Auditory Information Processing in the Amygdala

描述(由申请人提供)：这项工作的长期目标是提高对声学通信背后的神经机制的理解。这个项目的重点是杏仁核，这是一个以其在听觉恐惧条件反射中的作用而闻名的结构。对于这一角色，它接受来自丘脑和皮质的听觉输入，有助于识别刺激是厌恶的，并提供适当的情绪反应(例如，自主反应，冻结)。最近的研究表明，杏仁核在包括声音交流在内的听觉行为中发挥着更广泛的作用。这项工作是基于这样一种观点，即杏仁核通过参与几个过程在声学交流中发挥关键作用。1)杏仁核基于来自声音序列的上下文信息、其他感官信息和动物的内部状态来确定声音信号是否突出以及该突出是积极的还是消极的；2)它协调适合于所接收的声音通信信号及其背景的情感反应；3)它通过其对皮质和其他听觉的直接和间接投射来调节对后续声音信号的反应 结构。换句话说，杏仁核可能会影响我们听到和回应声音交流信号的方式。由于缺乏关于杏仁核神经元如何对通信信号做出反应的信息，对杏仁核如何促进声通信的了解一直受到限制。杏仁核神经元能区分社会发声吗？听觉诱发的棘波信号辨别有哪些特征？背景信息如何改变杏仁核神经元对社会发声的辨别和放电模式？这些问题是在研究听觉反应对几种形式的刺激环境的依赖的三个特定目标内进行的：声学环境(发声成分的排序)(目标1)、其他感觉环境(目标2)和内部状态(目标3)。在大多数实验中，听觉反应是通过从清醒的、无拘无束的动物的杏仁核进行慢性记录来获得的。两个动物模型，大棕色蝙蝠和CBA/CAJ小鼠，每个都为拟议的研究提供了特殊的优势。杏仁核功能障碍可能在自闭症、精神分裂症、创伤后应激和耳鸣等疾病的声音输入和情绪反应之间的异常关系中发挥关键作用。这项工作为在这些疾病的动物模型中研究杏仁核的功能奠定了基础。

DESCRIPTION (provided by applicant): The long-term goal of this work is to improve the understanding of neural mechanisms that underlie acoustic communication. This project focuses on the amygdala, a structure known for its role in auditory fear conditioning. For this role, it receives auditory input from the thalamus and cortex, contributes to identifying a stimulu as aversive, and provides for appropriate emotional responses (e.g., autonomic responses, freezing). Recent work demonstrates a broader role for the amygdala in auditory behavior, including acoustic communication. This work is based on the view that the amygdala plays a critical role in acoustic communication through participation in several processes. 1) The amygdala "decides" whether a vocal signal is salient and whether that salience is positive or negative, based on contextual information from the vocal sequence, other sensory information, and the animal's internal state, 2) It orchestrates emotional responses that are appropriate for the received vocal communication signals and their context, 3) It modulates responsiveness to subsequent vocal signals through its direct and indirect projections to cortical and other auditory structures. In other words, the amygdala is likely to influence how we hear and respond to vocal communication signals. Understanding how the amygdala contributes to acoustic communication has been limited by lack of information on how amygdalar neurons respond to communication signals. Do amygdalar neurons discriminate among social vocalizations? What features of the auditory-evoked spike trains signal discrimination? How does contextual information modify the discrimination and discharge pattern of amygdalar neurons in response to social vocalizations? These questions are addressed within three Specific Aims that investigate the dependence of auditory responses on several forms of stimulus context: acoustic context (the sequencing of composition of vocalizations) (Aims1), other sensory context (Aim 2), and internal state (Aim 3). Auditory responses are obtained using chronic recording from the amygdala of awake, unrestrained animals in most experiments. Two animal models, big brown bats and CBA/CaJ mice, each provide particular advantages for the proposed studies. Dysfunction in the amygdala may play a critical role in abnormal relationships between acoustic inputs and emotional responses in disorders such as autism, schizophrenia, post-traumatic stress, and tinnitus. This work lays groundwork for study of the function of the amygdala in animal models of these disorders.