Localization of NADPH diaphorase/nitric oxide synthase and choline acetyltransferase in the spinal cord of the frog,Rana perezi

Abstract

The localization of nitrergic cells and fibers and cholinergic cells has been analyzed in the spinal cord of the anuran amphibian Rana perezi. Histochemistry for nicotinamide adenine dinucleotide phosphate–diaphorase and nitric oxide synthase immunohistochemistry revealed a concurrent pattern of labeled structures. A large population of nitrergic spinal neurons was found from the level of the obex to the filum terminale. They are abundant in the dorsal horn and intermediate gray matter, but also occur in territories of the ventral horn and, only occasionally, in somatic motoneurons. Numerous nitrergic fibers were present in the spinal white matter, particularly in the dorsal and dorsolateral funiculi. A special arrangement of nitrergic axons is present in Lissauer's tract, where a collateral system is formed. Cholinergic cells, revealed by choline acetyltransferase immunohistochemistry, were observed throughout the spinal cord. The somatic motoneurons were the most conspicuously immunoreactive cells. A large population of cholinergic cells forms a discontinuous column in the intermediate gray, from the third spinal segment to lumbar segments. These cells were organized in a medially located or intercalated cell group, and a laterally located intermediolateral group. Numerous scattered cholinergic cells were present in the central zone of the ventral horn and were absent in the dorsal horn. Double‐labeling experiments revealed a high degree of codistribution of nitrergic and cholinergic cells, mainly in the intermediate gray, but colocalization of both markers in the same neurons was not found. This result contrasts with the situation found in mammals and raises the question of whether coexpression of both substances was acquired in spinal cord neurons through evolution only in amniotes or, even, only in mammals. J. Comp. Neurol. 419:451–470, 2000. © 2000 Wiley‐Liss, Inc.

Developmental and regional expression of NADPH‐diaphorase/nitric oxide synthase in spinal cord neurons correlates with the emergence of limb motor networks in metamorphosing Xenopus laevis

“…2, A and Ci) or nNOS immunofluorescence ( n = 8 stage 51 animals; Fig. 2B and D), in agreement with previous reports of a complete match between the distribution of NADPH‐d staining and NOS immunostaining in the CNS of amphibians (Munoz et al ., 2000; Bruning & Mayer, 2001; Cristino et al ., 2004; D.L. McLean and K.T.…”

DNA interaction with Mn2+ ions at elevated temperatures: VCD evidence of DNA aggregation

“…Finally, in the thoracic spinal cord, the ChATir cells located in the intermediate gray defined two distinct columns named intermediolateral and intercalated (Fig. 7j), as in the adult anuran spinal cord (Muñoz et al, 2000).…”

“…The lateral motoneurons that serve the limb muscles were also ChATir at “bud stages,” although with some delay compared with their AChE activity (Farel and McIlwain, 1983). Autonomous motoneurons in the intermediate gray of thoracic spinal segments were ChATir from stage 50 to adult life (Muñoz et al, 2000).…”

Descending supraspinal pathways in amphibians. II. Distribution and origin of the catecholaminergic innervation of the spinal cord

“…These correspond to the column of sympathetic preganglionic neurons studied in anurans with tracing techniques (Robertson, 1987;Horn and Stofer, 1988;Peruzzi and Forehand, 1994). In addition, the parasympathetic nucleus in the intermediate gray at sacral spinal levels has been described in anurans (Campbell et al, 1994;Muñ oz et al, 2000). The comparison of the distribution of CA fibers in spinal segments where the autonomic cells are located suggest the innervation of these neurons.…”

“…In amphibians, particularly in anurans, well-organized intermediolateral and intercalated groups of cholinergic cells have been characterized recently in the thoracic spinal cord (Muñ oz et al, 2000). These correspond to the column of sympathetic preganglionic neurons studied in anurans with tracing techniques (Robertson, 1987;Horn and Stofer, 1988;Peruzzi and Forehand, 1994).…”