Stochastic Nonlinear Dynamics of Sensory Nervous Systems

产品说明：（申请人提供）拟议研究的长远目的是更深入了解非线性和随机过程在脊椎动物感觉神经系统信息处理的神经机制中的功能作用。我们将使用白鲟的电感受器作为一个有利的实验模型，用于研究感觉系统的一般基本机制，特别是涉及振荡，爆发，噪声，同步和随机共振的机制。Paddlefish是一种新发展起来的模型系统，在研究感觉神经整合方面具有独特的实验优势。我们最近发现，电受体有一个新的双周期组织：它们有两种不同类型的自持振荡器，一个周期在40-70 Hz的初级传入，以及25-30 Hz的振荡器在电敏感上皮。这两种类型的振荡器通过毛细胞-传入兴奋性突触单向耦合。因此，电受体提供了一个明确的外周振荡神经网络，用于定义非线性和随机的感觉机制。该建议包括实验神经生理学，行为生物学和计算神经科学的组成部分，并以随机非线性系统的物理理论为基础。我们将研究白鲟在不同层次上的电感觉系统，使用：（i）体外制备以获得关于毛细胞和传入末梢中振荡的结构基础和细胞机制的信息，（ii）体内制备连同来自非线性动力学的方法以表征电受体响应动力学、它们的传递和感觉编码特性、随机共振、同步化，和噪声引起的过渡到突发模式的刺激编码，（iii）喂养行为实验，以确认建议的感官编码规则的有效性，和（iv）理论和计算机建模，以探索数值振荡活动在神经传感器的功能作用。拟议的研究旨在更好地了解毛细胞-初级传入感觉受体的基本生理特性，包括介导人类听觉和平衡的受体，以及振荡神经网络中感觉处理的一般基本机制，包括人类视觉，嗅觉，听觉和体感系统，以及癫痫和帕金森病患者的紊乱网络。

DESCRIPTION: (provided by applicant) The long-term objective of the proposed research is to gain a better understanding of the functional roles of nonlinear and stochastic processes in neural mechanisms of information processing in the sensory nervous systems of vertebrates. We will use the electro-receptors of paddlefish as an advantageous experimental model for studying general basic mechanisms of sensory systems, especially mechanisms involving oscillations, bursting, noise, synchronization, and stochastic resonance. Paddlefish are a newly developed model system presenting unique experimental advantages for studying sensorineural integration. We discovered recently that electro-receptors have a novel bi-periodic organization: they have two distinct types of self-sustained oscillators, one cycling at 40-70 Hz in the primary afferent, together with 25-30 Hz oscillators in the electro-sensitive epithelium. The two types of oscillators are coupled uni-directionally by hair cell -to- afferent excitatory synapses. Electro-receptors therefore offer a well-defined peripheral oscillatory neural network for defining nonlinear and stochastic sensory mechanisms. This proposal includes components of experimental neurophysiology, behavioral biology, and computational neuroscience, and is based on physical theory of stochastic nonlinear systems. We will study the electro-sensory system of paddlefish on different levels, using: (i) in vitro preparations to gain information about the structural basis and cellular mechanisms of oscillations in hair cells and afferent terminals, (ii) in vivo preparations together with approaches from nonlinear dynamics to characterize the electro-receptor response dynamics, their transfer and sensory encoding properties, stochastic resonance, synchronization, and noise-induced transitions to a bursting mode of stimulus encoding, (iii) feeding behavior experiments to confirm the validity of proposed sensory encoding rules, and (iv) theoretical and computer modeling to explore numerically the functional roles of oscillatory activity in neurosensors. The proposed research is intended to lead to a better understanding of basic physiological properties of hair cell - primary afferent sensory receptors, including those mediating hearing and balance in humans, as well as general fundamental mechanisms of sensory processing in oscillatory neural networks, which include the human visual, olfactory, auditory, and somatosensory systems, as well as the disordered networks of epileptic and Parkinsonian patients.