大蹄蝠适应于在高度杂波空间中感受回声定位信号的突触机制研究

项目名称： 大蹄蝠适应于在高度杂波空间中感受回声定位信号的突触机制研究

项目编号： No.31300982

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 生物科学

项目作者： 梅慧娴

作者单位： 湖北大学

项目金额： 24万元

中文摘要： 对于在高度杂波空间中捕食的CF-FM蝙蝠，如何从发声和众多由背景环境物体反射的杂波回声中分辨和判断来自靶物的回声所携带的信息是其所面临的问题？已有的研究表明，CF-FM蝙蝠可通过发出复杂的CF-FM声脉冲，并分析发声与回声信号的FM成分之间的延迟来确定靶物的距离，以及通过补偿回声中CF成分根据昆虫振翅产生的多普勒频率漂移来判断昆虫飞行的相对速度。然而蝙蝠听中枢神经元感受这些回声定位信号中特定参数的突触机制仍需进一步的研究。本研究拟在大蹄蝠下丘采用细胞内电生理记录方法，着重探讨不同特性的神经输入如何在下丘定型CF和FM声成分的反应，并通过时相和频率整合来处理杂波环境下发声-回声对中包含的靶物距离和相对移动速度的信息。这一研究将有助于从细胞水平认识大蹄蝠对回声定位适应性进化的神经机制，并促进人们对听中枢在复杂听环境下对回声定位信号加工原理的认识。

中文关键词： 回声定位；下丘；联合敏感；多普勒频移；突触机制

英文摘要： When a CF-FM bat preys in a narrow space it receives not only echoes reflected from it's target but also background clutters reflected from reverberant surface afer it emits an echolocation call. The CF-FM bat inevitablely faces a problem that how to distinguish and determine the echo carrying informations about target among emitted call and multiple reflections in this highly cluttered situation. Previous studies have suggested that the CF-FM bat which emitted complex CF-FM pulses could detect target range by analyzing the delay between FM signals in pulse and echo, and decide the relative speed between bat and moving target by compensating doppler shift of CF signal induced by insect fluttering. However, the synaptic mechanisms of bat auditory center neurons processing these specific parameters in echolocation signal are remained unclear. In this study of leaf-nosed bat with in vivo intracellular recording, we will explore in inferior colliculus (IC) how neural inputs shape neuron's responses to CF and FM signals, and how they temporally and spectrally integrate to encode the distance and relative speed of target included in pulse-echo pair in cluttered situation. Our finding will contribute to understand the neural mechanism of echolocation during adaptive evolution of leaf-nosed bat, and also to further reco

英文关键词： echolocation signal；inferior colliculus；combination-sensitivity；Doppler shift compensation；synaptic mechanism