BACKGROUND In an earlier study, we identified two neuronal populations, c673a and Fru-GAL4, that regulate fat storage in fruit flies. Both populations partially overlap with a structure in the insect brain known as the mushroom body (MB), which plays a critical role in memory formation. This overlap prompted us to examine whether the MB is also involved in fat storage homeostasis. METHODS Using a variety of transgenic agents, we selectively manipulated the neural activity of different portions of the MB and associated neurons to decipher their roles in fat storage regulation. RESULTS Our data show that silencing of MB neurons that project into the α'β' lobes decreases de novo fatty acid synthesis and causes leanness, while sustained hyperactivation of the same neurons causes overfeeding and produces obesity. The α'β' neurons oppose and dominate the fat regulating functions of the c673a and Fru-GAL4 neurons. We also show that MB neurons that project into the γ lobe also regulate fat storage, probably because they are a subset of the Fru neurons. We were able to identify input and output neurons whose activity affects fat storage, feeding, and metabolism. The activity of cholinergic output neurons that innervating the β'2 compartment (MBON-β'2mp and MBON-γ5β'2a) regulates food consumption, while glutamatergic output neurons innervating α' compartments (MBON-γ2α'1 and MBON-α'2) control fat metabolism. CONCLUSIONS We identified a new fat storage regulating center, the α'β' lobes of the MB. We also delineated the neuronal circuits involved in the actions of the α'β' lobes, and showed that food intake and fat metabolism are controlled by separate sets of postsynaptic neurons that are segregated into different output pathways.

中文翻译：

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鉴定和表征调节果蝇脂肪储存的蘑菇体神经元。

背景技术在较早的研究中，我们鉴定了两个神经元种群c673a和Fru-GAL4，它们调节果蝇中的脂肪储存。两种种群都与昆虫大脑中称为蘑菇体（MB）的结构部分重叠，该结构在记忆形成中起关键作用。这种重叠促使我们检查MB是否也参与脂肪存储动态平衡。方法使用多种转基因剂，我们选择性地操纵了MB和相关神经元不同部位的神经活动，以破译它们在脂肪储存调节中的作用。结果我们的数据表明，投射到α'β'裂片的MB神经元沉默会减少从头脂肪酸合成并引起瘦肉，而相同神经元的持续过度活化会导致过度摄食并产生肥胖。α'β' 神经元反对并主导c673a和Fru-GAL4神经元的脂肪调节功能。我们还表明，投射到γ瓣的MB神经元也调节脂肪存储，可能是因为它们是Fru神经元的子集。我们能够识别出输入和输出神经元，这些神经元的活动会影响脂肪的储存，喂养和代谢。支配β'2区（MBON-β'2mp和MBON-γ5β'2a）的胆碱能输出神经元的活动调节食物的消耗，而支配α'区（MBON-γ2α'1和MBON-α'2）的谷氨酸能输出神经元的活动。 ）控制脂肪代谢。结论我们确定了一个新的脂肪储存调节中心，即MB的α'β'瓣。我们还描述了参与α'β'瓣叶活动的神经元回路，