(A–F) Round and long non-peptidergic central arbors seen in top-down whole mount (A, C, D, F) and transverse section (B and E) spinal cords. Round arbors are in the medial lumbar enlargement (B and C) while long arbors are in the lateral lumbar enlargement and thoracic spinal cord (B–F). Dorsal roots are outlined and labeled in C. Red dashed lines outline the round arbor zone. Orange arrowhead marks a round arbor, purple arrowheads mark long arbors. M, medial. L, lateral. R, rostral. C, caudal. (G) Round and long (defined by ratio in H) arbor areas are comparable for all regions. (H) Arbor Width/Height ratios by ganglion of origin. Round terminals: W/H > 0.2. n = 368 arbors from seven animals (I) Comparison of the number of labeled arbors in the hind limb digit and plantar paw skin with the number of ipsilateral round arbors in the dorsal horn. n = 4 animals, dotted line shows 1:1 relationship. r, p values from Spearman’s rank correlation test. (J) Illustration showing the distribution of round (orange zone) and long (purple zone) arbors in the spinal cord. Scale bars = 50 µm (A and B, D and E), 250 µm (C and F).