Institute of Neurophysiopathology, Aix Marseille University, CNRS, INP, 13005 Marseille, France.
Int J Mol Sci. 2021 Jun 25;22(13):6858. doi: 10.3390/ijms22136858.
Animals strongly rely on chemical senses to uncover the outside world and adjust their behaviour. Chemical signals are perceived by facial sensitive chemosensors that can be clustered into three families, namely the gustatory (TASR), olfactory (OR, TAAR) and pheromonal (VNR, FPR) receptors. Over recent decades, chemoreceptors were identified in non-facial parts of the body, including the brain. In order to map chemoreceptors within the encephalon, we performed a study based on four brain atlases. The transcript expression of selected members of the three chemoreceptor families and their canonical partners was analysed in major areas of healthy and demented human brains. Genes encoding all studied chemoreceptors are transcribed in the central nervous system, particularly in the limbic system. RNA of their canonical transduction partners (G proteins, ion channels) are also observed in all studied brain areas, reinforcing the suggestion that cerebral chemoreceptors are functional. In addition, we noticed that: (i) bitterness-associated receptors display an enriched expression, (ii) the brain is equipped to sense trace amines and pheromonal cues and (iii) chemoreceptor RNA expression varies with age, but not dementia or brain trauma. Extensive studies are now required to further understand how the brain makes sense of endogenous chemicals.
动物强烈依赖化学感官来探索外部世界并调整其行为。化学信号由面部敏感化学感受器感知，这些感受器可以分为三类，即味觉（TASR）、嗅觉（OR、TAAR）和信息素（VNR、FPR）受体。在过去的几十年中，已经在身体的非面部部位（包括大脑）中鉴定出了化学感受器。为了在大脑中绘制化学感受器图谱，我们进行了一项基于四个脑图谱的研究。分析了三种化学感受器家族的选定成员及其典型伴侣在健康和痴呆人类大脑主要区域的转录表达。编码所有研究化学感受器的基因都在中枢神经系统中转录，特别是在边缘系统中。它们的典型转导伴侣（G 蛋白、离子通道）的 RNA 也存在于所有研究的脑区，这进一步证实了大脑化学感受器具有功能性的假设。此外，我们还注意到：（i）与苦味相关的受体表达丰富，（ii）大脑能够感知痕量胺和信息素线索，（iii）化学感受器 RNA 的表达随年龄而变化，但与痴呆或脑外伤无关。现在需要进行广泛的研究，以进一步了解大脑如何感知内源性化学物质。
