Inflections in threshold electrotonus to depolarizing currents in sensory axons

2007 ◽  
Vol 36 (6) ◽  
pp. 849-852 ◽  
Author(s):  
David Burke ◽  
James Howells ◽  
Louise Trevillion ◽  
Matthew C. Kiernan ◽  
Hugh Bostock
Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 73
Author(s):  
Bilal El Waly ◽  
Vincent Escarrat ◽  
Jimena Perez-Sanchez ◽  
Jaspreet Kaur ◽  
Florence Pelletier ◽  
...  

The extension of the lesion following spinal cord injury (SCI) poses a major challenge for regenerating axons, which must grow across several centimetres of damaged tissue in the absence of ordered guidance cues. Biofunctionalized electroconducting microfibres (MFs) that provide biochemical signals, as well as electrical and mechanical cues, offer a promising therapeutic approach to help axons overcome this blind journey. We used poly(3,4-ethylenedioxythiophene)-coated carbon MFs functionalized with cell adhesion molecules and growth factors to bridge the spinal cord after a partial unilateral dorsal quadrant lesion (PUDQL) in mice and followed cellular responses by intravital two-photon (2P) imaging through a spinal glass window. Thy1-CFP//LysM-EGFP//CD11c-EYFP triple transgenic reporter animals allowed real time simultaneous monitoring of axons, myeloid cells and microglial cells in the vicinity of the implanted MFs. MF biocompatibility was confirmed by the absence of inflammatory storm after implantation. We found that the sprouting of sensory axons was significantly accelerated by the implantation of functionalized MFs after PUDQL. Their implantation produced better axon alignment compared to random and misrouted axon regeneration that occurred in the absence of MF, with a most striking effect occurring two months after injury. Importantly, we observed differences in the intensity and composition of the innate immune response in comparison to PUDQL-only animals. A significant decrease of immune cell density was found in MF-implanted mice one month after lesion along with a higher ratio of monocyte-derived dendritic cells whose differentiation was accelerated. Therefore, functionalized carbon MFs promote the beneficial immune responses required for neural tissue repair, providing an encouraging strategy for SCI management.


Neuron ◽  
1993 ◽  
Vol 10 (4) ◽  
pp. 741-752 ◽  
Author(s):  
David J. Merritt ◽  
Andrew Hawken ◽  
Paul M. Whitington

1979 ◽  
Vol 57 (11) ◽  
pp. 1251-1255
Author(s):  
M. A. Bisby ◽  
C. E. Hilton

A previous study by McLean and co-workers reported that regenerating axons of the rabbit vagus nerve were unable to sustain axonal transport in vitro for several months after nerve injury. In contrast, we found that sensory axons of the rat sciatic nerve were able to transport 3H-labeled protein into their regenerating portions distal to the site of injury within a week after injury when placed in vitro. Transport in vitro was not significantly less than transport in axons maintained in vivo for the same period. Transport occurred in the medium that was used by the McLean group, but was significantly reduced in calcium-free medium. When axon regeneration was delared, only small amounts of activity were present in the nerve distal to the site of injury, showing that labeled protein normally present in that part of the nerve was associated with axons and was not a result of local precursor uptake by nonneural elements in the sciatic nerve. We were not able to explain the failure of McLean and co-workers to demonstrate transport in vitro in regenerating vagus nerve, but we conclude that there is no general peculiarity of growing axons that makes them unable to sustain transport in vitro.


Brain ◽  
2014 ◽  
Vol 137 (11) ◽  
pp. 2922-2937 ◽  
Author(s):  
Janina Hantke ◽  
Lucy Carty ◽  
Laura J. Wagstaff ◽  
Mark Turmaine ◽  
Daniel K. Wilton ◽  
...  

Development ◽  
1991 ◽  
Vol 113 (Supplement_2) ◽  
pp. 131-139 ◽  
Author(s):  
Roger J. Keynes ◽  
Karen F. Jaques ◽  
Geoffrey M. W. Cook

The guidance of axons during embryonic development is likely to involve both adhesive and repulsive interactions between growth cones and their environment. We are characterising the role and mechanism of repulsion during the segmental outgrowth of motor and sensory axons in the somite mesoderm of chick embryos. Axons are confined to the anterior half of each somite by the expression in the posterior half of a glycoconjugate system (48×103Mr and 55×103Mr) that causes the collapse of dorsal root ganglion growth cones when applied in vitro. Enzymatic cleavage of this fraction with specific combinations of endo- and exoglycosidases removes collapse activity, suggesting that carbohydrate residues are involved in the execution of collapse. A similar activity is also detectable in normal adult grey matter, suggesting roles for repulsion beyond the development of spinal nerve segmentation.


2000 ◽  
Vol 23 (4) ◽  
pp. 498-506 ◽  
Author(s):  
Qing Yang ◽  
Ryuji Kaji ◽  
Nobuyuki Hirota ◽  
Yasuhiro Kojima ◽  
Tsunekazu Takagi ◽  
...  

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