Mechanisms of Instructed Learning in the Auditory System

描述(申请人提供)：大脑从经验中学到的大部分东西，包括语言和声音识别和本地化，都是通过监督学习的机制获得的。在有监督的学习中，一个神经元网络的可塑性受到来自另一个网络的信息的调节或引导。在过去的十年里，我们对可塑性机制的了解有了极大的增长。相比之下，我们对调节和指导可塑性的机制的知识仍然是原始的。视觉系统对听觉系统空间地图的校准是有监督学习的一个很好的例子。在谷仓猫头鹰中，视觉信号在听觉通路中发挥作用的位置，以及它们引起的结构和功能变化，已经被确定。然而，指示信号本身的性质以及它们发挥作用的机制仍然是一个谜。计划中的研究将研究Owl中校准听觉空间映射的指示信号。细胞外电生理技术将被用来测量指导性神经活动对视觉、听觉和跨模式刺激参数的反应。药理学技术将被用来确定介导指示信号的神经递质，以及神经调节剂对听觉可塑性调节的作用。解剖学技术将被用来识别开启指导性活动的输入来源。行为技术将被用来研究指导性信号的特性，因为它是在经过训练的动物身上自然出现的。最后，我们将操纵指导性信号，试图训练神经对特定听觉刺激的反应。本研究旨在详细了解指导神经可塑性的机制。彻底了解这些有教育意义的机制和它们的运作原理将大大增加我们对神经系统如何从经验中学习的理解。这反过来可能导致改进教育正常儿童和学习障碍儿童的方法，以及改进治疗策略，以最大限度地恢复神经损伤或疾病后患者的功能。

DESCRIPTION (provided by applicant): Much of what the brain learns from experience, including language and sound identification and localization, is acquired through the mechanisms of supervised learning. In supervised learning, plasticity in one network of neurons is regulated or guided by information from another network. Our knowledge of the mechanisms of plasticity has increased tremendously over the past decade. In contrast, our knowledge of the mechanisms that regulate and instruct plasticity remains primitive.The calibration of the auditory system's map of space by the visual system is a well-characterized example of supervised learning. In the barn owl, the site in the auditory pathway where visual signals exert there effects, and the structural and functional changes they cause, have been determined. However, the properties of the instructive signals themselves, and the mechanisms by which they exert their effects, remain a mystery.The proposed research will study the instructive signals that calibrate the auditory space map in the owl. Extracellular electrophysiological techniques will be used to measure responses of instructive neural activity to visual, auditory and cross-modal parameters of stimulation. Pharmacological techniques will be used to determine the neurotransmitters that mediate the instructive signals, and the contribution of neuromodulators to the regulation of auditory plasticity. Anatomical techniques will be used to identify the source of input that gates the instructive activity. Behavioral techniques will be used to study the properties of the instructive signal as it occurs naturally in trained animals. Finally, we will manipulate the instructive signal in an attempt to train neural responses to specific auditory stimuli.This research aims at understanding, in detail, mechanisms that instruct neural plasticity. A thorough knowledge of these instructive mechanisms and the principles by which they operate will add substantially to our understanding of how the nervous system learns from experience. This, in turn, may lead to improved methods for teaching both normal and learning disabled children, as well as to improved therapeutic strategies for maximizing the restoration of function to patients following neurological injury or disease.