Susceptibility of primary culture neurons from rats of different ages to encephalomyocarditis (EMC) virus infection.
The changes in susceptibility of neurons to the D variant of EMC virus (EMC-D) (10(6) PFU/well) were investigated in developing hippocampal primary cultures from postnatal days of 1, 7, and 56 Fischer 344 rats (P1, P7, and P56) for up to 12 h after infection (12 HAI). The virus titer of primary culture neurons increased at 1 HAI, decreased at 2 HAI, increased at 3 HAI, peaked at 8 HAI, and decreased at 12 HAI in all age groups. The titers at 1 and 8 HAI were lowest in P56 cultures. The virus titer of neurons was always higher than that of culture media, especially at 1 HAI, in P1 cultures, whereas the former was lower than the latter from 2 to 3 HAI in P7 cultures and from 2 to 4 HAI in P56 cultures, respectively. Signals of viral RNA detected by in situ hybridization were first observed in the peripheral cytoplasm of neurons at 1 HAI in P1 and P7 cultures and at 4 HAI in P56 cultures, respectively. The signals spread to a large or whole area of cytoplasm and also to processes thereafter. The number of viral RNA-positive neurons and the amount of signals decreased with age. The present results indicated that the susceptibility of primary culture neurons to EMC-D decreased with age but viral replication still occurred in P56 cultures.
D000375:Aging; D000818:Animals; D000956:Antigens, Viral / Q000032:analysis; D046508:Culture Techniques; D004198:Disease Susceptibility; D004686:Encephalomyocarditis virus / Q000502:physiology*; D006624:Hippocampus / Q000166:cytology; D017403:In Situ Hybridization; D009474:Neurons / Q000821:virology*; D015347:RNA Probes; D012367:RNA, Viral / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D014779:Virus Replication
D000956:Antigens, Viral; D015347:RNA Probes; D012367:RNA, Viral