Representing direction in the fly A population of cells called compass neurons represents a fruitfly's heading direction. Kim et al. used imaging and optogenetics in behaving flies to elucidate the functional architecture of the underlying neuronal network. They observed local excitation and global inhibition between the compass neurons. The features of the network were best explained by a ring attractor network model. Until now, this hypothesized network structure has been difficult to demonstrate in a real brain. Science, this issue p. 849 A neuronal network in the fly brain uses global inhibition and local excitation to enforce an internal representation of heading direction. Ring attractors are a class of recurrent networks hypothesized to underlie the representation of heading direction. Such network structures, schematized as a ring of neurons whose connectivity depends on their heading preferences, can sustain a bump-like activity pattern whose location can be updated by continuous shifts along either turn direction. We recently reported that a population of fly neurons represents the animal’s heading via bump-like activity dynamics. We combined two-photon calcium imaging in head-fixed flying flies with optogenetics to overwrite the existing population representation with an artificial one, which was then maintained by the circuit with naturalistic dynamics. A network with local excitation and global inhibition enforces this unique and persistent heading representation. Ring attractor networks have long been invoked in theoretical work; our study provides physiological evidence of their existence and functional architecture.

中文翻译：

---

果蝇中央大脑中的环吸引子动力学

代表果蝇的方向 一组称为罗盘神经元的细胞代表果蝇的航向方向。金等人。在果蝇行为中使用成像和光遗传学来阐明潜在神经元网络的功能结构。他们观察到罗盘神经元之间的局部兴奋和全局抑制。网络的特征最好用环形吸引子网络模型来解释。直到现在，这种假设的网络结构还难以在真实大脑中证明。科学，这个问题 p。849 果蝇大脑中的神经元网络使用全局抑制和局部激发来强制执行航向方向的内部表示。环吸引子是一类循环网络，假设它是航向方向表示的基础。这样的网络结构，被设计为一环神经元，其连接性取决于它们的航向偏好，可以维持类似颠簸的活动模式，其位置可以通过沿任一转弯方向的连续移动来更新。我们最近报道了一群苍蝇神经元通过类似颠簸的活动动力学来代表动物的前进方向。我们将头部固定飞蝇中的双光子钙成像与光遗传学相结合，用人工表示覆盖现有的种群表示，然后由具有自然动力学的电路维持。具有局部激励和全局抑制的网络强制执行这种独特且持久的航向表示。环形吸引子网络长期以来一直在理论工作中被引用。我们的研究为它们的存在和功能结构提供了生理学证据。