SNAP25 and major depressive disorder: Summarizing the changes shown in the tested models, it can be said that in the depression model, changes such as lowering the level of the active form of SREBP-2, SNAP-25 and GLP-2R in the hippocampus and SNAP-25, GLP-1R and GLP-2R in the frontal cortex indicate disturbances in synaptic plasticity in both these brain regions as well as lowering molecules involved in cholesterol synthesis in the hippocampus.