OPTICAL STUDIES OF NEURON FUNCTION

这项研究的长期目标是推导出一般的 局部环路神经元的功能原理，特别是 那些通过整合而产生突触输出的细胞 区域(例如，树突-树突突触)，并且可以使用 突触传递分级低于峰电位阈值。这个 眼下的目标是了解 无脊椎动物系统，螃蟹的口胃神经节 北方癌症。这项研究的重点将是实验 旨在阐明钙在口腔胃细胞中的作用 功能。问题包括：1)什么时候与电压有关 钙内流主要是由于阶梯性电压变化(幽门 节奏)，什么时候主要是由于扣球？钙离子内流吗？ 根据细胞类型、神经元内的位置或 突触或神经调质活性？2)神经调质如何 影响静息内钙浓度和电压- 识别细胞不同区域的依赖性钙离子内流？ 本研究中使用的方法包括：细胞内体细胞和 脑电记录，同时测量的内部 应用于单个神经元不同区域的钙波动 钙指示剂染料偶氮砷III和光电二极管阵列， 和静息体内钙浓度的测量 富拉2和ccd摄像头。当然，大多数对神经元的研究 功能在空间上受到限制：细胞内电极 中只有一个或两个同时放置的位置 细胞，通常是胞体。这项研究将提供一个机会 观察整个神经元在其正常范围内的行为 因为它使用了可能被认为是其最多的 有趣的离子，钙。

The long-term objective of this study is to derive general principles for the functioning of local circuit neurons, especially those cells which have synaptic output from their integrating regions (e.g., dendro-dendritic synapses) and which may use graded synaptic transmission below the threshold for spikes. The immediate objective is to understand the functioning of an invertebrate system, the stomatogastric ganglion of the crab Cancer borealis. The focus of this study will be experiments designed to elucidate the role of calcium in stomatogastric cell function. Questions will include: 1) When is voltage-dependent calcium influx due mostly to graded voltage changes (the pyloric rhythm) and when is it due mostly to spikes? Does calcium influx vary with the cell type, the location within the neuron, or with synaptic or neuromodulator activity? 2) How do neuromodulators affect the resting internal calcium concentration and the voltage- dependent calcium influx in different regions of identified cells? Methods to be used in this study include: intracellular somatic and neuropil recording, simultaneous measurements of internal calcium fluctuations in different regions of single neurons by use of the calcium indicator dye Arsenazo III and a photodiode array, and measurements of resting internal calcium concentrations with Fura 2 and CCD camera. Of necessity, most studies of neuron function have been constrained spatially: intracellular electrodes are placed in only one or two simultaneous locations in single cells, typically the soma. This study will provide an opportunity to look at the behavior of an entire neuron during its normal range of behaviors as it uses what might be considered its most interesting ion, calcium.