The galaninergic enteric nervous system of pleuronectiformes (Pisces, Osteichthyes) : an immunohistochemical and confocal laser scanning immunofluorescence study

• Published in: General and Comparative Endocrinology
• Main Authors: G. Bosi, C. Domeneghini, R. Bermudez
• Format: Article in Journal/Newspaper
• Language: English
• Published: Academic Press 2007
• Subjects: galanin; gut; enteric nervous system; flatfishes; immunohistochemistry; confocal laser microscopy; Settore VET/01 - Anatomia degli Animali Domestici; Turbot
• Online Access: http://hdl.handle.net/2434/63860; https://doi.org/10.1016/j.ygcen.2007.02.007

The galaninergic enteric nervous system of three flatfishes was studied using immunohistochemical and immuno fluorescence methods. Galanin-like immunoreactivity was mainly detected within the enteric intramural neurons of the stomachs and the proximal intestines. The sole, Solea solea L. and the flounder, Platichthys flesus L. showed a similar occurrence and relative distribution of galaninergic intramural neurons. Rare nervous fibre immunoreactive to the anti-galanin serum were observed in the muscular layers of the oesophagus of the turbot, Psetta maxima L. The presence and relative abundance of galanin-like immunoreactive neurons in the remaining organs of the alimentary canal of the turbot showed a different pattern in comparison to those observed in the sole and the flounder. A galanin-like peptide was detected in nerve fibres running through the exocrine parenchyma of the pancreas of all three species. It is conceivable that the galaninergic system in these species plays a role in regulating gut muscle activity, and in controlling pancreatic secretion. Galanin and choline acetyltransferase were co-localized within the same neurons of the stomach and intestine. The result confirms the hypothesis that galanin in the gut of fish functions as a cholinergic modulator. Differently from other fish species, immunoreactive endocrine cells were not detected in the studied pleuronectiformes