TABLE 2.

Heterogeneity in virus load and/or distribution in the brain of LCMV-cgPi mice^a

Animal	Proportion of LCMVNP-positive neurons in different brain regions							Proportion of GFAP-positive astrocytes
	Hippocampus				Cortex	Cerebellum	Meninges	Cortex	Hippocampus	Cerebellum
	DG	CA3	CA2	CA1
1	+++	+++	+++	+++	+++	+++	++	+	−	−
2	+++	+++	+++	+++	+++	+++	++	+	−	−
3	+++	+++	+++	+++	+++	+++	++	+	−	−
4	+	+	+	+	+	++	++	−	−	−
5	++	+++	+++	+++	+++	+++	++	+	−	−
6	++	+++	++	++	+++	++	++	+	−	−
7	+	++	++	++	+++	++	++	−	−	−

^aImmunohistochemical examination of LCMV-cgPi mice. Six-month-old female LCMV-cgPi mice (n = 7) were examined by immunohistochemistry (Fig 2). Virus loads in neurons of the hippocampus dentate gyrus (DG) and regions CA1, CA2, and CA3 as well as the cortex and cerebellum were determined as described in Materials and Methods and are indicated as follows: +++, >30% infected neurons; ++, 10% to 30% infected neurons; +, <10% infected neurons; −, no detectable infection. All mice exhibited significant infection of meninges, choroid plexus, and cells of the ventricle walls. The immunohistochemical analysis of brain sections of mouse 2 is shown in Fig. 2. Some mice showed mild increases in the numbers of GFAP-positive astrocytes in the cerebral cortex but not in the hippocampus or cerebellum.