Food induces sexual desire: Chinese scientists "Nature" published an article to reveal the aphrodisiac effect of protein

▎WuXi AppTec Content Team Editor For any animal, including humans, eating and mating can be said to be the most basic two types of behaviors
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How to make decisions and weigh priorities between these two behaviors is crucial to the survival and evolution of animals
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But how animals make such decisions remains a mystery
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In a study published in the journal Nature, Professor Wang Jing's team at the University of California, San Diego, including postdoctoral fellows Lin Huihao and Kwong Meihua, solved the puzzle
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They found that fruit flies shifted their attention from feeding to mating behavior after ingesting a food rich in amino acids
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The key to this behavioral switch is a neuropeptide, diuretic hormone 31 (Dh31), released from the gut
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The discovery of the neuropeptide Dh31 opens a new window for understanding the role of the brain-gut axis beyond feeding behavior
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"It was surprising to us that just a single molecule could have such a huge impact on an individual's behavioral decision-making," said Professor Jing Wang, "Our study mechanistically explains how Dh31 acts on the brain to alter these two A behavioral driver that is critical to evolution
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" The team found that starving male flies would prefer to eat when faced with food versus female flies
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The flies fed on amino acid or high-protein diets initiated courtship behavior far more rapidly and more intensely than flies fed on sucrose, and the behavioral switch often occurred within minutes
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This result suggests that amino acids rapidly activate neural pathways related to courtship behavior through a certain pathway
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▲Amino acids inhibit feeding and increase the desire to mate in male Drosophila (Image source: Reference [1]) What signaling molecule is manipulating this behavioral switch? Previous studies have found that in mammals, some satiety hormones released by endocrine cells in the gastrointestinal tract can promote reproductive behavior, so the research team set out to find clues in the endocrine cells of fruit flies
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They found that Dh31 was released by enteroendocrine cells after the flies ingested amino acids
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In order to verify this finding, the research team used CRISPR to knock out the gene that regulates Dh31 in Drosophila flies.
At this time, even if Drosophila ingested amino acids, the proportion of mating did not increase; in another set of experiments, in the activation of endocrine cells expressing Dh31 After that, the flies immediately engaged in courtship behavior
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Further traceability of Dh31 signaling confirmed that the aphrodisiac Dh31 originates in the flies' gut, rather than the imagined brain
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Using three-photon calcium imaging, the research team demonstrated that the neuropeptide Dh31, released from the gut, travels through the circulatory system and reaches the brain within minutes, explaining the rapid behavioral transition from feeding to courtship
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▲The transition from eating to mating requires Dh31 and Dh31 receptors in the gut (image source: Reference [1]) and after entering the brain, Dh31 can activate two types of neurons that express Dh31 receptors, and then through two Separate neural pathways influence Drosophila behavior: One type of neurons inhibits feeding; another promotes courtship
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"The findings suggest that the signaling molecule Dh31 alters the priority of these two opposing behaviors: in the absence of Dh31, eating prevails; but when Dh31 is released from the gut, courtship becomes the priority,
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said Professor Jing Wang
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So, does this finding in fruit flies apply to mammals? Previous studies have found that in mammals, a neuropeptide molecule plays a similar role in regulating the transition between wakefulness and sleep, including REM sleep and non-REM sleep
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There is still a lot of research to be done on the role of gut hormones beyond eating
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Whether the pathways identified in this study apply to mammals also needs more research
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Future research will try to understand how microbes affect brain-gut interactions
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Reference: [1] Lin, HH.
, Kuang, MC, Hossain, I.
et al.
A nutrient-specific gut hormone arbitrates between courtship and feeding.
Nature (2022).
https://doi.
org/10.
1038/s41586 -022-04408-7