HPLC-MS composition of fatty acids esterified to cholesterol in brain extracts of uninfected, scrapie-infected, and scrapie-infected PRV-treated C57BL/6 mice. A) concentration of linoleic (C18:2) and arachidonic (C20:4) acid expressed in micromoles/g of brain tissue. Values represent the mean ± SD of triplicate determinations and are representative of at least three independent trials; B) each fatty acid as percentage of total cholesteryl esters (CE). Variation of C20:4 among groups, i.e. uninfected, Scrapie-infected, and PRV-treated Scrapie-infected, is statistically significant by ANOVA (p = 0.001).