Sterrett Scott C, Findley Teresa M, Rafilson Sidney E, Brown Morgan A, Weible Aldis P, Marsden Rebecca, Tarvin Takisha, Wehr Michael, Murray James M, Fairhall Adrienne L, Smear Matthew C
Department of Neurobiology & Biophysics, University of Washington, Seattle, Washington, United States.
Institute of Neuroscience, University of Oregon, Eugene, Oregon, United States.
bioRxiv. 2024 Nov 7:2024.11.06.622362. doi: 10.1101/2024.11.06.622362.
Vertebrates sniff to control the odor samples that enter their nose. These samples can not only help identify odorous objects, but also locations and events. However, there is no receptor for place or time. Therefore, to take full advantage of olfactory information, an animal's brain must contextualize odor-driven activity with information about when, where, and how they sniffed. To better understand contextual information in the olfactory system, we captured the breathing and movements of mice while recording from their olfactory bulb. In stimulus- and task-free experiments, mice structure their breathing into persistent rhythmic states which are synchronous with statelike structure in ongoing neuronal population activity. These population states reflect a strong dependence of individual neuron activity on variation in sniff frequency, which we display using "sniff fields" and quantify using generalized linear models. In addition, many olfactory bulb neurons have "place fields" that display significant dependence of firing on allocentric location, which were comparable with hippocampal neurons recorded under the same conditions. At the population level, a mouse's location can be decoded from olfactory bulb with similar accuracy to hippocampus. Olfactory bulb place sensitivity cannot be explained by breathing rhythms or scent marks. Taken together, we show that the mouse olfactory bulb tracks breathing rhythms and self-location, which may help unite internal models of self and environment with olfactory information as soon as that information enters the brain.
脊椎动物通过嗅闻来控制进入鼻腔的气味样本。这些样本不仅有助于识别有气味的物体，还能确定位置和事件。然而，对于位置或时间并没有相应的感受器。因此，为了充分利用嗅觉信息，动物的大脑必须将气味驱动的活动与关于它们何时、何地以及如何嗅闻的信息结合起来。为了更好地理解嗅觉系统中的情境信息，我们在记录小鼠嗅球活动的同时捕捉了它们的呼吸和运动情况。在无刺激和无任务的实验中，小鼠将呼吸构建为持续的节律状态，这些状态与正在进行的神经元群体活动中的类似状态结构同步。这些群体状态反映了单个神经元活动对嗅闻频率变化的强烈依赖性，我们使用“嗅闻场”来展示这一点，并使用广义线性模型进行量化。此外，许多嗅球神经元具有“位置场”，其放电对以体心为中心的位置表现出显著依赖性，这与在相同条件下记录的海马神经元相当。在群体水平上，小鼠的位置可以从嗅球中以与海马相当的精度解码出来。嗅球的位置敏感性无法用呼吸节律或气味标记来解释。综合来看，我们表明小鼠嗅球跟踪呼吸节律和自身位置，这可能有助于在嗅觉信息进入大脑时，将自我和环境的内部模型与嗅觉信息结合起来。
