Paradoxical sleep deprivation modulates depressive-like behaviors by regulating the MAOA levels in the amygdala and hippocampus.

Paradoxical sleep is closely associated with depression, and brain monoamine oxidase A (MAOA) plays an important role in depression. However, the precise relationship between sleep and depression and the role of MAOA in this process remains unknown. Therefore, we established a paradoxical sleep deprivation model using the "multiple small platforms over water" protocol. Mice deprived of paradoxical sleep for 3days showed no depressive-like behaviors; however, mice deprived of paradoxical sleep deprivation for 5days (P5d) showed decreased locomotive activity in the first 3days after P5d. Additionally, the P5d mice showed depressive-like behaviors one week after P5d, with a longer immobility time and a decreased sucrose preference rate. In addition, the levels of the MAOA protein and mRNA in the amygdala and hippocampus significantly increased. Furthermore, the immobility time and sucrose preference rate of P5d mice recovered when the mice were injected with phenelzine. The P5d mice displayed depressive-like behaviors, which were likely modulated by the MAOA levels in the amygdala and hippocampus.