Changes indicating a disturbance of synaptic plasticity and/or induction of nerve cell damage, such as decreased levels of SNAP-25 protein and GLP-1R and GLP-2R receptors, were also present in the frontal cortex, hence its being a structure in which disturbances like those found in the hippocampus are often observed in depression. The gene discussed is GLP1R; the disease is major depressive disorder.