Jones J E, Corwin J T
Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Virginia, Charlottesville 22908, USA.
J Neurosci. 1996 Jan 15;16(2):649-62. doi: 10.1523/JNEUROSCI.16-02-00649.1996.
The regeneration of sensory hair cells in lateral line neuromasts of axolotls was investigated via nearly continuous time-lapse microscopic observation after all preexisting hair cells were killed by a laser microbeam. The laser treatments left neuromasts with one resident cell type, which was supporting cells. Over the course of 1 week, replacement hair cells arose either directly via differentiation of cells present in the epithelium from the beginning of the time-lapse period or via the development of cells produced after one or two divisions of supporting cells. All of the cell divisions that produced hair cells were asymmetrical. During the first hour after the treatment, macrophages and smaller leukocytes were attracted to the laser-treated neuromasts. The smaller leukocytes returned to control levels 48-60 hr after the treatment, whereas macrophages remained active there throughout the period of hair cell replacement. Macrophage incidence peaked 36-48 hr after the laser treatment. Macrophages phagocytosed damaged hair cells and supporting cells, as well as new cells and preexisting cells without recognizable damage. The results provide direct evidence of hair cells arising as progeny produced from the divisions of supporting cells, evidence of hair cells and supporting cells arising from the same cell division, evidence relating to the timing of hair cell differentiation, and indirect evidence pertaining to proposals that hair cells sometimes arise via conversion of cells without an intervening division. The results also suggest that macrophages may influence early stages in the process of hair cell regeneration.
在所有现存毛细胞被激光微束杀死后，通过近乎连续的延时显微镜观察，研究了蝾螈侧线神经丘中感觉毛细胞的再生情况。激光处理使神经丘仅保留一种驻留细胞类型，即支持细胞。在1周的时间里，替代毛细胞的产生要么直接通过延时观察期开始时上皮中已存在的细胞分化而来，要么通过支持细胞一到两次分裂后产生的细胞发育而来。所有产生毛细胞的细胞分裂都是不对称的。在处理后的第一个小时内，巨噬细胞和较小的白细胞被吸引到经激光处理的神经丘。较小的白细胞在处理后48 - 60小时恢复到对照水平，而巨噬细胞在毛细胞替代期间一直保持活跃。巨噬细胞发生率在激光处理后36 - 48小时达到峰值。巨噬细胞吞噬受损的毛细胞和支持细胞，以及新细胞和未观察到明显损伤的已存在细胞。这些结果提供了毛细胞作为支持细胞分裂产生的后代出现的直接证据、毛细胞和支持细胞来自同一细胞分裂的证据、与毛细胞分化时间相关的证据，以及关于毛细胞有时通过无中间分裂的细胞转化产生这一观点的间接证据。结果还表明巨噬细胞可能影响毛细胞再生过程的早期阶段。
