Spread of hemagglutinating encephalomyelitis virus (HEV) in the CNS of rats inoculated by intranasal route.

Abstract

HEV is known to cause vomiting and wasting disease or encephalomyelitis in piglets (Andries et al., 1980,1981; Mengeling et al., 1972; Roe et al., 1958). In experimental oronasal infection of piglets, the virus spread to the CNS predominantly via the nerve pathways (Andries et al., 1980, 1981). In our previous study, 4-week-old rats died of encephalitis after inoculation by different routes including intranasal route (Hirano et al., 1993). In the infected animals, the virus reaches the CNS through the nerve pathways from peripheral nerve. Our previous studies have demonstrated that HEV propagated through nervous route and its infection was restricted to neurons after inoculation into sciatic nerve or footpad of rats (Hirano et al., 1995, 1998). Our findings suggest that HEV is useful as a trans-synaptic tracer for analyzing neuronal connections in the CNS.