Chen John, Condron Barry G
Department of Biology, University of Virginia, Gilmer Hall 071 Box 400328, Charlottesville, VA 22903, USA.
Dev Biol. 2008 Aug 1;320(1):30-8. doi: 10.1016/j.ydbio.2008.03.038. Epub 2008 Apr 9.
In the metazoan central nervous system (CNS), serotonergic neurons send projections throughout the synaptic neuropil. Little is known about the rules that govern these widespread neuromodulatory branching patterns. In this study, we utilize the Drosophila as a model to examine serotonergic branching. Using single cell GFP labeling we show that within each segment of the Drosophila ventral nerve cord (VNC), each of two serotonergic neurons tiles distinct innervation patterns in the contralateral neuropil. In addition, branches extend only a short distance from the target segment. Through ablation-mediated isolation of serotonergic cells, we demonstrate that the distinct areas of innervation are not maintained through competition between neighboring like-serotonergic neurites. Furthermore, the basic branching pattern of serotonergic neurons within the neuropil remains unchanged despite alterations of initial axonal trajectories.
在后生动物的中枢神经系统（CNS）中，5-羟色胺能神经元向整个突触神经纤维网发出投射。关于支配这些广泛的神经调节分支模式的规则，我们知之甚少。在本研究中，我们利用果蝇作为模型来研究5-羟色胺能神经元的分支。通过单细胞绿色荧光蛋白标记，我们发现，在果蝇腹神经索（VNC）的每个节段内，两个5-羟色胺能神经元中的每一个在对侧神经纤维网中形成不同的支配模式。此外，分支仅从目标节段延伸一小段距离。通过消融介导的5-羟色胺能细胞分离，我们证明，不同的支配区域并非通过相邻的同类5-羟色胺能神经突之间的竞争来维持。此外，尽管初始轴突轨迹发生改变，但神经纤维网内5-羟色胺能神经元的基本分支模式保持不变。
