Airway sensory receptors regulate cardiopulmonary function by providing constant information about the mechanical and chemical status of the lung to the central nervous system (CNS). There are at least three airway sensor types: slowly adapting receptors (SARs), rapidly adapting receptors (RARs), and C-fiber receptors (CFRs). We recently identified additional A-delta fiber receptors in intact rabbits that are different from SARs and RARs. Having a high mechanical threshold, they respond to hypertonic saline and are termed high threshold A-delta receptors (HTARs). SARs and RARs monitor airway mechanical changes, whereas HTARs and CFRs sense chemical alterations and may serve as nociceptors. As with nociceptors in other tissue, the latter are activated during lung inflammatory processes. Also, the airway houses neuroendocrine cells aggregated in organoids called neuroepithelial bodies (NEBs). NEBs are richly innervated by nerve fibers from different origins. Similar in structure to the carotid bodies, NEBs are believed to be sensors, with at least some sensory fibers that have cell bodies in the nodose ganglia. Therefore, they may serve CNS reflex functions. Strategically located at airway bifurcations, NEBs may signal the chemical composition of or presence of irritants in the air. This study intends to explore the possibility that NEBs are associated with nociceptors.
"NEBs release bioactive mediators and are closely associated with varied neural sources (vagal, spinal, and parabronchial) (Adriaensen et al., 2006). NEBs may be directly connected with airway sensory afferents in the lung (Yu et al., 2006). PNECs and NEBs contain many bioactive substances with growth factor and mitogenic properties, such as gastrin-releasing peptide (GRP), bombesin, calcitonin gene-related peptide (CGRP), and serotonin (5-HT) (Cutz et al., 2007). "
[Show abstract][Hide abstract] ABSTRACT: Neuroepithelial bodies (NEBs) serve a niche for lung stem cells and proliferate in a variety of pulmonary diseases. We hypothesize that NEBs play an important role in lung injury repair processes, such as during pulmonary fibrosis. To test this hypothesis, we examined NEBs in a bleomycin-induced lung fibrosis mouse model. We divided FVB/NJ mice into bleomycin-treated (BL) and normal saline-treated (NS) groups. Two weeks after intravenous treatment we immune-stained NEBs with anti-calcitonin gene-related peptide (CGRP) in whole mount preparations and found that the number of NEBs per unit area of airway almost tripled in the BL group (1.11±0.28 number/mm(2); n=5) compared with the NS group (0.32±0.14 number/mm(2); n=4, P=0.001). The size of NEBs increased significantly in the BL group. Our findings support that NEBs play an important role in the pathogenesis of pulmonary fibrosis.
[Show abstract][Hide abstract] ABSTRACT: An efficient video compression mechanism is presented, that
preserves not only the visual acuity but also the perception fidelity.
This is possible because we have made novel utilization of the human
vision system (HVS), since our eyes do not pay attention to image pixels
rather to intensity changes. We furthermore label the discontinuity of
the intensity with the derivative jump value across the boundary as the
finger print of the edge, and that label together with its actual gray
scale value are called the singularity map (SM) that enables us uniquely
identify those corresponding control points among neighborhood frames
without the usual exhaustive search at all image pixels level. The
proposed video compression consists of two parallel operations: (1)
sending the lossy compression of full image by the HVS wavelets without
the block artifact of DCT of JPEG or MPEG; and (2) inserting the
original gray scale edge preserved by the SM before the lossy
compression operation. The approach enables one to transmit live video
via the SINGARS radio at a narrow bandwidth of 16 K bps
Neural Networks, 2002. IJCNN '02. Proceedings of the 2002 International Joint Conference on; 02/2002
[Show abstract][Hide abstract] ABSTRACT: The epithelium of intrapulmonary airways in many species harbors diffusely spread innervated groups of neuroendocrine cells, called neuroepithelial bodies (NEBs). Data on the location, morphology, and chemical coding of NEBs in mammalian lungs are abundant, but none of the proposed functions has so far been fully established. Besides C-fiber afferents, slowly adapting stretch receptors, and rapidly adapting stretch receptors, recent reviews have added NEBs to the list of presumed sensory receptors in intrapulmonary airways. Physiologically, the innervation of NEBs, however, remains enigmatic. This short overview summarizes our present understanding of the chemical coding and exact location of the receptor end organs of myelinated vagal airway afferents in intrapulmonary airways. The profuse populations that selectively contact complex pulmonary NEB receptors are compared with the much smaller group of smooth muscle-associated airway receptors. The main objective of our contribution was to stimulate the idea that the different populations of myelinated vagal afferents that selectively innervate intraepithelial pulmonary NEBs may represent subpopulations of the extensive group of known electrophysiologically characterized myelinated vagal airway receptors. Future efforts should be directed toward finding out which airway receptor groups are selectively coupled to the complex NEB receptors.
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