Expression levels of Cx43 and Cx30 proteins, the two predominant gap junctions subunits in astrocytes, as well as their mRNAs have been found reduced in postmortem tissue from MDD patients and animal models of depression [94, 95] in brain regions involved in mood regulation, such as the PFC [93], orbitofrontal cortex [96], hippocampus [94], locus coeruleus [97], mediodorsal thalamus and caudate nucleus [98]. This evidence concerns the gene GJA1 and major depressive disorder.