Search

Your search keyword '"Bao, Nan"' showing total 6 results
Start Over Author "Bao, Nan" Journal neurogastroenterology & motility
6 results on '"Bao, Nan"'

4. Characterization of projections of longitudinal muscle motor neurons in human colon

Author

Chris I W Lauder, Phil G. Dinning, Simon J. H. Brookes, David Wattchow, Adam Humenick, Marcello Costa, Bao Nan Chen, Nick J. Spencer, and Vladimir P. Zagorodnyuk

Subjects
Male, 0301 basic medicine, Colon, Physiology, Biology, Inhibitory postsynaptic potential, Enteric Nervous System, Choline O-Acetyltransferase, 03 medical and health sciences, 0302 clinical medicine, Vesicular acetylcholine transporter, medicine, Humans, Aged, Cell Size, Fluorescent Dyes, Motor Neurons, Endocrine and Autonomic Systems, Gastroenterology, Muscle, Smooth, Smooth muscle contraction, Middle Aged, Motor neuron, Immunohistochemistry, Retrograde tracing, Choline acetyltransferase, Neuroanatomical Tract-Tracing Techniques, 030104 developmental biology, medicine.anatomical_structure, nervous system, Cholinergic, Female, Enteric nervous system, Nitric Oxide Synthase, Gastrointestinal Motility, Neuroscience, 030217 neurology & neurosurgery
Abstract

Background The enteric nervous system contains inhibitory and excitatory motor neurons which modulate smooth muscle contractility. Cell bodies of longitudinal muscle motor neurons have not been identified in human intestine. Methods We used retrograde tracing ex vivo with DiI, with multiple labeling immunohistochemistry, to characterize motor neurons innervating tenial and inter-tenial longitudinal muscle of human colon. Key results The most abundant immunohistochemical markers in the tertiary plexus were vesicular acetylcholine transporter, nitric oxide synthase (NOS), and vasoactive intestinal polypeptide (VIP). Of retrogradely traced motor neurons innervating inter-tenial longitudinal muscle, 95% were located within 6mm oral or anal to the DiI application site. Excitatory motor neuron cell bodies, immunoreactive for choline acetyltransferase (ChAT), were clustered aborally, whereas NOS-immunoreactive cell bodies were distributed either side of the DiI application site. Motor neurons had small cell bodies, averaging 438 + 18µm2 in cross-sectional area, similar for ChAT- and NOS-immunoreactive subtypes. Motor neurons innervating the tenia had slightly longer axial projections, with 95% located within 9mm. ChAT-immunoreactive excitatory motor neurons to tenia were clustered aborally, whereas NOS-immunoreactive inhibitory motor neurons had both ascending and descending projections. VIP immunoreactivity was rarely present without NOS immunoreactivity in motor neurons. Conclusions and inferences Tenial and inter-tenial motor neurons innervating the longitudinal muscle have short projections. Inhibitory motor neurons have less polarized projections than cholinergic excitatory motor neurons. Longitudinal and circular muscle layers are innervated by distinct local populations of excitatory and inhibitory motor neurons. A population of human enteric neurons that contribute significantly to colonic motility has been characterized.

Published
2019

6. Characterization of putative interneurons in the myenteric plexus of human colon.

Author

Humenick, Adam, Chen, Bao Nan, Wattchow, David A., Zagorodnyuk, Vladimir P., Dinning, Phil G., Spencer, Nick J., Costa, Marcello, and Brookes, Simon J. H.

Subjects
*ENTERIC nervous system, *INTERNEURONS, *MOTOR neurons, *NITRIC-oxide synthases, *COLON (Anatomy)
Abstract

Background: The enteric nervous system contains multiple classes of neurons, distinguishable by morphology, immunohistochemical markers, and projections; however, specific combinations differ between species. Here, types of enteric neurons in human colon were characterized immunohistochemically, using retrograde tracing combined with multiple labeling immunohistochemistry, focussing on non‐motor neurons. Methods: The fluorescent carbocyanine tracer, DiI, was applied to the myenteric plexus in ex vivo preparations, filling neurons projecting within the plexus. Limits of projection lengths of motor neurons were established, allowing them to be excluded from the analysis. Long ascending and descending interneurons were then distinguished by labeling for discriminating immunohistochemical markers: calbindin, calretinin, enkephalin, 5‐hydroxytryptamine, nitric oxide synthase, and substance P. These results were combined with a previous published study in which nitric oxide synthase and choline acetyltransferase immunoreactivities were established. Key Results: Long ascending neurons (with projections longer than 8 mm, which excludes more than 95% motor neurons) formed four types, in descending order of abundance, defined by immunoreactivity for: (a) ChAT+/ENK+, (b) ChAT+/ENK+/SP+, (c) ChAT+/Calb+, and (d) ChAT+/ENK+/Calb+. Long descending neurons, up to 70 mm long also formed at least four types, distinguished by immunoreactivity for (a) NOS + cells (without ChAT), (b) ChAT+/NOS+, (c) ChAT+/Calret+, and (d) ChAT+/5HT + cells (with or without NOS). Conclusions and Inferences: Long interneurons, which do not innervate muscularis externa, are likely to coordinate neural activity over distances of many centimeters along the colon. Characterizing their neurochemical coding provides a basis for understanding their roles, investigating their connectivity, and building a comprehensive account of human colonic enteric neurons. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results