Parallel Cortical Pathways Through the Pulvinar/LP Complex

LE摘要首席研究员：Bickford，Martha建议编号：IBN-9728089通过枕骨复合体的平行皮质通路大多数感觉信号必须通过背侧丘脑才能在皮质中有意识地识别。多年来，已知来自外周感受器的感觉信号是分离的，并以平行的路径通过丘脑背侧中继核传递到皮质的主要感觉区域。对感觉系统，特别是视觉系统中平行通路的研究，为理解大脑如何对各种传入信息进行编码提供了关键。意识到颜色、运动或对比度等特征是由不同的皮质下细胞类型编码的，这为研究大脑如何感知视觉信号提供了一个有价值的概念框架。这一提议验证了这样一种假设，即丘脑区存在类似的平行通路，将来自不同皮质区域的信息联系在一起。在这种情况下，所提出的平行通路起源于皮质，并通过不同类别的丘脑皮质神经元上的突触接触在丘脑中保持分离，这些突触投射到不同的皮质层。这一想法将在枕部和外侧后核进行测试，这两个核接受来自两种类型的V层皮质细胞的输入，并包含至少两种形态上不同的丘脑皮质细胞。有人认为，单独的皮质轴突接触不同类别的丘脑皮质细胞，这些细胞投射到不同的皮质板层。拟议的解剖学实验，包括神经解剖示踪剂注射和免疫细胞化学，将检验平行通路用于处理内部皮质信号的概念。预计类似于对平行感觉通路的研究，这些信息将为破译枕区和外侧后核的功能提供一个富有成效的起点。

LAY ABSTRACT Principal Investigator: Bickford, Martha Proposal Number: IBN- 9728089 PARALLEL CORTICAL PATHWAYS THROUGH THE PULVINAR COMPLEX Most sensory signals must pass through the dorsal thalamus before they are consciously recognized in the cortex. It has been known for a number of years that sensory signals from peripheral receptors are segregated, and travel in parallel pathways through the relay nuclei of the dorsal thalamus, to primary sensory areas of cortex. The study of parallel pathways in sensory system, particularly in the visual system, has provided a key to understanding how the brain codes the wide variety of incoming information. The realization that features such as color, motion, or contrast are coded by separate subcortical cell types has provided a valuable conceptual framework for studies of how visual signals are perceived by the brain. This proposal tests the hypothesis that similar parallel pathways exist in areas of the thalamus that associate information from a variety of cortical areas. In this case, the proposed parallel pathways originate in cortex, and remain segregated in the thalamus through synaptic contacts on distinct classes of thalamocortical neurons, which project to different cortical laminae. This idea will be tested in the pulvinar and lateral posterior nuclei, which receive input from two types of layer V cortical cells, and contain at least two morphologically distinct types of thalamocortical cells. It is proposed that separate cortical axons contact separate classes of thalamocortical cells that project to different cortical lamina. The proposed anatomical experiments, which involve the injection of neuroanatomical tracers and irnmunocytochemistry, wi ll test the concept that parallel pathways are utilized in the processing of internal cortical signals. It is anticipated that, similar to the study of parallel sensory pathways, this information will provide a fruitful starting point for deciphering the function of the pulvinar and lateral posterior nuclei.