Fig. 4.

Neurovirulence scoring from neonatal rat brains 25 days after inoculation with JL-CK, RIT4385 or Mu90. Neurovirulence calculated by measuring the cross-sectional areas of the ventricles expressed as the percentage of the cross-sectional area of the whole brain. The data shown is from nine brains from each group (except Mu90, n = 3), with measurements taken from four sections of each brain. JL-CK showed a significant increase in neurovirulence score compared to RIT4385 (*p = 0.0035 unpaired two-tailed t-test). As a control, the neurovirulent Mu90 strain cause significantly higher scores than JL-CK, RIT4385 or uninfected control (**p < 0.0001 unpaired two-tailed t-test for all).