Fig. 16
From: The complex simplicity of the brittle star nervous system
Distribution of the neuropeptide GFSKLYFamide (GFS) in the arm nervous system of O. brevispinum. a and a’ Low magnification view of a RNC segment. Whole-mount specimen, Z-projection of a confocal stack. b and c A pair of stereotypically positioned neurons in two different arm segments. Whole-mount specimen, volume-rendered confocal stack. d and d’ A branch of the longitudinal immunopositive tract contributing to the podial nerve. e and e’ Longitudinal section through the ectoneural neuroepithelium of the RNC. e shows triple staining with the anti-GFS antibodies, the ERG1 glial marker and the DRAQ5 nuclear stain, whereas e’ shows only the GFS-positive cells in a separate channel. f and f’ Cross section through the ectoneural epithelium of the RNC. f shows staining with the anti-GFS antibodies, ERG1 antibodies, and DRAQ5 nuclear dye, whereas f’ shows only anti-GFS immunostaining in a separate channel. Abbreviations: ec – epineural canal; pg – podial ganglion; open arrowhead – longitudinal immunopositive tracts; asterisk – median network of immunopositive fibers between the longitudinal tracts; filled arrowheads – a pair of stereotypically positioned neurons; filled arrow – a bundle of processes contributing to the podial nerve; open arrow – a bipolar neuron