González-Martínez Tatiana, Fariñas Isabel, Del Valle Miguel E, Feito Jorge, Germanà Giovanni, Cobo Juan, Vega José A
Departmento de Morfología y Biología Celular, Universidad de Oviedo, Spain.
Neurosci Lett. 2005 Mar 22;377(1):12-5. doi: 10.1016/j.neulet.2004.11.078. Epub 2004 Dec 19.
Meissner corpuscles are rapidly adapting cutaneous mechanoreceptors depending for development on TrkB expressing sensory neurons, but it remains to be established which of the known TrkB ligands, BDNF or NT-4, is responsible of this dependence. In this study we analyze Meissner corpuscles in the digital pads of mice with target mutations in the genes encoding for either BDNF or NT-4, using immunohistochemistry and transmission-electron microscopy, and they were identified based on their morphology and expression of S100 protein. All wild-type animals as well as NT-4(-/-) animals and BDNF and NT4 heterozygous animals have Meissner corpuscles that are normal in number and size. However, Meissner corpuscles are absent the BDNF(-/-) mice. These results suggest that BDNF is the only TrkB ligand involved in the development of Meissner corpuscles in murine glabrous skin, and it probably regulates the development of the sensory neurons that innervate Meissner corpuscles.
迈斯纳小体是快速适应的皮肤机械感受器，其发育依赖于表达TrkB的感觉神经元，但尚不清楚已知的TrkB配体BDNF或NT-4中的哪一种导致了这种依赖性。在本研究中，我们使用免疫组织化学和透射电子显微镜分析了编码BDNF或NT-4的基因发生靶向突变的小鼠趾垫中的迈斯纳小体，并根据其形态和S100蛋白的表达对它们进行了鉴定。所有野生型动物以及NT-4（-/-）动物和BDNF与NT4杂合动物都有数量和大小正常的迈斯纳小体。然而，BDNF（-/-）小鼠没有迈斯纳小体。这些结果表明，BDNF是参与小鼠无毛皮肤迈斯纳小体发育的唯一TrkB配体，它可能调节支配迈斯纳小体的感觉神经元的发育。
