Viral teratogenesis: brain developmental damage associated with maturationstate at time of infection

The rat brain continues to mature after birth and is particularly vulnerabl e to developmental damage following perinatal insult. Borna disease virus ( BDV) infection of postnatal day one (PND-1) rat brain causes a non-encephal itic, persistent infection associated with developmental neuroanatomical an d behavioral abnormalities. To test the hypothesis that BDV infection durin g different brain developmental stages yields variable pathological and cli nical disease sequelae, rats were examined for BDV-induced neuroanatomical and behavioral abnormalities following inoculation with BDV on PND-15, and the findings were compared to those resulting from inoculation on PND-1. Si milar to rats inoculated with BDV on PND-1, PND-15 inoculated rats develope d a persistent infection associated with body weight stunting, abnormal sal t taste preference and hippocampal neuron degeneration. However, unlike rat s infected with BDV on PND-1, PND-15 inoculated rats did not show signs of cerebellar hypoplasia or hyperactivity. Thus, the risk of BDV-induced damag e to specific brain regions, and their associated behaviors, appears, in pa rt, dependent upon the brain's developmental stage at time of BDV-infection . These studies provide evidence of the selective vulnerability of specific neuroanatomic regions and behaviors in developing nervous system to virus- induced damage. (C) 1999 Elsevier Science B.V. All rights reserved.