FIG. 6.

Neuronal lesions associated with apoptosis in brains of MV-infected animals. CD46 transgenic and nontransgenic mice were inoculated 2 days after birth with 3 × 10⁵ TCID₅₀ of MV (Edmonston strain). At day 5 animals were sacrificed, and serial frontal sections from frozen brains were prepared and stained as described in Materials and Methods. Hippocampal areas of TUNEL-stained, phloxine-counterstained transverse sections from brains of MV-infected CD46 transgenic (A) and nontransgenic (B) mice are shown. Pairs of adjacent transverse sections of MV-infected CD46 transgenic mice were processed for TUNEL (C and E) or cresyl violet (D and F) staining at the levels of motor cortex (C and D) and cerebellum (E and F). TUNEL-positive nuclei appear as black dots restricted to neuronal perikarya-enriched layers of the hippocampus (A) and cerebellum (E) and within anatomical boundaries of the primary motor cortex (C). Results are representative for three animals analyzed per group. The scale bar (E) represents 150 μm (A and B) and 100 μm (C to F). CA1 field of the hippocampus Ammonis horn (CA1), dentate gyrus (DG), and pyramidal cell layer of the hippocampus (p) are labeled.