ANALYSIS OF SPACE BY THE AUDITORY SYSTEM

在生命早期的感官体验可以有深刻的， 对大脑功能的长期影响。 在大脑的关键时期， 在发育过程中，神经连接的模式特别容易受到影响， 经历的塑造影响。 拟议的研究将 在细胞和分子水平上， 改变大脑以及关键时期的机制。 的 结果可能会对我们治疗各种疾病的能力产生重大影响， 人类功能障碍，特别是那些由出生缺陷引起的功能障碍， 儿童期疾病或损伤，必然导致异常 环境对大脑发育的影响 实验系统是中央听觉系统的一部分， 仓鸮中与声音定位有关的通路;仓 猫头鹰的听觉、声音定位能力和相关的神经系统 这些途径与人类相似。 行为研究表明 声音的定位是由 听觉和视觉的经验，以及敏感和 关键时期的特点已经详细说明。 一种神经关联 在视顶盖（上级）中发现了行为可塑性的主要部位 丘），神经元对听觉和视觉刺激都有反应， 一种空间特定的方式。 听觉空间的大的适应性变化 这些神经元的调谐在生命早期被慢性或慢性的 单耳闭塞（改变声音定位线索的值） 或棱镜位移的视野（这改变了 提示值对应的位置）。 神经生理学、药理学和解剖技术 将被用来研究这些机制的基础， 依赖经验的变化。 数字合成声音传送 通过耳机将被用来描述听觉的变化 空间调谐方面的变化，在单位调谐定位线索。 听觉通路中发生适应性变化的部位 将使用急性和慢性单位进行生理学鉴定 录制. 各种组织学技术将被用于搜索 可塑性的解剖学相关性。 一旦可塑性位点 决定，调整过程的动态， 指导性信号，并且该过程的药理学基础将是 研究了 有了这些信息，细胞和分子 相关的敏感和关键时期，调节这些 将确定适应性变化，并尝试阻止 或恢复其可塑性。 这项研究的结果将揭示的一般原则， 大脑发育早期正常和异常的后果 经验，以及大脑用来适应性地处理 不同的感官挑战。

Sensory experience during early life can have profound and long-lasting effects on brain function. During critical periods in brain development, patterns of neural connectivity are especially susceptible to the shaping influence of experience. The proposed research will investigate, at the cellular and molecular levels, how experience modifies the brain and what mechanisms underlie critical periods. The results could have a major impact on our ability to treat a wide variety of human dysfunctions, particularly those resulting from birth defects, childhood disease or injury which necessarily entail abnormal environmental influences on brain development. The experimental system is a portion of the central auditory pathway in barn owls that is involved with sound localization; the barn owl's hearing, sound localization capabilities and associated neural pathways are similar to those of humans. Behavioral studies have shown that sound localization is shaped powerfully by an interaction of auditory and visual experience during early life, and the sensitive and critical periods have been characterized in detail. A neural correlate of the behavioral plasticity has been found in the optic tectum (superior colliculus), where neurons respond to both auditory and visual stimuli in a space-specific manner. Large adaptive changes in the auditory spatial tuning of these neurons are induced during early life either by chronic monaural occlusion (which changes the values of sound localization cues) or prismatic displacement of the visual field (which changes the locations to which cue values correspond). Neurophysiological, pharmacological and anatomical techniques will be used to study the mechanisms that underlie these experience-dependent changes. Digitally synthesized sound delivered through earphones will be used to describe the changes in auditory spatial tuning in terms of changes in unit tuning for localization cues. The sites in the auditory pathway where the adaptive changes take place will be identified physiologically using acute and chronic unit recording. A variety of histological techniques will be used to search for anatomical correlates of the plasticity. Once the site of plasticity is determined, the dynamics of the adjustment process, the nature of the instructive signal, and the pharmacological basis of the process will be investigated. With this information in hand, cellular and molecular correlates of the sensitive and critical periods that regulate these adaptive changes will be determined, and attempts will be made to block or restore the plasticity. The results of this research will reveal general principles of brain development, the consequences of early normal and abnormal experience, and the strategies used by the brain to deal adaptively with different kinds of sensory challenges.