[Crazy horse disease].

This research discusses “Borna disease,” formerly known as an “ancient enzootic encephalo-myelitis” or “crazy horses disease.” The disease, which was thought to be viral and known to cause encephalopathy in various animal species, was found to have a presence in humans with psychiatric pathologies. The research also showcases the discovery of sequences in mammalian genomes, including humans, homologous to Borna’s nucleoprotein gene, leading scientists to question their function and how they integrated two million years ago.

Borna Disease and its History

• The so-called “crazy horses disease” was actually an old enzootic encephalo-myelitis, known since the 17th century.
• It was renamed as “Borna disease” in 1970, because severe outbreaks affecting horses were reported in this city of Germany since 1885.
• The disease was initially thought to be a prion disease like the “crazy cows disease” that appeared at the end of the 20th century, but it turned out to be viral instead.

Link to Encephalopathy and Other Species

• Borna disease has been reported to cause encephalopathy, a disease that affects the brain, in a number of animal species.
• The virus has not only been found in horses but also in various other mammals.
• The researchers found that the virus was also present in humans, specifically those with psychiatric pathologies, triggering an incentive to further research in the last decades of the twentieth century.

The Genome Structure of Bornavirus

• After much research, the genome structure of the Bornavirus, the virus causing Borna disease, was completely described.
• This significant progress in understanding the virus was a crucial step towards decoding its functions and behaviors.

Discovery of Endogenous Borna-like N (EBLN) Elements

• More recent discoveries by Japanese researchers found that elements related to the nucleoprotein gene of Bornavirus exist in the genomes of several mammalian species, including humans. These sequences are referred to as endogenous Borna-like N (EBLN) elements.
• This discovery raises questions about the function of EBLN elements within these genomes, especially considering that they are believed to have been integrated into their current locations about two million years ago.