[Neural pattern and limb development--normal development of the hindlimb nerve in the mouse and its aberrations induced by 5-fluorouracil].

Many ways of approach are available for the elucidation of the pathogenesis of congenital limb malformation. We examined the time course of the development of the nerve pattern in the whole mounted hindlimbs of mouse embryo stained with Karnovsky's method. The normal development and its aberrations induced with maternal administration of 5-fluorouracil at day 10.0 of gestation were studied. The basic development of the nerve pattern in normal limbs and 5-fluorouracil-induced poly-dactylic+ limbs was similar. At the stage of digital ray formation, distal tips of the nerve fibers were still reaching the base of the foot plate. Nerve fibers seem to reach the tip of the digit as a secondary phenomenon following formation of digital rays. These findings indicate that the developmental pattern of nerves in the mouse hindlimb is largely determined by the mesenchyme, rather than by the nerves themselves.