Peripheral specification of sensory connections in the spinal cord.

During development, primary sensory neurons innervate peripheral targets and then form central connections appropriate to these targets. Sensory neurons induced to innervate novel peripheral targets by surgical manipulations in Rana catesbeiana tadpoles form central connections appropriate to their novel targets even when they must project into novel areas of the spinal cord to do so. The selectivity displayed by sensory neurons innervating different peripheral targets suggests that they may acquire distinctive biochemical properties from their targets that endow them with affinities for appropriate central neurons.