Transient MCAo was performed as previously described with modifications80 (link). For stroke studies 2 weeks after siPtn or control siRNA ICV injections we used 30 minute MCAo and 24 hr reperfusion (Fig. 4l,m); for leucocyte and platelet control immunostaining we used 3 h MCAo and 24 h reperfusion (Fig. S5c); for edema (ADC) values after stroke we used 1 h MCAo and 15 days reperfusion (Fig. S5g). Infarction volume was determined as previously described80 (link). Fluoro-Jade B staining (EMD Millipore, AG310) was performed per manufacturer’s instructions.