Hayatou Zineb, Wang Hongkai, Chaillet Antoine, Shulz Daniel E, Ego-Stengel Valérie, Estebanez Luc
Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay (NeuroPSI), Saclay, France.
Faculty of Medicine, Dalian University of Technology, Dalian City, China.
PLoS Biol. 2025 Jun 5;23(6):e3003186. doi: 10.1371/journal.pbio.3003186. eCollection 2025 Jun.
Body ownership disorders can be triggered by disease or body damage. Methods to probe limb embodiment are required to address those disorders. This includes the development of neuroprostheses that better integrate into the body scheme of the user. To this end, the "rubber hand illusion" protocol is a key behavioral method to probe the powerful embodiment that can be triggered by congruent somatosensory and visual inputs from the limb. So far, the neurophysiology of limb embodiment remains poorly known, in part because translating the rubber hand illusion to animal models such as the mouse remains challenging. Yet, mapping out the brain circuits of embodiment thanks to the use of genetic and optogenetic research tools would allow to propose novel embodiment restoration strategies. Here, we show that the rubber hand illusion described in humans can be translated to the mouse forelimb model using an automated, videography-based procedure. We exposed head-fixed mice to a visible, static 3D-printed replica of the right forelimb, while their own forelimb was hidden from their sight. We synchronously brushed their hidden forelimb and the replica. Following these visuo-tactile associations, the replica was visually threatened, and we probed the reaction of the mice using automated tracking of pupils and facial expression. The mice focused significantly more of their gaze toward the threatened forelimb replica after receiving synchronous tactile and visual information compared to asynchronous. More generally, across test and control conditions, the mouse pupillary response was consistent with the human overt response to the rubber hand illusion. Thus, our results show that mice exhibit quantifiable behavioral markers of the embodiment of an artificial forelimb.
身体所有权障碍可由疾病或身体损伤引发。需要采用探测肢体具身化的方法来解决这些障碍。这包括开发能更好地融入使用者身体图式的神经假体。为此，“橡胶手错觉”实验方案是一种关键的行为学方法，用于探测由来自肢体的一致体感和视觉输入所引发的强大具身化。到目前为止，肢体具身化的神经生理学仍鲜为人知，部分原因是将橡胶手错觉转化到诸如小鼠等动物模型上仍然具有挑战性。然而，借助基因和光遗传学研究工具绘制具身化的脑回路，将有助于提出新的具身化恢复策略。在这里，我们表明，人类中描述的橡胶手错觉可以通过基于摄像的自动化程序转化到小鼠前肢模型上。我们将头部固定的小鼠暴露于右前肢的可见静态3D打印复制品面前，同时将它们自己的前肢隐藏起来不让它们看到。我们同步刷动它们隐藏的前肢和复制品。在这些视觉 - 触觉关联之后，对复制品进行视觉威胁，然后我们通过自动跟踪瞳孔和面部表情来探测小鼠的反应。与异步情况相比，小鼠在接收到同步触觉和视觉信息后，显著更多地将目光聚焦于受到威胁的前肢复制品。更普遍地说，在测试和对照条件下，小鼠的瞳孔反应与人类对橡胶手错觉的明显反应一致。因此，我们的结果表明，小鼠表现出人造前肢具身化的可量化行为标记。
