Contrast gain control and retinogeniculate communication. (23rd March 2018)

• Record Type: Journal Article
• Authors: Alitto, Henry J.; Rathbun, Daniel L.; Fisher, Tucker G.; Alexander, Prescott C.; Usrey, W. Martin
• Is Part Of: European journal of neuroscience. Volume 49:Number 8(2019)
• Page Start: 1061
• Page End: 1068
• Publication Date: 2018-03-23
• Subjects: cat -- lateral geniculate nucleus -- retina -- thalamus -- vision; Nervous system -- Periodicals; 612.8
• DOI: 10.1111/ejn.13904
• Languages: English
• ISSNs: 0953-816X

Abstract

Abstract: Visual information processed in the retina is transmitted to primary visual cortex via relay cells in the lateral geniculate nucleus (LGN) of the dorsal thalamus. Although retinal ganglion cells are the primary source of driving input to LGN neurons, not all retinal spikes are transmitted to the cortex. Here, we investigate the relationship between stimulus contrast and retinogeniculate communication and test the hypothesis that both the time course and strength of retinogeniculate interactions are dynamic and dependent on stimulus contrast. By simultaneously recording the spiking activity of synaptically connected retinal ganglion cells and LGN neurons in the cat, we show that the temporal window for retinogeniculate integration and the effectiveness of individual retinal spikes are inversely proportional to stimulus contrast. This finding provides a mechanistic understanding for the phenomenon of augmented contrast gain control in the LGN—a nonlinear receptive field property of LGN neurons whereby response gain during low‐contrast stimulation is enhanced relative to response gain during high‐contrast stimulation. In addition, these results support the view that network interactions beyond the retina play an essential role in transforming visual signals en route from retina to cortex. Abstract : By simultaneously recording the spiking activity of synaptically connected retinal ganglion cells and LGN neurons in vivo, this study investigates the relationship between stimulus contrast and the dynamics of retinogeniculate communication. Results reveal that the temporal window for retinogeniculate integration and the effectiveness of individual retinal spikes are inversely proportional to stimulus contrast, providing a mechanistic understanding for the phenomenon of augmented contrast gain control in the LGN.