不是来自于麻婆豆腐就是
https://imgur.com/ZoqLqzW
论文出处：
https://www.nature.com/articles/s41467-023-41637-4
Sensitivity to NH4Cl is conserved across species variants of OTOP1
We next asked if sensitivity to NH4Cl is conserved among different species
variants of OTOP channels, as might be expected given the broad range of
organisms that find the taste of NH4Cl aversive. When expressed in HEK-293
cells, human, chicken, and zebrafish OTOP1 channels all responded to NH4Cl
with large inward currents (Fig. 4a); in each case, the ammonium-induced
currents were inhibited by 1M Zn2+. For mouse OTOP1, we observed
potentiation of the response to NH4Cl following the removal of Zn2+, as
previously reported for mild acid-evoked responses36. Interestingly, we
observed variation in the magnitudes of the responses to NH4Cl among the
different species variants of OTOP1 (Fig. 4b). For example, relative to its
response to the acidic stimulus, chicken OTOP1 carried much larger inward
currents in response to NH4Cl. Meanwhile, zebrafish OTOP1 was less sensitive
to NH4Cl but responded well to the acid stimulus. Human OTOP1 was
intermediate, responding well to both the acid stimulus and NH4Cl but with
somewhat different kinetics than mouse OTOP1. Thus, in all species tested,
and likely all vertebrate species, OTOP1 could serve as a sensor for NH4Cl.
Differences in the sensitivity of the species variants of OTOP1 to NH4Cl and
acids may reflect a diversity in behavioral ecology.
研究人员之前发现，负责感知酸味的TRCs会表达一种名为otopterin1（Otop1）的基因，
这个基因会编码一种蛋白质OTOP1，它可以形成质子通道，让细胞能够感知到低pH值和酸
味。
在这项新的研究中，研究人员想要了解酸味的TRCs和OTOP1对于感知氨氯（ammonium
chloride）的贡献是什么。他们将Otop1基因引入到实验室培养的人类细胞中，并将一些
细胞暴露于酸或氨氯中。他们发现，氨氯能够像酸一样有效地激活OTOP1受体。进一步的
实验在老鼠身上得到了证实，具有Otop1基因的老鼠会避开氨氯，而那些基因被敲除的老
鼠则不会。
氨和它的气体态—氨气，是氨基酸的分解产物，对人类和其他动物来说通常是有毒的。基
于这项发现，研究人员推测，感知氨氯的能力可能是为了帮助生物避免摄入有害物质而演
化出来的。
研究人员也观察到了不同物种之间的差异。人类和老鼠的OTOP1通道会被氨氯强烈激活，
鸡的OTOP1通道对氨氯更敏感，而斑马鱼则对氨氯的敏感度较低。他们认为，这些物种间
的差异反映了每个生物的生态位。例如，众所周知，鸟类对酸味的敏感度较低，但它们需
要避免摄入存在于它们排泄物中的氨氯。