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

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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.