Anatomical variations of the upper thoracic sympathetic chain: a review.

ABSTRACT OBJECTIVES: The objective of this study is to provide a thorough overview of the anatomical variations of the upper thoracic sympathetic trunk to improve clinical results of upper thoracic sympathectomy. In addition, this study strives for standardization of future studies regarding the anatomy of the upper thoracic sympathetic chain. METHODS: The Web of Science, PubMed and Google Scholar databases were searched using keywords, alone or combined, regarding the anatomy of the thoracic sympathetic chain. The search was limited to studies performed in humans. RESULTS: Fifteen studies were finally included. Cervicothoracic ganglion and nerve of Kuntz were present in 77% and 53%, respectively. The upper thoracic ganglia were predominantly located in their corresponding intercostal space with a relatively downwards shift at the lower thoracic levels. The right sympathetic trunk is prone to have more communicating rami then the left. The lower levels of ganglia tend to have more normal rami. No clear pattern was found concerning the presence of the ascending rami and there was a decrease in the number of descending rami as the chain runs caudally. The intercostal rami remain a rare anatomical variation. CONCLUSIONS: This study presents an overview of the anatomy of the upper thoracic sympathetic chain. Its results may guide upper thoracic sympathectomy to improve clinical results. This review also provides a baseline for future studies on anatomical variations of the thoracic sympathetic trunk. More uniform reporting is necessary to compare different anatomical studies.

Effect of TNBS-induced colitis on enteric neuronal subpopulations in adult zebrafish.

Inflammatory bowel disease (IBD) includes inflammation of the gastrointestinal (GI) tract and is characterized by periods of acute inflammation and remission. Therapeutic management of IBD is still problematic, because of incomplete understanding its pathogenesis. This study focuses on the effect of 2,4,6-trinitrobenzene sulphonic acid (TNBS)-induced colitis on changes in enteric neuronal subpopulations in adult zebrafish. These changes are suggested to be related to the altered neuro-immune interactions and GI motility, and in IBD pathogenesis. New insights into neuroplasticity will be instrumental in finding appropriate therapeutic treatments. TNBS was intraluminally administered in the distal intestine (DI) of anesthetized adult zebrafish. A histological time course of the intestinal inflammatory response was created to establish optimal TNBS concentration and acute inflammation phase. Using double immunolabelling on whole mounts, the effect of inflammation on neuronal populations was analyzed. Based on intestinal wall thickening, epithelial fold disruption, reduced goblet cell number, and eosinophil infiltration, our analysis indicated that the optimal TNBS concentration (320 mM in 25% ethanol) inducing non-lethal inflammation reached a peak at 6 hours post-induction. The inflammatory response returned to baseline values at 3 days post-induction. At the acute inflammation phase, no influence on the distribution or proportion of nitrergic neurons was observed, while only the proportion of cholinergic neurons was significantly reduced in the DI. The proportion of serotonergic neurons was significantly increased in the entire intestine during inflammation. This study describes a method of TNBS-induced colitis in the adult zebrafish. Given that the acute inflammation phase is accompanied by neuroplasticity comparable to changes observed in IBD patients, and the unique and versatile characteristics of the zebrafish, allows this model to be used alongside IBD animal models to unravel IBD pathology and to test new IBD therapies.

An unusual case of aortic valve obstruction.

During a dissection class for anatomy, a white lipoid mass was found in the ascending aorta, which was partly attached to the wall and filled the sinuses ofValsalva and almost fitting as a cast. This mass prevented full opening of the mobile aortic valve leaflets, thereby causing an obstruction. Microscopic analysis revealed fibres and presence of polymorphonuclear white blood cells. It seems reasonable to assume that this mass has formed in the last weeks or months of the life of this subject, which is much quicker than for calcified aortic valve stenosis. Therefore, signs and symptoms of aortic obstruction might have been missed or misinterpreted. In case of timely detection during life, diagnostic imaging and therapeutic approach can be challenging.

Expression of neuropeptides and anoctamin 1 in the embryonic and adult zebrafish intestine, revealing neuronal subpopulations and ICC-like cells.

This immunohistochemical study in zebrafish aims to extend the neurochemical characterization of enteric neuronal subpopulations and to validate a marker for identification of interstitial cells of Cajal (ICC). The expression of neuropeptides and anoctamin 1 (Ano1), a selective ICC marker in mammals, was analyzed in both embryonic and adult intestine. Neuropeptides were present from 3 days postfertilization (dpf). At 3 dpf, galanin-positive nerve fibers were found in the proximal intestine, while calcitonin gene-related peptide (CGRP)- and substance P-expressing fibers appeared in the distal intestine. At 5 dpf, immunoreactive fibers were present along the entire intestinal length, indicating a well-developed peptidergic innervation at the onset of feeding. In the adult intestine, vasoactive intestinal peptide (VIP), pituitary adenylate cyclase-activating peptide (PACAP), galanin, CGRP and substance P were detected in nerve fibers. Colchicine pretreatment enhanced only VIP and PACAP immunoreactivity. VIP and PACAP were coexpressed in enteric neurons. Colocalization stainings revealed three neuronal subpopulations expressing VIP and PACAP: a nitrergic noncholinergic subpopulation, a serotonergic subpopulation and a subpopulation expressing no other markers. Ano1-immunostaining revealed a 3-dimensional network in the adult intestine containing multipolar cells at the myenteric plexus and bipolar cells interspersed between circular smooth muscle cells. Ano1 immunoreactivity first appeared at 3 dpf, indicative of the onset of proliferation of ICC-like cells. It is shown that the Ano1 antiserum is a selective marker of ICC-like cells in the zebrafish intestine. Finally, it is hypothesized that ICC-like cells mediate the spontaneous regular activity of the embryonic intestine.

Neurochemical coding of enteric neurons in adult and embryonic zebrafish (Danio rerio).

Although the morphology and development of the zebrafish enteric nervous system have been extensively studied, the precise neurochemical coding of enteric neurons and their proportional enteric distribution are currently not known. By using immunohistochemistry, we determined the proportional expression and coexpression of neurochemical markers in the embryonic and adult zebrafish intestine. Tyrosine hydroxylase (TH), vasoactive intestinal peptide (VIP), and pituitary adenylate cyclase-activating peptide (PACAP) were observed only in nerve fibers, whereas other markers were also detected in neuronal cell bodies. Calretinin and calbindin had similar distributions. In embryos, all markers, except for choline acetyltransferase (ChAT) and TH, were present from 72 hours postfertilization. Nitrergic neurons, evenly distributed and remaining constant in time, constituted the major neuronal subpopulation. The neuronal proportions of the other markers increased during development and were characterized by regional differences. In the adult, all markers examined were expressed in the enteric nervous system. A large percentage of enteric neurons displayed calbindin and calretinin, and serotonin was the only marker showing significant distribution differences in the three intestinal regions. Colocalization studies showed that serotonin was not coexpressed with any of the other markers. At least five neuronal subpopulations were determined: a serotonergic, a nitrergic noncholinergic, two cholinergic nonnitrergic subpopulations along with one subpopulation expressing both ChAT and neuronal nitric oxide synthase. Analysis of nerve fibers revealed that nitrergic neurons coexpress VIP and PACAP, and that nitrergic neurons innervate the tunica muscularis, whereas serotonergic and cholinergic nonnitrergic neurons innervate the lamina propria and the tunica muscularis.