Müller glia are a potential source of neural regeneration in the postnatal chicken retina

The retina of warm-blooded vertebrates is believed to be incapable of neural regeneration. Here we provide evidence that the retina of postnatal chickens has the potential to generate new neurons. In response to acute damage, numerous Müller glia re-entered the cell cycle, and shortly thereafter, expressed CASH-1, Pax6 and Chx10, transcription factors expressed by embryonic retinal progenitors. These progenitor-like cells transiently expressed neurofilament. Newly formed cells became distributed throughout the inner and outer nuclear layers of the retina, and remained for at least three weeks after damage. Some of these newly formed cells differentiated into retinal neurons, a few formed Müller glia, and most remained undifferentiated, with continued expression of Pax6 and Chx10. These cells continued to proliferate when grown in culture, with some differentiating into retinal neurons or Müller glia. We propose that, in response to damage, Müller glia in the retina are a potential source of neural regeneration.