ADAPTIVE CHANGES IN VESTIBULAR SYSTEM

比目鱼是研究适应性变化的自然范例 在中枢神经系统中，因为他们的前庭和眼神经 坐标系在运动期间经历90度相对位移， 变态 这种位移需要引入新的 前庭编码信号传输的转换因子 转换成用眼肌坐标编码的运动指令。 我们 先前的研究显示，在中学阶段， 前庭神经元连接到水平管道系统，表现出一个 垂直眼神经元池的广泛终止模式， 这些连接在迄今为止研究的所有其他脊椎动物中都不存在。 计划进行实验，以充分描述前和后的情况。 在比目鱼的变性后前庭眼反射（VOR）系统。 这些包括，首先，细胞外和细胞间HRP的应用， 双侧前庭初级和次级传入水平 包括定量分析周围神经供应 前庭终器，以显示前庭的对称性 连接以及双重细胞内记录，以确定 兴奋性或抑制性的识别次级前庭 VOR系统的推挽系统内的神经元。 第二、 视动刺激期间的细胞外记录将提供 关于这些动物视觉空间的组织的信息。 第三，对行为警觉的比目鱼的实验将揭示 形态学描述的结构与功能关系 与鱼的眼球运动的联系。 四、实验 在前变质和变质的动物和鱼类中， 在变态的某些阶段， 这些新形成的连接的发生，无论它们是否来自 新生的神经元或突触连接 以前。 这些实验涉及创造超维度 幼虫的环境和药理学操作，以及 使用放射自显影技术。 拟议的实验不会 这只能是一个全面的方式来描述VOR系统在成人 比目鱼，但也提供有关的机制， 适应性大脑，特别是在适应性可塑性的背景下， 实验扰动

Flatfish constitute a natural paradigm for investigating adaptive changes in the central nervous system, because their vestibular and oculomotor coordinate systems undergo a 90 degrees relative displacement during metamorphosis. This displacement requires the introduction of a new conversion factor for the transmission of signals coded in vestibular coordinates into motor commands coded in eye muscle coordinates. Our previous studies revealed a dramatic rewiring at the level of secondary vestibular neurons connected to the horizontal canal system, exhibiting an extensive termination pattern in vertical oculomotor neuron pools via connections which are absent in all other vertebrates studied so far. Experiments are planned to give a full description of the pre- and postmetamorphic vestibulo-ocular reflex (VOR) system in the flatfish. These include, first, extracellular and intercellular HRP applications at the level of primary and secondary vestibular afferents of both labyrinths including a quantitative analysis of the peripheral nerves supplying vestibular end-organs in order to demonstrate symmetry of the labyrinthine connections as well as double intracellular recordings to ascertain the excitatory or inhibitory nature of the identified secondary vestibular neurons within the push-pull system of the VOR system. Secondly, extracellular recordings during optokinetic stimulation will provide information about the organization of the visual space of these animals. Thirdly, experiments in the alert behaving flatfish will reveal the structure-function relationship of the morphologically described connections to the actual eye movements of the fish. Fourth, experiments in premetamorphic and metamorphosing animals and in fish which are locked in certain stages of the metamorphosis will reveal the nature of the occurrance of these newly formed connections, whether they originate from newly born neurons or from synaptic connections which have been there previously. These experiments involve the creation of hyperdimensional larvae by environmental and pharmacological manipulations, as well as the usage of autoradiographic techniques. The proposed experiments would not only be a comprehensive way to describe the VOR system in the adult flatfish, but also give information about the mechanisms involved in an adpating brain, especially in the context of adaptive plasticity during experimental perturbation.