Nystagmus in patients with congenital stationary night blindness (CSNB) originates from synchronously firing retinal ganglion cells

by Beerend H. J. Winkelman, Marcus H. C. Howlett, Maj-Britt H ölzel, Coen Joling, Kathryn H. Fransen, Gobinda Pangeni, Sander Kamermans, Hiraki Sakuta, Masaharu Noda, Huibert J. Simonsz, Maureen A. McCall, Chris I. De Zeeuw, Maarten Kamermans Congenital nystagmus, involuntary oscillating small eye movements, is commonly thought to originate from aberrant interactions between brainstem nuclei and foveal cortical pathways. Here, we investigated whether nystagmus associated with congenital stationary night blindness (CSNB) results from pr imary deficits in the retina. We found that CSNB patients as well as an animal model (nob mice), both of which lacked functional nyctalopin protein (NYX, nyx) in ON bipolar cells (BCs) at their synapse with photoreceptors, showed oscillating eye movements at a frequency of 4 –7 Hz.nob ON direction-selective ganglion cells (DSGCs), which detect global motion and project to the accessory optic system (AOS), oscillated with the same frequency as their eyes. In the dark, individual ganglion cells (GCs) oscillated asynchronously, but their oscillations became synchronized by light stimulation. Likewise, both patient andnob mice oscillating eye movements were only present in the light when contrast was present. Retinal pharmacological and genetic manipulations that blockednob GC oscillations also eliminated their oscillating eye movements, and retinal pharmacological manipulations that reduced the oscillation frequency ofnob GCs also reduced the ...
Source: PLoS Biology: Archived Table of Contents - Category: Biology Authors: Source Type: research