果蝇嗅觉系统神经环路模型研究

Neural information processing is a complicated biophysical process, it involves chemical and electrical interactions at many different levels. With the development of experimental technologies, more and more details about the circuit properties of drosophila olfactory system have been well understood, both in the level of a single neuron and in a local functional network level. However, although the general structure of the olfactory neural circuit has been well known, the computational roles of these neural circuits in terms of information processing remain unclear. In this project, we aim to make a comprehensive study on the computational roles of the neural circuit of drosophila olfactory system, based on recent discoveries of the circuit properties of drosophila olfactory system. The project will comprise theoretical analysis and numerical simulations in the early two stages of drosophila olfactory system, these are: 1) analyze the capabilities of a neural circuit with mechanisms of short term depression and pre-synaptic inhibition to process neural information; 2) analyze the computational roles of gap junction mediated sister cells and other aspects; 3) analyze the impact of synaptic scaling and synaptic plasticity on drosophila sparse coding network. By studying the drosophila olfactory system in the level of neural circuits, it may help to reveal the general working principles of neural information processing.

神经信息处理是一个复杂的生物物理过程，它涉及在神经系统不同层次上的电化学交互作用。随着实验技术的发展，研究发现相比于脊椎动物简单很多的果蝇的嗅觉系统在细胞、突触层面存在着精巧细致的环路结构，然而目前还不清楚这些环路结构的计算功能。本项目将根据实验上发现的果蝇初级嗅觉系统神经环路上的结构特点，应用理论模型和计算机分析，探讨果蝇嗅觉系统气味信息处理的计算功能。具体地，本项目将研究以下几个问题：1）分析具有短时程衰减和突触前抑制机制的神经环路的神经信息处理能力；2）分析姊妹细胞电突触耦合作用等因素的计算功能；3）分析突触归一化机制和突触可塑性机制对稀疏编码的影响。通过从神经环路的水平研究相对简单的果蝇嗅觉系统，有助于揭示神经信息处理的普遍规律。

神经信息处理是一个复杂的生物物理过程，它涉及在神经系统不同层次上的电化学相互作用。本项目以简单的模式动物果蝇的嗅觉系统为研究对象，根据实验上发现的果蝇嗅觉系统细胞突触层面上的存在的独特而精巧的环路结构，从计算模型和实验相结合的方式解读这种独特结构所对应的计算功能。具体的，本项目的研究结果表明：1）具有短时程衰减和突触前抑制的神经环路可以实现生物系统中广泛发现的是适应微分处理；2）过表达或欠表达姊妹细胞电突触基因可以增强或减弱电突触耦合强度；3）乘法性突触整合规则可以实现平衡网络中一种新的混沌-有序边界，有利于神经信息处理。通过从环路水平研究相对简单的果蝇嗅觉系统，有助于揭示神经信息处理的普遍规律。