Regrowth of Grafted Human Scalp Hair after Removal of the Bulb

BACKGROUND The bulbar region of the hair follicle contains the dermal papilla, hair germinative epithelial component, and active melanocytes. Thus, it has been assumed that the bulbar region plays a central role in hair growth, differentiation, and pigmentation. OBJECTIVE To assess the regenerative capacity of human hair. METHODS Individual anagen hair follicles were isolated from the occipital scalp and grafted onto the leg after removal of the bulb. RESULTS The grafts of follicles from which the bulb and complete papilla have been excised regenerated new papillae and grew new pigmented hairs. CONCLUSION The middle portion of the outer root sheath and dermal sheath may also contain epithelial, mesenchymal, and melanocyte reservoirs.