In experimental species it provides an informative model for study of persistent CNS infections. Experimental Borna Disease, based selleck chemicals on well-characterized rodent models of viral-induced neuroinflammation and degeneration and dependant on host strain, genetics and age of exposure, is used for study of acute and chronic CNS infections and their treatments. Male Lewis rats infected at adolescence develop persistent infection, inflammation and regional neurodegeneration (Narayan et al., 1983, Solbrig et al., 1994 and Planz et al.,
1995). One week treatment of adolescent-infected Lewis rats (BD rats) by the general cannabinoid agonist WIN55,212-2 (with CB1 and CB2 receptor activity) limits reactive gliogenesis and macrophage activity in favor of new cell, particularly oligodendroglia, development. The neuroprotective effect depends on restricting microglial activation and is independent of endocannabinoid (anandamide, 2-AG) levels
and antiviral effect (Solbrig et al., 2010). Here, we test the efficacy of the general cannabinoid agonist WIN 55,212-2 and compare it with the more specific CB2 agonist HU-308 as adjunctive Gefitinib long-term therapy in chronic viral encephalitis. Since CB2 receptors are upregulated in response to lesion or inflammation in a variety of cell types (Cabral and Griffin-Thomas, 2009), are known to be renewed during microglia proliferation and action (Maresz et al., 2005 and Racz et al., 2008), and inhibit populations of microglia/macrophages after neural injuries (Zarruk et al., 2012), we test the specific hypothesis that administration of a selective CB2 agonist provides sustained neuroprotective and anti-inflammatory effects. BrdU immunohistochemistry (IHC) was used to quantify 14 day old BrdU+ cells, a measure of precursor cell survival. PFC subfields, or the striatum plus subventricular zone (SVZ), were combined for quantitative much analysis. BrdU cell counts in both regions were significantly decreased in BD rats compared to NL uninfected rats [BD vs. NL p<0.001]. BrdU counts in PFC and striatum of BD rats were unchanged by WIN [for PFC BD vs. BD+WIN p>0.05 Tukey's post hoc following significant ANOVA F(3,16)=64.46 p<0.0001; for striatum BD vs. BD+WIN p>0.05 Tukey's
post hoc following significant ANOVA F(3,16)=48.30 p<0.0001] (Experiment 1)( Fig. 1A). Double label IHC with cell-type specific markers were used to evaluate phenotype of new cells. ED1 antibody, which recognizes an antigen in lysosomal membranes of phagocytes, is expressed by activated microglia and the majority of tissue macrophages (Bauer et al., 1994). Here, ED1 antibody with BrdU labeling would identify newly generated cells of microglia/macrophage lineage and phagocytosed BrdU cells. Each of the BD groups was compared to NLs. When percentages of NG2/BrdU, GFAP/BrdU, NeuN/BrdU and ED1/BrdU colabeled cells were compared, the greatest changes were significant increases in percentage of ED1 double labeled cells, in BD and BD+WIN animals [PFC BD vs. NL χ2=33.