DOT1L and depressive symptom measurement: In adult mice, knockout of the DOT1L or overexpression of the KDM2B in NAc D2-MSN neurons attenuated maternal separation-induced depression-like behavior, including increased social interaction, increased open field exploration, and decreased despair-like behaviors, whereas the same treatment in Nac D1-MSNs had no changes in depression-like behaviors (Kronman et al., 2021).