美国霍华德休斯医学研究所Vivek Jayaraman和Sung Soo Kim研究组发现，果蝇在不同的视觉场景中生成稳定的航向表示形式。该项研究成果11月20日在线发表在《自然》上。

研究人员将拴系蝇中的双光子钙成像和光遗传学与电路建模相结合，并表明罗盘和视觉神经元的相关活动如何驱动可塑性，从而灵活地转换二维视觉线索，将其变成稳定的导航表示形式。他们还描述了这种可塑性如何使果蝇将部分方位表示形式（从在新环境的一部分中的定位确定）转换为完整的导航表示形式。他们的结果提供了对与记忆相关的计算的机械洞察力，这对于在各种环境中进行灵活导航至关重要。

据了解，不同的环境中导航时，许多动物都依赖内部导航表示。目前尚不清楚该表示如何与定义不同环境的感觉线索相关联。在果蝇大脑中，航向由“罗盘”神经元代表，这些神经元支配着一个称为椭球体的环形结构。每个罗盘神经元接收来自“环形”神经元的输入，这些输入对于特定的视觉特征具有选择性；这种结合为从视觉场景中提取方向信息提供了理想的基础。

附：英文原文

Title: Generation of stable heading representations in diverse visual scenes

Author: Sung Soo Kim, Ann M. Hermundstad, Sandro Romani, L. F. Abbott & Vivek Jayaraman

Issue&Volume: 2019-11-20

Abstract: Many animals rely on an internal heading representation when navigating in varied environments. How this representation is linked to the sensory cues that define different surroundings is unclear. In the fly brain, heading is represented by compass neurons that innervate a ring-shaped structure known as the ellipsoid body. Each compass neuron receives inputs from ring neurons that are selective for particular visual features; this combination provides an ideal substrate for the extraction of directional information from a visual scene. Here we combine two-photon calcium imaging and optogenetics in tethered flying flies with circuit modelling, and show how the correlated activity of compass and visual neurons drives plasticity, which flexibly transforms two-dimensional visual cues into a stable heading representation. We also describe how this plasticity enables the fly to convert a partial heading representation, established from orienting within part of a novel setting, into a complete heading representation. Our results provide mechanistic insight into the memory-related computations that are essential for flexible navigation in varied surroundings. Two-photon calcium imaging and optogenetic experiments in tethered flying flies, combined with modelling, demonstrate how the correlation of compass and visual neurons underpins plasticity that enables the transformation of visual cues into stable heading representations.

DOI: 10.1038/s41586-019-1767-1

Source:https://www.nature.com/articles/s41586-019-1767-1