Many N52-identified nerve fibers lack myelin staining within different regions of the human dental pulp. A and B. Confocal micrographs showing N52 (red) and myelin basic protein (MBP; green) staining relationships in the coronal region (A; longitudinal plane) and in nerve fiber bundles located in the center of the radicular area (B; cross-section). Both images show the presence of N52-identified nerve fibers that lack myelin (arrowhead) and fibers with myelin (arrow). The nerve fibers without myelin are common in both pulpal regions but more so within the coronal region. The outline shown in A indicates the approximate position of the odontoblastic layer. Scale bar, 20 μm.