Hébert Marie, Bulla Jan, Vivien Denis, Agin Véronique
Normandie Université, UNICAEN, INSERM, Physiopathology and Imaging of Neurological DisordersCaen, France.
Center for Mind/Brain Sciences, University of TrentoRovereto, Italy.
Front Behav Neurosci. 2017 Jun 6;11:109. doi: 10.3389/fnbeh.2017.00109. eCollection 2017.
Animals use distal and proximal visual cues to accurately navigate in their environment, with the possibility of the occurrence of associative mechanisms such as cue competition as previously reported in honey-bees, rats, birds and humans. In this pilot study, we investigated one of the most common forms of cue competition, namely the overshadowing effect, between visual landmarks during spatial learning in mice. To this end, C57BL/6J × Sv129 mice were given a two-trial place recognition task in a T-maze, based on a novelty free-choice exploration paradigm previously developed to study spatial memory in rodents. As this procedure implies the use of different aspects of the environment to navigate (i.e., mice can perceive from each arm of the maze), we manipulated the distal and proximal visual landmarks during both the acquisition and retrieval phases. Our prospective findings provide a first set of clues in favor of the occurrence of an overshadowing between visual cues during a spatial learning task in mice when both types of cues are of the same modality but at varying distances from the goal. In addition, the observed overshadowing seems to be non-reciprocal, as distal visual cues tend to overshadow the proximal ones when competition occurs, but not vice versa. The results of the present study offer a first insight about the occurrence of associative mechanisms during spatial learning in mice, and may open the way to promising new investigations in this area of research. Furthermore, the methodology used in this study brings a new, useful and easy-to-use tool for the investigation of perceptive, cognitive and/or attentional deficits in rodents.
动物利用远距离和近距离视觉线索在其环境中准确导航，正如之前在蜜蜂、大鼠、鸟类和人类中所报道的那样，有可能出现诸如线索竞争等联想机制。在这项初步研究中，我们调查了线索竞争最常见的形式之一，即在小鼠空间学习过程中视觉地标之间的遮蔽效应。为此，基于先前开发的用于研究啮齿动物空间记忆的新颖自由选择探索范式，给C57BL/6J×Sv129小鼠在T迷宫中进行了两次试验的位置识别任务。由于此过程意味着利用环境的不同方面来导航（即小鼠可以从迷宫的每个臂感知），我们在获取和检索阶段都操纵了远距离和近距离视觉地标。我们的前瞻性研究结果提供了第一组线索，支持在小鼠空间学习任务中，当两种类型的线索具有相同模态但与目标的距离不同时，视觉线索之间会发生遮蔽。此外，观察到的遮蔽似乎是非相互的，因为当竞争发生时，远距离视觉线索往往会遮蔽近距离视觉线索，反之则不然。本研究结果首次揭示了小鼠空间学习过程中联想机制的发生情况，并可能为该研究领域有前景的新研究开辟道路。此外，本研究中使用的方法为研究啮齿动物的感知、认知和/或注意力缺陷带来了一种新的、有用且易于使用的工具。
