小柯机器人

近日，英国伦敦大学学院Tiago Branco及其团队报道在逃亡过程中确定庇护方向的一条皮层-丘脑回路。相关论文于2022年12月21日发表在《自然》杂志上。

研究人员表明，小鼠压后皮层（RSP）和上丘（SC）形成了一个编码庇护所方向矢量的回路，在逃逸过程中准确定位到庇护所尤为需要。庇护所方向在RSP和SC神经元中以自我为中心的坐标进行编码，SC庇护所方向的调整取决于RSP活动。RSP-SC通路的失活破坏了对庇护所的定向，并导致逃离时偏离最佳的庇护所定向路线，但不会导致定向或空间导航的一般缺陷。研究人员发现，RSP和SC是单突触连接的，并形成了一个前馈的侧向抑制微循环，该微循环强烈地驱动着抑制性丘脑网络，因为在抑制性SC神经元中有更高的RSP输入会聚和突触整合效率。这导致了抑制性SC神经元广泛的庇护方向调谐和兴奋性SC神经元尖锐的调谐。这些发现被一个生物学上受限制的脉冲网络模型所重现，在该模型中，RSP输入到局部SC的递归环结构产生了一个圆形的庇护方向图。研究人员提出，这种RSP-SC回路可能专门用于生成记忆的空间目标的丘脑表征，这些表征在逃跑过程中容易被运动系统获得，或者更广泛地说，在导航过程中必须尽可能快地达到目标。

据介绍，当面临掠夺性威胁时，向庇护所逃跑是一种适应性行动，可以提供对攻击者的长期保护。动物依靠对环境中安全位置的了解，本能地执行快速的以庇护所为导向的逃跑行动。虽然以前的工作已经确定了逃跑启动的神经机制，但不知道逃跑回路是如何结合空间信息，沿着最有效的路线执行快速飞行到庇护所。

附：英文原文

Title: A cortico-collicular circuit for orienting to shelter during escape

Author: Campagner, Dario, Vale, Ruben, Tan, Yu Lin, Iordanidou, Panagiota, Pavn Arocas, Oriol, Claudi, Federico, Stempel, A. Vanessa, Keshavarzi, Sepiedeh, Petersen, Rasmus S., Margrie, Troy W., Branco, Tiago

Issue&Volume: 2022-12-21

Abstract: When faced with predatory threats, escape towards shelter is an adaptive action that offers long-term protection against the attacker. Animals rely on knowledge of safe locations in the environment to instinctively execute rapid shelter-directed escape actions1,2. Although previous work has identified neural mechanisms of escape initiation3,4, it is not known how the escape circuit incorporates spatial information to execute rapid flights along the most efficient route to shelter. Here we show that the mouse retrosplenial cortex (RSP) and superior colliculus (SC) form a circuit that encodes the shelter-direction vector and is specifically required for accurately orienting to shelter during escape. Shelter direction is encoded in RSP and SC neurons in egocentric coordinates and SC shelter-direction tuning depends on RSP activity. Inactivation of the RSP–SC pathway disrupts the orientation to shelter and causes escapes away from the optimal shelter-directed route, but does not lead to generic deficits in orientation or spatial navigation. We find that the RSP and SC are monosynaptically connected and form a feedforward lateral inhibition microcircuit that strongly drives the inhibitory collicular network because of higher RSP input convergence and synaptic integration efficiency in inhibitory SC neurons. This results in broad shelter-direction tuning in inhibitory SC neurons and sharply tuned excitatory SC neurons. These findings are recapitulated by a biologically constrained spiking network model in which RSP input to the local SC recurrent ring architecture generates a circular shelter-direction map. We propose that this RSP–SC circuit might be specialized for generating collicular representations of memorized spatial goals that are readily accessible to the motor system during escape, or more broadly, during navigation when the goal must be reached as fast as possible.

DOI: 10.1038/s41586-022-05553-9

Source: https://www.nature.com/articles/s41586-022-05553-9

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
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