Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America.
Plaksha University, Sahibzada Ajit Singh Nagar, Punjab, India.
PLoS One. 2023 Jul 10;18(7):e0284641. doi: 10.1371/journal.pone.0284641. eCollection 2023.
Many animals display innate preferences for some odors, but the physiological mechanisms underlying these preferences are poorly understood. Here, with behavioral tests, we establish a model system well suited to investigating olfactory mechanisms, the locust Schistocerca americana. We conducted open field tests in an arena designed to provide only olfactory cues to guide navigation choices. We found that newly hatched locusts navigated toward, and spent more time near, the odor of wheat grass than humidified air. In similar tests, we found that hatchlings avoided moderate concentrations of major individual components of the food blend odor, 1-hexanol (1% v/v) and hexanal (0.9% v/v) diluted in mineral oil relative to control presentations of unscented mineral oil. Hatchlings were neither attracted nor repelled by a lower concentration (0.1% v/v) of 1-hexanol but were moderately attracted to a low concentration (0.225% v/v) of hexanal. We quantified the behavior of the animals by tracking their positions with the Argos software toolkit. Our results establish that hatchlings have a strong, innate preference for food odor blend, but the valence of the blend's individual components may be different and may change depending on the concentration. Our results provide a useful entry point for an analysis of physiological mechanisms underlying innate sensory preferences.
许多动物对某些气味表现出先天的偏好，但这些偏好背后的生理机制还了解甚少。在这里，我们通过行为测试，建立了一个非常适合研究嗅觉机制的模型系统，即美洲飞蝗（Schistocerca americana）。我们在一个设计成只能通过嗅觉线索来引导导航选择的竞技场中进行了野外试验。我们发现，刚孵化的蝗虫会朝着小麦草的气味，而不是加湿空气的气味，并且在那里停留更长时间。在类似的测试中，我们发现幼虫会回避食物混合气味中主要个体成分 1-己醇（1%v/v）和己醛（0.9%v/v）的中等浓度，相对于无味矿物油的对照，这些成分在矿物油中被稀释了。幼虫既不被 0.1%v/v 的 1-己醇吸引，也不被其排斥，但对 0.225%v/v 的低浓度己醛有中等吸引力。我们通过 Argos 软件工具包跟踪动物的位置来量化它们的行为。我们的结果表明，幼虫对食物气味混合物有强烈的先天偏好，但混合物中各成分的效价可能不同，并且可能会根据浓度而变化。我们的结果为分析先天感觉偏好背后的生理机制提供了一个有用的切入点。
