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Fig. 3. Afferent and efferent innervation of transplanted ears. (A) Transplanted ear that had dextran amine (red) injected into the spinal cord. Autofluorescence of the tissue is green. Inset: higher magnification of boxed area. (B) Transplanted ear that had lipophilic dyes injected into the spinal cord rostral (red) and caudal (green) to the ear. (C) Acetylated tubulin immunostaining (red) of boxed area in B showing ganglion cells apposed to hair cells. Autofluorescence of the tissue is green. (D) Cells in the ventral spinal cord positive for dextran amine dyes that had been injected into the transplanted ear. (E) Neuromasts in the skin showing vesicular acetylcholine transporter (VAChT)-positive terminals on the hair cells. Autofluorescence is blue. (F) Hair cells in a control ear immunostained for acetylated tubulin and VAChT. (G) Transplanted ear that had lipophilic dye injected ventral to the spinal cord show nerve fibers extending to the ear. (H) Transplanted ear in G immunostained for acetylated tubulin. (I) Transplanted ear in G immunostained for acetylated tubulin and VAChT. Inset: higher magnification of boxed area. Red arrows indicate VAChT immunostaining. (J) Transplanted ear immunostained for acetylated tubulin and VAChT. Inset: single optical section of VAChT staining (red arrows) at the base of hair cells. (K) Electron micrograph of an afferent terminal on a hair cell. A synaptic ribbon (arrow) is observed on the hair cell above the afferent terminal (L) Electron micrograph of an efferent terminal with vesicles (circled) making a synapse on a hair cell. These TEM images were obtained from ears previously processed for immunohis- tochemistry to confirm the presence of VAChT, hence poor preservation of membranes. GC, ganglion cell; HC, hair cell; MN, motor neuron cell body; NM, neuromasts; Aff, afferent terminal; Eff, efferent terminal; V, vesicles; Mt, mitochondria. Scale bar is 100 um in (A,B,C,D,G,H); 25 um in (E,F,I,J) and 1 um in (K,L). |
