Therefore, this group has developed a new blood vessel casting method and a transparency method optimized for it.First, in the conventional blood vessel casting method, infarction occurred in microvessels because the polymer in the middle of polymerization was poured, so it was considered to start the polymerization after spreading the unpolymerized monomer to all blood vessels. ..Therefore, we succeeded in casting and staining almost all cerebral blood vessels by pouring a fluorescent substance that does not leak from the blood vessels that was originally synthesized from the heart and using a polymerization initiator that initiates polymerization by heating.

　Next, as the most suitable clearing method for this blood vessel casting method, lipid removal using a kind of bile acid salt was performed, and clearing was possible more quickly than the existing method.In addition, by suppressing the swelling of the tissue to about 10%, the whole brain of the mouse is transparent while preventing the rupture of blood vessels and preserving the molecular information of the brain tissue such as blood vessel binding and protein expression. It was shown that it can be converted.

　As an application example of this method, the group discovered the existence of previously unknown microvessels connecting the cortex and hippocampus.In this way, this method is expected to be a useful tool that contributes to the development of cerebrovascular network science, and not only contributes to the elucidation of the pathophysiology of cerebrovascular disorders such as cerebral infarction and cerebral hemorrhage, but also signals obtained from blood vessels. It is expected to contribute to the decoding of functional MRI signals, which is used as an index that correlates with neural activity.

Paper information:[Nature Communications] Visualization and molecular characterization of vascular network with capillary resolution