Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14627, USA.
Department of Neuroscience, Neuroscience Graduate Program, Del Monte Institute for Neuroscience, Center for Visual Sciences, Intellectual and Developmental Disability Research Center, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
Cell Rep. 2022 Mar 22;38(12):110545. doi: 10.1016/j.celrep.2022.110545.
In chemical sensation, multiple models have been proposed to explain how odors are represented in the olfactory cortex. One hypothesis is that the combinatorial identity of active neurons within sniff-related time windows is critical, whereas another model proposes that it is the temporal structure of neural activity that is essential for encoding odor information. We find that top-down feedback to the main olfactory bulb dictates the information transmitted to the piriform cortex and switches between these coding strategies. Using a detailed network model, we demonstrate that feedback control of inhibition influences the excitation-inhibition balance in mitral cells, restructuring the dynamics of piriform cortical cells. This results in performance improvement in odor discrimination tasks. These findings present a framework for early olfactory computation, where top-down feedback to the bulb flexibly shapes the temporal structure of neural activity in the piriform cortex, allowing the early olfactory system to dynamically switch between two distinct coding models.
在化学感觉中，已经提出了多种模型来解释气味如何在嗅觉皮层中被表示。一种假设是，与嗅探相关的时间窗口内活跃神经元的组合身份是关键的，而另一个模型则提出，对于编码气味信息，神经活动的时间结构是必不可少的。我们发现，到主嗅球的自上而下的反馈决定了传递到梨状皮层的信息，并在这些编码策略之间切换。使用详细的网络模型，我们证明了对抑制的反馈控制会影响到嗅球中僧帽细胞的兴奋-抑制平衡，从而重构梨状皮层细胞的动力学。这导致在气味辨别任务中的性能提高。这些发现为早期嗅觉计算提供了一个框架，其中到嗅球的自上而下的反馈灵活地塑造了梨状皮层中神经活动的时间结构，允许早期嗅觉系统在两种不同的编码模型之间动态切换。
