Investigating human non-lemniscal inferior colliculus contributions to auditory learning with 7T MRI

使用 7T MRI 研究人类非丘系下丘对听觉学习的贡献

• 批准号: 10371381
• 负责人: Kevin Richard Sitek
• 金额: $ 14.05万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-16 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10371381
• 关键词: Acoustics; Adult; Anatomy; Animal Model; Auditory; Auditory area; Auditory system; Brain; Brain region; Categories; Cell Nucleus; Clinical; Cochlear Implants; Communication; Complex; Diffusion Magnetic Resonance Imaging; Dorsal; Ear; Electrophysiology (science); Environment; Foundations; Frequencies; Functional Magnetic Resonance Imaging; Future; Hearing problem; Human; Human Characteristics; Image; Imaging Techniques; Implant; Individual; Inferior Colliculus; Investigation; Learning; Location; Magnetic Resonance Imaging; Maps; Mediating; Mentors; Methodology; Methods; Midbrain structure; Participant; Pathway interactions; Pattern; Phase; Play; Process; Property; Protocols documentation; Research; Research Project Grants; Resolution; Role; Route; Scalp structure; Self-Help Devices; Sensorineural Hearing Loss; Sensory Disorders; Signal Transduction; Specificity; Speech; Speech Sound; Stimulus; Structure; System; Testing; Time; Tinnitus; Tissues; Training; auditory pathway; auditory processing; auditory thalamus; base; clinical application; clinically relevant; contrast imaging; hearing impairment; in vivo; in vivo imaging; magnetic field; neural implant; next generation; novel; programs; relating to nervous system; response; sound; theories; tractography; white matter

PROJECT SUMMARY Human inferior colliculus (IC) plays a critical role in auditory processing. However, the anatomy and function of the lemniscal (primary) and non-lemniscal subdivisions of IC in living humans are poorly understood due to the technical challenges of in vivo magnetic resonance imaging (MRI) of the small midbrain structures deep within the brain. In particular, despite predominant top-down and bottom-up theories of auditory learning, the neural systems underlying human speech category learning is unknown. Recent advances in MRI acquisition open the door for focused investigations into the anatomy and functional processing of human auditory midbrain. My research environment and mentor team will allow me to gain the expertise necessary to independently investigate the subcortical auditory system in living humans using MRI. In this project, we will use ultra-high field 7T MRI to quantify anatomical midbrain tissue contrast in a sub- structure dependent manner. We will also map the structural connections from each IC subdivision throughout the auditory system. Quantifying the specific anatomical MRI contrasts and connectivity patterns in living human midbrain will enable future clinical applications for investigating hearing disorders such as sensorineural hearing loss and tinnitus. A possible functional role for non-lemniscal IC is in learning novel speech sound categories. We will collect 7T functional MRI at multiple timepoints during a sound-to-category learning program to assess the contribution of IC and auditory cortex to sound category learning. Our results will elucidate whether novel categories are learned via cortically driven plasticity (cortex represents categorical features at an earlier stage than IC’s relevant acoustic enhancement) or stimulus feature enhancement (IC and cortex have similar time courses of plasticity). Existing methods for probing auditory processing, such as the scalp-recorded frequency following response (FFR), have both subcortical and cortical generators, but their relative contributions throughout the auditory learning process have not been investigated in humans. Participants in our sound-to-category learning paradigm will also undergo FFR recordings. Using representational similarity analysis, we will assess whether sound category feature representation in FFRs primarily follows that of auditory cortex or that of IC, suggesting the relative contribution of each generator at each phase of sound-to-category learning. This project implements state-of-the-art anatomical and functional 7T MRI techniques to quantify foundational characteristics of the human inferior colliculus, a key but poorly investigated subcortical auditory structure. The methods we utilized can be adapted to investigate other small, deep structures throughout the human auditory system and will enhance our understanding of IC contributions to tinnitus and optimal placement of auditory brain implants for individuals with sensorineural hearing loss.

项目摘要 人类下丘（IC）在听觉处理中起着至关重要的作用。但是，解剖学和 IC在活人中的lemaniSiscal（主要）和非稳定细分的功能知之甚少 由于小型中脑结构的体内磁共振成像（MRI）的技术挑战 大脑深处。尤其是，多斯蒂斯的主要自上而下和自下而上的听觉学习理论， 人类语音类别学习的基础神经系统尚不清楚。 MRI获取的最新进展 打开大门，重点研究人类听觉中脑的解剖结构和功能处理。 我的研究环境和导师团队将允许我获得独立的专业知识 使用MRI调查生命人类皮质下听觉系统。 在这个项目中，我们将使用超高场7T MRI来量化子脑中脑组织对比 结构依赖方式。我们还将绘制每个IC分区的结构连接 听觉系统。量化生命人类的特定解剖学MRI对比和连通性模式 中脑将实现未来的临床应用，以调查听力障碍，例如感官听力 损失和耳鸣。 非稳定IC的可能作用是学习新颖的语音类别。我们将 在声音到类别学习计划中，在多个时间点收集7T功能性MRI，以评估 IC和听觉皮层对声音类别学习的贡献。我们的结果将阐明是否新颖 类别是通过皮质驱动的可塑性来学习的（皮质代表早期的特征 比IC相关的声学增强）或刺激功能增强（IC和皮层具有相似的时间 可塑性课程）。 现有用于探测听觉处理的方法，例如头皮录制的频率以下 反应（FFR），具有皮质下和皮质发电机，但它们在整个过程中的相对贡献 在人类中尚未研究听觉学习过程。我们的声音类别学习的参与者 范式也将进行FFR录音。使用代表性相似性分析，我们将评估是否 FFR中的声音类别特征表示主要遵循听觉皮层或IC的皮层的表现形式 每个发电机在声音到类别学习的每个阶段的相对贡献。 该项目实施了最新的解剖学和功能性7T MRI技术来量化 人类下丘的基础特征，这是一个关键但未研究的皮层下听觉 结构。我们使用的方法可以适应整个过程中的其他小型结构 人类听觉系统，并将增强我们对IC对耳鸣和最佳位置的贡献的理解 听觉大脑的感官听力损失的患者会渗入。