Neurochemistry study of spinal cord in non-human primate (Sapajus spp.)

Abstract

The spinal cord is involved in local, ascending and descending neural pathways. Few studies analyzed the distribution of neuromediators in the laminae of non-human primates along all segments. The present study described the classic neuromediators in the spinal cord of the non-human primate Sapajus spp. through histochemical and immunohistochemical methods. Nicotinamide adenine dinucleotide hydrogen phosphate-diaphorase (NADPH-d) method showed neuronal somata in the intermediolateral column (IML), central cervical nucleus (CCN), laminae I, II, III, IV, V, VI, VII, VIII and X, besides dense presence of nerve fibers in laminae II and IX. Acetylcholinesterase (AChE) activity was evident in the neuronal somata in laminae V, VI, VII, VIII, IX, CCN, IML and in the Clarke’s column (CC). Immunohistochemistry data revealed neuronal nitric oxide synthase (nNOS) immunoreactivity in neuronal somata and in fibers of laminae I, II, III, VII, VIII, X and IML; choline acetyltransferase (ChAT) in neuronal somata and in fibers of laminae VII, VIII and IX; calcitonin gene-related peptide (CGRP) was noticed in neuronal somata of lamina IX and in nerve fibers of laminae I, II, III, IV, V, VI and VII; substance P (SP) in nerve fibers of laminae I, II, III, IV, V, VI, VII, VIII, IX, X, CCN, CC and IML; serotonin (5-HT) and vesicular glutamate transporter-1 (VGLUT1) was noticed in nerve fibers of all laminae; somatostatin (SOM) in neuronal somata of laminae III, IV, V, VI, VII, VIII and IX and nerve fibers in laminae I, II, V, VI, VII, X and IML; calbindin (Cb) in neuronal somata of laminae I, II, VI, VII, IX and X; parvalbumin (PV) was found in neuronal somata and in nerve fibers of laminae III, IV, V, VI, VII, VIII, IX and CC; finally, gamma-amino butyric acid (GABA) was present in neuronal somata of laminae V, VI, VII, VIII, IX and X. This study revealed interesting results concerning the chemoarchitecture of the Sapajus spp. spinal cord with a distribution pattern mostly similar to other mammals. The data corroborate the result described in literature, except for some differences in CGRP, SP, Cb, PV and GABA immunoreactivities present in neuronal somata and in nerve fibers. This could suggest certain specificity for the neurochemistry distribution in this non-human primate species, besides adding relevant data to support further studies related to processes involving spinal cord components.

Time course and expression pattern of the neuronal markers in the developing human spinal cord

“…Higher levels of CGRP facilitate trigeminal ways of sensitizations of primary nociceptive neurons in upper SC (Cornelison et al, 2016; Miller et al, 2016). Since CGRP was also found in motorneurons (Marti et al, 1987; Harmann et al, 1988; Torres‐Da‐Silva et al, 2016), it was proposed that CGRP can be involved in axonal elongation as well in synapsis formation (Kim et al, 2016). Present study suggests that CGRP could be expressed in both nociceptors and mehanoceptors as was also proposed by Bae et al (2018).…”

“…It is a marker of sensory neuron population of nociceptive neurons as well (Yoshimura et al, 1998; Suzuki et al, 2003) CGRP is expressed in small‐diameter unmyelinated nociceptive neurons (Marmigère and Ernfors, 2007) activated by thermal, chemical and mechanical stimuli with sensitivity to capsaicin. CGRP was reported in small diametar fibers in the SC of lower vertebrates (Carlton et al, 1987; Torres‐Da‐Silva et al, 2016) and humans (Harmann et al, 1988), in motoneurons of the adult rats, in the fibres and terminals of dorsal horn and epidermis of the skin (Marti et al, 1987) as well as in small neurons of trigeminal and vagal ganglia (Poyner, 1992). VR1 is a non‐selective cation channel from the transient receptor potential (TRP) family (Anand et al, 2008), activated by capsaicin and by noxious heat and protons (Hou et al, 2002; Huang et al, 2002; Vulcu et al, 2003).…”

The tracts, cytoarchitecture, and neurochemistry of the spinal cord

“…Their firing pattern is thought to be the same as that of multipolar neurons, though the distinction between the two has not yet been made (Dougherty et al, 2005), presumably due to the scarcity of this morphological subtype compared with those aforementioned. Flattened neurons in the rat and cat are immunoreactive for substance P (Lima et al, 1993; Takahashi & Otsuka, 1975) but are completely absent in the non‐human primate (Torres‐da‐Silva et al, 2016); a neuropeptide implicated in nociception (Simmons & Substance, 2010), the maintenance of hyperalgesia (Mantyh et al, 1997) and in particular, pain associated with inflammation (Doyle & Hunt, 1999; Simmons & Substance, 2010).…”

Histochemistry as a versatile research toolkit in biological research, not only an applied discipline in pathology

“…[37][38][39][40][41][42] The biology of stem cells was extensively investigated through the labelling by specific molecular markers, during development and in the adult. [43][44][45][46] The molecular organization of cells and tissues was carefully analyzed [47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63] especially in poorly described species of mammals [55][56][57] and non-mammalian vertebrates [58][59][60][61] or in invertebrates, 62,63 while immunohistochemistry was crucial to elucidate the topographic distribution of cell lineages in different organs, [64][65][66] especially in the nervous system, [67][68][69][70][71] and during embryogenesis and the pre-or postnatal development, [72][73]…”