Fig. 1.
siRNA-induced specific, temporal, and widespread knockdown of EGFP mRNA in the brain. EGFP-expressing mice received an infusion of vehicle, EGFP-targeting siRNA, or scrRNA into the dorsal third ventricle for the indicated time. EGFP mRNA levels were reduced, in a temporal fashion, in several brain regions of mice infused with siRNA as compared with levels in vehicle- and scrRNA-treated mice. Levels of GABAAα2 mRNA were unaffected. (A) Low-magnification (×10), dark-field photomicrographs of representatives of in situ hybridization with EGFP (Left) and GABAAα2 (Right) riboprobes in adjacent coronal brain sections, after emulsion-dipping of slides. (B) Densitometric quantification of mRNA-positive grains in each brain region is expressed as percent OD values of those in corresponding regions from vehicle-treated mice. Bars represent means ± SEM of 16–36 observations (four to six observations per animal and four to six animals per group). *, P < 0.05; **, P < 0.01; ***, P < 0.001, significantly different from vehicle- and scrRNA-treated mice in each brain region. #, P < 0.05; ###, P < 0.001, significantly different from siRNA treatment for 1 week in the same region, two-way ANOVA followed by Tukey's post hoc test.