Neurons communicate with one another via long cable-like structures called axons. Failure to maintain the integrity of the axon results in compromised neuronal function, which is characteristic of both traumatic injury and neurodegenerative diseases.
Researchers at UQ’s Queensland Brain Institute (QBI) and the School of Biomedical Sciences have discovered a nanoscale molecular scaffold that exists in the tissue that surrounds the axon that protects sensory axons from degenerating.
According to Dr Sean Coakley and Professor Massimo Hilliard from QBI’s Clem Jones Centre for Ageing Dementia Research this discovery shows that the protective skin and nervous system work together to keep nerve connections strong.
“Axons are under constant strain as our body moves, for example as our arms and legs flex during everyday tasks," Dr Coakley said.
"Yet under normal circumstances they remain intact for our entire lifetime.
“Axonal damage disrupts the connections between neurons and is a devastating event for the normal brain and body function.
"This discovery tells us that neurons aren't protected only from inside; they also rely on outside support from surrounding tissues."
Professor Hilliard said that the structure of the axon is thought to be preserved by an internal scaffold of nanometre sized trusses and beams, made of molecules called spectrins.
“We discovered a similar spectrin scaffold that is present in the tissue that surrounds the axons and that is necessary to protect the axon,” he said.
“In the roundworm C. elegans, as well as in humans and other species, the sensory axons that are necessary to detect touch, temperature and pain are embedded in the skin.
“We have revealed the existence of an ‘imprint’ of the nervous system within the skin; much like having a molecular ‘skin cast’ that protects the underlying axons from mechanical trauma and degeneration.”
Dr Bonacossa-Pereira, a contributing author of this study, said this new knowledge can inform and re-direct existing and novel therapies aimed at protecting the axonal structure and function.
“Spectrins are present and conserved in all animals, which suggests these molecules are a critical building block,” Dr Bonacossa-Pereira said.
“Focusing on their function in the tissue surrounding the axon might uncover new ways of treating and preventing injury and disease.”
This research was published in the journal Science Advances and featured on the cover.
