Herzog K H, Bailey K, Barde Y A
Max-Planck Institute for Psychiatry, Department of Neurobiochemistry, Planegg-Martinsried, Germany.
Development. 1994 Jun;120(6):1643-9. doi: 10.1242/dev.120.6.1643.
Using a sensitive and quantitative method, the mRNA levels of brain-derived neurotrophic factor (BDNF) were determined during the development of the chick visual system. Low copy numbers were detected, and BDNF was found to be expressed in the optic tectum already 2 days before the arrival of the first retinal ganglion cell axons, suggesting an early role of BDNF in tectal development. After the beginning of tectal innervation, BDNF mRNA levels markedly increased, and optic stalk transection at day 4 (which prevents subsequent tectal innervation) was found to reduce the contralateral tectal levels of BDNF mRNA. Comparable reductions were obtained after injection of tetrodotoxin into one eye, indicating that, already during the earliest stages of target encounter in the CNS, the degree of BDNF gene expression is influenced by activity-dependent mechanisms. BDNF mRNA was also detected in the retina itself and at levels comparable to those found in the tectum. Together with previous findings indicating that BDNF prevents the death of cultured chick retinal ganglion cells, these results support the idea that the tightly controlled expression of the BDNF gene might be important in the co-ordinated development of the visual system.
运用一种灵敏且定量的方法，在鸡视觉系统发育过程中测定脑源性神经营养因子（BDNF）的mRNA水平。检测到了低拷贝数，并且发现早在第一批视网膜神经节细胞轴突到达前2天，BDNF就在视顶盖中表达，这表明BDNF在顶盖发育中起早期作用。在顶盖开始接受神经支配后，BDNF mRNA水平显著升高，并且发现第4天进行视柄横切（这会阻止随后的顶盖神经支配）可降低对侧顶盖中BDNF mRNA的水平。向一只眼睛注射河豚毒素后也得到了类似的降低结果，这表明在中枢神经系统中最早接触靶标的阶段，BDNF基因表达程度就受活性依赖机制的影响。在视网膜本身也检测到了BDNF mRNA，其水平与在顶盖中发现的水平相当。连同先前表明BDNF可防止培养的鸡视网膜神经节细胞死亡的研究结果，这些结果支持这样一种观点，即BDNF基因的严格调控表达可能在视觉系统的协调发育中很重要。
