Mapping Brain Activity with High Spatiotemporal Resolution using Graphene Probes

项目摘要 中枢神经系统(CNS)是自然界中发现的最复杂和最动态的网络，由 数十亿个神经元的树突和突触，包括突触前和突触后的终末。 突触的突触后侧可以采取树突棘的形式，树突是一种小的富含肌动蛋白的突起 它们是中枢神经系统中大多数兴奋性突触的突触后接触和信号整合的场所。 突触在大型神经元网络中的相邻神经元之间传递信号，突显出它们至关重要 在中枢神经系统中发挥作用。毫不奇怪，树突棘/突触的异常与许多 中枢神经系统疾病，包括脆性X综合征、唐氏综合症、阿尔茨海默病、自闭症、精神分裂症、 以及癫痫、青光眼和智力障碍。因此，理解这些关系是至关重要的。 神经网络的功能连通图与神经网络的生理或病理功能之间的关系 单个突触和神经元。为了应对这一挑战，我们建议将二维柔性 扫描光电流显微镜下石墨烯膜探测单个突触的电活动 以及视网膜和大脑中的神经元，这是中枢神经系统的三个组成部分中的两个。石墨烯的独特优势 它的整个体积都暴露在环境中，这使其对局部电化学的敏感度最大化 潜在的变化。例如，石墨烯晶体管能够检测单个气体分子，这是因为 它的高表面积体积比和高电子迁移率(比硅高100到1000倍)。高潮 电子迁移率还使石墨烯晶体管能够在非常高的频率(高达500 GHz)下工作，领先于 到高时间分辨率。由于其强度和柔韧性，石墨烯薄膜可以附着在细胞上 薄膜或组织切片，以实现高电敏性。此外，单层石墨烯还可以传输 超过97%的入射光，使其成为兼容的透明电子设备的理想选择 利用光学成像技术。此外，石墨烯晶体管和电极已经证明 伸长率可达9%的稳定运行能力。因此，我们建议创造一个前所未有的 通过灵活的石墨烯晶体管和扫描光电流的罕见组合实现的神经技术 用显微镜同时研究大量突触和神经元的电活动 体外、在体和在体。这项技术将使我们能够破译神经元的功能连接图 具有高时空分辨率和高吞吐量的网络。

Project Summary The central nervous system (CNS), the most complex and dynamic network found in nature, is composed of billions of neurons with trillions of dendritic spines and synapses, including pre- and postsynaptic terminals. The postsynaptic side of synapses can take the form of dendritic spines, which are small, actin-rich protrusions that serve as sites of postsynaptic contact and signal integration for most of the excitatory synapses in the CNS. Synapses relay signals between neighboring neurons in large neuronal networks, underscoring their vital function in the CNS. Not surprisingly, abnormalities in dendritic spines/synapses are associated with a number of CNS disorders, including Fragile-X syndrome, Down’s syndrome, Alzheimer’s disease, autism, schizophrenia, and epilepsy, glaucoma, and intellectual disorders. It is, therefore, crucial to understand the relationships between the functional connectivity map of neuronal networks and the physiological or pathological functions of individual synapses and neurons. To address this challenge, we propose to integrate two-dimensional flexible graphene membranes with scanning photocurrent microscopy to probe electrical activities of individual synapses and neurons in the retina and brain, two of the three components of the CNS. A unique advantage of graphene is that its whole volume is exposed to the environment, which maximizes its sensitivity to local electrochemical potential change. For example, graphene transistors are capable of detecting individual gas molecules, due to its high surface-area-to-volume ratio and high electron mobility (100 to 1000 times higher than silicon). The high electron mobility also enables graphene transistors to operate at very high frequencies (up to 500 GHz), leading to high temporal resolution. Because of its strength and flexibility, graphene membranes can adhere to cell membranes or tissue slices to achieve high electrical sensitivity. Furthermore, monolayer graphene transmits more than 97% of incident light, making it ideal to be used as transparent electrical devices that are compatible with optical imaging techniques. In addition, graphene transistors and electrodes have demonstrated the capability of stable operation at stretching up to 9%. As such, we propose to create an unprecedented neurotechnology through a rare combination of flexible graphene transistors and scanning photocurrent microscopy to simultaneously study the electrical activities of a large population of synapses and neurons in vitro, in situ, and in vivo. This technology will allow us to decipher the functional connectivity map of neuronal networks with high spatiotemporal resolution and high throughput.