Encoding information that coordinates distributed neural microcircuits

神经科学的一个主要目标是了解神经回路的动态。在大多数情况下，对神经的内在特性和神经回路的突触组织的无知限制了我们理解神经回路的功能或治疗由其功能失调引起的神经系统紊乱的能力。递质和激素的调节可以极大地改变这些回路中神经元和突触的特性，但奇怪的是，回路的一些功能却保持不变。该项目利用了小龙虾中枢神经系统（CNS）回路中突触组织的新发现，该回路在运动过程中协调肢体运动。这种协调回路连接了分布在中枢神经系统不同部位的四对模块化局部回路，这些局部回路控制着单个肢体，并在运动时活跃。这些局部电路的周期性电机输出是同步的，但在相邻电路之间存在稳定的相位差。这项研究的目的是理解和解释在细胞术语的信息编码需要协调这些分布式电路。电生理实验和计算分析将用于研究和模拟电路的关键协调神经元的信息编码。面对神经调节，如何维持稳定的相位差是一个深层次的问题。例如，该系统的胆碱能调制改变了其电机输出的周期和强度，但不影响相邻电路之间的相位差。电生理和药理学实验将用于分析胆碱能调节如何调节编码，使相位在周期变化时保持不变。这项研究将产生见解和分析方法，可应用于脑干和脊髓的类似系统，以及大脑中有节奏的神经回路。学生参与者将参与项目的各个方面。研究结果也将直接适用于柔性和自适应机器人装置的开发。

A major goal of neuroscience is to understand the dynamics of neural circuits. In most cases, ignorance of intrinsic neural properties and the synaptic organization of circuits limit our ability to understand a circuit's function or to cure disorders of the nervous system caused by its malfunction. Modulation by transmitters and hormones can change the properties of neurons and synapses in these circuits dramatically, but leave some features of the circuit's performance strangely unmodified. This project exploits new discoveries of the synaptic organization of a circuit in the crayfish central nervous system (CNS) that coordinates limb movements during locomotion. This coordinating circuit links four pairs of modular local circuits distributed in different parts of the CNS that control individual limbs and are active during locomotion. Periodic motor output from these local circuits is synchronized, but occurs with a stable difference in phase between neighboring circuits. The goal of this research is to understand and explain in cellular terms the encoding of information needed to coordinate these distributed circuits. Electrophysiological experiments and computational analyses will be used to study and model encoding of information by the circuit's key coordinating neurons. How stable phase differences are maintained in the face of neuromodulation is a deep problem. For example, cholinergic modulation of this system changes the period and strength of its motor output, but does not affect the phase differences between neighboring circuits. Electrophysiological and pharmacological experiments will be used to analyze how cholinergic modulation tunes encoding so that phase remains constant when period changes. This research will generate insights and analytical methods that can be applied to similar systems in the brain stem and spinal cord, and to rhythmic neural circuits in the brain. Student participants will be involved in all aspects of the project. The results will also be directly applicable to the development of flexible and adaptive robotic devices.