Mechanisms of Instructed Learning in the Auditory System

描述（由申请人提供）：大脑从经验中学习的大部分内容，包括语言和声音识别和定位，都是通过监督学习机制获得的。在监督学习中，一个神经元网络的可塑性由来自另一个网络的信息调节或指导。在过去的十年里，我们对可塑性机制的了解有了巨大的增长。相比之下，我们对调节和指导可塑性的机制的了解仍然很原始，视觉系统对听觉系统空间地图的校准是监督学习的一个很好的例子。在仓鸮中，视觉信号在听觉通路中发挥作用的部位以及它们引起的结构和功能变化已经确定。然而，这些指导信号本身的性质以及它们发挥作用的机制仍然是一个谜。拟议的研究将研究猫头鹰听觉空间图校准的指导信号。细胞外电生理技术将用于测量指导性神经活动对视觉、听觉和跨模态刺激参数的反应。药理学技术将用于确定介导指导信号的神经递质，以及神经调质对听觉可塑性调节的贡献。将使用解剖技术来识别控制指导活动的输入来源。行为技术将用于研究指导信号的性质，因为它在训练的动物中自然发生。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。彻底了解这些指导性机制及其运作原理，将大大有助于我们理解神经系统如何从经验中学习。反过来，这可能会导致改善正常和学习障碍儿童的教学方法，以及改善治疗策略，以最大限度地恢复神经损伤或疾病后的患者的功能。

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.