Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Instituto de Fisiología, Biología Molecular y Neurociencias, Universidad de Buenos Aires-CONICET), Ciudad Universitaria, Buenos Aires 1428, Argentina.
J Exp Biol. 2022 Jun 1;225(11). doi: 10.1242/jeb.244229.
Real-world experiences often mix appetitive and aversive events. Understanding the ability of animals to extract, store and use this information is an important issue in neurobiology. We used honey bees as model organism to study learning and memory after a differential conditioning paradigm that combines appetitive and aversive training trials. First, we used an aversive conditioning paradigm that constitutes a clear opposite of the well-known appetitive olfactory conditioning of the proboscis extension response. A neutral odour is presented paired with the bitter substance quinine. Aversive memory is evidenced later as an odour-specific impairment in appetitive conditioning. Then, we tested the effect of mixing appetitive and aversive conditioning trials distributed along the same training session. Differential conditioning protocols like this were used previously to study the ability to discriminate odours; however, they were not focused on whether appetitive and aversive memories are formed. We found that after differential conditioning, honey bees establish independent appetitive and aversive memories that do not interfere with each other during acquisition or storage. Finally, we moved the question forward to retrieval and memory expression to evaluate what happens when appetitive and the aversive learned odours are mixed during a test. Interestingly, opposite memories compete in such a way that they do not cancel each other out. Honey bees showed the ability to switch from expressing appetitive to aversive memory depending on their satiation level.
真实世界的经验往往混合了令人愉悦和厌恶的事件。理解动物提取、存储和利用这些信息的能力是神经生物学中的一个重要问题。我们使用蜜蜂作为模型生物，研究了在结合了令人愉悦和厌恶训练试验的差异条件作用范式后学习和记忆的能力。首先，我们使用了一种厌恶条件作用范式，它构成了众所周知的嗅觉延伸反应的令人愉悦的嗅觉条件作用的明显对立面。中性气味与苦味物质奎宁配对呈现。厌恶记忆后来表现为对令人愉悦的条件作用的气味特异性损害。然后，我们测试了在同一训练过程中混合令人愉悦和厌恶的条件作用试验的效果。像这样的差异条件作用方案以前曾被用于研究区分气味的能力；然而，它们并没有关注是否形成了令人愉悦和厌恶的记忆。我们发现，经过差异条件作用后，蜜蜂建立了独立的令人愉悦和厌恶的记忆，在获取或存储过程中彼此不干扰。最后，我们将问题推进到检索和记忆表达，以评估在测试中混合令人愉悦和厌恶的学习气味时会发生什么。有趣的是，相反的记忆以相互竞争的方式出现，而不是相互抵消。蜜蜂表现出根据其饱腹感水平从表达令人愉悦的记忆切换到表达厌恶的记忆的能力。
