We have an emerging understanding of how retinal circuits work in starlight, when rods dominate retinal inputs, and daylight, when cones dominate retinal inputs. We know much less about how the retina works when rods and cones are coactive?as they are from moonlight to dawn or dusk. Interactions between rod and cone signals under these conditions shape the temporal, chromatic and spatial acuity of vision. Because rod- and cone-derived signals converge upon the same retinal output cells, interactions between these signals are very likely to play a substantial role in shaping perception. The broad goal of our work is to understand the mechanisms that dictate how rod- and cone-mediated signals interact to control retinal outputs and perception. We will focus on three questions: (1) What routes do rod-derived signals take through the primate retina, and does the route depend on light level? (2) Do rod and cone signals adapt independently or are there shared adaptational mechanisms? (3) What circuit mechanisms control integration of time-varying rod and cone signals and what are the consequences for the retinal output and perception? We will answer these questions using electrophysiological recordings of responses from all major cells types in primate retina. Similar issues arise in many other neural circuits; thus, the proposed work will improve our general understanding of neural function.
The ability of rod photoreceptors to detect single photons has helped make rod phototransduction the best understood of the many G-protein cascades in biological systems and has led to direct medical bene?ts. We know much less about the retinal readout of rod and cone signals, particularly under conditions (such as dawn or dusk) when both rods and cones are active and reliable vision is challenging. These lighting conditions span about 30% of the operational range of vision, and include a number of situations, such as night driving, under which vision is essential. The long-term aim of the work described here is to help ?ll this gap in our knowledge, speci?cally in primate retina where we can make a direct connection with human perception and disease.
| Rivlin-Etzion, Michal; Grimes, William N; Rieke, Fred (2018) Flexible Neural Hardware Supports Dynamic Computations in Retina. Trends Neurosci 41:224-237 |
| Grimes, William N; Songco-Aguas, Adree; Rieke, Fred (2018) Parallel Processing of Rod and Cone Signals: Retinal Function and Human Perception. Annu Rev Vis Sci 4:123-141 |
| Grimes, William N; Baudin, Jacob; Azevedo, Anthony W et al. (2018) Range, routing and kinetics of rod signaling in primate retina. Elife 7: |
