Abstract：
A major challenge in neuroscience is to understand how neural representations of sensory information are transformed by the network of ascending and descending connections in each sensory system. By recording from neurons at several levels of the auditory pathway, we show that much of the nonlinear encoding of complex sounds in auditory cortex can be explained by transformations in the midbrain and thalamus. Modeling cortical neurons in terms of their inputs across these subcortical populations enables their responses to be predicted with unprecedented accuracy. By contrast, subcortical responses cannot be predicted from descending cortical inputs, indicating that ascending transformations are irreversible, resulting in increasingly lossy, higher-order representations across the auditory pathway. Rather, auditory cortex selectively modulates the nonlinear aspects of thalamic auditory responses and the functional coupling between subcortical neurons without affecting the linear encoding of sound. These findings reveal the fundamental role of subcortical transformations in shaping cortical responses.
摘要：
神经科学的一个主要挑战是理解感觉信息的神经表征是如何通过每个感觉系统中的上升和下降连接网络来转换的。通过在听觉通路的几个层面上记录神经元，我们表明，听觉皮层中复杂声音的大部分非线性编码可以通过中脑和丘脑的转换来解释。根据这些皮层下群体的输入对皮层神经元进行建模，可以以前所未有的准确性预测它们的反应。相比之下,皮层下反应不能从下降的皮层输入预测，表明升序变换是不可逆的，导致越来越多的损耗，跨听觉通路的高阶表示。相反，听觉皮层选择性地调节丘脑听觉反应的非线性方面和皮层下神经元之间的功能耦合，而不影响声音的线性编码。这些发现揭示了皮层下转化在塑造皮层反应中的基本作用。
