Live longitudinal imaging of meningeal cerebrovascular injury and its sequelae in adult zebrafish.

Nearly 1.4 million people in the United States sustain a traumatic brain injury (TBI) each year, with almost half of those hospitalized for TBI developing long-term disability. For many patients, prolonged bleeding and inflammation from damaged vessels in the meninges result in longlasting sequelae. Although their injured blood vessels regrow, the site of injury is full of inflammatory immune cells that may influence vascular function. Adult zebrafish have a thin, translucent skull and a mammalian-like meninges that is easily imaged in living animals. We have established a novel adult zebrafish model to investigate vessel-immune cell interactions after meningeal cerebrovascular injury (mCVI). We use carefully calibrated sonication to rupture meningeal blood vessels without breaching the skull or causing damage to the underlying brain. By performing longitudinal live imaging of intubated adult fish we observe vascular regrowth and immune responses to mCVI over time in the same animal with unprecedented resolution allowing measurement of blood flow, dynamics of vessel regrowth, and interactions between individual immune and vascular cells. This newly developed zebrafish model provides a powerful tool for longitudinal live imaging of meningeal immune cell-vascular interactions after cerebrovascular injury, opening the door to new insights into chronic neuroinflammatory disease.