title: The ON Crossover Circuitry Shapes Spatiotemporal Profile in the Center and Surround of Mouse OFF Retinal Ganglion Cells.
abstract: Retinal ganglion cells (RGCs) are often grouped based on their functional properties. Many of these functional properties, such as receptive field (RF) size, are driven by specific retinal circuits. In this report, we determined the role of the ON bipolar cell (BC) mediated crossover circuitry in shaping the center and surround of OFF RGCs. We recorded from a large population of mouse RGCs using a multielectrode array (MEA) while pharmacologically removing the ON BC-mediated crossover circuit. OFF sustained and transient responses to whole field stimuli are lost under scotopic conditions, but maintained under photopic conditions. Though photopic light responses were grossly maintained, we found that photopic light response properties were altered. Using linear RF mapping, we found a significant reduction in the antagonistic surround and a decrease in size of the RF center. Using a novel approach to separate the distinct temporal filters present in the RF center, we see that the crossover pathway contributes specifically to the sluggish antagonistic filter in the center. These results provide new insight into the role of crossover pathways in driving RGCs and also demonstrate that the distinct inputs driving the RF center can be isolated and assayed by RGC activity.
authors.affiliation: Medical Scientist Training Program, Baylor College of MedicineHouston, TX, USA; Department of Neuroscience, Baylor College of MedicineHouston, TX, USA; Department of Ophthalmology, Baylor College of MedicineHouston, TX, USA.
authors.forename: Jasdeep
authors.initials: J
authors.lastname: Sabharwal
authors.affiliation: Medical Scientist Training Program, Baylor College of MedicineHouston, TX, USA; Department of Ophthalmology, Baylor College of MedicineHouston, TX, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Seilheimer
authors.affiliation: Department of Ophthalmology, Baylor College of Medicine Houston, TX, USA.
authors.forename: Cameron S
authors.initials: CS
authors.lastname: Cowan
authors.affiliation: Department of Neuroscience, Baylor College of MedicineHouston, TX, USA; Department of Ophthalmology, Baylor College of MedicineHouston, TX, USA.
authors.forename: Samuel M
authors.initials: SM
authors.lastname: Wu
mesh_terms: D025042:Amacrine Cells / Q000502:physiology; D000818:Animals; D055724:Electrophysiological Phenomena / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D012165:Retinal Ganglion Cells / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*
keywords: L-AP4; amacrine cell; antagonistic surround; crossover circuit; ganglion cell; mouse retina; retinal circuitry; spatiotemporal processing