Tucker Eric S, Oland Lynne A, Tolbert Leslie P
Department of Cell Biology and Anatomy, University of Arizona, Tucson, Arizona 85724-5044, USA.
J Comp Neurol. 2004 May 10;472(4):478-95. doi: 10.1002/cne.20058.
During development, the axons of olfactory receptor neurons project to the CNS and converge on glomerular targets. For vertebrate and invertebrate olfactory systems, neuron-glia interactions have been hypothesized to regulate the sorting and targeting of olfactory receptor axons and the development of glomeruli. In the moth Manduca sexta, glial reduction experiments have directly implicated two types of central olfactory glia, the sorting zone- and neuropil-associated glia, in key events in olfactory development, including axon sorting and glomerulus stabilization. By using cocultures containing central olfactory glial cells and explants of olfactory receptor epithelium, we show that olfactory receptor growth cones elaborate extensively and cease advancement following contact with sorting zone- and neuropil-associated glial cells. These effects on growth cone behavior were specific to central olfactory glia; peripheral glial cells of the olfactory nerve failed to elicit similar responses in olfactory receptor growth cones. We propose that sorting zone- and neuropil-associated glial cells similarly modify axon behavior in vitro by altering the adhesive properties and cytoskeleton of olfactory receptor growth cones and that these in vitro changes may underlie functionally relevant changes in growth cone behavior in vivo.
在发育过程中，嗅觉受体神经元的轴突投射至中枢神经系统并汇聚于肾小球靶点。对于脊椎动物和无脊椎动物的嗅觉系统，人们推测神经元与神经胶质细胞的相互作用可调节嗅觉受体轴突的分选和靶向以及肾小球的发育。在烟草天蛾中，神经胶质细胞减少实验直接表明，两种类型的中枢嗅觉神经胶质细胞，即分选区相关神经胶质细胞和神经纤维网相关神经胶质细胞，参与了嗅觉发育的关键事件，包括轴突分选和肾小球稳定。通过使用含有中枢嗅觉神经胶质细胞和嗅觉受体上皮外植体的共培养物，我们发现嗅觉受体生长锥在与分选区相关神经胶质细胞和神经纤维网相关神经胶质细胞接触后会大量延伸并停止前进。这些对生长锥行为的影响是中枢嗅觉神经胶质细胞特有的；嗅神经的外周神经胶质细胞未能在嗅觉受体生长锥中引发类似反应。我们提出，分选区相关神经胶质细胞和神经纤维网相关神经胶质细胞通过改变嗅觉受体生长锥的黏附特性和细胞骨架，在体外类似地改变轴突行为，并且这些体外变化可能是体内生长锥行为功能相关变化的基础。
