PDF(Pubmed)
Abstract：
Dopamine (DA) is a key regulator of associative learning and memory in both vertebrates and invertebrates, and it is widely believed that DA plays a key role in aversive conditioning in invertebrates. However, the idea that DA is involved only in aversive conditioning has been challenged in recent studies on the fruit fly (Drosophila melanogaster), ants and crabs, suggesting diverse functions of DA modulation on associative plasticity. Here, we present the results of DA modulation in aversive olfactory conditioning with DEET punishment and appetitive olfactory conditioning with sucrose reward in the oriental fruit fly, Bactrocera dorsalis. Injection of DA receptor antagonist fluphenazine or chlorpromazine into these flies led to impaired aversive learning, but had no effect on the appetitive learning. DA receptor antagonists impaired both aversive and appetitive long-term memory retention. Interestingly, the impairment on appetitive memory was rescued not only by DA but also by octopamine (OA). Blocking the OA receptors also impaired the appetitive memory retention, but this impairment could only be rescued by OA, not by DA. Thus, we conclude that in B. dorsalis, OA and DA pathways mediate independently the appetitive and aversive learning, respectively. These two pathways, however, are organized in series in mediating appetitive memory retrieval with DA pathway being at upstream. Thus, OA and DA play dual roles in associative learning and memory retrieval, but their pathways are organized differently in these two cognitive processes - parallel organization for learning acquisition and serial organization for memory retrieval.
摘要：
多巴胺（DA）是脊椎动物和无脊椎动物联想学习和记忆的关键调节因子。人们普遍认为，DA在无脊椎动物的厌恶调节中起着关键作用。然而,DA只参与厌恶调节的想法在最近的果蝇（果蝇）研究中受到了挑战，蚂蚁和螃蟹,表明DA调制对缔合可塑性的不同功能。这里,我们介绍了DA调制在东方果蝇中带有DEET惩罚的厌恶嗅觉调理和带有蔗糖奖励的食欲嗅觉调理中的结果，背软杆菌.向这些果蝇中注射DA受体拮抗剂氟奋乃静或氯丙嗪会导致厌恶学习受损，但对食欲学习没有影响。DA受体拮抗剂会损害厌恶性和食欲性的长期记忆保留。有趣的是,不仅通过DA，而且通过章鱼胺（OA）也可以挽救食欲记忆的损害。阻断OA受体也损害了食欲记忆的保留，但是这种损伤只能通过OA来挽救，不是DA。因此，我们得出的结论是，在背腹中，OA和DA途径独立介导食欲和厌恶学习，分别。这两种途径，然而,在DA通路位于上游的情况下，以串联的方式组织调节食欲记忆检索。因此，OA和DA在联想学习和记忆检索中起着双重作用，但是在这两个认知过程中，它们的路径有不同的组织——学习习得的并行组织和记忆检索的串行组织。
