Doctoral Dissertation Research: Hippocampal Modulation of Auditory Representations

在国家科学基金会的支持下，Orduna先生和他的顾问Gluck博士将进行为期一年的研究，研究听觉辨别训练如何影响复杂声音的皮层表征。自然环境中充满了复杂的声音，其中包含了与行为相关的各种信息。 对声音或图像的学习可以导致感知灵敏度的变化，从而促进对行为相关事件的处理。 虽然这些变化背后的神经机制还没有得到很好的理解，但它们被认为取决于大脑适应性地修改其感觉皮层表征的能力。 Orduna和Gluck将测量大鼠和人类在训练受试者辨别复杂声音之前和之后对这些声音的电生理反应。 皮质和海马处理的计算模型表明，海马修改皮质表示，以促进学习。 研究人员将通过比较正常和海马损伤大鼠听觉皮层中学习诱导的表征变化（测量为诱发反应的变化）来评估海马在听觉学习中的作用。联合使用的行为和电生理技术，结合病变技术，将有利于在人类和其他哺乳动物的听觉学习的神经机制之间的比较。 这个项目将说明一种新的方法来评估当前的理论，即大脑皮层和海马体在学习和记忆过程中如何相互作用。 这些科学结果应该为学习和记忆的大脑基础提供新的知识。

With National Science Foundation support, Mr. Orduna and his advisor Dr. Gluck will conduct a year long investigation of how auditory discrimination training affects cortical representations of complex sounds. The natural environment is full of complex sounds containing a variety of information relevant to behavior. Learning about sounds or images can lead to changes in perceptual sensitivities that facilitate the processing of behaviorally relevant events. Although the neural mechanisms underlying these changes are not well understood, they are thought to depend on the brain's capacity to adaptively modify its cortical representations of sensations. Orduna and Gluck will measure electrophysiological responses of rats and humans to complex sounds before and after subjects have been trained to discriminate these sounds. Computational models of cortical and hippocampal processing suggest that the hippocampus modifies cortical representations to facilitate learning. The investigators will evaluate the role of the hippocampus in auditory learning by comparing learning-induced representational changes (measured as changes in evoked responses) in the auditory cortices of normal and hippocampal-lesioned rats. The joint use of behavioral and electrophysiological techniques, in combination with lesion techniques, will facilitate comparisons between the neural mechanisms underlying auditory learning in humans and other mammals. This project will illustrate a new way of evaluating current theories of how the cortex and the hippocampus interact during learning and memory processes. These scientific results should provide new knowledge about the brain basis of learning and memory.