The encoding of odors is believed to begin as a combinatorial code consisting of distinct patterns of responses from odorant receptors (ORs), trace-amine associated receptors (TAARs), or both. To determine how specific response patterns arise requires detecting patterns in vivo and understanding how the components of an odor, which are nearly always mixtures of odorants, give rise to parts of the pattern. Cigarette smoke, a common and clinically relevant odor consisting of >400 odorants, evokes responses from 144 ORs and 3 TAARs in freely behaving male and female mice, the first example of in vivo responses of both ORs and TAARs to an odor. As expected, a simplified artificial mimic of cigarette smoke odor tested at low concentration to identify highly sensitive receptors evokes responses from four ORs, all also responsive to cigarette smoke. Human subjects of either sex identify 1-pentanethiol as the odorant most critical for perception of the artificial mimic; and in mice the OR response patterns to these two odors are significantly similar. Fifty-eight ORs respond to the headspace above 25% 1-pentanethiol, including 9 ORs responsive to cigarette smoke. The response patterns to both cigarette smoke and 1-pentanethiol have strongly responsive ORs spread widely across OR sequence diversity, consistent with most other combinatorial codes previously measured in vivo. The encoding of cigarette smoke is accomplished by a broad receptor response pattern, and 1-pentanethiol is responsible for a small subset of the responsive ORs in this combinatorial code.

SIGNIFICANCE STATEMENT Complex odors are usually perceived as distinct odor objects. Cigarette smoke is the first complex odor whose in vivo receptor response pattern has been measured. It is also the first pattern shown to include responses from both odorant receptors and trace-amine associated receptors, confirming that the encoding of complex odors can be enriched by signals coming through both families of receptors. Measures of human perception and mouse receptor physiology agree that 1-pentanethiol is a critical component of a simplified odorant mixture designed to mimic cigarette smoke odor. Its receptor response pattern helps to link those of the artificial mimic and real cigarette smoke, consistent with expectations about perceptual similarity arising from shared elements in receptor response patterns.

据信，气味的编码始于组合代码，该组合代码由来自气味受体（OR），痕量胺相关受体（TAAR）或两者的响应的不同模式组成。要确定特定的响应模式是如何产生的，需要在体内检测模式并了解几乎总是加味剂混合物的气味成分如何引起该模式的某些部分。香烟烟雾是一种常见的且与临床相关的气味，由> 400种气味组成，可引起行为自如的雄性和雌性小鼠的144个OR和3个TAAR产生响应，这是体内的第一个例子OR和TAAR对气味的响应。如预期的那样，在低浓度下对香烟烟雾气味进行简化的人工模拟，以识别高度敏感的受体，从而引起四个OR的响应，所有OR均对香烟烟雾做出响应。男女两性都认为1-戊硫醇是对人工模拟物的感知最关键的气味。在小鼠中，对这两种气味的OR反应模式非常相似。58％的OR对25％以上的1-戊烷硫醇有顶空响应，包括9个对香烟烟雾有响应的OR。对香烟烟雾和1-戊硫醇的响应模式均具有很强的响应性OR，其跨OR序列多样性广泛分布，这与先前在体内测得的大多数其他组合密码一致。香烟烟雾的编码是通过广泛的受体反应模式完成的，而1-戊硫醇负责此组合代码中反应性OR的一小部分。

意义声明复杂的气味通常被视为不同的气味对象。香烟烟雾是体内第一种复杂的气味受体反应模式已被测量。这也是第一个显示出包括来自气味受体和痕量胺相关受体的响应的模式，这证实了通过两个受体家族发出的信号都可以丰富复杂气味的编码。人类感知和小鼠受体生理的测量结果一致认为，1-戊硫醇是简化的模仿香烟烟雾气味的气味混合物的关键成分。它的受体反应模式有助于将人造模拟烟和真实香烟烟雾联系起来，这与对受体反应模式中共享元素引起的感知相似性的期望相一致。