Nonlinear information processing in a model sensory system
Nonlinear information processing in a model sensory system
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DOI：
10.1152/jn.01296.2005
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发表时间：
2006-05-01
影响因子：
2.5
通讯作者：
Chacron, MJ
中科院分区：
文献类型：
--
作者：
Chacron, MJ
了解感觉神经元编码和解码信息的机制仍然是神经科学的一个重要目标。我们量化了最佳线性和非线性编码模型在一个特征良好的感觉系统中的性能：弱电鱼的电感觉。我们发现，线性编码模型一般表现更好的空间局部刺激下比空间扩散刺激。通过药理学阻断反馈输入和空间饱和的感受野中心，我们发现，有显着更少的空间扩散刺激下的突触噪声相比，空间定位的刺激。建模结果表明，锥体细胞的非线性编码的感觉信息，通过分流在他们的树突和澄清的线性编码模型的性能上的突触噪声的影响。最后，我们使用信息论来量化线性解码器的性能。空间定位刺激的最佳线性解码器可以捕获锥体细胞锋电位序列中60%的信息，而空间扩散刺激的最佳线性解码器只能捕获40%的信息。这些结果表明，非线性解码器是必要的，以充分访问信息的锥体细胞尖峰序列，我们讨论了潜在的机制，高阶神经元可以解码这些信息。
Understanding the mechanisms by which sensory neurons encode and decode information remains an important goal in neuroscience. We quantified the performance of optimal linear and nonlinear encoding models in a well-characterized sensory system: the electric sense of weakly electric fish. We show that linear encoding models generally perform better under spatially localized stimulation than under spatially diffuse stimulation. Through pharmacological blockade of feedback input and spatial saturation of the receptive field center, we show that there is significantly less synaptic noise under spatially diffuse stimuli as compared with spatially localized stimuli. Modeling results suggest that pyramidal cells nonlinearly encode sensory information through shunting in their dendrites and clarify the influence of synaptic noise on the performance of linear encoding models. Finally, we used information theory to quantify the performance of linear decoders. While the optimal linear decoder for spatially localized stimuli could capture 60% of the information in pyramidal cell spike trains, the optimal linear decoder for spatially diffuse stimuli could only capture 40% of the information. These results show that nonlinear decoders are necessary to fully access information in pyramidal cell spike trains, and we discuss potential mechanisms by which higher-order neurons could decode this information.