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内容記述 |
Oligodendrocytes are the myelinating cells of the rodent central nervous system. In the mouse spinal cord, oligodendrocytes are generated from strictly restricted regions of the ventral ventricular zone. To investigate how they originate from these specific regions, he established an explant culture system of embryonic days 12 (E 12) mouse cervical spinal cord and hindbrain, named flat whole-mount preparation. Alpha subunit of the receptor for platelet derived growth factor (PDGFR α) mRNA-expressing cells, which are the major progenitors of oligodendrocytes in the spinal cord, were first detected in the ventral half of the explant near the ventral midline of the cervical spinal cord, and subsequently distributed dorsally When he cultured the ventral and dorsal cord separately, a robust increase in the number of PDGFRα positive cells was observed in the ventral fragment of the cervical spinal cord. The number of proliferating cells, mainly Musashi positive neuroepithelial cells increased in the ventral fragment, suggesting that factors from the dorsal spinal cord inhibit a step switching the cells from proliferating stage to differentiating stage. The increase in numbers of immature and mature oligodendrocytes in the ventral fragment suggests that these factors also inhibit oligodendrocyte maturation. Bone morphogenetic protein 4 (BMP4), a strong candidate for this factor, which is secreted from the dorsal spinal cord, did not affect oligodendrocyte development. Previous studies demonstrated that signals from notochord and the ventral spinal cord, such as sonic hedgehog and neuregulin, promote the ventral region specific development of oligodendrocytes. His present study showed that the dorsal spinal cord negatively regulate oligodendrocyte development. These results, in conjunction with the previous studies, indicate that glial cell development is regulated along the dorso-ventral axis similarly to the dorso-ventral organization of spinal cord neurons. |
要旨・審査要旨 / Abstract, Screening Result (259.9 kB)
