Initiation of Retina Regeneration By a Conserved Mechanism of Adult Neurogenesis

Abstract Retina damage or disease in humans often leads to reactive gliosis, preventing the formation of new cells and resulting in visual impairment or blindness. Current efforts to repair damaged retinas are inefficient and not capable of fully restoring vision. Conversely, the zebrafish retina is capable of spontaneous regeneration upon damage, using Müller glia (MG) derived progenitors. Understanding how zebrafish MG initiate regeneration may help develop new treatments that prompt mammalian retinas to regenerate. Here we show that inhibition of GABA signaling facilitates initiation of MG proliferation. GABA levels decrease following damage, and MG are positioned to detect the decrease. Using pharmacological and genetic approaches we demonstrate that GABAA receptor inhibition stimulates regeneration in undamaged retinas while activation inhibits regeneration in damaged retinas. GABA induced proliferation causes upregulation of regeneration associated genes. This is the first evidence that neurotransmitters control retina regeneration in zebrafish through an evolutionarily conserved mechanism of neurogenesis.