Fig. 3.

Synaptic degeneration within axotomized motor units of Wld^S mouse muscle is also asynchronous. (A) Whole-mount montage of a single fluorescent motor unit in a thy1.2YFPH:Wld^S mouse DL muscle, 5 days after tibial nerve section. Only about 5% of motor units express YFP in the YFP-H transgenic line. In this, fortuitous instance, only a single unit (axon indicated by yellow arrow) was fluorescent. In this unit, some NMJs were still fully occupied (B, B′); others were partially occupied (C, C′) or almost vacant (D, D′). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)