Department of Anatomy, School of Life Dentistry at Tokyo, Nippon Dental University, Tokyo, Japan.
Division of Pediatric Dentistry, Nippon Dental University Graduate School of Life Dentistry, Tokyo, Japan; Department of Pediatric Dentistry, School of Life Dentistry at Tokyo, Nippon Dental University, Tokyo, Japan.
Ann Anat. 2020 Jan;227:151401. doi: 10.1016/j.aanat.2019.07.002. Epub 2019 Jul 19.
The neuropeptide calcitonin gene-related peptide (CGRP) is a well-characterized neurotransmitter. Glutamate receptor, ionotropic, kainate 1 (Grik1) has also been demonstrated to generate high-affinity kainate receptors. However, little is known about the roles of CGRP and Grik1 during the developmental formation of teeth. In this study, we endeavoured to analyse the expression and localization of CGRP and Grik1 mRNAs using in situ hybridization on the mouse maxilla during development from the embryonic stage (E18.5) to after birth (P10, P15 and P20). We found that hybridization with an anti-sense probe for CGRP clearly localized in the maxilla at E18.5 in contrast to that of P15 and P20. Hybridization with an anti-sense probe for CGRP was not detected in the dental pulp of molars in the maxilla at P10, which is in contrast to Grik1 mRNA at the same developmental stage. Hybridization with an anti-sense probe for Grik1 mRNA was detected in the basal region of the dental pulp of molars at P10 and P15. Finally, these markers were not detected in molars in the mouse maxilla at P20. The ratio of positive cells for the hybridization signals of Grik1and CGRP in the dental pulp decreased from E18.5 (p<0.001). These features in CGRP and Grik1r mRNAs may indicate roles of function during tooth development between embryonic and postnatal stages with root formation and erupted movements.
降钙素基因相关肽（CGRP）是一种特征明确的神经递质。谷氨酸受体，离子型， kainate 1（Grik1）也已被证明能产生高亲和力的 kainate 受体。然而，关于 CGRP 和 Grik1 在牙齿发育形成过程中的作用知之甚少。在这项研究中，我们试图通过胚胎阶段（E18.5）到出生后（P10、P15 和 P20）的小鼠上颌骨原位杂交，分析 CGRP 和 Grik1mRNA 的表达和定位。我们发现，与 P15 和 P20 相比，在 E18.5 时，抗 CGRP 反义探针的杂交明显定位于上颌骨。在 P10 时，上颌骨磨牙牙髓中未检测到抗 CGRP 反义探针的杂交，而在同一发育阶段的 Grik1mRNA 则有杂交。抗 Grik1mRNA 反义探针的杂交在 P10 和 P15 时在磨牙牙髓的基底区被检测到。最后，在 P20 时，这些标记物在小鼠上颌骨的磨牙中没有被检测到。牙髓中 Grik1 和 CGRP 杂交信号阳性细胞的比例从 E18.5 开始下降（p<0.001）。这些 CGRP 和 Grik1r mRNA 的特征可能表明在胚胎和出生后阶段，与根形成和萌出运动有关的牙齿发育过程中具有功能作用。
