This image depicts a Müller glia cell regenerating neurons in vivo in an adult mouse retina. Müller glia cells are the primary glia in the vertebrate retina. In species such as fish and amphibians, these glia can regenerate functional neurons after neurodegeneration. However, in mammalian species, Müller glia do not naturally regenerate neurons and instead activate an inflammatory response to neurodegeneration. See the article by Nicolai Blasdel et al. for information on how the authors developed ways to overcome this inflammation barrier to regeneration in the mammalian retina. Cover image: Levi Todd.