Imaging of an early memory trace in the Drosophila mushroom body
Imaging of an early memory trace in the Drosophila mushroom body
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DOI：
10.1523/jneurosci.2958-07.2008
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发表时间：
2008-04-01
影响因子：
5.3
通讯作者：
Zhong, Yi
中科院分区：
文献类型：
--
作者：
Wang, Yalin;Mamiya, Akira;Zhong, Yi
广泛的分子、遗传和解剖学分析表明，嗅觉记忆储存在蘑菇体（MB）中，蘑菇体是昆虫大脑中的高级嗅觉中心。MB包括三种亚型的神经元，其轴突延伸到不同的叶中。最近的一项功能成像研究揭示了长期记忆痕迹，表现为MB神经元亚型轴突分支中Ca 2+活性的增加。然而，MB中的早期记忆痕迹仍然难以捉摸。我们在这里报告学习诱导的变化，在早期记忆形成过程中的不同亚型的MB神经元中的Ca 2+活动。我们使用了三个独立的在体内和体外制剂，他们都表明，在α '/β'神经元的轴突分支中的钙离子活动在响应条件嗅觉刺激变得更大相比，没有条件。这些变化依赖于MB中适当的G蛋白信号传导。通过在学习和记忆过程中破坏这些神经元中的G-蛋白信号传导或阻断其突触输出，在行为上进一步测试了在早期记忆形成期间α '/β'神经元的Ca 2+活性的这些变化的重要性。我们的研究结果表明，增加的钙离子活性在响应条件嗅觉刺激可能是一个神经相关的早期记忆中的MB。
Extensive molecular, genetic, and anatomical analyses have suggested that olfactory memory is stored in the mushroom body (MB), a higher-order olfactory center in the insect brain. The MB comprises three subtypes of neurons with axons that extend into different lobes. A recent functional imaging study has revealed a long-term memory trace manifested as an increase in the Ca2+ activity in an axonal branch of a subtype of MB neurons. However, early memory traces in the MB remain elusive. We report here learning-induced changes in Ca2+ activities during early memory formation in a different subtype of MB neurons. We used three independent in vivo and in vitro preparations, and all of them showed that Ca2+ activities in the axonal branches of alpha'/beta' neurons in response to a conditioned olfactory stimulus became larger compared with one that was not conditioned. The changes were dependent on proper G-protein signaling in the MB. The importance of these changes in the Ca2+ activity of alpha'/beta' neurons during early memory formation was further tested behaviorally by disrupting G-protein signaling in these neurons or blocking their synaptic outputs during the learning and memory process. Our results suggest that increased Ca2+ activity in response to a conditioned olfactory stimulus may be a neural correlate of early memory in the MB.