A mouse model of neurological Lyme disease would be helpful in understanding how patients develop symptoms and how to treat them. Until now, laboratory mice have not developed neuroborreliosis, which mimics human disease with demonstrated colonization of the central nervous system. However, a new report by Divan et al. gives hope that this may be possible. Using two different strains of B. burgdorferi and infecting mice via the skin, the researchers were able to consistently detect spirochetes in the membranes that surround the brain, called the dura and pia mater. Particularly compelling was the fact that they detected spirochetes 75 days after infection, adhering to blood vessels in the dura and pia mater, and that replicating spirochetes could be cultured from these samples. This suggests that long after acute infection, live spirochetes were still present at these sites. There were also more CD3+ T cells present in the dura of infected animals than in uninfected animals, suggesting an immune response. These findings open the door to new ways of studying neuroborreliosis in vivo. By identifying a site in the brain that is consistently colonized by spirochetes, as well as suggesting which immune pathways may be affected, further studies may reveal potential ways to alleviate the suffering of neuroborreliosis patients.
