Microfabricated interface for organotypic neural circuits.

描述（由申请人提供）：该项目的总体目标是开发一个有机型脑神经回路和电生理记录设备之间的接口，该设备能够长期（数周），高度并行刺激并记录单个细胞及其过程水平的电活动。我们对单个神经元在中枢神经系统神经回路中的作用的理解将受益于工具的引入，这些工具允许研究人员在体外长期操纵回路连接并监测电活动，并且在包含体内回路的基本功能单元（如皮质柱或海马体切片）的系统中。我们建议开发一个体外平台，将器官型脑切片培养与微型装置相结合，该微型装置能够几何限制连接电路各个部分的轴突束。该装置将由用于轴突引导的聚合物微通道和用于刺激和记录神经回路信号的集成微电极阵列组成。将轴突限制在绝缘微通道中，可以模拟体内轴突通路的功能，从而使正在研究的通路中的许多轴突并行和独立刺激成为可能。我们将重点研究两种模型通路，一种是丘脑皮质通路，它可以通过丘脑核和初级皮层的切片共培养在体外重建；另一种是通过海马和内嗅皮质切片共培养重建穿孔通路。这些通路在体外用一种设备重建，使研究人员能够选择性地（对单个轴突）施加刺激，并长期记录来自受体神经网络中的多个细胞。本提案的具体目标是：(1)制造具有聚合物通道的界面微装置，用于轴突约束和集成的多电极阵列，用于长期记录；(2)在微制造装置上进行穿孔和丘脑皮质通路的器官型培养；(3)从模型通路刺激/记录神经活动。在拟议的研究过程中开发的平台将能够详细调查时间依赖性突触可塑性在神经回路发展中的作用，以及Hebbian学习机制，有助于理解发育和学习障碍的原因。器官型培养-电极阵列平台在医学研究中也有重要的应用，作为体外模型，用于评估药物、电刺激和/或细胞疗法（干细胞等）对神经回路的影响，以及对重建通路轴突的生长速度、髓鞘形成和信号传导的影响。

DESCRIPTION (provided by applicant): The overall aim of this project is to develop an interface between organotypic brain neural circuits and electrophysiological recording equipment that is capable of long-term (weeks), highly parallel stimulation and recording of electrical activity at the level of individual cells and their processes. Our understanding of the role of individual neurons in the neural circuits of the central nervous system will benefit from the introduction of tools that allow the researcher to manipulate the circuit connectivity and monitor the electrical activity in vitro, over long term, and in a system that contains a basic functional unit of the in vivo circuit such as a cortical column or a slice of the hippocampus. We propose to develop an in vitro platform that combines organotypic brain slice cultures with a microdevice that is capable of geometric confinement of the axonal tracts connecting various parts of the circuit. The device will consist of polymer microchannels for axon guidance and an integrated microelectrode array for stimulation and recording of the signals in the neural circuit. The confinement of axons in insulated microchannels will enable parallel and independent stimulation of many axons in a pathway under study, mimicking the functionality of axonal pathways in vivo. We will focus on two model pathways, the thalamocortical pathway that can be recreated in vitro by coculturing slices from the thalamic nuclei and the primary cortices, and the perforant path, recreated by coculture of hippocampus and entorhinal cortex slices. These pathways, when recreated in vitro in a device that enables the researcher to apply stimulation selectively (to individual axons) and record from multiple cells in the recepient neural network over long term. The specific aims of this proposal are: (1) Fabrication of the interface microdevice with polymer channels for axon confinement and integrated multiple electrode array for long-term recording, (2) Organotypic cultures of perforant and thalamocortical pathways on microfabricated devices, and (3) Stimulation/recording of neural activity from model pathways. The platform developed in the course of proposed research will enable detailed investigation of the role timing-dependent synaptic plasticity plays in the development of neural circuitry, and of Hebbian learning mechanisms, contributing to understanding of the causes of developmental and learning disorders. The organotypic culture-electrode array platform also has an important application in medical research as an in vitro model for evaluation of the effects drugs, electrical stimulation, and/or cellular therapies (stem cells, etc) have on the neural circuitry, and on the growth rate, myelination, and signal conduction in the axons of the re-created pathway.