Figure 2.

Temporal dynamics of [¹⁸F]DPA-714 and [¹⁸F]BR-351 uptake after transient middle cerebral artery occlusion (tMCAo). Dual micro positron emission tomography (μPET) imaging employing [¹⁸F]DPA-714 and [¹⁸F]BR-351 was performed at four different time points after tMCAo (24 to 48 hours, 7 days, 14 days, and 21 days). Lesion to contralateral (L/C) ratios were calculated. (A) Representative images of different animals showing time-dependent radiotracer uptake were depicted at areas with the largest/highest extent of radiotracer uptake at a given time point. (B) [¹⁸F]DPA-714 uptake was significantly increased from day 7 (L/C: 1.77±0.39; ANOVA, *P<0.05; n=8), peaked at day 14 (L/C: 2.81±0.76; ANOVA, ***P<0.001; n=8), and was still significantly elevated 21 days after tMCAo (L/B: 2.14±0.46; ANOVA, ***P<0.001; n=7). [¹⁸F]BR-351 was significantly increased after 24 to 48 hours after tMCAo (L/B: 1.37±0.19; ANOVA, *P<0.05; n=8), and 7 days (L/B: 1.47±0.39; ANOVA, *P<0.05; n=8). (C) Individual quantification of [¹⁸F]DPA-714 (left) and [¹⁸F]BR-351 (right). [¹⁸F]DPA-714 uptake is significantly increased in the infarct compared with the contralateral reference region at day 7 (t-test, **P>0.01; n=8), day 14 (t-test, ***P<0.001; n=8) and day 21 (t-test, ***P<0.001; n=7). [¹⁸F]BR-351 uptake is significantly increased in the infarct 24 to 48 hours (t-test, *P<0.05; n=8) and 7 days (t-test, *P<0.05; n=8) after tMCAo. Data are represented as ratio±s.d.