The dysfunction of astrocytes is closely related to the development of various neurodegenerative diseases, and one of the important mechanisms is the abnormality of gap junctions. Gap junctions are primarily composed of connexins (Cx), and they serve as the main structures for metabolic and ionic coupling, as well as electrical transmission between adjacent cells. Cx43 and Cx30 are the most abundant Cx subtypes in the brain, with Cx43 being predominant. The content or distribution of Cx43 in the brain is closely associated with the development of Alzheimer’s disease (AD). This article provides an overview of the relationship between Cx43 and AD.