Baratti Greta, Rizzo Angelo, Miletto Petrazzini Maria Elena, Sovrano Valeria Anna
CIMeC, Center for Mind/Brain Sciences, University of Trento, 38068 Rovereto, Italy.
School of Natural Sciences, University of Torino, 10124 Torino, Italy.
Animals (Basel). 2021 Jul 5;11(7):2001. doi: 10.3390/ani11072001.
Zebrafish spontaneously use distance and directional relationships among three-dimensional extended surfaces to reorient within a rectangular arena. However, they fail to take advantage of either an array of freestanding corners or an array of unequal-length surfaces to search for a no-longer-present goal under a spontaneous cued memory procedure, being unable to use the information supplied by corners and length without some kind of rewarded training. The present study aimed to tease apart the geometric components characterizing a rectangular enclosure under a procedure recruiting the reference memory, thus training zebrafish in fragmented layouts that provided differences in surface distance, corners, and length. Results showed that fish, besides the distance, easily learned to use both corners and length if subjected to a rewarded exit task over time, suggesting that they can represent all the geometrically informative parts of a rectangular arena when consistently exposed to them. Altogether, these findings highlight crucially important issues apropos the employment of different behavioral protocols (spontaneous choice versus training over time) to assess spatial abilities of zebrafish, further paving the way to deepen the role of visual and nonvisual encodings of isolated geometric components in relation to macrostructural boundaries.
斑马鱼能自发地利用三维扩展表面之间的距离和方向关系，在矩形区域内重新定向。然而，在自发线索记忆程序下，它们无法利用一系列独立的角落或一系列不等长的表面来寻找不再存在的目标，在没有某种奖励训练的情况下，它们无法利用角落和长度提供的信息。本研究旨在通过一种采用参考记忆的程序，梳理出表征矩形围栏的几何成分，从而在提供表面距离、角落和长度差异的碎片化布局中训练斑马鱼。结果表明，如果随着时间的推移让鱼接受奖励性出口任务，除了距离之外，它们还能轻松学会利用角落和长度，这表明当持续接触矩形区域时，它们能够表征其所有几何信息部分。总之，这些发现突出了在评估斑马鱼空间能力时，采用不同行为方案（自发选择与随时间训练）的至关重要的问题，进一步为深入研究孤立几何成分的视觉和非视觉编码相对于宏观结构边界的作用铺平了道路。
