Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Biochem Biophys Res Commun. 2010 Oct 1;400(4):734-8. doi: 10.1016/j.bbrc.2010.08.139. Epub 2010 Sep 15.
To visualize the neural pathways originating from bitter taste receptor cells (TRCs), we generated transgenic mice expressing the transneuronal tracer wheat germ agglutinin (WGA) under the control of the mouse T2R5 gene promoter/enhancer (t2r5-WGA mice). WGA mRNA was specifically expressed in bitter TRCs. The WGA protein was detected in bitter TRCs and nerve processes in taste buds, but not in sweet, umami, or sour TRCs. The WGA protein was transferred to a subset of sensory neurons in the geniculate and nodose/petrosal ganglia. These results suggest that bitter TRCs, which are devoid of synaptic structures, are innervated by gustatory neurons and that bitter sensory information is directly transmitted to specific gustatory neurons. The t2r5-WGA mice provide a useful tool for identifying gustatory relay neurons in the peripheral sensory ganglia responsible for aversive sensations.
为了可视化源自苦味受体细胞 (TRC) 的神经通路，我们生成了表达在小鼠 T2R5 基因启动子/增强子控制下的转神经元示踪剂麦胚凝集素 (WGA) 的转基因小鼠 (t2r5-WGA 小鼠)。WGA mRNA 特异性地在苦味 TRC 中表达。WGA 蛋白在苦味 TRC 和味蕾中的神经突起中被检测到，但在甜味、鲜味或酸味 TRC 中未被检测到。WGA 蛋白被转移到神经节和神经节中的感觉神经元亚群中。这些结果表明，缺乏突触结构的苦味 TRC 由味觉神经元支配，苦味感觉信息直接传递给特定的味觉神经元。t2r5-WGA 小鼠为鉴定负责厌恶感觉的外周感觉神经节中的味觉中继神经元提供了有用的工具。
