Connexins, Pannexins, and Epilepsy

Excerpt

Connexins are proteins that form gap junctions which “connect” cells together, permitting the passage of small molecules and electricity. Since epilepsy is thought of as a disease of neuronal hypersynchrony, it is natural to consider these molecules with the gap junctions they form as playing a significant role in epilepsy. Over time, the “connections” of connexins to epilepsy are becoming more complicated and deeper. Adding to the complexity was the discovery of a family of membrane channels, the pannexins, which were initially mistaken for a second family of gap junction forming proteins. However, they, too, clearly play a major role in epilepsy. Herein we start with an introduction to the complex biology of both protein classes, followed by discussions of their multiple roles in epilepsy. These include such phenomena as direct intercellular communication between neurons and more recently, between glia, now increasingly recognized as key players in epilepsy. Also, the functions of membrane channels formed by connexins (hemichannels) and pannexins in promoting seizure activity and pathological consequences are discussed.