Illuminating the Function of the Hydroxyl Radical in the Brains of Mice with Depression Phenotypes by Two-Photon Fluorescence Imaging

Depression is intimately linked with oxidative stress. As one of the most reactive and oxidative Reactive Oxygen Species that is overproduced during oxidative stress, the hydroxyl radical (^. OH) can cause macromolecular damage and subsequent neurological diseases. However, due to the high reactivity and low concentration of ^. OH, precise exploration of ^. OH in brains remains a challenge. The two-photon fluorescence probe MD-B was developed for in situ ^. OH imaging in living systems. This probe achieves exceptional selectivity towards ^. OH through the one-electron oxidation of 3-methyl-pyrazolone as a new specific recognition site. MD-B can be used to map ^. OH in mouse brain, thereby revealing that increased ^. OH is positively correlated with the severity of depression phenotypes. Furthermore, ^. OH has been shown to inactivate deacetylase SIRT1, thereby leading to the occurrence and development of depression phenotypes. This work provides a new strategy for the future treatment of depression.

depression; fluorescence imaging; fluorogenic probes; hydroxyl radicals; oxidative stress.