OFF direction-selective cells in the mouse retina
Our vision is extremely sensitive to object motion. Detection of motion starts in the retina, and the motion information is further extracted, processed, and refined along the visual pathway. The mouse retina has three types of retinal ganglion cell that report object motion in a specific direction. Based on morphology and response properties, one distinguishes: the ON-OFF direction selective-ganglion cells (DSGCs), the ON DSGCs, and the recently discovered OFF DSGCs, also known as J-RGCs [1]. For both the ON-OFF and the ON DSGCs, direction selectivity depends on synaptic input from starburst amacrine cells, which is itself already directionally selective. J-RGCs, on the other hand, receive little or no input from starburst cells, and therefore must generate direction selectivity by different means. To explore these mechanisms, we exploited a transgenic mouse line in which J-RGCs are fluorescently marked, and targeted these neurons for electrical recording. J-RGCs have a highly asymmetric organization: Their dendritic arbors are fan-shaped and point from dorsal to ventral across the retina. This same axis corresponds to the preferred direction for spot movement. We recorded the synaptic input currents of J-RGCs and studied their roles in the emergence of direction selectivity. Using reverse correlation to flicker stimuli, combined with whole-cell voltage clamp at a range of holding potentials, we measured the receptive fields for both the excitatory and inhibitory inputs. The receptive field for inhibition has an ON center and is limited to a region close to the soma. By contrast the receptive field for excitation has an OFF center that extends over the entire dendritic tree. Moreover, the excitatory input to the J-RGCs is ''directionally asymmetric'': a stimulus applied at the distal dendrites paradoxically excites the cell with shorter delay than one at the proximal dendrites. We propose that this timing difference between spatially offset excitatory inputs combined with a spiking threshold could produce the observed direction selectivity in J-RGCs.
Acknowledgments
This work was supported by NIH grant EY10020-11 and Damon Runyon Fellowship.
References
1. Molecular identification of a retinal cell type that responds to upward motion. Kim IJ, Zhang Y,
2. Yamagata M, Meister M, Sanes JR. Nature 452(7186):478-82.
Conference:
Computational and systems
neuroscience 2009, Salt Lake City, UT, United States, 26 Feb - 3 Mar, 2009.
Presentation Type:
Poster and Short Oral Presentation
Topic:
Poster and Short Oral Presentations
Citation:
(2009). OFF direction-selective cells in the mouse retina.
Front. Syst. Neurosci.
Conference Abstract:
Computational and systems
neuroscience 2009.
doi: 10.3389/conf.neuro.06.2009.03.316
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
04 Feb 2009;
Published Online:
04 Feb 2009.