Ursino Mauro, Cuppini Cristiano, Magosso Elisa, Serino Andrea, di Pellegrino Giuseppe
Department of Electronics, Computer Science and Systems, University of Bologna, Bologna, Italy.
J Comput Neurosci. 2009 Feb;26(1):55-73. doi: 10.1007/s10827-008-0096-4. Epub 2008 May 14.
Neurons in the superior colliculus (SC) are known to integrate stimuli of different modalities (e.g., visual and auditory) following specific properties. In this work, we present a mathematical model of the integrative response of SC neurons, in order to suggest a possible physiological mechanism underlying multisensory integration in SC. The model includes three distinct neural areas: two unimodal areas (auditory and visual) are devoted to a topological representation of external stimuli, and communicate via synaptic connections with a third downstream area (in the SC) responsible for multisensory integration. The present simulations show that the model, with a single set of parameters, can mimic various responses to different combinations of external stimuli including the inverse effectiveness, both in terms of multisensory enhancement and contrast, the existence of within- and cross-modality suppression between spatially disparate stimuli, a reduction of network settling time in response to cross-modal stimuli compared with individual stimuli. The model suggests that non-linearities in neural responses and synaptic (excitatory and inhibitory) connections can explain several aspects of multisensory integration.
已知上丘（SC）中的神经元会按照特定特性整合不同模态的刺激（例如视觉和听觉）。在这项工作中，我们提出了一个上丘神经元整合反应的数学模型，以揭示上丘多感官整合背后可能的生理机制。该模型包括三个不同的神经区域：两个单模态区域（听觉和视觉）致力于外部刺激的拓扑表示，并通过突触连接与负责多感官整合的第三个下游区域（在上丘中）进行通信。目前的模拟表明，该模型使用一组参数，就可以模拟对不同外部刺激组合的各种反应，包括在多感官增强和对比度方面的反向有效性、空间上不同刺激之间的模态内和跨模态抑制的存在、与单个刺激相比，对跨模态刺激的网络稳定时间的减少。该模型表明，神经反应和突触（兴奋性和抑制性）连接中的非线性可以解释多感官整合的几个方面。
