Transsynaptic transport of wheat germ agglutinin expressed in a subset of type II taste cells of transgenic mice
Transsynaptic transport of wheat germ agglutinin expressed in a subset of type II taste cells of transgenic mice
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DOI：
10.1186/1471-2202-9-96
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发表时间：
2008-10-02
期刊：
影响因子：
2.4
通讯作者：
Margolskee, Robert F.
中科院分区：
文献类型：
--
作者：
Damak, Sami;Mosinger, Bedrich;Margolskee, Robert F.
背景资料：对源自味觉受体细胞特定子集的神经回路的解剖追踪可能会揭示味蕾内味觉细胞之间的相互作用以及味觉细胞与神经之间的相互作用。例如，目前还不清楚II型细胞的激活是否会导致味觉神经的直接激活，或者信息是否通过III型细胞传递。为了确定T1 r3表达的味细胞中产生的WGA如何被转运到味觉神经元中，产生了由T1 r3启动子驱动的WGA-IRES-GFP转基因小鼠。结果：免疫组织化学显示，在转基因小鼠的味蕾细胞中，WGA、GFP和内源性T1 r3共表达：唯一对WGA免疫反应的味细胞是T1 r3表达的细胞。WGA抗体还染色胚内神经。在转基因小鼠的膝状体和岩神经节中发现了WGA，但未发现GFP免疫反应性，表明WGA通过突触转运。三叉神经节中也发现了WGA免疫反应性，表明T1 r3表达细胞与三叉神经元形成突触。在延髓，WGA检测到孤束核，但也在疑核，前庭核，三叉神经核和延髓网状细胞核。WGA没有检测到在臂旁核，或味觉cortex.Conclusion：这些结果表明的有用性的遗传编码的WGA作为示踪剂的第一和第二阶神经元，支配的一个子集的味觉细胞，但不为高阶神经元，并证明，从II型味觉细胞的输出的主要途径是味觉神经元，而不是III型细胞。
Background: Anatomical tracing of neural circuits originating from specific subsets of taste receptor cells may shed light on interactions between taste cells within the taste bud and taste cell-to nerve interactions. It is unclear for example, if activation of type II cells leads to direct activation of the gustatory nerves, or whether the information is relayed through type III cells. To determine how WGA produced in T1r3-expressing taste cells is transported into gustatory neurons, transgenic mice expressing WGA-IRES-GFP driven by the T1r3 promoter were generated.Results: Immunohistochemistry showed co-expression of WGA, GFP and endogenous T1r3 in the taste bud cells of transgenic mice: the only taste cells immunoreactive for WGA were the T1r3-expressing cells. The WGA antibody also stained intragemmal nerves. WGA, but not GFP immunoreactivity was found in the geniculate and petrosal ganglia of transgenic mice, indicating that WGA was transported across synapses. WGA immunoreactivity was also found in the trigeminal ganglion, suggesting that T1r3-expressing cells make synapses with trigeminal neurons. In the medulla, WGA was detected in the nucleus of the solitary tract but also in the nucleus ambiguus, the vestibular nucleus, the trigeminal nucleus and in the gigantocellular reticular nucleus. WGA was not detected in the parabrachial nucleus, or the gustatory cortex.Conclusion: These results show the usefulness of genetically encoded WGA as a tracer for the first and second order neurons that innervate a subset of taste cells, but not for higher order neurons, and demonstrate that the main route of output from type II taste cells is the gustatory neuron, not the type III cells.