A brain-derived insulin signal encodes protein satiety for nutrient-specific feeding inhibition

作者：Xiaoyu Li, Yang Yang, Xiaobing Bai, Xiaotong Wang, Houqi Tan, Yanbo Chen, Yan Zhu, Qili Liu, Mark N. Wu, Yan Li · 发表于：Cell Reports · 年份：2024 · DOI：10.1016/j.celrep.2024.114282 · 被引用次数：15 · 研究领域：Neurobiology and Insect Physiology Research、Retinal Development and Disorders、Circadian rhythm and melatonin

The suppressive effect of insulin on food intake has been documented for decades. However, whether insulin signals can encode a certain type of nutrients to regulate nutrient-specific feeding behavior remains elusive. Here, we show that in female Drosophila, a pair of dopaminergic neurons, tritocerebrum 1-dopaminergic neurons (T1-DANs), are directly activated by a protein-intake-induced insulin signal from insulin-producing cells (IPCs). Intriguingly, opto-activating IPCs elicits feeding inhibition for both protein and sugar, while silencing T1-DANs blocks this inhibition only for protein food. Elevating insulin signaling in T1-DANs or opto-activating these neurons is sufficient to mimic protein satiety. Furthermore, this signal is conveyed to local neurons of the protocerebral bridge (PB-LNs) and specifically suppresses protein intake. Therefore, our findings reveal that a brain-derived insulin signal encodes protein satiety and suppresses feeding behavior in a nutrient-specific manner, shedding light on the functional specificity of brain insulin signals in regulating behaviors.