Puri Sonali, Lee Youngseok
Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul 02707, Korea.
Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 02707, Korea.
Metabolites. 2021 Mar 17;11(3):175. doi: 10.3390/metabo11030175.
Taste sensation and regulation are highly conserved in insects and mammals. Research conducted over recent decades has yielded major advances in our understanding of the molecular mechanisms underlying the taste sensors for a variety of taste sensations and the processes underlying regulation of ingestion depending on our internal state. Salt (NaCl) is an essential ingested nutrient. The regulation of internal sodium concentrations for physiological processes, including neuronal activity, fluid volume, acid-base balance, and muscle contraction, are extremely important issues in animal health. Both mammals and flies detect low and high NaCl concentrations as attractive and aversive tastants, respectively. These attractive or aversive behaviors can be modulated by the internal nutrient state. However, the differential encoding of the tastes underlying low and high salt concentrations in the brain remain unclear. In this review, we discuss the current view of taste sensation and modulation in the brain with an emphasis on recent advances in this field. This work presents new questions that include but are not limited to, "How do the fly's neuronal circuits process this complex salt code?" and "Why do high concentrations of salt induce a negative valence only when the need for salt is low?" A better understanding of regulation of salt homeostasis could improve our understanding of why our brains enjoy salty food so much.
味觉感知和调节在昆虫和哺乳动物中高度保守。近几十年来进行的研究在我们对各种味觉感知的味觉传感器的分子机制以及取决于我们内部状态的摄食调节过程的理解方面取得了重大进展。盐（氯化钠）是一种必需的摄入营养素。调节包括神经元活动、液体容量、酸碱平衡和肌肉收缩在内的生理过程中的内部钠浓度，是动物健康中的极其重要的问题。哺乳动物和果蝇分别将低浓度和高浓度的氯化钠检测为有吸引力和令人厌恶的味觉物质。这些有吸引力或令人厌恶的行为可以受到内部营养状态的调节。然而，大脑中低浓度和高浓度盐味觉的差异编码仍不清楚。在这篇综述中，我们讨论了目前关于大脑中味觉感知和调节的观点，重点是该领域的最新进展。这项工作提出了一些新问题，包括但不限于“果蝇的神经回路如何处理这种复杂的盐编码？”以及“为什么只有当对盐的需求较低时，高浓度的盐才会引发负价？”更好地理解盐稳态的调节可以增进我们对为什么我们的大脑如此喜欢咸味食物的理解。
