scholarly journals Regulation of Axon Growth by Alpha 7 Nicotinic Receptor Calcium Transients at the Growth Cone

2017 ◽  
Vol 112 (3) ◽  
pp. 539a
Author(s):  
E. Bak ◽  
J. Jedrzejewska-Szmek ◽  
J. King ◽  
K. Blackwell ◽  
N. Kabbani
Keyword(s):  
Growth Cone ◽  
Nicotinic Receptor ◽  
Axon Growth ◽  
Calcium Transients ◽  
Alpha 7

The metalloproteinase ADAM10 is required for retinal ganglion cell axon guidance in the developing visual systems

2007 ◽  
Vol 30 (4) ◽  
pp. 77
Author(s):  
Y. Y. Chen ◽  
C. L. Hehr ◽  
K. Atkinson-Leadbeater ◽  
J. C. Hocking ◽  
S. McFarlane
Keyword(s):  
Ganglion Cell ◽  
Axon Guidance ◽  
Retinal Ganglion Cell ◽  
Growth Cone ◽  
Expression Patterns ◽  
Optic Tract ◽  
Axon Growth ◽  
Proteolytic Processing ◽  
Retinal Ganglion

Background: The growth cone interprets cues in its environment in order to reach its target. We want to identify molecules that regulate growth cone behaviour in the developing embryo. We investigated the role of A disintegrin and metalloproteinase 10 (ADAM10) in axon guidance in the developing visual system of African frog, Xenopus laevis. Methods: We first examined the expression patterns of adam10 mRNA by in situ hybridization. We then exposed the developing optic tract to an ADAM10 inhibitor, GI254023X, in vivo. Lastly, we inhibited ADAM10 function in diencephalic neuroepithelial cells (through which retinal ganglion cell (RGC) axons extend) or RGCs by electroporating or transfecting an ADAM10 dominant negative (dn-adam10). Results: We show that adam10 mRNA is expressed in the dorsal neuroepithelium over the time RGC axons extend towards their target, the optic tectum. Second, pharmacological inhibition of ADAM10 in an in vivo exposed brain preparation causes the failure of RGC axons to recognize their target at low concentrations (0.5, 1 μM), and the failure of the axons to make a caudal turn in the mid-diencephalon at higher concentration (5 μM). Thus, ADAM10 function is required for RGC axon guidance at two key guidance decisions. Finally, molecular inhibition of ADAM10 function by electroporating dn-adam10 in the brain neuroepithelium causes defects in RGC axon target recognition (57%) and/or defects in caudal turn (12%), as seen with the pharmacological inhibitor. In contrast, molecular inhibition of ADAM10 within the RGC axons has no effect. Conclusions: These data argue strongly that ADAM10 acts cell non-autonomously within the neuroepithelium to regulate the guidance of RGC axons. This study shows for the first time that a metalloproteinase acts in a cell non-autonomous fashion to direct vertebrate axon growth. It will provide important insights into candidate molecules that could be used to reform nerve connections if destroyed because of injury or disease. References Hattori M, Osterfield M, Flanagan JG. Regulated cleavage of a contact-mediated axon repellent. Science 2000; 289(5483):1360-5. Janes PW, Saha N, Barton WA, Kolev MV, Wimmer-Kleikamp SH, Nievergall E, Blobel CP, Himanen JP, Lackmann M, Nikolov DB. Adam meets Eph: an ADAM substrate recognition module acts as a molecular switch for ephrin cleavage in trans. Cell 2005; 123(2):291-304. Pan D, Rubin GM. Kuzbanian controls proteolytic processing of Notch and mediates lateral inhibition during Drosophila and vertebrate neurogenesis. Cell 1997; 90(2):271-80.

Semaphorin3A regulates axon growth independently of growth cone repulsion via modulation of TrkA signaling

2008 ◽  
Vol 20 (3) ◽  
pp. 467-479 ◽  
Author(s):  
A. Ben-Zvi ◽  
L. Ben-Gigi ◽  
Z. Yagil ◽  
O. Lerman ◽  
O. Behar
Keyword(s):  
Growth Cone ◽  
Axon Growth

scholarly journals Cholinergic signaling through the alpha 7 nicotinic receptor inhibits atherosclerosis in hypercholesterolemic mice (671.7)

2014 ◽  
Vol 28 (S1) ◽  
Author(s):  
Marcus Ulleryd ◽  
Maria Johansson ◽  
Anna Lundberg ◽  
Lasse Folkersen ◽  
Linda Fogelstrand ◽  
...  
Keyword(s):  
Nicotinic Receptor ◽  
Cholinergic Signaling ◽  
Alpha 7

scholarly journals Evidence for linkage disequilibrium between the alpha 7-nicotinic receptor gene (CHRNA7) locus and schizophrenia in Azorean families

2001 ◽  
Vol 105 (8) ◽  
pp. 669-674 ◽  
Author(s):  
Junzhe Xu ◽  
Michele T. Pato ◽  
Camille Dalla Torre ◽  
Helena Medeiros ◽  
Celia Carvalho ◽  
...  
Keyword(s):  
Linkage Disequilibrium ◽  
Nicotinic Receptor ◽  
Receptor Gene ◽  
Alpha 7

Alpha-7 Nicotinic Receptor-Targeted Cinobufagin Induces Antinociception and Inhibits NF-κB Signaling Pathway in DRG Neurons

2018 ◽  
Vol 10 (1) ◽  
pp. 497-506 ◽  
Author(s):  
Longsheng Xu ◽  
Xiaoping Zhang ◽  
Qingli Feng ◽  
Ying Zheng ◽  
Huadong Ni ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Nicotinic Receptor ◽  
Drg Neurons ◽  
Alpha 7

scholarly journals Axon growth regulation by a bistable molecular switch

2018 ◽  
Vol 285 (1877) ◽  
pp. 20172618 ◽  
Author(s):  
Pranesh Padmanabhan ◽  
Geoffrey J. Goodhill
Keyword(s):  
Growth Cone ◽  
Neural Development ◽  
Growth Regulation ◽  
Axon Growth ◽  
Interaction Network ◽  
Growth Cones ◽  
Extrinsic Factors ◽  
Environmental Signals ◽  
Switching Behaviour ◽  
The Right

For the brain to function properly, its neurons must make the right connections during neural development. A key aspect of this process is the tight regulation of axon growth as axons navigate towards their targets. Neuronal growth cones at the tips of developing axons switch between growth and paused states during axonal pathfinding, and this switching behaviour determines the heterogeneous axon growth rates observed during brain development. The mechanisms controlling this switching behaviour, however, remain largely unknown. Here, using mathematical modelling, we predict that the molecular interaction network involved in axon growth can exhibit bistability, with one state representing a fast-growing growth cone state and the other a paused growth cone state. Owing to stochastic effects, even in an unchanging environment, model growth cones reversibly switch between growth and paused states. Our model further predicts that environmental signals could regulate axon growth rate by controlling the rates of switching between the two states. Our study presents a new conceptual understanding of growth cone switching behaviour, and suggests that axon guidance may be controlled by both cell-extrinsic factors and cell-intrinsic growth regulatory mechanisms.

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