Department of Physiology and Center for Integrative Neuroscience, University of California, San Francisco, California 94158; email:
Annu Rev Neurosci. 2015 Jul 8;38:247-68. doi: 10.1146/annurev-neuro-071013-014038. Epub 2015 Apr 9.
Maps serve as a ubiquitous organizing principle in the mammalian brain. In several sensory systems, such as audition, vision, and somatosensation, topographic maps are evident throughout multiple levels of brain pathways. Topographic maps, like retinotopy and tonotopy, persist from the receptor surface up to the cortex. Other maps, such as those of orientation preference in the visual cortex, are first created in the cortex itself. Despite the prevalence of topographic maps, it is still not clear what function they subserve. Although maps are topographically smooth at the macroscale, they are often locally heterogeneous. Here, we review studies describing the anatomy and physiology of topographic maps across various spatial scales, from the smooth macroscale to the heterogeneous local microarchitecture, with emphasis on maps of the visual and auditory systems. We discuss the potential advantages of local heterogeneity in brain maps, how they reflect complex cortical connectivity, and how they may impact sensory coding and local computations.
地图是哺乳动物大脑中无处不在的组织原则。在听觉、视觉和体感等几种感觉系统中，地形图在多个大脑通路层次上都很明显。地形图，如视网膜和音高拓扑，从受体表面一直延伸到皮层。其他地图，如视觉皮层中的朝向偏好图，最初是在皮层本身中创建的。尽管地形图很普遍，但它们的功能仍不清楚。尽管地图在宏观尺度上是地形平滑的，但它们通常在局部是不均匀的。在这里，我们回顾了描述各种空间尺度上的地形图的解剖结构和生理学的研究，从平滑的宏观尺度到不均匀的局部微观结构，重点是视觉和听觉系统的地图。我们讨论了脑图中局部异质性的潜在优势，它们如何反映复杂的皮质连接，以及它们如何影响感觉编码和局部计算。
