ADAPTIVE CHANGES IN VESTIBULAR SYSTEM

比目鱼是研究适应性的自然范例 脊椎动物中枢神经系统的变化。 期间 它们的变态、前庭和眼轴坐标 相对于彼此旋转90度。 虽然成鱼 有一个双边不对称的外观，有一个中央 前庭-眼神经系统对称性的重建。 因此，保持对称性似乎是一个重要的 脑功能的运作原理。 拟议研究 将集中在中枢神经对称性的问题， 形态不对称的前庭眼系 的影响以及触发比目鱼 对称性在鱼的变态。 关于前庭的对称组织- 成人三神经元弧水平的眼反射系统 比目鱼，耳石，视动和 眼睛运动相关的信号和底层电路将被 测定 神经行为学、电生理学和 神经解剖学（细胞外和细胞内HRP，WGA-HRP） 方法将被使用。 在变质前和变质作用中 比目鱼，适应性反射的个体发育， 关于行为，前庭核活动，以及 特定抑制性神经递质的发展 垂直和水平系统（GABA，甘氨酸）将 研究了 使用的方法包括眼睛 通过录像进行运动分析，（14 C）-2-脱氧葡萄糖 放射自显影和免疫组织化学， 电子显微镜 此外，更普遍的问题是， 诱导变质作用将在 应用甲状腺素对全身内分泌水平影响 拮抗剂，并在比目鱼的物种特异性水平， 利用化学（链霉素，红藻氨酸）和手术损伤 前庭和橄榄小脑系统的实验， 以及视觉系统的自然感官剥夺。 拟议的实验将全面描述 完整的三神经元弧-前庭-眼反射系统及其 不对称成人的对称中心表征 比目鱼 本研究的长期计划针对空间 和时间机制参与的过渡， 前变质到后变质的对称性及其问题 尤其是比目鱼的变态诱导， 脊椎动物，一般来说。

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.