Relevant odors signaling food, mates, or predators can be masked by unpredictable mixtures of less relevant background odors. Here, we developed a mouse behavioral paradigm to test the role played by the novelty of the background odors. During the task, mice identified target odors in previously learned background odors and were challenged by catch trials with novel background odors, a task similar to visual CAPTCHA. Female wild-type (WT) mice could accurately identify known targets in novel background odors. WT mice performance was higher than linear classifiers and the nearest neighbor classifier trained using olfactory bulb glomerular activation patterns. Performance was more consistent with an odor deconvolution method. We also used our task to investigate the performance of female Cntnap2^-/- mice, which show some autism-like behaviors. Cntnap2^-/- mice had glomerular activation patterns similar to WT mice and matched WT mice target detection for known background odors. However, Cntnap2^-/- mice performance fell almost to chance levels in the presence of novel backgrounds. Our findings suggest that mice use a robust algorithm for detecting odors in novel environments and this computation is impaired in Cntnap2^-/- mice.

发出食物、配偶或捕食者信号的相关气味可能会被不太相关的背景气味的不可预知的混合物所掩盖。在这里，我们开发了一种小鼠行为范式来测试背景气味的新颖性所起的作用。在任务期间，小鼠在先前学习的背景气味中识别出目标气味，并接受具有新背景气味的捕捉试验的挑战，该任务类似于视觉验证码。雌性野生型 (WT) 小鼠可以准确识别新背景气味中的已知目标。WT 小鼠的性能高于线性分类器和使用嗅球肾小球激活模式训练的最近邻分类器。性能与气味反卷积方法更一致。我们还使用我们的任务来调查女性Cntnap2的表现^-/-小鼠，表现出一些类似自闭症的行为。Cntnap2 ^-/-小鼠具有与 WT 小鼠相似的肾小球激活模式，并匹配 WT 小鼠对已知背景气味的目标检测。然而，Cntnap2 ^-/-小鼠的性能在新背景下几乎下降到随机水平。我们的研究结果表明，小鼠使用强大的算法来检测新环境中的气味，并且这种计算在Cntnap2 ^-/-小鼠中受损。