Chytrova Gabriela, Johnson James E
Neuroscience Program, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
Mol Cell Neurosci. 2004 Apr;25(4):549-57. doi: 10.1016/j.mcn.2003.11.009.
Both neuronal activity and neurotrophin signaling play critical roles in normal CNS development. This study examined whether spontaneous retinal activity (SRA) also governs the axonal transport of endogenous brain-derived neurotrophic factor (BDNF) protein within the developing chick visual system. In previous work, we have found that during the normal period of SRA, retinal BDNF protein levels decrease by about 50% while BDNF mRNA levels remain elevated. Here, we show that the blockade of SRA with tetrodotoxin (TTX), or the blockade of axonal transport with colchicine, both reversed the normal mismatch between retinal BDNF mRNA and protein. The axonal transport of retinal-derived BDNF in segments of the optic nerve as well as tectal-derived BDNF protein transported in segments of the optic tract were both significantly reduced after very brief periods of activity blockade. These results suggest that normal SRA plays a role in regulating the axonal transport of endogenous BDNF protein.
神经元活动和神经营养因子信号传导在中枢神经系统的正常发育中都起着关键作用。本研究探讨了自发视网膜活动（SRA）是否也在发育中的雏鸡视觉系统内调控内源性脑源性神经营养因子（BDNF）蛋白的轴突运输。在之前的工作中，我们发现，在SRA的正常时期，视网膜BDNF蛋白水平下降约50%，而BDNF mRNA水平仍保持升高。在此，我们表明，用河豚毒素（TTX）阻断SRA，或用秋水仙碱阻断轴突运输，均可逆转视网膜BDNF mRNA与蛋白之间的正常不匹配。在短暂的活动阻断后，视神经节段中视网膜源性BDNF的轴突运输以及视束节段中顶盖源性BDNF蛋白的运输均显著减少。这些结果表明，正常的SRA在调节内源性BDNF蛋白的轴突运输中发挥作用。
