A bitter substance induces specific orofacial and somatic behavioral reactions such as gapes in mice as well as monkeys and humans. These reactions have been proposed to represent affective disgust, and therefore, understanding the neuronal basis of the reactions would pave the way to understand affective disgust. It is crucial to identify and access the specific neuronal ensembles that are activated by bitter substances, such as quinine, the intake of which induces disgust reactions. However, the method to access the quinine-activated neurons has not been fully established yet. Here, we show evidence that a targeted recombination in active populations (TRAP) method, induces genetic recombination in the quinine-activated neurons in the central nucleus of the amygdala (CeA). CeA is one of the well-known emotional centers of the brain. We found that the intraoral quinine infusion, that resulted in disgust reactions, increased both cFos-positive cells and Arc-positive cells in the CeA. By using Arc-CreER;Ai3 TRAP mice, we induced genetic recombination in the quinine-activated neurons and labelled them with fluorescent protein. We confirmed that the quinine-TRAPed fluorescently-labelled cells preferentially coexpressed Arc after quinine infusion. Our results suggest that the TRAP method can be used to access specific functional neurons in the CeA.

苦味物质会引起特定的口腔和躯体行为反应，例如小鼠，猴子和人类的缝隙。已经提出这些反应代表情感厌恶，因此，了解反应的神经元基础将为理解情感厌恶铺平道路。识别和进入由苦味物质（例如奎宁）激活的特定神经元集合至关重要，摄入这种物质会引起令人反感的反应。但是，访问奎宁激活的神经元的方法尚未完全建立。在这里，我们显示证据表明，在活动人群中进行有针对性的重组（TRAP）方法，可在杏仁核（CeA）中央核的奎宁活化神经元中诱导基因重组。CeA是大脑中众所周知的情感中心之一。CeA中的cFos阳性细胞和Arc阳性细胞。通过使用Arc- CreER; Ai3 TRAP小鼠，我们在奎宁激活的神经元中诱导了基因重组，并用荧光蛋白标记了它们。我们确认，奎宁注入后，奎宁陷阱荧光标记的细胞优先共表达弧。我们的结果表明，TRAP方法可用于访问CeA中的特定功能神经元。