title: Natural and lesion-induced decrease in cell proliferation in the medial nucleus of the trapezoid body during hearing development.
abstract: The functional interactions between neurons and glial cells that are important for nervous system function are presumably established during development from the activity of progenitor cells. In this study we examined proliferation of progenitor cells in the medial nucleus of the trapezoid body (MNTB) located in the rat auditory brainstem. We performed DNA synthesis labeling experiments to demonstrate changes in cell proliferation activity during postnatal stages of development. An increase in cell proliferation correlated with MNTB growth and the presence of S100β-positive astrocytes among MNTB neurons. In additional experiments we analyzed the fate of newly born cells. At perinatal ages, newly born cells colabeled with the astrocyte marker S100β in higher numbers than when cells were generated at postnatal day 6. Furthermore, we identified newly born cells that were colabeled with caspase-3 immunohistochemistry and performed comparative experiments to demonstrate that there is a natural decrease in cell proliferation activity during postnatal development in rats, mice, gerbils, and ferrets. Lastly, we found that there is a stronger decrease in MNTB cell proliferation after performing bilateral lesions of the auditory periphery in rats. Altogether, these results identify important stages in the development of astrocytes in the MNTB and provide evidence that the proliferative activity of the progenitor cells is developmentally regulated. We propose that the developmental reduction in cell proliferation may reflect coordinated signaling between the auditory brainstem and the auditory periphery.
authors.affiliation: Biology Department, City College of New York, New York, New York, 10031.
authors.forename: Aminat
authors.initials: A
authors.lastname: Saliu
authors.forename: Shana
authors.initials: S
authors.lastname: Adise
authors.forename: Sandy
authors.initials: S
authors.lastname: Xian
authors.forename: Kamila
authors.initials: K
authors.lastname: Kudelska
authors.forename: Adrián
authors.initials: A
authors.lastname: Rodríguez-Contreras
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001306:Auditory Pathways / Q000254:growth & development / Q000293:injuries; D001933:Brain Stem / Q000254:growth & development* / Q000293:injuries*; D053148:Caspase 3 / Q000378:metabolism; D002452:Cell Count; D049109:Cell Proliferation; D004622:Embryo, Mammalian; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005849:Gerbillinae; D006309:Hearing; D051379:Mice; D008808:Mice, Inbred CBA; D004676:Myelin Basic Protein / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010671:Phenylurea Compounds / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013234:Stem Cells / Q000502:physiology
chemical_list: D004676:Myelin Basic Protein; D009419:Nerve Tissue Proteins; D010671:Phenylurea Compounds; C032766:ethylene diurea; D053148:Caspase 3
keywords: S100β; apoptosis; auditory brainstem; glia; hearing onset