Sodium Imaging of Synaptic Function

描述(申请人提供)：光学方法发生了一场革命，现在可以窥视大脑并监测其功能。然而，一直缺乏测量单个突触强度的光学方法。这种方法的出现将彻底改变我们监测单个突触的能力，并使我们有可能通过光学方法来检测和监测构成学习和记忆基础的突触强度的变化。我们建议采用现代技术来改进成像树突等小神经元隔室中[Na+]i变化的方法。这些改进将包括使用LED光源和快速CCD摄像机来改进对微小快速荧光变化的检测，以及使用新一代更灵敏的钠指示剂。我们还将使用几种技术来分离脊椎信号和树突信号，而不需要双光子显微镜系统。这些脊髓定位的钠荧光信号可以解释为反映了突触激活的Na+电流。测量这些电流将揭示与单个突触位置的突触信号有关的受体类型的信息。我们还将测量这些信号如何在与突触可塑性相关的刺激方案下发生变化。

DESCRIPTION (provided by applicant): There has been a revolution in optical methods that now make it possible to peer into the brain and monitor its function. However, optical methods for measuring the strength of individual synapses have been lacking. The availability of such a method would revolutionize our ability to monitor single synapses and make it possible, by optical methods, to detect and monitor the changes in synaptic strength that underlie learning and memory. We propose to adapt modern technologies to improve methods for imaging [Na+]i changes in small neuronal compartments like dendritic spines. These improvements will include using LED light sources and fast CCD cameras to improve the detection of small rapid fluorescence changes and the use of a new generation of more sensitive sodium indicator dyes. We will also use several techniques to separate spine signals from dendrite signals without the need for a 2- photon microscope system. These spine localized sodium fluorescence signals can be interpreted as reflecting synaptically activated Na+ currents. Measuring these currents will reveal information about the receptor types involved in synaptic signaling at individual synaptic sites. We will also measure how these signals change following stimulation protocols related to synaptic plasticity.