CRCNS: Collaborative Research: How is Information Coded in Turtle Visual Cortex?

EIA-0217884 Robbins，Kay德克萨斯大学CRCNS：合作研究：海龟视觉皮层中的信息是如何编码的？视觉刺激在淡水龟的视觉皮层中引起一种传播波的活动。 初步工作表明，在视觉空间中的刺激的位置信息编码在这些波的时空动态。 实际上，可能存在视觉空间到视觉皮层的动态的映射。 这一假设正在三个实验室的合作努力中得到检验。 圣安东尼奥的大卫森斯曼正在使用电压敏感染料方法记录视网膜上35个光点产生的波。 这些研究将根据35个位点的刺激的重复呈现来表征地图的特征。 芝加哥的菲利普·乌林斯基（Philip Ulinski）正在开发一个海龟视觉通路的大型模型。 正在构建个体视网膜神经节细胞的模型，该模型将经典的基于滤波器的神经节细胞建模方法与神经节细胞的房室建模结合联合收割机。 它们被用来构建35个与35个位点相匹配的模型视网膜。 目前正在进行海龟外侧膝状体神经元生物物理学的生理学研究。 它们用于开发外侧膝状体复合体的模型，这是视网膜-膝状体-皮质通路建模的最后一步。 圣路易斯的Bijoy Ghosh正在开发精确的估计技术，可以从皮层波的动态来估计视觉刺激的位置。 这项工作提供了所需的数学框架，以表征一个潜在的地图的视觉空间的动态波。 这项工作意义重大，因为它描述了一种在视觉皮层中编码信息的新方法，这种方法可能适用于哺乳动物和海龟的高级皮层区域。

EIA-0217884Robbins, Kay AUniv of Texas CRCNS: Collaborative Research : How is Information Coded in Turtle Visual Cortex ?Visual stimuli evoke a propagating wave of activity in the visual cortex of freshwater turtles. Preliminary work suggested that information about the position of stimuli in visual space is coded in the spatiotemporal dynamics of these waves. Effectively, there may be a map of visual space to the dynamics of the visual cortex. This hypothesis is being examined in a collaborative effort involving three laboratories. David Senseman in San Antonio is using voltage sensitive dye methods to record the waves produced by presenting spots of light at 35 spots on the retina. These studies will characterize the features of the map based on repeated presentations of stimuli at 35 loci. Philip Ulinski in Chicago is developing a large-scale model of the visual pathway of turtles. Models of individual retinal ganglion cells that combine both classic filter-based approaches to modeling ganglion cells, with compartmental modeling of ganglion cells are being constructed. They are being used to construct 35 patches of a model retina that match the 35 loci. Physiological studies of the biophysics of neurons in the lateral geniculate complex of turtles are being carried out. They are used to develop a model of the lateral geniculate complex, which is the last step in modeling the retino-geniculate-cortical pathway. Bijoy Ghosh in St. Louis is developing refined estimation techniques that allow the position of a visual stimulus to be estimated from the dynamics of the cortical waves. This work is providing the mathematical framework needed to characterize a potential map of visual space to the dynamics of the wave. This work is significant because it is characterizing a novel method of coding information in visual cortex that may apply to higher order cortical areas in mammals, as well as turtles.