In vivo whole-cell patch study of excitation and inhibition interplay in auditory cortical plasticity

感官知觉是大脑中编码的感觉信息的神经解释。神经解释由先前的经验决定，反映了我们日常生活中大脑机器的学习过程。研究表明，从早期发育到成年，最高感觉信息处理中心（感觉皮层）的功能不断被感觉学习/经验重塑。 在听觉皮层中，声音频率（音高）信息由神经元感受野（RF）编码。当一个声音具有行为意义时，皮层神经元的RF向这个声音的频率移动，因此，这个声音频率的皮层表征被扩大（频率特异性可塑性）。一般认为，听觉皮层中的线路在皮层下神经结构输入信息的引导下具有变化的能力。我们最近的研究证实，如果向皮层发送信息的皮层下神经元被强烈激活，则听觉皮层也会发生同样的神经可塑性。我们还证明了长时程增强和抑郁都有助于听觉皮层的频率特异性可塑性。在皮层中，兴奋和抑制在单个神经元中耦合，这决定了神经元RF。皮质可塑性可能是兴奋和抑制耦合变化的结果。下一个重要问题是皮质兴奋和抑制如何共同作用来影响频率特定的皮质RF可塑性。 为了回答这个问题，我将研究在一个单一的皮质神经元的音调诱导的兴奋和抑制的相互作用，通过使用在体内全细胞膜片钳，一个国家的最先进的技术。我认为神经元的兴奋和抑制是耦合的，并会影响这个神经元的放电。我将进一步研究皮层下神经元的强烈激活如何影响耦合，这些神经元将信息发送到听觉皮层。我认为皮层神经元的功能重塑依赖于兴奋和抑制的耦合变化，这种耦合变化以特定于激活的皮层下输入的方式进行，因为特定于输入的耦合变化解释了特定于频率的皮层RF可塑性。 本研究的结果将提供一个全面的了解在听觉皮层的线路自我适应的声学环境。

Sensory perception is the neural interpretation of encoded sensory information in the brain. The neural interpretation is determined by previous experience, reflecting a learning process of brain machinery for our everyday life. Studies have revealed that the function of the highest sensory information processing center (sensory cortex) is continuously remodeled by sensory learning/experience from early development to adulthood.       In the auditory cortex, sound frequency (pitch) information is encoded by neuronal receptive fields (RF). When a sound is of behavioral significance, the RFs of cortical neurons shift towards the frequency of this sound and, as a consequence, the cortical representation of this sound frequency is enlarged (frequency-specific plasticity). It is generally thought that the wiring in the auditory cortex has the capacity for change under the guidance of inputting information from subcortical neural structures. Our recent studies have confirmed that, if the subcortical neurons that send information to cortex are intensively activated, identical neural plasticity occurs in the auditory cortex. We have also demonstrated that both long-term potentiation and depression contribute to such frequency-specific plasticity in the auditory cortex. In the cortex, excitation and inhibition are coupled in a single neuron, which determines neuronal RF. Cortical plasticity can be a result of changes in excitation and inhibition coupling. The next important question is how cortical excitation and inhibition work together to influence frequency-specific cortical RF plasticity.       To answer this question, I will study the interaction of tone-induced excitation and inhibition in a single cortical neuron by using in vivo whole-cell patch-clamp, a state-of-the-art technique. I expect that neuronal excitation and inhibition are coupled and will impact the firing of this neuron. I will further examine how the coupling is influenced following the intensive activation of subcortical neurons that send information to the auditory cortex. I expect that the functional remodeling of the cortical neuron relies on the coupling changes of excitation and inhibition in a manner specific to the activated subcortical inputs since input-specific coupling changes account for frequency-specific cortical RF plasticity.       The outcomes of this study will provide a comprehensive understanding of the wirings in the auditory cortex for self-adaptation to the acoustic environment.