Neurologic Alterations Due to Respiratory Virus Infections

Bohmwald, Karen; Gálvez, Nicolás M. S.; Ríos, Mariana; Kalergis, Alexis M.

HCoV capacity to reach CNS after the nasal infection has been described previously in mice, particularly for HCoV-OC43 (St-Jean et al., 2004) . St-Jean et al. (2004) reported that upon infection, viral antigens are detected in the olfactory bulb 3 days later, with no presence of virus in perivascular blood cells or any other part of the brain. After 7 days, the virus is detected throughout the whole brain tissue, indicating that it can rapidly propagate once set in CNS. This replication leads to a rapid death by acute encephalitis of infected mice. Remarkably, ablation of the olfactory bulb prevented the spread of mouse hepatitis virus (MHV), upon nasal infection (Perlman et al., 1990) . Therefore, HCoV exhibits an intrinsic capability to infect neural cells and spread from CNS to the periphery via a transneural route, as has also been seen for MHV (Perlman et al., 1990; Barthold et al., 1990 ; Figure 3) .