Experimental herpes simplex virus infection in the immature mouse brain.

Mice of different ages during the postnatal development were injected intracerebrally with herpes simplex virus, type 1. Ultrastructurally, virus particles were demonstrated in the undiffereniated neuroectodermal cells of the subventricular zone and in the external layer of the cerebellum. Virus particles were also seen in endothelial cells of immature animals. The virus gave rise to an acute infection; which caused more extensive necrosis and bleeding in the cerebrum and cerebellum of the immature than the older mice.