SYNAPTIC TRANSMISSION DURING NEURONAL DIFFERENTIATION

这项工作的主要主题是表征功能性和 前庭初级纤维形成突触的结构可塑性 发育过程中脑干前庭感觉神经元的研究 描述前庭后这些前庭神经元的特性 神经切除术。 所有的研究都将在切线的切片准备上进行 前庭核是雏鸡前庭外侧核的一部分。这个 最大直径的初级前庭纤维，或巨大的纤维，形成 TN主细胞上的轴体末端--勺状末端。这项工作 集中在两个年龄：L)胚胎15/16天，当缝隙连接 化学突触在勺子末端形成“混合突触”，以及2) 新生儿，当缝隙连接在勺子末端起作用时。这个 使用的技术包括细胞内电流和电压钳， 细胞内染料注射、电子显微镜和免疫细胞化学。 具体目的是：刻画……的发育表象 勺状突触的功能性缝隙连接；定义前庭突触 前庭感觉神经元产生的电流；决定可塑性 前庭突触对破伤风和药物的反应； 研究缺血缺血区神经元的膜和突触特性 单侧前庭神经切断术后对侧TN；注射染料 细胞内研究前庭与前庭间的暂态电耦合 并确定TN轴突是否投射到运动神经元池 反射来自初级前庭纤维的输入的模式；并识别 免疫细胞化学缝隙连接蛋白、谷氨酸受体和GABA- 在显影的TN中包含终端。 随着我们对影响前庭突触变化的因素了解得越来越多， 我们可以应用这一点来增强或促进新的突触形成以取代 中枢性突触因疾病、损伤或衰老而丧失。第二，这很重要 研究突触传递以便药物在中枢神经系统中的作用 前庭突触可以被澄清。第三，这项工作将增加新的 关于前庭解剖的信息，这对设计模型很重要 前庭系统功能。最后，我们将应用多种方法来 分析神经元缝隙连接的功能。因为缝隙连接是已知的 几乎存在于每一条主要的中枢神经系统通路中，确定 缝隙连接在牙周炎的发生和功能中的具体作用 中枢神经回路。

The major theme of this work is to characterize the functional and structural plasticity of synapses formed by the primary vestibular fibers on vestibular sensory neurons in the brainstem during development and to characterize the properties of these vestibular neurons after vestibular neurectomy. All studies will be performed on slice preparations of the tangential vestibular nucleus (TN), part of the chick lateral vestibular nucleus. The largest diameter primary vestibular fibers, or colossal fibers, form large axosomatic endings-the spoon endings- on the TN principal cells. The work is focused on two ages: l) embryonic days 15/16, when gap junctions join chemical synapses to form "mixed synapses" at the spoon endings, and 2) newborns, when the gap junctions are functional at the spoon endings. The techniques used will include intracellular current and voltage clamp, intracellular dye injection, electron microscopy, and immunocytochemistry. The specific aims are to: characterize the developmental appearance of functional gap junctions at spoon synapses; define the vestibular synaptic currents generated at vestibular sensory neurons; determine the plasticity of vestibular synapses in response to tetanus and pharmacologic agents; study the membrane and synaptic properties of neurons in the ipsi- and contralateral TN after unilateral vestibular neurectomy; inject dyes intracellularly to study transient electrical coupling between vestibular neurons and determine whether TN axons project to motor neuron pools in a pattern reflecting inputs from primary vestibular fibers; and identify immunocytochemically gap junction connexins, glutamate receptors and GABA- containing terminals in the developing TN. As we learn more about the factors influencing vestibular synaptic change, we can apply this to enhance or promote new synapse formation to replace central synapses lost to disease, injury or aging. Second, it is important to study synaptic transmission so that the action of drugs on central vestibular synapses can be clarified. Third, this work will add new information on vestibular anatomy which is important to devise models on vestibular system function. Finally, we will apply multiple approaches to analyze the function of neuronal gap junctions. As gap junctions are known to exist in almost every major CNS pathway, it is meaningful to determine the specific roles that gap junctions play in the genesis and function of the central neural circuitry.