@article{oai:niigata-u.repo.nii.ac.jp:00006503,
 author = {Kishino, Masaru and Hamada, Takeshi and Inoue, Takao},
 issue = {2},
 journal = {Acta medica et biologica, Acta medica et biologica},
 month = {Jun},
 note = {The distal surface of rat incisor ameloblasts at the early stage of enamel maturation was investigated by high resolution scanning electron microscopy (SEM). Specimens were fixed by perfusion with 0.5% formaldehyde and 0.5% glutaraldehyde followed by decalcification, then freeze-cracked and treated with dilute osmium tetroxide to digest the dense lamina lining the distal surface of the ameloblasts. In this preparation, the unobscured distal surface was clearly demonstrated three-dimensionally under SEM. The following three types of ameloblasts were identified based on their ultrastructural features: ruffle-ended ameloblasts (RA); smooth-ended ameloblasts (SA); and transitional ameloblasts (Ruffle- to smooth-ended ameloblasts, R-SA). The surface of the RA was characterized by a complex labyrinth formed by protrusions and invaginations of the plasma membrane. In the RA and R-SA, microfibrils connecting the protrusions of the plasma membrane were observed on the distal surface. In these ameloblasts, small granules, presumably connecting the dense lamina to the distal surface of the ameloblasts, were also visible. The distal surface of SA was smooth, and no granular substances were visible on it. Mitochondria accumulated under the distal cell surface or the ruffle border. The surface structures of the R-SA displayed a pattern intermediate between those of the RA and SA. SA were distributed as several band-like structures at the stage of enamel maturation. These structural differences of the ameloblasts appeared closely related to enamel maturation.},
 pages = {63--70},
 title = {Scanning Electron Microscopic Study of Rat Ameloblasts during Enamel Maturation},
 volume = {42},
 year = {1994}
}