University of Leipzig, Institute for Biology, Talstraße 33, 04103 Leipzig, Germany.
Leibniz Institute for Neurobiology (LIN), Department of Genetics, Brenneckestr. 6, 39118 Magdeburg, Germany; Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany; Otto von Guericke University Magdeburg, Institute for Biology, Universitätsplatz 2, 39106 Magdeburg, Germany.
Curr Opin Neurobiol. 2019 Feb;54:146-154. doi: 10.1016/j.conb.2018.10.007. Epub 2018 Oct 24.
The Drosophila larva is a relatively simple, 10 000-neuron study case for learning and memory with enticing analytical power, combining genetic tractability, the availability of robust behavioral assays, the opportunity for single-cell transgenic manipulation, and an emerging synaptic connectome of its complete central nervous system. Indeed, although the insect mushroom body is a much-studied memory network, the connectome revealed that more than half of the classes of connection within the mushroom body had escaped attention. The connectome also revealed circuitry that integrates, both within and across brain hemispheres, higher-order sensory input, intersecting valence signals, and output neurons that instruct behavior. Further, it was found that activating individual dopaminergic mushroom body input neurons can have a rewarding or a punishing effect on olfactory stimuli associated with it, depending on the relative timing of this activation, and that larvae form molecularly dissociable short-term, long-term, and amnesia-resistant memories. Together, the larval mushroom body is a suitable study case to achieve a nuanced account of molecular function in a behaviorally meaningful memory network.
果蝇幼虫是一个相对简单的 10000 神经元的学习和记忆研究案例，具有诱人的分析能力，结合了遗传易处理性、可靠的行为测定法的可用性、单细胞转基因操作的机会，以及其完整中枢神经系统的新兴突触连接组。事实上，尽管昆虫的蘑菇体是一个研究较多的记忆网络，但连接组揭示了蘑菇体中超过一半的连接类型都被忽视了。连接组还揭示了在大脑半球内和之间整合高级感觉输入、交叉效价信号和指导行为的输出神经元的电路。此外，人们发现，激活单个多巴胺能蘑菇体输入神经元对与其相关的嗅觉刺激可能产生奖励或惩罚效果，这取决于这种激活的相对时间，并且幼虫形成分子上可分离的短期、长期和抗遗忘记忆。总的来说，幼虫的蘑菇体是一个合适的研究案例，可以在一个具有行为意义的记忆网络中实现对分子功能的细致描述。
