The role of the superficial cortical layers in whisker-based shape discrimination

 描述(申请人提供)：大脑皮层是大脑中的一种结构，对感觉处理和决策非常重要。尽管大脑皮层的不同区域专用于不同的行为功能，但所有区域都共享相同的基本解剖结构--最引人注目的是，它的六个解剖层。这些层包含的神经元类型不同，它们与大脑其他部分的连接方式也不同。这表明，不同的层可能具有不同的功能，无论是在它们执行的计算中，还是在它们产生的行为中。特别是，我们假设最浅层的皮质对于整合不同皮质区域的信息是至关重要的。这一假说是基于这样的观察，即表层是紧密相连的，并发送长距离投射来连接感觉、联想和更高阶区。如果这一假设是正确的，那么表层对于需要整合信息的行为尤其重要，例如，跨越感觉世界的不同部分或跨越 身体。为了验证这一假设，我们使用老鼠胡须系统作为模型。老鼠依靠它们的胡须来研究周围的世界；它们的胡须系统使用专门的马达电路来产生细微而复杂的胡须运动，以便对它们环境中的物体做出精细的区分。尽管外围机制不同，但这与我们使用指尖探索周围世界的方式大致相似。在这两个系统中，躯体感觉皮层都面临着一个问题，那就是将来自每个感官感受器的信息，无论是胡须还是手指，整合成对物体形式和身份的整体感知。因此，我们认为这是一个很好的行为，可以测试我们的假设，即表层整合了信息。特别是，我们将测试老鼠辨别形状所需的表层活动，我们将记录这一活动，以确定大脑如何代表物体并对它们产生适当的行为反应。

 DESCRIPTION (provided by applicant): The cerebral cortex is a structure in the brain that is important for sensory processing and decision making. Although different regions of cortex are specialized for different behavioral functions, all regions share the same basic anatomical structure - most strikingly, its six anatomical layers. The layers differ in the types of neurons they contain and the way in which they connect to other parts of the brain. This suggests that the different layers may have different functions, either in the computations they perform or the behaviors they produce. In particular, we hypothesize that the most superficial layers of cortex are critical for integrating information across different cortical regions. This hypothesis is base on the observation that the superficial layers are strongly interconnected and send long-distance projections to connect sensory, associative, and higher-order regions. If this hypothesis is true, then the superficial layers would be especially important for behaviors that require integrating information, for instance, across different parts of the sensory world or across different parts of the body. To test this hypothesis, we are using as a model the mouse whisker system. Mice rely on their whiskers to investigate the world around them; their whisker system uses specialized motor circuits to generate nuanced and complex whisker motions in order to make fine discriminations about objects in their environment. Though the peripheral mechanics differ, this is broadly similar to the way we use our fingertips to explore the world around us. In both systems, the somatosensory cortex faces the problem of combining information from each sensory receptor, be it whisker or finger, into an overall perception of object form and identity. We thus consider this behavior to be an excellent one to test our hypothesis that the superficial layers integrate information. In particular, we will test that activity in the superficial layers i necessary for mice to discriminate shapes, and we will record that activity to determine how the brain represents objects and generates appropriate behavioral responses to them.