Rashwan Ahmed, Konishi Hiroyuki, El-Sharaby Ashraf, Kiyama Hiroshi
Department of Functional Anatomy & Neuroscience, Nagoya University, Graduate School of Medicine, Nagoya 466-8550, Japan; Department of Anatomy & Embryology, Damanhour University, Veterinary Medicine, Damanhour 22511, Egypt.
Department of Functional Anatomy & Neuroscience, Nagoya University, Graduate School of Medicine, Nagoya 466-8550, Japan.
J Chem Neuroanat. 2016 Jan;71:26-40. doi: 10.1016/j.jchemneu.2015.11.003. Epub 2015 Dec 12.
We investigated the relationship between mouse taste bud development and innervation of the soft palate. We employed scanning electron microscopy and immunohistochemistry using antibodies against protein gene product 9.5 and peripherin to detect sensory nerves, and cytokeratin 8 and α-gustducin to stain palatal taste buds. At E14, nerve fibers were observed along the medial border of the palatal shelves that tracked toward the epithelium. At E15.5, primordial stages of taste buds in the basal lamina of the soft palate first appeared. At E16, the taste buds became large spherical masses of columnar cells scattered in the soft palate basal lamina. At E17, the morphology and also the location of taste buds changed. At E18-19, some taste buds acquired a more elongated shape with a short neck, extending a variable distance from the soft palate basal lamina toward the surface epithelium. At E18, mature taste buds with taste pores and perigemmal nerve fibers were observed on the surface epithelium of the soft palate. The expression of α-gustducin was demonstrated at postnatal day 1 and the number of pored taste buds increased with age and they became pear-shaped at 8 weeks. The percent of pored fungiform-like papillae at birth was 58.3% of the whole palate; this increased to 83.8% at postnatal day 8 and reached a maximum of 95.7% at 12 weeks. The innervation of the soft palate was classified into three types of plexuses in relation to taste buds: basal nerve plexus, intragemmal and perigemmal nerve fibers. This study reveals that the nerve fibers preceded the development of taste buds in the palate of mice, and therefore the nerve fibers have roles in the initial induction of taste buds in the soft palate.
我们研究了小鼠味蕾发育与软腭神经支配之间的关系。我们采用扫描电子显微镜和免疫组织化学方法，使用针对蛋白质基因产物9.5和外周蛋白的抗体来检测感觉神经，并用细胞角蛋白8和α - 味导素对腭味蕾进行染色。在胚胎第14天，沿着腭突内侧边缘观察到神经纤维，这些纤维向上皮方向延伸。在胚胎第15.5天，软腭基底层中味蕾的原始阶段首次出现。在胚胎第16天，味蕾在软腭基底层中变成了由柱状细胞组成的大球形团块。在胚胎第17天，味蕾的形态和位置发生了变化。在胚胎第18 - 19天，一些味蕾呈现出更细长的形状，有短颈，从软腭基底层向表面上皮延伸不同的距离。在胚胎第18天，在软腭表面上皮观察到带有味孔和味蕾周围神经纤维的成熟味蕾。出生后第1天可检测到α - 味导素的表达，有味孔的味蕾数量随年龄增加，在8周时变成梨形。出生时，有孔的菌状乳头样乳头在整个腭部中所占百分比为58.３％；出生后第8天增加到83.8％，在12周时达到最大值95.7％。软腭的神经支配相对于味蕾可分为三种类型的神经丛：基底神经丛、味蕾内和味蕾周围神经纤维。本研究表明，在小鼠腭部，神经纤维先于味蕾发育，因此神经纤维在软腭味蕾的初始诱导中起作用。
