Terminal arborization of individual sensory axons in dentin and pulp of rat molars.

Single sensory arbors labeled by axonal transport of [3H]proline were identified in rat molars and reconstructed from serial autoradiograms. Some axons ended in pulp, other made numerous endings in both dentin and pulp. Receptive fields in dentin varied from narrow (40-60 micrometers diameter) to elongated areas (80 x 350 micrometers). Sensory arbors had brush-like or fan-like shapes, the largest innervated more than 100 dentinal tubules.