Neuromodulation and differential learning across mosquito species
Neuromodulation and differential learning across mosquito species
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不同蚊子物种的神经调节和差异学习
DOI：
10.1098/rspb.2022.2118
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Riffell, Jeffrey A.
中科院分区：
文献类型：
--
作者：
Wolff, Gabriella H.;Lahondère, Chloé;Vinauger, Clément;Rylance, Elizabeth;Riffell, Jeffrey A.
蚊子可以根据过去的经验改变它们的取食行为，例如从咬动物转变为咬人或避开防御性宿主(Wolff&Riffell 2018J)。实验Biol.221，Jeb157131。(DOI：10.1242/jeb.157131)多巴胺是昆虫的关键神经调节剂，允许它们灵活地选择食物，但它在初级嗅觉中枢--触角叶(AL)中的作用尚不清楚(Vinaugeret al.2018 Curr.Biol.28,333-344.e8.(DOI：10.1016/j.cu.2017.12.015)蚊子是否能学会一些气味而不能学会其他气味，或者不同的物种是否能学会相同的气味线索，也是未知的。我们测试了具有不同寄主偏好的四种蚊子的厌恶嗅觉学习，发现它们对偏爱寄主的气味有不同的学习。偏爱人类的蚊子学会了哺乳动物皮肤中的气味，而不是花香，而以花蜜为食的物种只学会了花香。对这四个物种的大脑进行比较，发现多巴胺能神经元在AL中的神经支配模式明显不同。埃及伊蚊的钙成像和多巴胺能神经支配的三维图像分析表明，适应可学习气味的肾小球具有显著更高的多巴胺能神经支配。昆虫AL中多巴胺表达的变化可能是一种进化机制，在不改变大脑结构的情况下适应嗅觉学习回路，并赋予蚊子适应新宿主的能力。
Mosquitoes can change their feeding behaviours based on past experiences, such as shifting from biting animals to biting humans or avoiding defensive hosts (Wolff & Riffell 2018J. Exp. Biol.221, jeb157131. (doi:10.1242/jeb.157131)). Dopamine is a critical neuromodulator for insects, allowing flexibility in their feeding preferences, but its role in the primary olfactory centre, the antennal lobe (AL), remains unclear (Vinaugeret al.2018Curr. Biol.28, 333–344.e8. (doi:10.1016/j.cub.2017.12.015)). It is also unknown whether mosquitoes can learn some odours and not others, or whether different species learn the same odour cues. We assayed aversive olfactory learning in four mosquito species with different host preferences, and found that they differentially learn odours salient to their preferred host. Mosquitoes that prefer humans learned odours found in mammalian skin, but not a flower odour, and a nectar-feeding species only learned a floral odour. Comparing the brains of these four species revealed significantly different innervation patterns in the AL by dopaminergic neurons. Calcium imaging in theAedes aegyptiAL and three-dimensional image analyses of dopaminergic innervation show that glomeruli tuned to learnable odours have significantly higher dopaminergic innervation. Changes in dopamine expression in the insect AL may be an evolutionary mechanism to adapt olfactory learning circuitry without changing brain structure and confer to mosquitoes an ability to adapt to new hosts.