Each sensory nerve arising from the geniculate ganglion expresses a unique fingerprint of neurotrophin and neurotrophin receptor genes
Each sensory nerve arising from the geniculate ganglion expresses a unique fingerprint of neurotrophin and neurotrophin receptor genes
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DOI：
10.1002/jnr.20297
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发表时间：
2004-12-01
影响因子：
4.2
通讯作者：
Hill, DL
中科院分区：
文献类型：
--
作者：
Farbman, AI;Guagliardo, N;Hill, DL
膝状体神经节中的神经元，像其他感觉神经节中的神经元一样，依赖于神经营养因子生存。大多数膝状体神经节神经元支配舌的两个区域和腭的两个区域中的味蕾;其余的是耳皮肤的皮肤神经。我们研究了四种神经营养因子，神经生长因子（NGF），脑源性神经营养因子（BDNF），神经营养因子3（NT-3），和NT-4，和五种神经营养因子受体，trkA，trkB，trkC，p75，和trkB截短（Trn-B）在单个感觉神经元的成年大鼠膝状体神经节与五个神经支配领域。对于菌状乳头，将含有生物素化葡聚糖的玻璃移液管置于靶乳头上，并将示踪剂离子电渗至靶乳头中。对于其他靶野，显微注射Fluoro-Gold。3天后，收获膝状体神经节，切片，并进行组织化学（生物素化葡聚糖）或荧光化学（FluoroGold）处理，以显示含有示踪剂的神经元。从载玻片收获单个标记的神经元，并进行RNA扩增和RT-PCR以揭示表达的神经营养因子或神经营养因子受体基因。从膝状体神经节投射到五个靶区域的神经元具有神经营养因子和神经营养受体基因的独特表达谱。几个单独的神经元表达一个以上的神经营养因子受体或一个以上的神经营养因子基因。虽然BDNF在味蕾中显著表达，但其主要的高亲和力受体trkB在神经元中不显著表达。结果是一致的解释，至少有一些，也许是大部分，对感觉神经元的营养影响是来自神经元胞体，和营养效应是旁分泌或自分泌，而不是目标衍生。如其他人所示，味蕾中的BDNF也可以以旁分泌或自分泌的方式作用于味蕾中表达的trkB。(C)2004 Wiley-Liss，Inc.
Neurons in the geniculate ganglion, like those in other sensory ganglia, are dependent on neurotrophins for survival. Most geniculate ganglion neurons innervate taste buds in two regions of the tongue and two regions of the palate; the rest are cutaneous nerves to the skin of the ear. We investigated the expression of four neurotrophins, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), and NT-4, and five neurotrophin receptors, trkA, trkB, trkC, p75, and truncated trkB (Trn-B) in single sensory neurons of the adult rat geniculate ganglion associated with the five innervation fields. For fungiform papillae, a glass pipette containing biotinylated dextran was placed over the target papilla and the tracer was iontophoresed into the target papilla. For the other target fields, Fluoro-Gold was microinjected. After 3 days, geniculate ganglia were harvested, sectioned, and treated histochemically (for biotinylated dextran) or immunohistochemically (for FluoroGold) to reveal the neurons containing the tracer. Single labeled neurons were harvested from the slides and subjected to RNA amplification and RT-PCR to reveal the neurotrophin or neurotrophin receptor genes that were expressed. Neurons projecting from the geniculate ganglion to each of the five target fields had a unique expression profile of neurotrophin and neurotrophic receptor genes. Several individual neurons expressed more than one neurotrophin receptor or more than one neurotrophin gene. Although BDNF is significantly expressed in taste buds, its primary high affinity receptor, trkB, was not prominently expressed in the neurons. The results are consistent with the interpretation that at least some, perhaps most, of the trophic influence on the sensory neurons is derived from the neuronal somata, and the trophic effect is paracrine or autocrine, rather than target derived. The BDNF in the taste bud may also act in a paracrine or autocrine manner on the trkB expressed in taste buds, as shown by others. (C) 2004 Wiley-Liss, Inc.