FIGURE 3.

Distribution of GRP-ir fibers in the trigeminal nuclei and spinal dorsal horn of the adult macaque monkey, (a–l) Distribution of GRP-ir fibers in the trigeminal nuclei, (a, d, g, and j) show toluidine blue stained sections to visualize the localization of cell bodies. GRP-ir fibers were rare in the principal sensory trigeminal nucleus (PrV) (a–c),oral part of the spinal trigeminal nucleus (Sp50) (d–f), and interpolar part of the spinal trigeminal nucleus (Sp5l) (g–i). GRP-ir was dense in the caudal part of the spinal trigeminal nucleus (Sp5C) (j–l). (c, f, i) and (I) are enlargements of the boxed areas in (b, e, h) and (k), respectively. Bars = 1 mm (j, k); 100 μm (l).6N,abducens nucleus; 7N, facial nucleus; 7n, facial nerve; Cu, cuneate nucleus; DRt, dorsal reticular nucleus; ECu, external cuneate nucleus; Gi, gigantocellular reticular nucleus; icp, inferior cerebellar peduncle; LRt, lateral reticular nucleus; ml, medial lemniscus; MVe, medial vestibular nucleus; PrV, principal part of the trigeminal nucleus; py, pyramidal tract; RMg, raphe magnus nucleus; sp5, spinal trigeminal tract; Sp5C, caudal part of the trigeminal nucleus; Sp5l, interpolar part of the trigeminal nucleus; Sp50, oral part of the trigeminal nucleus; Sol, solitary nucleus; VRt, ventral reticular nucleus, (m–p) Distribution of GRP-ir fibers in the spinal dorsal horn of adult male macaque monkeys. GRP-ir fibers were observed in the cervical (m), thoracic (n), lumbar (o), and sacral (p) levels in the superficial laminae of the spinal dorsal horn. Bar= 200 μm (p)