Retinal Defects in Mice Lacking the Autism-Associated Gene Engrailed-2

Publication date: Available online 10 April 2019Source: NeuroscienceAuthor(s): Xuwen Zhang, Ilaria Piano, Andrea Messina, Vanessa D'Antongiovanni, Fabiana Crò, Giovanni Provenzano, Yuri Bozzi, Claudia Gargini, Simona CasarosaAbstractDefective cortical processing of visual stimuli and altered retinal function have been described in autism spectrum disorder (ASD) patients. In keeping with these findings, anatomical and functional defects have been found in the visual cortex and retina of mice bearing mutations for ASD-associated genes. Here we sought to investigate the anatomy and function of the adult retina of Engrailed 2 knockout (En2−/−) mice, a model for ASD. Our results showed that En2 is expressed in all three nuclear layers of the adult retina. When compared to age-matched En2+/+ controls, En2−/− adult retinas showed a significant decrease in the number of calbindin+ horizontal cells, and a significant increase in calbindin+ amacrine/ganglion cells. The total number of ganglion cells was not altered in the adult En2−/− retina, as shown by Brn3a+ cell counts. In addition, En2−/− adult mice showed a significant reduction of photoreceptor (rhodopsin) and bipolar cell (Pcp2, PKCα) markers. Functional defects were also present in the retina of En2 mutants, as indicated by electroretinogram recordings showing a significant reduction in both a-wave and b-wave amplitude in En2−/− mice as compared to controls. These data show for the first time that anatomi...
Source: Neuroscience - Category: Neuroscience Source Type: research