Systems Science Program, Portland State University, Portland, Oregon 97207-0751, USA.
J Neurosci. 2010 Jan 20;30(3):802-19. doi: 10.1523/JNEUROSCI.1964-09.2010.
An important question in sensory neuroscience is what coding strategies and mechanisms are used by the brain to detect and discriminate among behaviorally relevant stimuli. There is evidence that sensory systems migrate from a distributed and redundant encoding strategy at the periphery to a more heterogeneous encoding in cortical structures. It has been hypothesized that heterogeneity is an efficient encoding strategy that minimizes the redundancy of the neural code and maximizes information throughput. Evidence of this mechanism has been documented in cortical structures. In this study, we examined whether heterogeneous encoding of complex sounds contributes to efficient encoding in the auditory midbrain by characterizing neural responses to behaviorally relevant vocalizations in the mouse inferior colliculus (IC). We independently manipulated the frequency, amplitude, duration, and harmonic structure of the vocalizations to create a suite of modified vocalizations. Based on measures of both spike rate and timing, we characterized the heterogeneity of neural responses to the natural vocalizations and their perturbed variants. Using information theoretic measures, we found that heterogeneous response properties of IC neurons contribute to efficient encoding of behaviorally relevant vocalizations.
在感觉神经科学中，一个重要的问题是大脑使用什么编码策略和机制来检测和区分行为相关的刺激。有证据表明，感觉系统从外围的分布式和冗余编码策略迁移到皮质结构中的更异构的编码。有人假设，异质性是一种有效的编码策略，它可以最大限度地减少神经码的冗余，并最大限度地提高信息吞吐量。这一机制的证据在皮质结构中已经有记录。在这项研究中，我们通过描述在小鼠下丘脑中对行为相关发声的神经反应，研究了复杂声音的异质编码是否有助于听觉中脑的有效编码。我们独立地操纵发声的频率、幅度、持续时间和谐波结构，以创建一系列经过修改的发声。基于尖峰率和时间的测量，我们描述了对自然发声及其受干扰变体的神经反应的异质性。使用信息论测度，我们发现，IC 神经元的异质反应特性有助于对行为相关发声的有效编码。
