Short-term synaptic plasticity and intensity coding in *

* 中的短期突触可塑性和强度编码

• 批准号: 7035540
• 负责人: KATRINA M MACLEOD
• 金额: $ 7.43万
• 依托单位: UNIV OF MARYLAND, COLLEGE PARK
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-12-15 至 2008-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7035540
• 关键词: AMPA receptors; acoustic nerve; auditory nuclei; cell type; depression; hearing; model; neurons; synapses

DESCRIPTION (provided by applicant): Dynamic changes in synaptic amplitude over short time periods, known as short-term synaptic plasticity, may have profound effects on the transmission of information between neurons. Our recent results on the short-term synaptic plasticity properties in the avian cochlear nucleus angularis (NA) demonstrated a remarkable ability to transmit information at firing frequencies that cause severe depression at other excitatory synapses in the brain. Furthermore, the depressing and facilitating plasticity components appear to be tuned such that these synapses will transmit rate information linearly, which may be critical for the encoding of acoustic intensity information. We will take advantage of an established in vitro model for cellular studies of auditory function, the brainstem slice preparation from young chickens. Using intracellular electrophysiological recordings and computational modeling, we will investigate the mechanisms responsible for the short-term plasticity at the nerve to NA synapse. We will determine whether variations in the short-term synaptic plasticity expressed in different NA neurons might contribute to distinct processing streams within the auditory brainstem. We will investigate the implications of this short-term plasticity for auditory coding by stimulating with dynamic stimuli such as simulated amplitude-modulation signals. Finally, by using the dynamic clamp method, we will investigate how synaptic inputs and their dynamic modulation combine with NA neuronal intrinsic properties to generate the action potential output. These experiments are critical to our understanding of intensity processing for localization and non-localization tasks, and offer an excellent opportunity to study the implications of short-term synaptic dynamics for sensory processing. This work also has broader implications for the development of improved cochlear implant devices to recover hearing in hearing-impaired people. The cochlear nucleus is the first receiving station in the central nervous system for auditory information. While our research is focused on basic properties, a better understanding of how sound information is transformed at the auditory nerve to cochlear nucleus connection will help guide the design of cochlear implants that can stimulate more efficient, enriched sound inputs, enhancing the quality of life for the hearing-impaired.

描述（由申请人提供）：短期内突触振幅的动态变化，被称为短期突触可塑性，可能对神经元之间的信息传递有深远的影响。我们最近对鸟类耳蜗角核（NA）短期突触可塑性特性的研究结果表明，它具有显著的传递信息的能力，其发射频率会导致大脑中其他兴奋性突触的严重抑制。此外，抑制和促进可塑性的成分似乎被调谐，使得这些突触将线性地传输速率信息，这可能对声强度信息的编码至关重要。我们将利用一种已建立的体外模型进行听觉功能的细胞研究，即雏鸡的脑干切片制备。利用细胞内电生理记录和计算模型，我们将研究神经突触短期可塑性的机制。我们将确定不同NA神经元中表达的短期突触可塑性的变化是否有助于听觉脑干中不同的加工流。我们将通过动态刺激（如模拟调幅信号）研究这种短期可塑性对听觉编码的影响。最后，我们将利用动态箝位方法，研究突触输入及其动态调制如何与NA神经元的内在特性相结合，从而产生动作电位输出。这些实验对我们理解定位和非定位任务的强度加工至关重要，并为研究短期突触动力学对感觉加工的影响提供了极好的机会。这项工作也有更广泛的意义，发展改进人工耳蜗装置，以恢复听力受损的人的听力。耳蜗核是中枢神经系统中听觉信息的第一个接收站。虽然我们的研究主要集中在基本特性上，但更好地了解声音信息如何在听神经到耳蜗核的连接上转化，将有助于指导人工耳蜗的设计，从而刺激更有效、更丰富的声音输入，提高听障人士的生活质量。