Distributed Dendritic Processing Facilitates Object Detection: A Computational Analysis on the Visual System of the Fly
Distributed Dendritic Processing Facilitates Object Detection: A Computational Analysis on the Visual System of the Fly
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DOI：
10.1371/journal.pone.0003092
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发表时间：
2008-08-28
期刊：
影响因子：
3.7
通讯作者：
Egelhaaf, Martin
中科院分区：
文献类型：
--
作者：
Hennig, Patrick;Moeller, Ralf;Egelhaaf, Martin
背景：在自然环境中移动时，检测物体是一项重要任务。例如，苍蝇可能会落在显着的物体上或避免与它们碰撞。果蝇视觉系统中的图形检测细胞（FD-细胞）的神经元群很可能参与控制这些行为，因为这些细胞对物体比对扩展的背景结构更敏感。到目前为止，FD 细胞突触前神经元网络中的计算，特别是实验上建立的兴奋性和抑制性输入的分布式树突处理的功能意义尚不清楚。方法/主要发现：我们使用模型模拟来分析负责 FD 细胞对小物体偏好的神经元计算。我们采用了一种新的建模方法，使我们能够解释树突中电信号的空间传播，同时避免详细的分区建模。这些模型基于可用的生理和解剖数据。测试了三个模型，每个模型都实现了抑制性神经回路，但抑制性相互作用的空间排列有所不同。使用进化算法进行参数优化表明，只有分布式树突处理才能满足电生理学实验中产生的约束。与 FD 细胞的直接树突状抑制（直接分布式抑制模型）相反，对其突触前视网膜专题元件的抑制（间接分布式抑制模型）需要视觉刺激期间受抑制神经元的输入电阻发生较小的变化。结论/意义：在我们的间接分布式抑制模型中实施的视网膜专题元件的分布式树突抑制是神经元最合理的接线方案。 FD 单元电路。该微电路在计算上类似于视网膜专题元件之间的侧向抑制。因此，分布式抑制可能是目前由侧抑制网络解释的知觉现象的另一种解释。
Background: Detecting objects is an important task when moving through a natural environment. Flies, for example, may land on salient objects or may avoid collisions with them. The neuronal ensemble of Figure Detection cells (FD-cells) in the visual system of the fly is likely to be involved in controlling these behaviours, as these cells are more sensitive to objects than to extended background structures. Until now the computations in the presynaptic neuronal network of FD-cells and, in particular, the functional significance of the experimentally established distributed dendritic processing of excitatory and inhibitory inputs is not understood.Methodology/Principal Findings: We use model simulations to analyse the neuronal computations responsible for the preference of FD-cells for small objects. We employed a new modelling approach which allowed us to account for the spatial spread of electrical signals in the dendrites while avoiding detailed compartmental modelling. The models are based on available physiological and anatomical data. Three models were tested each implementing an inhibitory neural circuit, but differing by the spatial arrangement of the inhibitory interaction. Parameter optimisation with an evolutionary algorithm revealed that only distributed dendritic processing satisfies the constraints arising from electrophysiological experiments. In contrast to a direct dendro-dendritic inhibition of the FD-cell (Direct Distributed Inhibition model), an inhibition of its presynaptic retinotopic elements (Indirect Distributed Inhibition model) requires smaller changes in input resistance in the inhibited neurons during visual stimulation.Conclusions/Significance: Distributed dendritic inhibition of retinotopic elements as implemented in our Indirect Distributed Inhibition model is the most plausible wiring scheme for the neuronal circuit of FD-cells. This microcircuit is computationally similar to lateral inhibition between the retinotopic elements. Hence, distributed inhibition might be an alternative explanation of perceptual phenomena currently explained by lateral inhibition networks.