Sabharwal Jasdeep, Seilheimer Robert L, Cowan Cameron S, Wu Samuel M
Medical Scientist Training Program, Baylor College of MedicineHouston, TX, USA; Department of Neuroscience, Baylor College of MedicineHouston, TX, USA; Department of Ophthalmology, Baylor College of MedicineHouston, TX, USA.
Medical Scientist Training Program, Baylor College of MedicineHouston, TX, USA; Department of Ophthalmology, Baylor College of MedicineHouston, TX, USA.
Front Neural Circuits. 2016 Dec 22;10:106. doi: 10.3389/fncir.2016.00106. eCollection 2016.
Retinal ganglion cells (RGCs) are often grouped based on their functional properties. Many of these functional properties, such as receptive field (RF) size, are driven by specific retinal circuits. In this report, we determined the role of the ON bipolar cell (BC) mediated crossover circuitry in shaping the center and surround of OFF RGCs. We recorded from a large population of mouse RGCs using a multielectrode array (MEA) while pharmacologically removing the ON BC-mediated crossover circuit. OFF sustained and transient responses to whole field stimuli are lost under scotopic conditions, but maintained under photopic conditions. Though photopic light responses were grossly maintained, we found that photopic light response properties were altered. Using linear RF mapping, we found a significant reduction in the antagonistic surround and a decrease in size of the RF center. Using a novel approach to separate the distinct temporal filters present in the RF center, we see that the crossover pathway contributes specifically to the sluggish antagonistic filter in the center. These results provide new insight into the role of crossover pathways in driving RGCs and also demonstrate that the distinct inputs driving the RF center can be isolated and assayed by RGC activity.
视网膜神经节细胞（RGCs）通常根据其功能特性进行分类。这些功能特性中的许多，如感受野（RF）大小，是由特定的视网膜回路驱动的。在本报告中，我们确定了ON双极细胞（BC）介导的交叉回路在塑造OFF RGCs的中心和周边方面的作用。我们使用多电极阵列（MEA）记录了大量小鼠RGCs的活动，同时通过药理学方法去除了ON BC介导的交叉回路。在暗视条件下，OFF对全视野刺激的持续和瞬态反应消失，但在明视条件下得以维持。尽管明视光反应总体上得以维持，但我们发现明视光反应特性发生了改变。通过线性RF映射，我们发现拮抗性周边显著减少，RF中心大小减小。使用一种新颖的方法来分离RF中心存在的不同时间滤波器，我们发现交叉通路特别有助于中心的迟缓拮抗性滤波器。这些结果为交叉通路在驱动RGCs中的作用提供了新的见解，同时也表明驱动RF中心的不同输入可以通过RGC活动进行分离和检测。
