Department of Biological Sciences, Western Michigan University, 1903 W. Michigan Ave, Kalamazoo, MI, 49008-5410, USA.
J Bioenerg Biomembr. 2019 Feb;51(1):29-40. doi: 10.1007/s10863-018-9772-x. Epub 2018 Sep 13.
The removal of afferent input to the olfactory bulb by both cautery and chemical olfactory organ ablation in adult zebrafish results in a significant decrease in volume of the ipsilateral olfactory bulb. To examine the effects of deafferentation at a cellular level, primary output neurons of the olfactory bulb, the mitral cells, were investigated using retrograde tract tracing with fluorescent dextran using ex vivo brain cultures. Morphological characteristics including the number of major dendritic branches, total length of dendritic branches, area of the dendritic arbor, overall dendritic complexity, and optical density of the arbor were used to determine the effects of deafferentation on mitral cell dendrites. Following 8 weeks of permanent deafferentation there were significant reductions in the total length of dendritic branches, the area of the dendritic arbor, and the density of fine processes in the dendritic tuft. With 8 weeks of chronic, partial deafferentation there were significant reductions in all parameters examined, including a modified Sholl analysis that showed significant decreases in overall dendritic complexity. These results show the plasticity of mitral cell dendritic structures in the adult brain and provide information about the response of these output neurons following the loss of sensory input in this key model system.
成年斑马鱼中，通过烧灼和化学嗅球消融去除传入输入，会导致同侧嗅球体积明显减小。为了在细胞水平上检查去传入的影响，使用体外脑培养物中的荧光葡聚糖逆行追踪技术研究了嗅球的主要输出神经元——僧帽细胞。使用主要树突分支的数量、树突分支的总长度、树突分支的面积、整体树突复杂性和树突分支的光密度等形态特征来确定去传入对僧帽细胞树突的影响。在永久性去传入 8 周后，树突分支的总长度、树突分支的面积和树突末梢的精细过程密度均显著降低。慢性部分去传入 8 周后，所有检查的参数均显著降低，包括修改后的 Sholl 分析显示整体树突复杂性显著降低。这些结果表明成年大脑中僧帽细胞树突结构具有可塑性，并提供了有关在这个关键模型系统中失去感觉输入后这些输出神经元反应的信息。
