates of recycled and pre-existing AChRs at the NMJ. (A) AChRs at denervated NMJs were first labeled with BTX-biotin/strept-488, and 3 days later recycled AChRs were labeled with strept-594. Fluorescence signals from both receptor pools were then imaged, and re-imaged 1 day later. (B) Bar graph showing the lifetime of recycled and pre-existing AChRs from the same synapses as assessed by the change in fluorescence over the 1-day period. In innervated synapses, recycled AChRs had an average half-life of 28 hours, whereas pre-existing AChRs had an average half-life of 102 hours. In denervated synapses, recycled AChR half-life dropped to 15 hours, and pre-existing AChR half-life decreased by the same proportion to 48 hours. Scale bar: 20 µm.