森 勇樹: “Single cell tracking using 11.7T MRI”
For more than a century, scientists have believed that the blood-brain barrier (BBB) is a sacred and impermeable wall, and that maintains the central nervous system (CNS) homeostasis and protects the brain from harmful substances. Yet results from diverse fields show clear and convincing evidence of bidirectional communication between the nervous and immune systems. In addition to brain injuries and neurological diseases, there are now growing evidences that the neural-immune crosstalk may even occur in non-disease conditions, including in the healthy brain. To understand this cross-talk is important because it affects not only brain function but also psychiatric state, emotion, learning, and so on. The dynamical behavior of immune cells in intact/injured CNS has not been well characterized with in-vivo imaging techniques. Non-invasive monitoring of immune cells before/after damage may lead to a greater understanding of the mechanisms of the crosstalk. Ultra high-field 11.7 T MRI with superparamagnetic particles of iron oxide (SPIO) injection can successfully monitor the recruitment of peripheral macrophages into the CNS even in normal as well as abnormal condition. In addition, our novel time-lapse MRI techniques as a tool to monitor dynamic behaviors of cell migration may reveal critical insights into cell behaviors that are not obtained by optical microscopy. I hope we discuss about the possibility of those cellular imaging to understand the neural-immune crosstalk and to reveal the mechanisms of immune cell dynamics in the normal CNS as well as injuries, inflammation and diseases.