Figure 2. ASIC3-expressing DRG afferent neurons in muscle and proprioceptors.

(a,b) eGFP immunofluorescence in horizontal sections of gastrocnemius muscle is low in wild-type but high in Asic3Δ^EGFPf/EGFPf mice. Scale bar, 200 μm. (c–e) eGFP and the nerve marker PGP9.5 co-localize in the nerves of gastrocnemius muscle (transverse section: scale bar, 100 μm). (f–h) eGFP is present in most (∼90%) parvalbumin positive, large diameter neurons in the lumbar DRG of the Asic3Δ^EGFPf/EGFPf mice, as well as many smaller, parvalbumin-negative somata. Scale bar, 200 μm. (i–k) Co-localization of GFP and myelinated-nerve marker neurofilament heavy chain (NF-H) in annulospiral endings characteristic of spindles in the soleus muscle of an Asic3Δ^EGFPf/EGFPf mouse (scale bar, 50 μm). (l–n) Co-localization of GFP and NF-H in the Golgi tendon organs from an Asic3Δ^EGFPf/EGFPf mouse embryo's gluteus muscle (scale bar, 50 μm).