ADAPTIVE CHANGES IN VESTIBULAR SYSTEM

比目鱼构成了研究适应性的自然范例 脊椎动物中枢神经系统的变化。在.期间 它们的变态、前庭和动眼坐标 相对于彼此旋转90度。尽管成鱼 有一个两侧不对称的外观，有一个中央 前庭-眼球运动系统的对称性重建。 因此，保持对称性显得很重要 脑功能的工作原理。拟议的研究 将集中在中枢神经对称性的问题上 形态不对称的前庭-动眼系统 比目鱼及其引发重建的因素 鱼在变态过程中的对称性。 关于前庭的对称组织- 成人三个神经元-弧形水平的眼反射系统 比目鱼，耳石的中心代表，视动和 眼球运动相关信号和底层电路将 下定决心。神经行为学、电生理学和 神经解剖学(细胞内外HRP、WGA-HRP) 方法将被使用。在变质前和变质过程中 比目鱼适应反射的个体发育 关于行为，前庭核活动，以及 体内特异性抑制性神经递质的发展 垂直和水平系统(GABA、甘氨酸)将 调查过了。要使用的方法包括眼睛 通过录像进行运动分析，(14C)-2-脱氧葡萄糖 放射自显影，还有免疫组织化学和 电子显微镜。此外，更普遍的问题是 变形的诱导将在 甲状腺激素的应用对系统内分泌水平的影响 拮抗剂，并在比目鱼物种特有的水平上通过 利用化学物质(链霉素、红藻氨酸)和外科手术损伤 前庭和橄榄-小脑系统的实验，AS 以及对视觉系统的自然感觉剥夺。 拟议的实验将全面描述 完整的三神经元-弧形-前庭-眼反射系统及其 不对称成人的对称性中枢表征 比目鱼。这项研究的长期计划是以空间为目标 和时间机制参与从 变质前到变质后的对称性及问题 特别是关于诱导比目鱼的变态，以及 一般而言，脊椎动物。

Flatfish constitute a natural paradigm to investigate adaptive changes in the central nervous system of vertebrates. During their metamorphosis, vestibular and oculomotor coordinates rotate 90 degree relative to each other. Although the adult fish has a bilaterally asymmetric appearance, there is a central reconstitution of symmetry in the vestibulo-oculomotor system. Thus, the maintenance of symmetry appears to be an important operational principle of brain function. The proposed research will focus on the question of central nervous symmetry within the vestibulo-oculomotor system of the morphologically asymmetric flatfish and on the factors triggering re-establishment of symmetry during metamorphosis of the fish. In regard to the SYMMETRIC ORGANIZATION of the vestibulo- ocular reflex system at the three-neuron-arc level in the adult flatfish, the central representation of otolithic, optokinetic and eye-movement related signals and the underlying circuitry will be determined. Neuroethological, electrophysiological and neuroanatomical (extra- and intracellular HRP, WGA-HRP) method will be used. In premetamorphic and metamorphosing flatfish, the ontogenetic development of the adaptive reflex in regard to behavior, vestibular nucleus activity, and the development of specific inhibitory neurotransmitters within vertical and horizontal systems (GABA, glycine) will be investigated. The methods to be utilized encompass eye movement analysis via video-recordings, (14C)-2-deoxyglucose autoradiography, and also immunohistochemistry and electronmicroscopy. In addition, the more general question of INDUCTION OF METAMORPHOSIS will be addressed at the systemic endocrinological level by application of thyroxin antagonists, and at the species-specific level of the flatfish by utilizing chemical (streptomycin, kainic acid) and surgical lesion experiments in the vestibular and olivo-cerebellar systems, as well as natural sensory deprivation to the visual system. The proposed experiments will describe comprehensively the entire three-neuron-arc-vestibulo-ocular reflex system and its symmetric central representation in the asymmetric adult flatfish. The long-term plans of this research target the spatial and temporal mechanisms involved in the transition from premetamorphic to postmetamorphic symmetry and questions about induction of metamorphosis in the flatfish in particular, and vertebrates, in general.