Roska Botond, Werblin Frank
Department of Molecular and Cell Biology, University of California Berkeley, 145 LSA, California 94720, USA.
Nat Neurosci. 2003 Jun;6(6):600-8. doi: 10.1038/nn1061.
The mammalian retina contains more than a dozen different ganglion cell types, each with dendrites ramifying at different strata within the inner plexiform layer (IPL) and each carrying a unique representation of the visual world. We studied the inhibitory and excitatory inputs, as well as the spiking output, of each of the rabbit retinal ganglion cell type during rapid global shifts in 'natural' videos designed to mimic saccadic eye movements. These shifts generated stratum-specific transient inhibitory activity, affecting only those ganglion cells whose dendrites ramify within the central strata of the IPL. The inhibition was GABA-mediated, acted both pre- and postsynaptically and was fast enough to either prevent or delay spiking. These findings indicate that the fast, transient elevation of visual threshold during rapid shifts in scene has a significant retinal component.
哺乳动物的视网膜包含十几种不同类型的神经节细胞，每种神经节细胞的树突在内网状层（IPL）的不同层次呈放射状分布，且每种都携带视觉世界的独特表征。我们研究了在旨在模拟眼球扫视运动的“自然”视频快速全局切换期间，每种兔视网膜神经节细胞类型的抑制性和兴奋性输入以及动作电位输出。这些切换产生了层特异性的瞬时抑制活动，仅影响那些树突在IPL中央层呈放射状分布的神经节细胞。这种抑制是由GABA介导的，在突触前和突触后均起作用，并且速度足够快，足以阻止或延迟动作电位发放。这些发现表明，在场景快速切换期间视觉阈值的快速、瞬时升高具有重要的视网膜成分。
