Space–time codependence of retinal ganglion cells can be explained by novel and separable components of their receptive fields. Issue 17 (7th September 2016)

• Record Type: Journal Article
• Authors: Cowan, Cameron S.; Sabharwal, Jasdeep; Wu, Samuel M.
• Is Part Of: Physiological reports. Volume 4:Issue 17(2016)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2016-09-07
• Subjects: Retinal ganglion cells -- space–time separability -- spatiotemporal tuning; Physiology -- Periodicals; 571
• DOI: 10.14814/phy2.12952
• Languages: English
• ISSNs: 2051-817X

Abstract

Abstract: Reverse correlation methods such as spike‐triggered averaging consistently identify the spatial center in the linear receptive fields (RFs) of retinal ganglion cells (GCs). However, the spatial antagonistic surround observed in classical experiments has proven more elusive. Tests for the antagonistic surround have heretofore relied on models that make questionable simplifying assumptions such as space–time separability and radial homogeneity/symmetry. We circumvented these, along with other common assumptions, and observed a linear antagonistic surround in 754 of 805 mouse GCs. By characterizing the RF's space–time structure, we found the overall linear RF's inseparability could be accounted for both by tuning differences between the center and surround and differences within the surround. Finally, we applied this approach to characterize spatial asymmetry in the RF surround. These results shed new light on the spatiotemporal organization of GC linear RFs and highlight a major contributor to its inseparability. Abstract : Reverse correlation methods, such as spike‐triggered averaging, have provided much insight about the receptive fields (RFs) of retinal ganglion cells (GCs), but have been unable to study the antagonistic surround. By removing commonly used assumptions, such as space–time separability, we observed a linear antagonistic surround in 754 of 805 mouse GCs. By characterizing the RF's space–time structure, we found the space–time inseparability present in mouse RGCs could be accounted for both by tuning differences between the center and surround and differences within the surround. Finally, we identified the spatial structure of this antagonistic surround and found significant spatial asymmetry and inhomogeneity in the structure of the surround. These results shed new light on the spatiotemporal organization of GC linear RFs and highlight a major contributor to its inseparability.