Anatomical and immunohistochemical considerations on the microinnervation of trachea in humans
The anatomy of the tracheal microinnervation is understudied in humans; the purpose of our study was to fill this gap by working on human adult tracheas, to compare the results with those obtained from animal studies, and to checking whether or not these studies are suitable to be translated from comparative to the human anatomy. The study was designed as a qualitative one. The present work was performed on human adult tracheas dissected out in 15 human adult cadavers. Microdissections were performed in eight tracheas and revealed the outer peritracheal plexus, segmentally supplied and distributed to trachea and esophagus, with longitudinal intersegmentary anastomoses but also with bilateral interrecurrential anastomoses previously undescribed in anatomy. Seven different tracheas were transversally cut and paraffin embedded. Histological stains (HE, toluidine blue, luxol fast blue, Giemsa on tissues and trichrome Gieson) and immunohistochemistry using primary antibodies for nNOS, neurofilament, SMA and the cocktail of citokeratines CK AE1-AE3+8/18 were done. According to the histological individual variation, the neural layers of the posterior wall of the human trachea could be considered as it follows: (a) an outer neural layer, ganglionated, associated with the connective covering layers, adventitia and the posterior fibroelastic membrane (external elastic lamina); (b) a submucosal ganglionated neural layer, mainly with juxtaglandular microganglia that may expand, as glands do, through the outer covering layers; (c) intrinsic nerves of the transverse trachealis muscle; (d) the neural layer intrinsic to the longitudinal elastic band (internal elastic lamina) and supplied from the inner submucosa; (e) the neural plexus of the lamina propria, with scarcely distributed neurons. We also bring here the first evidences for the in vivo nNOS phenotype of mast cells that were identified, but not exclusively, within the trachealis muscle.
Available from: Baik Hwan Cho
- "The SG may issue nNOS positive nerves to the tongue although, according to our experiences, commercially obtained antibodies for nNOS are not available for identification of nerve fibers in human body. Rusu et al. (2011) demonstrated a difference in discrimination between the human mast cell and ganglion cell in immunohistochemistry of nNOS. Actually, we also observed mast cell-like nNOS-positive cells near a CG (Fig. 4A). "
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ABSTRACT: The cranial parasympathetic ganglia have been reported to paradoxically contain the sympathetic nerve marker, tyrosine hydroxylase (TH), in addition to neurons expressing parasympathetic markers such as vasoactive intestinal peptide (VIP) and neuronal nitric oxide synthase (nNOS). However, the distribution of these molecules in the cranial ganglia of human fetuses has not yet been examined. Using paraffin sections from 10 mid-term human fetuses (12-15 weeks), we performed immunohistochemistry for TH, VIP, and nNOS in the parasympathetic ciliary, pterygopalatine, otic, and submandibular ganglia, and for comparison, the sensory inferior vagal ganglion. The ciliary and submandibular ganglia contained abundant TH-positive neurons. In the former, TH-positive neurons were much more numerous than nNOS-positive neurons, whereas in the latter, nNOS immunoreactivity was extremely strong. No or a few cells in the pterygopalatine, otic, and inferior vagal ganglia expressed TH. Ciliary TH neurons appeared to compensate for classically described sympathetic fibers arising from the superior cervical ganglion, whereas in the submandibular ganglion, nNOS-positive neurons as well as TH neurons might innervate the lingual artery in addition to the salivary glands. Significant individual variations in the density of all these markers suggested differences in sensitivity to medicine affecting autonomic nerve function. Consequently, in the human cranial autonomic ganglia, it appears that there is no simple dichotomy between sympathetic and parasympathetic function.
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ABSTRACT: The Longwood Medical Area Network (LMAnet) is a high speed fiber optic network that connects several patient care, research, and educational organizations in Boston's Longwood Medical Area. This paper describes the architecture of the network, current and potential future uses of the network, network costs and administration, and management issues associated with the use of LMAnet.
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ABSTRACT: The presence of c-kit positive neurons in sensory ganglia has been verified in various species but not in humans. Our aim has been to identify whether human primary trigeminal neurons label with c-kit/CD117 and thus, whether data gathered in animal studies can be extrapolated to humans. We also intended to establish whether, and which non-neuronal cells also label with c-kit in the trigeminal ganglion.
Human adult trigeminal ganglia from eight cadavers were processed for immunohistochemistry on paraffin embedded samples using monoclonal antibodies for CD117/c-kit, and three additional trigeminal ganglia were used for transmission electron microscopy (TEM). To evaluate which neuronal type (A or B) was labeled with c-kit, we evaluated the same neurons on adjacent sections labeled with antibodies for neurofilaments (NF).
c-kit has labeled trigeminal neurons (TNs), mast cells and interstitial cells (ICs) within the trigeminal ganglion. c-kit+TNs were NF-and thus were strongly presumed to be nociceptive, as such neurons are known to be NF-poor. c-kit+ICs with long and moniliform processes intermingled with the satellite glial cells (SGCs) of the neuronal envelopes. TEM evaluations confirmed this mixed composition of the neuronal envelopes and demonstrated that the perineuronal ICs are in fact interstitial Cajal-like cells (ICLCs) and/or telocytes.
c-kit+TNs were objectified in humans and strongly presumed to be nociceptive. TNs envelopes mostly consist of SGCs, but are also combined with ICLCs/telocytes.
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