Excitation and Inhibition in Neural Circuits of the Visual Cortex

项目摘要 初级视觉皮层的神经回路对于产生对我们大脑的准确感知至关重要。 外部世界这些电路在功能上是在垂直和水平方向上组织起来的 视觉皮层的轴。尽管如此，垂直和水平的不同贡献 对视觉计算的预测知之甚少。特别是， 和抑制（E/I平衡），垂直和水平投影在感觉过程中产生 由于缺乏适当的方法，诱发活动没有得到很好的表征。第一个目标 这项建议的目的是实施一种新的方法，有选择地激活垂直和 使用细胞类型特异性基因的组合， 靶向和光遗传学工具。第二个目标是使用这种新方法来测试 假设垂直和水平投影产生了特定层的E/I平衡， 决定其对皮质活动的功能影响的皮质。第三个目标是建立 不同的E/I如何平衡视觉皮层中产生的垂直和水平投射 电路介导基本刺激特征如对比度和大小的编码。

PROJECT SUMMARY Neural circuits of the primary visual cortex are critical for generating accurate perceptions of our external world. These circuits are functionally organized across both the vertical and horizontal axes of the visual cortex. Nonetheless, the distinct contributions of vertical and horizontal projections to visual computation are poorly understood. In particular, the balance of excitation and inhibition (the E/I balance) that vertical and horizontal projections generate during sensory evoked activity is not well characterized due to a lack of appropriate methodology. The first goal of this proposal is to implement a new approach to selectively activate the vertical and horizontal projections for each layer of the cortex using a combination of cell-type specific gene targeting and optogenetic tools. The second goal is to use this new approach to test the hypothesis that vertical and horizontal projections generate layer-specific E/I balances in the cortex that determine their functional impact on cortical activity. The third goal is to establish how the distinct E/I balances that vertical and horizontal projections generate in visual cortical circuits mediate the encoding of fundamental stimulus features such as contrast and size.