Cerebral edema is a dangerous complication in many brain-related conditions such as strokes. Researchers at the Institute of Neurobiology at Heinrich Heine University Düsseldorf (HHU) have developed a new measurement method in collaboration with colleagues from Bonn and with the involvement of a Berlin-based optoelectronics company that enables better understanding of the cellular causes of cerebral edema. In the latest issue of the The Journal of Neuroscience they describe how the TRPV4 ion channel in particular plays an important role.