GJA1 and Parkinson disease: Studies in a 6-hydroxydopamine (6-OHDA)-induced rat model of PD showed that levels of Cx30, but not of Cx43, the two major gap junction connexins (Cxs) in astrocytes, were increased in the striatum of 6-OHDA rats, suggesting that Cx30 levels may be associated with the disease process [14].