A Common Cause for Nystagmus in Different Congenital Stationary Night Blindness Mouse Models

Abstract

AbstractInNyxnobmice, a model for congenital nystagmus associated with congenital stationary night blindness (CSNB), synchronous oscillating retinal ganglion cells (RGCs) lead to oscillatory eye movements, i.e., nystagmus. Given the distribution ofmGluR6andCav1.4in the retina as well as their clinical association with CSNB, we hypothesize thatmGluR6-/-andCav1.4-/-mutants show, like theNyxnobmouse, oscillations that originate in the AIIamacrine cells (AIIACs). Using eye movement and multi-electrode array (MEA) recordings of RGCs we show that the nystagmus as well as the underlying RGC oscillations are also present inmGluR6-/-andCav1.4-/-mice. Yet, we find that the oscillations in themGluR6-/-andCav1.4-/-mutants slightly differ from each other and also from those of theNyxnobmice. Moreover, each of the three mutations likely impacts the membrane potential of the AIIACs differently. Together our results indicate that nystagmus and oscillating RGCs are generalizable features associated with CSNB mutations localized at the photoreceptor-bipolar cell synapse.