Denervation does not affect the growth of rat vibrissae

This study examines the hypothesis that neural factors influence the growth of rat vibrissae. We divided the vibrissae in rows alpha-delta, 1 and 2 and examined their regrowth during the first complete growth period in normal and nerve-lesioned rats. The lesions used were denervation through neonatal capsaicin treatment, surgical sympathecomy in adult rats, neurectomy of the mandibular and buccal branches of the facial nerve in adult rats or division of the infraorbital nerve in adult rats. Normal vibrissae developed a length of 51.1 mm and a diameter of 178 microm (row alpha-delta), 44.1 mm and 181 microm (row 1) and 33.2 mm and 165 microm (row 2). In all experimental groups the examined vibrissae developed a normal final length and proximal diameter. This indicates that local nerves do not influence vibrissal growth to any major extent.