BDNF in adult mouse taste cells

这项研究的目的是利用BDNF-LacZ转基因“敲入”小鼠来确定BDNF在成年小鼠味觉细胞中的作用。第一个目标将确定在成年小鼠中哪些味觉细胞类型表达BDNF。具体地说，BDNF是否存在于新分裂的味觉细胞、未成熟的味觉细胞或表型成熟的味觉细胞。如果BDNF存在于成熟的味觉细胞中，我感兴趣的是确定BDNF存在于哪种免疫组织化学和形态分类的味觉细胞中。我将使用双标记免疫组织化学来实现这一目的。对于出生的细胞，我将给小鼠注射5‘-溴-2’脱氧尿苷，这种脱氧尿苷结合到分裂细胞的DNA中。我也有兴趣确定(S)味蕾神经支配的丧失会对脑源性神经营养因子的表达产生什么影响，以及(S)味蕾随后的再生和神经支配会对脑源性神经营养因子的表达产生什么影响。为了达到这一目的，我将通过手术切断BDNF-LacZ小鼠的味觉神经，并在神经挤压后让小鼠连续存活更长时间，以观察(S)神经退变和再生对味蕾中BDNF表达的影响。为了我的最终目标，凌晨1点我有兴趣研究(S)成年人味蕾中脑源性神经营养因子表达的缺失对味蕾、味觉神经纤维和味觉神经节细胞的影响。由于我对BDNF表达缺失对成人味觉系统的影响很感兴趣，而且我不想破坏味蕾的初始发育，我将使用组织特异性的条件性基因敲除小鼠，并仅在成年小鼠的舌头中敲除BDNF表达。我还可以使组织特异性条件性BDNF基因敲除小鼠的味蕾失去神经，看看神经纤维是否会再生并重新支配不再表达BDNF的味蕾。这一目标将确定脑源性神经营养因子在成年小鼠味觉细胞中的作用(S)，而不影响味蕾的初始发育。

The goals of this study are to use BDNF-LacZ transgenic "knock-in" mice to determine the role of BDNF in adult mouse taste cells. The first aim will determine which taste cell types express BDNF in the adult mouse. Specifically, whether BDNF is present in newly divided taste cells, immature taste cells, or phenotypically mature taste cells. If BDNF is present in mature taste cells, I am interested in determining which immunohistochemical and morphological classes of taste cells BDNF is present in. I will use double-label immunohistochemistry to achieve this aim. To birthdate cells I will inject mice with 5'-Bromo-2' deoxyuridine which incorporates into the DNA of dividing cells. I am also interested in determining what effect(s) loss of taste bud innervation will have on the expression of BDNF and what effect(s) subsequent regeneration and innervation of taste buds will have on the expression of BDNF. To achieve this aim I will surgically crush the gustatory nerves in BDNF-LacZ mice and let the mice live for successively longer days post nerve crush to look at the effect(s) nerve degeneration and regeneration has on BDNF expression in taste buds. For my final aim, 1 am interested in determining what effect(s) adult loss of BDNF expression in taste buds has on taste buds, gustatory nerve fibers and gustatory ganglion cells. Since I am interested in looking at the effect loss of BDNF expression has on the adult taste system and I do not want to disrupt the initial development of taste buds, I will use a tissue-specific conditional knockout mouse and knockout BDNF expression only in the tongues of adult mice. I can also denervate the taste buds in the tissue-specific conditional BDNF knockout mice to see whether nerve fibers will regenerate and reinnervate taste buds that no longer express BDNF. This aim will determine the role(s) of BDNF in adult mouse taste cells, without affecting the initial development of taste buds.