Study Exocytosis in the Region of Synaptic Cleft using Electrochemical Nanoprobe

描述(申请人提供)：神经递质的囊状释放，即胞吐作用的过程，影响神经系统的许多功能方面。神经递质释放的变化与药物滥用、疾病(如帕金森氏症、阿尔茨海默氏症)、衰老和记忆力丧失有关。通过微电极对神经递质的电化学研究，已经在理解胞吐作用方面取得了重大进展。然而，目前的技术仅限于大约一微米的空间分辨率，这使得研究突触附近和突触内的神经递质动力学变得困难。为了通过显著提高空间分辨率记录和测量来研究胞吐作用，需要具有纳米分辨率的方法和仪器。此外，使用传统传感器研究非电化学活性神经递质(如乙酰胆碱)已变得困难。在这里，我们建议开发一种电化学传感器，使我们能够以纳米分辨率询问胞吐作用。一个关键的目标是在适当的电刺激(动作电位)和化学刺激(如K+，Ca~(2+))的情况下，定性和定量地测量海兔神经元模型突触内神经递质的释放和摄取。这种新型纳米传感器可以检测电化学活性和非活性神经递质。我们的医疗设备包括基于扫描电化学显微镜的新型纳米定位、成像和测量系统。这些紧密结合的技术开发和神经科学努力将解决与神经递质的身份、浓度和以纳米空间分辨率、提高信噪比和高时间分辨率释放递质所需的条件相关的问题。这些努力与PA-11-149“生物和医学中的纳米科学和纳米技术”的目标很好地匹配。这些方法是通用的，适用于一系列神经细胞。由此产生的关于神经传递的新工具包和新知识将可转移到更广泛的研究界，并将对神经化学研究产生重大影响。

DESCRIPTION (provided by applicant): Vesicular release of neurotransmitters, the process of exocytosis, impacts many functional aspects of the nervous system. Changes in neurotransmitter release are implicated in drug abuse, diseases (e.g. Parkinson's, Alzheimer's), aging and memory loss. Significant progress has been made in understanding exocytosis via electrochemical studies of neurotransmitters via microelectrodes. However, current techniques are limited to a spatial resolution of approximately a micron, making it difficult to study neurotransmitter dynamics near and within the synapse. In order to study exocytosis with significantly improved spatial resolution recording and measurement, methods and instruments with nanometer resolution are needed. In addition, it has been difficult to study non-electrochemically active neurotransmitters (e.g., acetylcholine) using traditional sensors. Here we propose to develop electrochemical sensor that will enable us to interrogate exocytosis with a nanometer resolution. A key objective is qualitative and quantitative measurement of neurotransmitter release and uptake within model synapses of Aplysia californica neurons with both appropriate electrical (action potentials) and chemical stimuli (e.g. K+, Ca2+). The novel nanosensor allows the detection of both electrochemical active and non-active neurotransmitters. Our armamentarium includes novel nanopositioning, imaging and measurement systems based on scanning electrochemical microscope. These tightly coupled technology development and neuroscience efforts will resolve issues related to neurotransmitter identity, concentration, and the conditions needed for transmitter release with nanometer spatial resolution, improved signal to noise ratio, and high temporal resolution. These efforts are well matched to the goal of PA-11-149, "Nanoscience and Nanotechnology in Biology and Medicine." The approaches are general and adaptable to a range of neuronal cells. The resulting new toolset and new knowledge about neurotransmission will be transferrable to broader research community and will have a high impact on the neurochemical research.