Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Dying nerves cause even more harm after spinal cord injury


A new study in rats has found that after severe spinal cord injury, molecules intended to help nerves communicate can attack the tissue surrounding the initial injury and cause further damage.

Interestingly, this latent, or secondary, injury develops over days and even weeks after the initial injury. It also appears to cause larger, more debilitating lesions in the spinal cord, said Randy Christensen, the study’s lead author and a postdoctoral researcher in neuroscience at Ohio State University.

Receiving the initial brunt of the secondary trauma seem to be the neurons, or the cells in gray matter. As time passes, however, tissue in the white matter is also destroyed by secondary damage. Oligodendrocytes, the main cell type in white matter, begin to self-destruct during the secondary injury.

Oligodendrocytes protect the white matter’s axons – long, skinny tails attached to nerve cells that carry nerve cell messages throughout the body.

"These long, fragile extensions of nerve cells are probably very vulnerable," Christensen said.

The researchers presented their results Nov. 12 in New Orleans at the annual Society for Neuroscience meeting. Christensen conducted the study with Jacqueline Bresnahan, a professor of neuroscience at Ohio State, and Michael Beattie, the chair of Ohio State’s neuroscience department.

The researchers injected glutamate, tumor necrosis factor-alpha (TNFa) or both molecules into the spinal cords of healthy, uninjured rats. Glutamate is a neurotransmitter, while TNFa is a potent cell stimulator – its function includes stimulating the body’s immune response after injury. Both are released in dangerously high concentrations at the site of a spinal cord injury.

Christensen and his colleagues suspect that glutamate and TNFa work in tandem, essentially over-stimulating the tissue surrounding the original site of damage, causing the surrounding cells to “go into shock” and die.

In these experiments, the rats’ spinal cords weren’t injured, but the injections of glutamate and TNFa mimicked the effects of secondary injury. A group of control rats was injected with albumin, an innocuous protein, to make sure the injection itself hadn’t caused the secondary injury.

The researchers found a delayed reaction . . . the axons near the injection site began breaking two days after injection. In related work, these researchers have found evidence of axons breaking up to fourteen weeks after an injury.

"While we’re not sure why the axons begin to break so long after the initial injection, the cells meant to help the wound heal may get overly excited – so much so that they destroy the axons," Christensen said. “Another possibility is that the protective oligodendrocytes take a couple of days to die, finally exposing the bare axons to damage.

"Preventing over-stimulation caused by glutamate and TNFa together may be a viable strategy for therapeutic intervention after human spinal cord injury."

While there was noticeable nerve cell loss and tissue damage in gray matter 90 minutes after injections, the axons were not affected at this point in time.

By day two after the injection, however, there were large lesions in the white matter surrounding the injection site as well as noticeable damage to the axons.

"The time course is pretty important, because in spinal cord injury, many of the cells don’t die until long after the initial injury," Christensen said. "Dying neurons might release glutamate and TNFa, and that release eventually kills neighboring nerve cells, oligodendrocytes, and axons."

This research was supported by a grant from the National Institutes of Health.

Holly Wagner | OSU
Further information:

More articles from Studies and Analyses:

nachricht Rutgers-led innovation could spur faster, cheaper, nano-based manufacturing
14.02.2018 | Rutgers University

nachricht New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>