Transcript analysis of astroglial and microglial markers in thalamic RNA samples from mice infected with scrapie strains 22L, RML, or ME7.

<p>(A) The ΔC_T of <i>Gfap</i>, an indicator of astroglial activation (open circles), showed astrogliosis was significantly increased early in 22L-infected thalamus (40 dpi) and increased further at 60 and 80 dpi. Infection with RML reached a similar increase in <i>Gfap</i> by 60 dpi, whereas ME7-infected mice demonstrated a significant increase in <i>Gfap</i> similar to that of RML and 22L by 80 dpi. Likewise, the ΔC_T of <i>Gpr84</i>, an indicator of microglial activation (closed circles), illustrated a temporal increase in thalamic expression during infection by all three scrapie strains tested, albeit delayed by 20 dpi relative to <i>Gfap</i>. The dashed horizontal line indicates the mean ΔC_T of <i>Gfap</i> and the solid horizontal line indicates the mean <i>Gpr84</i> ΔC_T in mock infected mice. (B) The relatively unchanged expression of vimentin (<i>Vim</i>), an astrocyte associated gene, or the chemokine receptor <i>Cx3cr1</i>, a microglia associated gene, suggested the early transcriptional changes observed in the gliosis markers <i>Gfap</i> and <i>Gpr84</i> in infected thalamus were not due to an overt expansion of either cell population. The dashed horizontal lines indicate the mean ΔC_T in mock infected mice as a reference. The bars for all samples indicate the mean and 1 standard deviation. The ΔC_T for each mouse RNA sample was calculated by subtracting the geometric mean C_T of three housekeeping genes (<i>Actin</i>, <i>Gapdh</i>, and <i>Hsp90ab1</i>) from the C_T of the gene of interest. Each dot represents an individual mouse.