Precise mapping of functional somatotopy in sensorimotor cortex

感觉运动皮层功能躯体的精确映射

• 批准号: 371676-2011
• 负责人: Winship, Ian
• 金额: $ 2.91万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=515257
• 关键词: Precise; mapping; functional; somatotopy; sensorimotor

Recent innovations in live animal imaging permit real-time measurement of cellular signalling in the intact brain and visualization of the microscopic structure of the neurons that form the framework for brain function. By combining these cellular imaging techniques with regional functional imaging and measures of brain anatomy, this research will precisely map the function, connectivity, and adaptive changes the cortex associated with limb sensation in mice and rats. Regional imaging maps the cortical areas responsive to sensory stimulation, while cellular imaging of sensory-evoked calcium signals enables simultaneous assessment of spiking activity and the precise three-dimensional organization of hundreds to thousands of optically-recorded neurons. Using stimuli that deliver precise mechanical stimulation to discrete regions of the fore- or hind-paw, these imaging techniques will precisely map the borders between regions of cortex responding to stimulation of different areas of the limbs. Moreover, calcium indicators can be administered in a manner that permits calcium imaging with subcellular resolution to single axons and synapses. As such, our imaging approach can define precise three-dimensional functional organization not possible through any other method. Targeted injections of neuronal tracers, compounds that allow one to identify the individual neurons that project to or receive projections from the injection site, will also be made within these functional maps such that the organization of the projections to and from these discrete somatosensory regions can be described. Finally, to assess how the shape of the functional representations, the activity of individual neurons, and their anatomical connections are altered by behavioural experience, the imaging and tract tracing techniques described above will be performed in rats undergoing environmental enrichment, voluntary endurance exercise, or skilled-reaching training. Combined, the proposed studies combine innovative imaging techniques with established protocols for neuronal tract tracing to define the neuronal organization and experience-dependent plasticity of the rodent sensorimotor cortex.

活体动物成像技术的最新创新使我们能够实时测量完整大脑中的细胞信号，并对构成大脑功能框架的神经元的微观结构进行可视化。通过将这些细胞成像技术与区域功能成像和脑解剖学测量相结合，本研究将精确地绘制出小鼠和大鼠与肢体感觉相关的皮层的功能、连通性和适应性变化。区域成像绘制皮层区域对感觉刺激的反应，而感觉诱发钙信号的细胞成像可以同时评估峰值活动和数百到数千个光学记录的神经元的精确三维组织。通过对前肢或后肢的离散区域进行精确的机械刺激，这些成像技术将精确地绘制出对四肢不同区域的刺激做出反应的皮层区域之间的边界。此外，钙指示剂可以通过亚细胞分辨率对单个轴突和突触进行钙成像。因此，我们的成像方法可以定义精确的三维功能组织，这是任何其他方法都无法做到的。靶向注射神经元示踪剂，这种化合物允许人们识别投射到注射部位或从注射部位接收投射的单个神经元，也将在这些功能图中进行，这样就可以描述来自这些离散体感区域的投射组织。最后，为了评估功能表征的形状、单个神经元的活动以及它们的解剖连接是如何被行为经验所改变的，我们将在经历环境丰富、自愿耐力锻炼或技能达到训练的大鼠身上进行上述成像和神经束追踪技术。这些研究结合了创新的成像技术和已建立的神经束追踪协议，以定义啮齿动物感觉运动皮层的神经元组织和经验依赖的可塑性。