Human tooth is made of three different hard tissues: enamel—recovering the crown and corresponding to the most mineralized tissue found in the body; cementum— deposited on the root surface; and dentine—underlying the enamel and cementum and forming the bulk of the tooth. Dentine covers the pulp, which lies in the center of the tooth. Pulp, the vital mesenchymal tissue, contains: (1) a specialized layer of cells at its periphery (the odontoblast layer) that is responsible for the dentine matrix synthesis and (2) blood vessels and nerves. During development, tooth pulp acquires a profuse nociceptive and sympathetic innervation from the trigeminal ganglion (TG) and the superior cervical ganglion, respectively.
The purpose of this chapter is to briefly review the core components and signaling mechanism of the Reelin pathway, and then to present evidence on possible downstream components. Issues related to the first two questions, the timing and site of Reelin action and the possible changes in cell biology, are left for other chapters.
KeywordsNerve Growth Factor Trigeminal Ganglion Dental Pulp Tooth Development Dentinal Tubule
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- Borrell, V., Del Rio, J. A., Alcantara, S., Derer, M., Martinez, A., D’Arcangelo, G., Nakajima, K., Mikoshiba, K., Derer, P., Curran, T., and Soriano, E. (1999). Reelin regulates the development and synaptogenesis of the layer-specific entorhino-hippocampal connections. J. Neurosci. 19:1345-1358.PubMedGoogle Scholar
- Brannstrom, M. (1962). A hydrodynamic mechanism in the transmission of pain producing stimuli through the dentine. In: Anderson, D. J. (ed.), Sensory Mechanisms in Dentine. Pergamon Press, Oxford, pp. 73-79.Google Scholar
- Fried, K., Sime, W., Lillesaar, C., Virtanen, I., Tryggvasson, K., and Patarroyo, M. (2005). Laminins 2 (alpha2beta1gamma1, Lm-211) and 8 (alpha4beta1gamma1, Lm-411) are synthesized and secreted by tooth pulp fibroblasts and differentially promote neurite outgrowth from trigeminal ganglion sensory neurons. Exp. Cell Res. 307:329-341.CrossRefPubMedGoogle Scholar
- Ibuki, T., Kido, M. A., Kiyoshima, T., Terada, Y., and Tanaka, T. (1996). An ultrastructural study of the relationship between sensory trigeminal nerves and odontoblasts in rat dentin/pulp as demonstrated by the anterograde transport of wheat germ agglutinin-horseradish peroxidase (WGA-HRP). J. Dent. Res. 75:1963-1970.CrossRefPubMedGoogle Scholar
- Kettunen, P., Loes, S., Furmanek, T., Fjeld, K., Kvinnsland, I. H., Behar, O., Yagi, T., Fujisawa, H., Vainio, S., Taniguchi, M., and Luukko, K. (2005). Coordination of trigeminal axon navigation and patterning with tooth organ formation: epithelial-mesenchymal interactions, and epithelial Wnt4 and Tgfbeta1 regulate semaphorin 3a expression in the dental mesenchyme. Development 132:323-334.CrossRefPubMedGoogle Scholar