Sodium Imaging of Synaptic Function

描述（由申请人提供）：光学方法发生了革命，现在可以窥视大脑并监测其功能。然而，测量单个突触强度的光学方法一直缺乏。这种方法的可用性将彻底改变我们监测单个突触的能力，并使通过光学方法检测和监测作为学习和记忆基础的突触强度变化成为可能。我们建议采用现代技术，以改善成像方法[Na+]i的变化，在小神经元室，如树突棘。这些改进将包括使用LED光源和快速CCD相机，以改善对微小快速荧光变化的检测，并使用新一代更灵敏的钠指示染料。我们还将使用几种技术来分离棘信号从树突信号，而不需要一个双光子显微镜系统。这些棘定位的钠荧光信号可以被解释为反映突触激活的Na+电流。测量这些电流将揭示在单个突触部位参与突触信号传导的受体类型的信息。我们还将测量这些信号在与突触可塑性相关的刺激方案后如何变化。

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.