Imaging the role of toll-like receptor 4 on cell proliferation and inflammation after cerebral ischemia by positron emission tomography

The influence of toll-like receptor 4 on neurogenesis and inflammation has been scarcely explored so far by using neuroimaging techniques. For this purpose, we performed magnetic resonance imaging and positron emission tomography with 3′-deoxy-3′-[18F]fluorothymidine and [11C]PK11195 at 2, 7, and 14 days following cerebral ischemia in TLR4+/+ and TLR4−/− mice. MRI showed similar infarction volumes in both groups. Despite this, positron emission tomography with 3′-deoxy-3′-[18F]fluorothymidine and [11C]PK11195 evidenced an increase of neurogenesis and a decrease of inflammation in TLR4−/− mice after ischemia. These results evidence the versatility of neuroimaging techniques to monitor the role of toll-like receptor 4 after cerebral ischemia.

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