A tropical fish study has found clues about the human nervous system that may help multiple sclerosis treatment.
An examination of the transparent zebrafish has shed light on how the nerve network protects itself.
Scientists have discovered "vital" information on how the body produces myelin, a fatty sheath that insulates and protects nerve fibres.
Edinburgh University studied zebrafish because they share more than 80% of the genes associated with human diseases.
The species has also been shown to respond to drugs in a similar way to humans.
Their transparent bodies allows researchers to look directly into their nervous system without surgical or physical intervention.
Myelin is critical for allowing nerve impulses to be transmitted quickly and affects our ability to walk, speak and see.
The scientists found individual cells in the brain and central nervous system have only a matter of hours in which to generate this protective coating.
They are now studying how the manipulation of genes and the use of drugs might promote myelin formation in zebrafish, potentially paving the way for the treatment of myelin-related conditions such as multiple sclerosis.
Myelin is made by specialised cells called oligodendrocytes.
When it breaks down and is not repaired properly it can cause numbness, loss of vision and dizziness.
It also leads to the debilitating symptoms of diseases such as MS.
Although MS patients have an abundance of oligodendrocytes in their brains, these fail to produce sufficient myelin to bring about repair, researchers said.
David Lyons, from Edinburgh University's Centre for neuroregeneration, said: "To enhance myelin repair, we will need to improve either their ability to make myelin during the short time in which they have to do this, or find a way to allow them to produce myelin for a longer period of time."
The study was carried out in collaboration with the university's MRC Centre for Regenerative Medicine and was supported by the Biotechnology and Biological Sciences Research Council, the Lister Institute, the Wellcome Trust and an EMBO fellowship.
The research is being published in Developmental Cell journal.