Vision begins in specialized photoreceptor cells, the rods and cones in the retina. These receptors absorb light and transform this information into electrical signals that are processed by the retinal circuitry. The most sensitive signal is carried in a specialized pathway called the Rod Bipolar Pathway, or the Primary Rod Pathway. Studies of rod phototransduction for several decades have revealed a complex signaling pathway that controls the shape of the rod photoresponse, but what happens downstream of rod phototransduction is less well understood. The Pahlberg Lab mission is to find out mechanisms and strategies used by the retina to increase sensitivity and maximize the encoded information in the Primary Rod Pathway.
The Primary Rod Pathway is a conserved pathway in all mammalian retinas, where the rod photoreceptors send information about absorbed photons to dedicated Rod Bipolar Cells.
The vertebrate retina, which is a part of the brain, is the best model system to study how the processing of signals and noise is optimized in a neural circuitry. The retina is quite easily accessible for experiments, we can control the natural stimulus precisely, we can calculate how many photons a specific light stimulus contains, we can record the electrical response in every layer of the retina, and the relation to behavior is quite clear. By studying the relationship between molecular mechanisms, retinal physiology, and behavior, we will investigate how neural processing in the retina shapes the signals relevant for visually-guided behavior at different light levels. A greater understanding of rod vision and the pathways that mediate vision in dim light also support the long-term goal to understand disorders due to deficiencies in the rod circuitry.