Substance P, enkephalins, somatostatin, cholecystokinin, oxytocin, and vasopressin in human spinal cord

Abstract

Several neuropeptides were immunohistologically studied in normal human spinal cords. Substance P, methionine-enkephalin, leucine-enkephalin, and cholecystokinin positive fibers were found in all cytoarchitectonic layers, with a specific distribution pattern for each peptide. Somatostatin, oxytocin, and vasopressin immunoreactivities were restricted to particular spinal layers. Perikarya and proximal dendrites were visualized and classified by comparison with previous Golgi analyses. Substance P was contained in "radiate cells" of layer III, methionine-enkephalin in marginal neurons as well as in layer II "stellate cells," and somatostatin in layer II "islet cells." Several results differed from those reported in other species. Chemical neuroanatomy may provide new insights into the neuronal organization of the human spinal cord.

Elevated Cerebrospinal Fluid Substance P Concentrations in Posttraumatic Stress Disorder and Major Depression

“…Numerous experiments over subsequent decades led to the characterization of an 11-amino acid peptide, substance P (2), now recognized to be the preferred ligand at the neurokinin-1 receptor (3,4). Human CNS tissue exhibits a heterogeneous distribution of neurokinin-1 receptors that is especially enriched throughout the spinal cord, brainstem, and limbic system (5)(6)(7)(8)(9)(10)(11). Among its many actions, substance P has a major role in facilitating or transmitting nociceptive and stressful stimuli in the CNS (12)(13)(14).…”

Brain control of penile erection

“…The SPN neurons synthesize and release a variety of neuromediators, and they receive synaptic contacts from a variety of ®bers. Among others, acetylcholine, calcitonin gene-related peptide (CGRP) [55], cholecystokinin, dynorphin [64], enkephalin [67], galanin [56], glutamate [3], nitric oxide (NO) [12,18,63,82,84,85], oxytocin [79,83], serotonin, somatostatin [64,67,68], and substance P [55, 64,67] are neurochemicals that are likely to govern the activity of SPN neurons. An illustration of that is the demonstration of synaptic contacts between oxytocinergic terminals and sacral preganglionic neurons [79] or spinal neurons connected to the penis in rats [83].…”

“…Oxytocin terminals make synaptic contacts on IML neurons [62], and oxytocin binding sites have been described in the same location [59]. In the SPN, although oxytocinergic ®bres are sparse, they make synaptic contacts onto sacral preganglionic neurons [67,77,79]. In the rat lumbosacral spinal cord, binding sites-speci®c to OT-receptor labelling have been demonstrated in the super®cial dorsal horn, SPN and DGC [83].…”

Spinal control of penile erection

“…Dopaminergic fibers also run in the SPN [151]. Calcitonin gene-related peptide (CGRP) terminals and bombesin-, somatostatin-, substance P-, vasoactive intestinal polypeptide (VIP)-, and enkephalin-positive fibers are apposed to or run in the vicinity of SPN neurons [21,117,126,144,177]. SPN also receives a dense neuropeptide Y (NPY) innervation [140].…”

“…Cholecystokinin neurons present in the intermediate gray and the dorsal horn of the lumbosacral spinal cord contribute fibers to the SPN [146]. Oxytocinergic fibers are sparse in the SPN [144,162] and make synaptic contacts onto sacral preganglionic neurons [163]. Furthermore, specific oxytocin receptors have recently been evidenced in the SPN [170].…”