Fig. 6.

Patterns of MOC labeling resulting from extracellular injections of neural tracer. Micrograph of the injection site in 1 case (A) and reconstructions of 2 other cases (B and C). In B and C, the dots and fibers represent all labeled MOC endings and tunnel-crossing branches within a half-turn from the injection site. In B, a case with many labeled fibers, the MOC labeling is dense adjacent and apical to the injection site, but it diminishes adjacent to the injection site to become sparse basally (gray arrows). Labeling extends along the organ of Corti for 1,429 μm from the basalmost edge of the labeled peripheral ANFs (gray shaded band). In C, a case with few labeled fibers, the basal labeling consists of only 1 cluster of MOC endings (gray arrow) located 731 μm basal to the ANFs. Ovals indicate labeled cell bodies of the spiral ganglion that give rise to the ANFs. IGSB, intraganglionic spiral bundle.