据10月16日的《科学》杂志报道说，我们舌头上的能够体验酸味的细胞同时也能体验碳酸化饮料的味道。体验一种嘶嘶冒泡的软饮料牵涉到一种生理感觉以及对二氧化碳的味觉，而研究人员在迄今之前对此所知甚少。
Jayaram Chandrashekar及其同僚灭活了在小鼠味觉细胞中的一组特别的基因。他们发现，这些缺乏体验酸味细胞的小鼠也无法尝试二氧化碳。 对这些味觉细胞所表达的特别基因进行筛检之后，研究人员发现了一个编码碳酸酐酶4这种酶的基因，该酶所催化的反应可将二氧化碳与水转化为碳酸氢根与游离氢。 看来这些质子才是真正刺激酸感受细胞的物质。 不表达该基因的基因剔除小鼠其感受二氧化碳的能力也会下降。 文章的作者推测，二氧化碳感受细胞可能是作为识别发酵食物的一种方法而演化成的。（生物谷Bioon.com）
生物谷推荐原始出处：
Science 16 October 2009:DOI: 10.1126/science.1174601
The Taste of Carbonation
Jayaram Chandrashekar,1 David Yarmolinsky,1 Lars von Buchholtz,2 Yuki Oka,1 William Sly,3 Nicholas J. P. Ryba,2 Charles S. Zuker1,*,
Carbonated beverages are commonly available and immensely popular, but little is known about the cellular and molecular mechanisms underlying the perception of carbonation in the mouth. In mammals, carbonation elicits both somatosensory and chemosensory responses, including activation of taste neurons. We have identified the cellular and molecular substrates for the taste of carbonation. By targeted genetic ablation and the silencing of synapses in defined populations of taste receptor cells, we demonstrated that the sour-sensing cells act as the taste sensors for carbonation, and showed that carbonic anhydrase 4, a glycosylphosphatidylinositol-anchored enzyme, functions as the principal CO2 taste sensor. Together, these studies reveal the basis of the taste of carbonation as well as the contribution of taste cells in the orosensory response to CO2.
1 Howard Hughes Medical Institute and Departments of Neurobiology and Neurosciences, University of California, San Diego, La Jolla, CA 92093, USA.
2 National Institute of Dental and Craniofacial Research (NIDCR), Bethesda, MD 20892, USA.
3 Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO 63104, USA.
