Single-trial learning leads to mid-term memory formation in an ant during an appetitive but not an aversive task

Insects have been models of associative learning and its underlying memory
mechanisms. Research on the fruit fly Drosophila melanogaster and the
honeybee Apis mellifera yielded deep insights into the different memory
types and their formation dynamics following repeated stimulus exposure.
However, less is understood about the ability of insects to learn from a
single exposure. Accumulating evidence is revealing that several insect
species are able to learn from a single trial. Studies have largely
focused on odour appetitive learning. In this study, we investigated the
ability of the ant Lasius niger to learn from a single trial to associate
a reward or a punishment with one side of a Y-maze. The ants successfully
demonstrated appetitive learning but no aversive learning. This appetitive
learning led to the rapid formation of mid-term memory, remaining
sensitive to anaesthesia for at least 15 minutes post-training. Contrary
to single trial appetitive odour learning described in other species, this
learning did not induce the formation of long-term memory, calling for
further comparison between learning types.

昆虫一直是联想学习及其潜在记忆机制的经典研究模型。针对黑腹果蝇（Drosophila melanogaster）与西方蜜蜂（Apis mellifera）的相关研究，已在重复刺激暴露后的不同记忆类型及其形成动态方面取得了深刻认知。然而，学界对昆虫单次暴露后的学习能力仍了解有限。越来越多的研究证据表明，多种昆虫物种可通过单次尝试完成学习。现有研究大多聚焦于气味奖赏性学习。本研究以黑毛蚁（Lasius niger）为实验对象，探究其通过单次尝试将奖赏或惩罚与Y型迷宫（Y-maze）单侧建立关联的学习能力。实验结果显示，黑毛蚁可成功完成奖赏性学习，但未表现出厌恶性学习能力。该奖赏性学习可快速形成中期记忆，且在训练结束后至少15分钟内仍对麻醉处理敏感。与其他物种中报道的单次尝试气味奖赏性学习不同，本次实验中的学习过程并未诱导长期记忆的形成，这一发现亟待学界开展不同学习类型间的进一步比较研究。