MAPK1 and major depressive disorder: For example, in the MAPK signaling pathway, mouse model studies have shown that compared with depressed mice, the hippocampus of wild-type mice had higher expression of p-JNK and p-p38 proteins, which indicated that the mitochondrial activated protein kinase (MAPK) pathway was activated, and further research on inflammatory signaling pathways may have a bright future in the prevention and treatment of depression (51).