Upregulation of MAOA in the hippocampus results in delayed depressive-like behaviors in burn mice

Objective: To observe depressive-like behavior and hippocampus monoamine oxidase A (MAOA) changes in burned mice.

Methods: We tested depression and anxiety like behaviors of burn C57 mice with the sucrose preference test, forced swimming test (FST), open field test and elevated plus maze test and then detected the MAOA content and MAOA gene transcriptional levels in the hippocampus with western blot analysis and real-time quantitative PCR analysis. We then sought to reverse depressive-like behavior of burned mice with an MAOA inhibitor.

Results: (1) Mice showed depressive and anxiety like behaviors one week after they were burned; (2) The content of MAOA in the hippocampus of burned mice was significantly higher than that in control mice (P<0.05); (3) MAOA gene transcription in the hippocampus of burned mice was significantly increased (MAOA mRNA was increased, P<0.05); (4) treatment with a MAOA inhibitor (phenelzine) significantly increased the sucrose preference rate and decreased FST immobility time in burned mice, and also decreased elevated expression of MAOA in the hippocampus of burned mice.

Conclusion: Burned mice showed "delayed" depressive-like behavior combined with a degree of anxiety; this phenomenon is likely associated with the increase in MAOA expression in the hippocampus.