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基础的神经机制的理解。这个项目的重点是杏仁核，这个结构以其在听觉恐惧调节中的作用而闻名。对于这个角色，它接收来自丘脑和皮层的听觉输入，有助于识别令人厌恶的刺激，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，杏仁核在听觉行为中扮演着更广泛的角色，包括声音交流。这项工作是基于杏仁核通过参与几个过程在声学通信中起关键作用的观点。1)杏仁核根据声音序列、其他感觉信息和动物的内部状态，“决定”声音信号是否显著，以及这种显著性是积极的还是消极的；2)它协调与接收到的声音交流信号及其环境相适应的情绪反应；3)它通过对皮层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

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. PUBLIC HEALTH RELEVANCE: Dysfunction in the amygdala may play a critical role in the abnormal emotional responses to speech and other sounds that occurs in autism, schizophrenia, post-traumatic stress, and tinnitus. This work will establish how amygdalar neurons normally function in response to speech-like sounds, laying groundwork for study of the function of the amygdala in animal models of these disorders. !