Neurobiology graduate student Kiersten Ruda (Field Lab) presents her dissertation seminar Retinal Ganglion Cell Population Codes from Starlight to Sunlight. Email DGSA LaDonna Huseman for connection details.
Abstract: The retina conveys visual information to the brain with the parallel channels of different retinal ganglion cell (RGC) types, whose signals ultimately lead to visual perception. Between cloudy nights and sunny days, the retina must combat the trillion-fold change in mean light intensity to successfully transmit visual information. The nature of both signal and noise in RGC populations is altered across this broad range of light levels, creating a rich problem of how visual messages are encoded by the retina and processed by the brain. I addressed these topics using large-scale multielectrode array recordings of RGC populations in different light conditions. First, I characterized how retinal signaling is altered over a wide range of light intensities. I then investigated how adaptation impacts visual encoding of different RGC types. My results suggest that although retinal computations change substantially over light conditions, there are some elements of visual encoding that are invariant to light adaptation. Finally, I examined adaptation-induced changes in the structure of correlated activity and the subsequent impact on processing retinal output. These findings clarify the nature of RGC responses crucial for downstream readout across light levels. Overall, this work identifies aspects of RGC activity that are important for encoding visual information and decoding retinal output from starlight to sunlight.