Figure 3.

Schematic representation of the structural components of the piloneural collar mechanoreceptor. Sensory projections from dorsal root ganglion neurons innervate the isthmus/upper bulge region of hair follicles in the pelage skin in circumferential (CF) and longitudinal (LF) patterns. The terminal endings of these sensory afferents are tightly associated with the upward processes of terminal Schwann cells (tSCs; red). Both the fibers and tIISC processes are associated with the outer root sheath keratinocytes in the hair follicle. The four types of pelage follicles, zigzag, awl, auchene, and guard, and the accompanying afferent combinations are shown. Bg, bulge; CF, circumferential fibers; IFE, interfollicular epidermis; Is, isthmus; LF, lanceolate fibers; SG, sebaceous gland.