Orbitofrontal Cortex Modulates Auditory Cortical Sensitivity and Sound Perception in Mongolian gerbils

Sensory perception is dynamic, quickly adapting to sudden shifts in environmental or behavioral context. Though decades of work have established that these dynamics are mediated by rapid fluctuations in sensory cortical activity, we have a limited understanding of the brain regions and pathways that orchestrate these changes. Neurons in the orbitofrontal cortex (OFC) encode contextual information, and recent data suggest that some of these signals are transmitted to sensory cortices. Whether and how these signals shape sensory encoding and perceptual sensitivity remains uncertain. Here, we asked whether the OFC mediates context-dependent changes in auditory cortical sensitivity and sound perception by monitoring and manipulating OFC activity in freely moving Mongolian gerbils of both sexes under two behavioral contexts: passive sound exposure and engagement in an amplitude modulation (AM) detection task. We found that the majority of OFC neurons, including the specific subset that innervate the auditory cortex, were strongly modulated by task engagement. Pharmacological inactivation of the OFC prevented rapid context-dependent changes in auditory cortical firing, and significantly impaired behavioral AM detection. Our findings suggest that contextual information from the OFC mediates rapid plasticity in the auditory cortex and facilitates the perception of behaviorally relevant sounds.

感官知觉具有动态性，能够迅速适应环境或行为情境的突然变化。尽管数十年的研究已经确立这些动态变化是通过感官皮层活动的快速波动来介导的，但我们对于调控这些变化的脑区和通路仍缺乏深入了解。位于眶额皮层（OFC）的神经元编码情境信息，最新的数据表明其中一些信号被传递至感官皮层。这些信号是否以及如何塑造感官编码和感知敏感性尚不明确。在本研究中，我们通过监测和操纵自由移动的蒙古沙鼠（包括雄性和雌性）在两种行为情境下的眶额皮层活动，即被动声音暴露和参与幅度调制（AM）检测任务，来探究OFC是否介导情境依赖性的听觉皮层敏感性和声音感知变化。我们发现，包括向听觉皮层提供神经支配的特定神经元子集在内的OFC神经元大多数受到任务参与度的强烈调节。通过药物抑制OFC活性，可以防止听觉皮层发放的快速情境依赖性变化，并显著损害行为AM检测。我们的研究结果表明，来自OFC的情境信息介导了听觉皮层的快速可塑性，并促进了与行为相关的声音感知。