Long-range synchronization of oscillatory light responses in the cat retina and lateral geniculate nucleus.

Visual responses in the retina and the lateral geniculate nucleus (LGN) exhibit oscillatory patterning within a broad range of frequencies. Oscillatory activity is often associated with the synchronization of spatially distributed responses. Here we demonstrate, with simultaneous multi-electrode recordings from the retina and the LGN, that stationary and moving light stimuli evoke in retinal ganglion cells oscillatory responses in the frequency range of 61 to 114 Hz that become synchronized over distances larger than 20 degrees of visual angle across the nasal and temporal halves of the retina. This temporal patterning of retinal responses is transmitted reliably by LGN neurons, such that stimuli crossing the vertical meridian evoke synchronous responses in the LGNs of both hemispheres. The oscillatory responses are not phase-locked to the stimulus onset, indicating that synchronization results from horizontal interactions in the retina. The occurrence of synchronization depends on global stimulus properties such as size and continuity, suggesting that temporal correlation among responses of spatially segregated ganglion cells can be exploited to convey information relevant for perceptual grouping.