Biophysical mechanisms and computational principles of weak signal detection.

弱信号检测的生物物理机制和计算原理。

• 批准号: 237638727
• 负责人: Dr. Sarah Nicola Jung
• 金额: --
• 依托单位: Department of Physics
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/237638727?language=en
• 关键词: Biophysical; mechanisms; computational; principles; weak

The nature of the neural code is one of the fundamental questions in neuroscience. Understanding the neural code for sensory systems requires both specifying a map between external signals and the resulting spike trains and demonstrating that downstream neural circuits can interpret or decode this mapping and therefore direct behavioral output. By combining electrophysiology, modeling and pharmacology I want to understand explicitly on a cellular level how decoding of a temporal neural code is performed by downstream neurons. Weak signal detection in pyramidal cells (PC) of weakly electric fish is an excellent model to study this question. Neuroanatomical work has thoroughly described the network connectivity of the electrosensory circuits. The input neurons (primary afferents) to PCs have been investigated electrophysiologically and modeled in great detail. Using a relatively simple model system (e.g. as compared to mammalian cortex) will enable me to link cellular coding mechanisms to a specific sensory task, e.g. amplification of weak signals. The project will consist of three major elements: 1) determining the neuronal code of PCs for weak signals using extracellular recordings; 2) using these data to develop a model of the cellular dynamics that transforms the primary afferent code into the PC code; 3) using the model to make strong predictions as to the cellular basis of decoding and testing these predictions by intracellular recordings and pharmacological manipulations. Since the cellular basis of PC synaptic input amplification (e.g. AMPA, NMDA and GABA receptors plus various voltage-gated ion channels) is found in all mammalian sensory systems, the decoding algorithm I will develop should be generally applicable and neuroscientists working on other systems will be able to evaluate whether it is realized by the synaptic dynamics in the visual, auditory or somatosensory system.

神经密码的本质是神经科学的基本问题之一。理解感觉系统的神经编码需要指定外部信号和由此产生的尖峰序列之间的映射，并证明下游神经回路可以解释或解码该映射，从而指导行为输出。通过结合电生理学，建模和药理学，我想在细胞水平上明确地了解下游神经元如何解码时间神经代码。弱电鱼锥体细胞（PC）的微弱信号检测是研究这一问题的一个很好的模型。神经解剖学的工作已经彻底地描述了电感觉回路的网络连接。对pc的输入神经元（初级传入）进行了电生理学研究，并建立了详细的模型。使用一个相对简单的模型系统（例如，与哺乳动物皮层相比）将使我能够将细胞编码机制与特定的感官任务联系起来，例如，微弱信号的放大。该项目将包括三个主要内容：1)利用细胞外记录确定pc的神经元编码，以获取弱信号；2)利用这些数据建立细胞动力学模型，将主要传入代码转换为PC代码；3)使用该模型对解码的细胞基础做出强有力的预测，并通过细胞内记录和药理操作测试这些预测。由于PC突触输入放大的细胞基础（例如AMPA， NMDA和GABA受体加上各种电压门控制离子通道）存在于所有哺乳动物的感觉系统中，因此我将开发的解码算法应该是普遍适用的，并且研究其他系统的神经科学家将能够评估它是否通过视觉，听觉或体感系统中的突触动力学实现。