The Role of Tonic Neural Responses in Auditory Pitch Perception in Awake Rat A1

描述（由申请人提供）：细粒度听觉音高感知缺陷与语言学习障碍、某些形式的阅读障碍和更严重的神经系统疾病有关。细粒度的频率辨别被认为是初级听觉皮层（A1）的功能，但其机制尚不清楚。在个体A1神经对等频音调反应的时间过程中，相对非频率选择性的相位兴奋让位给更窄选择性的音调兴奋，这种兴奋持续整个音调的持续时间。A1的张力反应可能编码细粒度的频谱感知。本研究将采用神经记录、微刺激和行为技术相结合的方法，探讨清醒大鼠在纯音音高感知方面的张力反应的作用和功能。来自多通道电极阵列的神经记录将用于充分表征A1到等频音调的tonic神经反应。同时神经记录和微刺激范例将被用来检查皮质内调制对处理等频刺激的贡献。最后，微刺激将与行为范式配对，以模拟自然等频反应的模式，研究人工激活A1所引起的感觉知觉音高。这些技术的结合将为A1中有关细粒度音高感知的主音反应的机制和功能提供一个独特的详细视图。这项研究将有助于理解大脑是如何将声音信息分解成声音频率的。从这项研究中获得的知识可能有助于开发更好的治疗儿童语言学习障碍或中风和其他脑损伤引起的语言障碍的方法。

DESCRIPTION (provided by applicant): Deficits in fine-grained auditory pitch perception have been implicated in language learning disorders, certain forms of dyslexia, and more severe neurological conditions. Fine-grained frequency discrimination is believed to be a function of the primary auditory cortex (A1), but the mechanism responsible is still unclear. In the time-course of individual A1 neural responses to iso-frequency tones, relatively non-frequency- selective phasic excitation gives way to more narrowly selective tonic excitation that is sustained throughout the duration of the tone. Tonic responses in A1 may code for fine-grained spectral perception. This study will investigate the role and functionality of tonic responses with respect to pitch perception of pure tones in awake rats using a combination of neural recording, microstimulation, and behavioral techniques. Neural recordings from multichannel electrode arrays will be used to fully characterize tonic neural responses in A1 to iso-frequency tones. A simultaneous neural recording and microstimulation paradigm will be used to examine the contribution of intracortical modulation to processing of iso-frequency stimuli. Finally, microstimulation will be paired with a behavioral paradigm to investigate the perceived pitch of sensation elicited by artificial activation of A1 in a pattern mimicking natural iso-frequency responses. The combination of these techniques will provide a uniquely detailed view of the mechanisms and functionality of tonic responses in A1 with respect to fine-grained pitch perception. This study will help in understanding how the brain breaks down sound information into sound frequency. The knowledge gained from this study could be useful in developing better treatments for childhood language learning disorders or for language disorders stemming from strokes and other brain damage.