著者：Ikezoe K, Mori Y, Kitamura K, Tamura H, Fujita I
タイトル：Spatial arrangement of orientation selectivity in layer 2/3 of macaque V1 revealed with in vivo 2-photon calcium imaging
発表日：28 Jul., 2009
In the monkey primary visual cortex (V1), neurons are arranged according to their preferred orientation. Because the arrangement has been studied with recording techniques with limited spatial resolution, the organization at single-cell resolution is still unclear. In this study, we investigated the spatial arrangement of layer 2/3 neurons based on their preferred orientation with in vivo 2-photon calcium imaging techniques. We recorded calcium signals from neurons in response to drifting square-wave gratings in opiate-anesthetized and paralyzed monkeys. About half of the neurons showed orientation-selective modulation in calcium signal. The tuning width of the orientation tuning curve based on calcium measurements was similar to that of previously reported spike responses. The median preferred orientation difference in neuron pairs separated by less than 50 μm tangential to the cortical surface was 11.3 degrees (1219 pairs). This value monotonically increased with separation. In neuron pairs separated by 150 to 200 μm, the median difference was 36.7 degree (734 pairs). Thus, in macaque V1, we found that neurons are orderly arranged based on preferred orientation at single-cell resolution. This research was supported by CREST, JST.