SYNAPTIC INTEGRATION OF SENSORY AFFERENTS IN BRAINSTEM

描述：神经元通过整合多个突触来处理信息 输入到其树枝状树上，导致其尖峰输出。这 该项目将通过刺激来研究这种神经过程。 脊椎动物脑干中神经元的个体感觉传入， 使用感官通路，它具有缺乏的独特优势 地形。因此，它的传入胞体广泛存在。 分布在感觉外周。具体地说，细胞内 在辅助光学系统中的记录将以独特的 在体外甲鱼脑制剂中，眼睛保持附着并 大脑在视觉上保持反应。副视神经中的神经元 系统可能从不同的类别接收它们的突触输入 视网膜细胞，方向敏感的神经节细胞。互动 在突触前终末和突触后细胞之间执行 从局部视网膜方向信息到视网膜方向的基本转换 全球影像运动的量度，称为视网膜滑移，它有一个井 在前庭和动眼反射中扮演明确的角色。乌龟的 附属视神经系统称为基底核，是一种表面 脑干结构，其神经元在体外很容易定位。 视神经基底核细胞的突触后事件 使用贴片在整个单元配置中高保真地记录 移液器。个体视网膜的视觉和电刺激 传入神经将被用来研究单位神经的大小和形状 突触后事件及其方向调整。刺激两个人 传入神经元将决定两个突触电位如何在 突触后膜。这种相互作用因这一发现而变得复杂 对单个传入的突触反应在 幅度和突触后膜具有电压敏感性 可以被突触电位调制的通道。为了进一步 了解了这种相互作用，我们还将研究被动膜 每个电池的特性，其膜中的电压敏感通道， 突触电流的离子和药理学性质以及 细胞的形态。这一完整的分析最终将澄清 从视网膜突触输入到附件的神经转化 光学系统输出。这些研究的结果将提供一些见解 到编码视觉方向的神经元的功能 为了保持我们的平衡和稳定我们的凝视，我们需要进行场运动。 这样的视觉处理也将提供一个很好的模型来理解 突触整合和感觉加工的一般机制 脑干。

DESCRIPTION: A neuron processes information by integrating many synaptic inputs onto its dendritic tree, leading to its spike output. This project will investigate this neural processing by stimulating individual sensory afferents to a neuron in the vertebrate brainstem, using a sensory pathway which has the unique advantage of lacking topography. As a consequence, its afferent cell bodies are widely distributed in the sensory periphery. Specifically, intracellular recordings in the accessory optic system will be performed in a unique in vitro turtle brain preparation in which the eyes remain attached and the brain remains visually responsive. Neurons in the accessory optic system presumably receive their synaptic inputs from a distinct class of retinal cell, the direction sensitive ganglion cell. The interaction between the presynaptic terminals and a postsynaptic cell performs an essential conversion from local retinal directional information into a measure of global image motion, called retinal slip, that has a well defined role in vestibular and oculomotor reflexes. The turtle's accessory optic system is called the basal optic nucleus, a surface brainstem structure whose neurons are easy to locate in vitro. Postsynaptic events of cells in the basal optic nucleus are readily recorded with high fidelity in the whole cell configuration using patch pipettes. Visual and electrical stimulation of individual retinal afferents will be used to study the size and shape of unitary postsynaptic events as well as their direction tuning. Stimulating two afferents will determine how two synaptic potentials interact on the postsynaptic membrane. This interaction is complicated by the finding that synaptic responses to individual afferents are quite variable in amplitude and that the postsynaptic membrane has voltage sensitive channels that can be modulated by synaptic potentials. To further understand this interaction, we will also study the passive membrane properties of each cell, the voltage sensitive channels in its membrane, the ionic and pharmacological nature of the synaptic currents and the cell's morphology. This full analysis will ultimately clarify the neural transformations from the retinal synaptic input to the accessory optic system output. The results of these studies will provide insights into the functioning of neurons that encode the direction of visual field motion in order to maintain our balance and stabilize our gaze. Such visual processing will also provide an excellent model to understand general mechanisms of synaptic integration and the sensory processing of the brainstem.