Dysfunction of astrocytic connexins 30 and 43 in the medial prefrontal cortex and hippocampus mediates depressive-like behaviours.

Astrocytic connexin dysfunction is closely associated with synaptic impairment and contributes to the pathological development of depressive-like behaviours. However, little is known about the expression of connexins in astrocytes from different brain regions, or how tissue specific connexin expression affects local neuronal activity. Here, we established a mouse model of chronic social defeated stress (CSDS), from which we isolated astrocytes from the medial prefrontal cortex (mPFC), hippocampus, amygdala, and ventral tegmental area (VTA). Expression profiling was then performed for connexins Cx26, Cx30, and Cx43. Expression of Cx30 and Cx43 was significantly decreased in mPFC and hippocampus of CSDS mice and was strongly associated with decreases in neuronal activity. Furthermore, overexpression of Cx30 and Cx43 in the mPFC and hippocampus increased neuronal activity and inhibited depressive-like behaviours; while suppression of Cx30 and Cx43 in normal mice was sufficient to reduce neuronal activity and induced depressive-like behaviours. Taken togetner, aberrant expression of astrocytic Cx30 and Cx43 in the mPFC and hippocampus significantly affects brian region-specific neuronal activity and drives depressive-like behaviours. These observations provide novel insights into the role of astrocyte gene expression in stress-induced depressive-like behaviours.