Optical Imaging of Tactile Information in SI Cortex

描述（由申请人提供）：本提案旨在通过检查不同麻醉和警觉状态（戊硫醚和异氟醚麻醉以及清醒状态）下的皮质图来研究皮质表征的稳定性。以往的研究假设，单个丘脑皮质木杆的不同部位对3b区有不同程度的支配，这些次级木杆输入的影响可能在某些条件下被掩盖，而在另一些条件下被揭示。利用光学成像和电生理方法，我们将通过研究松鼠猴3b区和1区手指垫表征的三个方面来探讨这一假设：地形、振动触觉信息（压力SA、颤振RA和振动PC）和空间整合（两指）。我们将研究数字表示是否可以，与标准的体位图相比，采取以热点和次级激活区为特征的非地形组织。我们将检查SA、RA和PC输入是否可以在表层以重叠和分离的方式映射。为了研究3b区和1区的空间整合，我们将研究同时进行两指刺激模式的测绘是否会导致地形的明显变化，以及这种变化是否在1区更明显，在清醒状态下更明显。这些对可选地形和移动地形的检查可能会修改科学探究中地形组织的定义，哪些移动地形可能会修改科学探究中地形组织的定义，以及清醒动物中地形组织的用途。此外，这些研究可能揭示地形的建立是区域特异性的，是基于刺激驱动或行为驱动的特征整合，而不是感觉上皮的简单表示。

DESCRIPTION (provided by applicant): This proposal aims to study the stability of cortical representation by examining cortical maps under different states of anesthesia and alertness (pentothal and isofluane anesthesia, and awake state). Previous studies have hypothesized that different parts of single thalamocortical arbors have different degrees of dominance in Area 3b and that the effects of these secondary arbor inputs may be masked under some conditions and revealed under others. Using optical imaging and electrophysiological methods, we will probe this hypothesis by examining three aspects of finger pad representation in Area 3b and Area 1 of the squirrel monkey: topography, vibrotactile information (pressure SA, flutter RA, and vibration PC), and spatial integration (two digit). We will examine whether digit representation can, in contrast to the standard somatotopic maps, take on non-topographic organizations that are characterized by hotspots and secondary activation zones. We will examine whether SA, RA, and PC inputs can map in both overlapping and segregated manners in the superficial layers. To examine spatial integration in Area 3b and 1, we will examine whether mapping with simultaneous two-finger stimulation paradigm will result in an apparent shift in topography, and whether such a shift is more pronounced in Area 1 and more pronounced in the awake state. These examinations of alternative and shifting topographies are likely to modify the definition of topographic organization in SI and what shifting topographies are likely to modify the definition of topographic organization in SI and what topographic organization is used for in the awake animal. Furthermore, these studies may reveal that the establishment of topography is area-specific and is based on a stimulus-driven or behavior-driven integration of features rather than a simple representation of the sensory epithelium.