Journal Article

Neurochemical characterization of myenteric neurons in the juvenile gilthead sea bream (Sparus aurata) intestine

Crema, Francesca, Terova, Genciana, Viola, Manuela, Bistoletti, Michela, Ceccotti, Chiara, Giaroni, Cristina

2018

Overview

We evaluated the chemical coding of the myenteric plexus in the proximal and distal intestine of gilthead sea bream (Sparus aurata), which represents one of the most farmed fish in the Mediterranean area. The presence of nitric oxide (NO), acetylcholine (ACh), serotonin (5-HT), calcitonin-gene-related peptide (CGRP), substance P (SP) and vasoactive intestinal peptide (VIP) containing neurons, was investigated in intestinal whole mount preparations of the longitudinal muscle with attached the myenteric plexus (LMMP) by means of immunohistochemical fluorescence staining. The main excitatory and inhibitory neurochemicals identified in intestinal smooth muscle were ACh, SP, 5HT, and NO, VIP, CGRP. Some neurons displayed morphological features of ascending and descending interneurons and of putative sensory neurons. The expression of these pathways in the two intestinal regions is largely superimposable, although some differences emerged, which may be relevant to the morphological properties of each region. The most important variances are the higher neuronal density and soma size in the proximal intestine, which may depend on the volume of the target tissue. Since in the fish gut the submucosal plexus is less developed, myenteric neurons substantially innervate also the submucosal and epithelial layers, which display a major thickness and surface in the proximal intestine. In addition, myenteric neurons containing ACh and SP, which mainly represent excitatory motor neurons and interneurons innervating the smooth muscle were more numerous in the distal intestine, possibly to sustain motility in the thicker smooth muscle coat. Overall, this study expands our knowledge of the intrinsic innervation that regulates intestinal secretion, absorption and motility in gilthead sea bream and provides useful background information for rational design of functional feeds aimed at improving fish gut health.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Acetylcholine / Animal tissues / Animals / Aquaculture / Biology and Life Sciences / Bream / Calcitonin / Calcitonin gene-related peptide / Cell Size / Characterization / Cod / Coding / Digestive system / Digestive tract / Enteric nervous system / Fish / Fish farms / Fluorescence / Fluorescence in situ hybridization / Gastrointestinal tract / Health aspects / Immunohistochemistry / Innervation / Interneurons / Intestine / Intestines / Life sciences / Mammals / Marine fishes / Medicine / Medicine and Health Sciences / Motor neurons / Muscle, Smooth - cytology / Muscle, Smooth - growth & development / Muscle, Smooth - innervation / Muscle, Smooth - metabolism / Muscles / Myenteric plexus / Myenteric Plexus - cytology / Myenteric Plexus - growth & development / Myenteric Plexus - metabolism / Nervous system / Neural coding / Neurons / Neurons - cytology / Neurons - metabolism / Neurosciences / Neurotransmitter Agents - metabolism / Neurotransmitters / Nitric oxide / Organic chemistry / Peptides / Rodents / Sea Bream - anatomy & histology / Sea Bream - growth & development / Sea Bream - metabolism / Sensory neurons / Serotonin / Smooth muscle / Sparus aurata / Submucosal plexus / Substance P / Surgery / Vasoactive agents / Vasoactive intestinal peptide / Zebrafish