Confocal imaging and phylogenetic considerations of the subcutaneous neurons in the Atlantic hagfish Myxine glutinosa

Abstract

Zaccone, G., Fudge, D.S., Winegard, T.M., Capillo, G., Kuciel, M., Funakoshi, K. and Lauriano, E.R. 2015. Confocal imaging and phylogenetic considerations of the subcutaneous neurons in the Atlantic hagfish Myxine glutinosa. -Acta Zoologica (Stockholm) 96: 209-217.We used confocal microscopy and immunohistochemistry to characterize the morphology of the subcutaneous neurons and the innervation of the slime glands and striated muscles in the hagfish Myxine glutinosa. A rich plexus of 5HT-, ChAT-and TH-positive neurons is described in the capsule of the slime glands. These neurons, like those of the subcutaneous plexus, receive pericellular terminations from the axons of central cells. Capsular neurons receive innervation from 5HT-positive and nNOS-positive nerve fibres. Other nerve endings belonging to two separate nerve populations are identified in the striated muscles. They contain TH and nNOS immunoreactivity. Due to the lack of any topographical labelling, the cell origin and the projections of the neurons into the cranial and spinal nerves are unknown. This study provides anatomical evidence of multiple (5HT and nNOS) peripheral innervation of the neurons. However, it does not provide information about the function of these neurons in the hagfish. We suggest that hagfish neurons have a phylogenetic relationship with the spinal group of the dorsal cells of lampreys and the supramedullary cells of teleosts.

Immunohistochemical colocalization of G protein alpha subunits and 5-HT in the rectal gland of the cartilaginous fishScyliorhinus canicula

“…The presence of myoepithelial cells in the S. canicula rectal gland secretion has been challenged (Shuttleworth, 1988), because the glands of S. canicula did not respond to VIP (Anderson et al, 1995;Thorndyke & Shuttleworth, 1985). But in the present study has been demonstrated numerous nerve fibers both of the capsule that of the parenchyma of the rectal gland peptide (VIP) and substance P positive; furthermore nNOS immunoreactivity in nerve fibers of the gland capsular wall and nerve varicosities in close proximity to the secretory cells, show that these substances are expressed by nerves close glandular parenchyma and the nerve fibers directly innervate the secretory epithelium (Zaccone et al, 2015a(Zaccone et al, , 2015b. Already, Chan and Phillips (1967) described argentaffin cells in lip-shark Hemiscyllium plagiosum rectal gland, we detected VIP and substance P immunoreactive cells (neuroendocrine like cell) in the glandular parenchyma between secretary cells.…”

“…Smooth muscle cells in the layer are continuous with the smooth muscle that forms a sphincter around the gland. In a previous study has been used this antibody to mark smooth muscle cells in the connective tissue of the hagfish Myxine glutinosa slime gland capsule (Zaccone et al, ). Also, this antibody has been used as a marker to demonstrate the presence of myoepithelial cells in the gland central duct.…”

Confocal Characterization of Intestinal Dendritic Cells from Myxines to Teleosts

“…A Zeiss LSM DUO confocal laser scanning microscope with a META module (Carl Zeiss MicroImaging GmbH, Jena, Germany) equipped with an argon laser (458, 488 l) and two helium–neon lasers was used to examine sections and take images (543 and 633 l) [ 33 ]. All the images were digitalized into a 2048 by 2048 pixel array at an 8-bit resolution.…”

Confocal immunohistochemistry of the dermal glands and evolutionary considerations in the caecilian, Typhlonectes natans (Amphibia: Gymnophiona)

“…Techniques for immunolabelling were similar to those previously described for adult fish visceral organ tissues (Zaccone et al . , ). Details of antibodies used in this study are summarized in Table .…”

“…Nerve fibres and bundles were also identified using antibodies to calbindin that is a general neuronal marker, and its labelling of neural structures in various fish species has been previously characterized (Zaccone et al . , ; Kuciel et al . ).…”