Induction of Follicle Formation and Hair Growth by Vibrissa Dermal Papillae Implanted into Rat Ear Wounds: Vibrissa-Type Fibres Are Specified

The study demonstrated that adult vibrissa follicle dermal papillae could induce hair growth and follicle formation when implanted into small incisional cuts on rat ear pinnae. The resulting hair fibers were abnormally large and exhibited vibrissa-type characteristics, indicating that the papillae interacted with the wound epidermis to produce new follicles. Histological and immunohistochemical analyses showed that early follicle construction involved a significant presence of laminin and type IV collagen in the dermis. These findings suggested that adult rat papillae retained the ability to determine vibrissa specificity in induced follicles, similar to embryonic dermis.