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 an d examined their regrowth during the first complete growth period in normal and nerve-lesioned rats. The lesions used were denervation through neonata l capsaicin treatment, surgical sympathecomy in adult rats, neurectomy of t he mandibular and buccal branches of the facial nerve in adult rats or divi sion of the infraorbital nerve in adult rats. Normal vibrissae developed a length of 51.1 mm and a diameter of 170 mu m (row alpha-delta), 44.1 mm and 181 mu m (row 1) and 33.2 mm and 165 mu m (row 2). In all experimental gro ups the examined vibrissae developed a normal final length and proximal dia meter. This indicates that local nerves do not influence vibrissal growth t o any major extent. (C) 1999 Published by Elsevier Science Ireland Ltd. All rights reserved.