Stochastic Nonlinear Dynamics of Sensory Nervous Systems

描述：（由申请人提供）本研究的长期目标是更好地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。我们将利用白鲟的电感受器作为一个有利的实验模型来研究感觉系统的一般基本机制，特别是涉及振荡、破裂、噪声、同步和随机共振的机制。白鲟是一种新兴的模型系统，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，电感受器具有一种新的双周期组织：它们具有两种不同类型的自持振荡器，一种在初级传入中以40-70 Hz的频率循环，另一种在电敏感上皮中以25-30 Hz的频率循环。这两种振子由毛细胞向传入兴奋性突触单向耦合。因此，电感受器为定义非线性和随机感觉机制提供了一个定义良好的外围振荡神经网络。本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。我们将在不同层次上研究白鲟的电感觉系统，使用：(i)体外制剂，以获得有关毛细胞和传入末端振荡的结构基础和细胞机制的信息；（ii）体内制剂，结合非线性动力学方法，表征电受体反应动力学、它们的传递和感觉编码特性、随机共振、同步和噪声诱导的刺激编码爆发模式的过渡；（iii）进食行为实验，以证实所提出的感官编码规则的有效性；（iv）理论和计算机建模，以数值方式探索神经传感器振荡活动的功能作用。该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，包括人类听觉和平衡的调节，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.