Distinct Functional Properties of Primary and Posteromedial Visual Area of Mouse Neocortex
Distinct Functional Properties of Primary and Posteromedial Visual Area of Mouse Neocortex
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DOI：
10.1523/jneurosci.0110-12.2012
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发表时间：
2012-07-11
影响因子：
5.3
通讯作者：
Kampa, Bjoern M.
中科院分区：
文献类型：
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作者：
Roth, Morgane M.;Helmchen, Fritjof;Kampa, Bjoern M.
视觉输入为在环境中导航提供了重要的地标，在哺乳动物中，信息由视觉皮层中的专门区域处理。在啮齿类动物中，后内侧区（PM）在初级视觉皮层（V1）和压后皮层之间介导视觉信息，压后皮层进一步投射到海马。为了理解区域PM的功能作用，需要对其空间频率（SF）和时间频率（TF）调谐进行详细分析。在这里，我们应用双光子钙成像映射神经元调谐的方向，方向，SF和TF，和速度在V1和PM的麻醉小鼠的漂移光栅响应。取向和方向调谐在V1和PM中的分布相似。值得注意的是，在这两个领域，我们发现了一个偏好的基数相比，倾斜的方向。红衣主教调谐神经元的过度表达是特别强烈的PM显示水平和垂直方向的调谐带宽窄。SF和TF调谐的详细分析揭示了V1中广泛的高度调谐神经元。相反，PM包含一个具有高空间敏锐度的神经元亚群和第二个广泛调整为低SF的亚群。此外，与V1相比，V1中20%的响应神经元和PM中仅12%的响应神经元被调谐到漂移光栅的速度，PM更喜欢较慢的漂移速率。总之，PM被调谐为基本方向，高SF和低速，并进一步位于V1和压后皮层之间，这与空间导航过程中处理自然场景的作用一致。
Visual input provides important landmarks for navigating in the environment, information that in mammals is processed by specialized areas in the visual cortex. In rodents, the posteromedial area (PM) mediates visual information between primary visual cortex (V1) and the retrosplenial cortex, which further projects to the hippocampus. To understand the functional role of area PM requires a detailed analysis of its spatial frequency (SF) and temporal frequency (TF) tuning. Here, we applied two-photon calcium imaging to map neuronal tuning for orientation, direction, SF and TF, and speed in response to drifting gratings in V1 and PM of anesthetized mice. The distributions of orientation and direction tuning were similar in V1 and PM. Notably, in both areas we found a preference for cardinal compared to oblique orientations. The overrepresentation of cardinal tuned neurons was particularly strong in PM showing narrow tuning bandwidths for horizontal and vertical orientations. A detailed analysis of SF and TF tuning revealed a broad range of highly tuned neurons in V1. On the contrary, PM contained one subpopulation of neurons with high spatial acuity and a second subpopulation broadly tuned for low SFs. Furthermore, similar to 20% of the responding neurons in V1 and only 12% in PM were tuned to the speed of drifting gratings with PM preferring slower drift rates compared to V1. Together, PM is tuned for cardinal orientations, high SFs, and low speed and is further located between V1 and the retrosplenial cortex consistent with a role in processing natural scenes during spatial navigation.