Karlsson M, Hallböök F
Department of Developmental Neuroscience, BMC, Uppsala University, Sweden.
Neuroscience. 1998 Mar;83(1):137-50. doi: 10.1016/s0306-4522(97)00340-0.
Increasing evidence underlies the importance of neurotrophins as neuron-derived trophic signals in the developing visual system, although their precise roles are still undefined. Here we show that brain-derived neurotrophic factor messenger RNA is simultaneously expressed in a subpopulation of retinal ganglion cells and in their target during late embryogenesis. Moreover, light as well as the excitotoxin; kainic acid, induced an increase of the brain-derived neurotrophic factor messenger RNA, which could be blocked by the sodium-channel blocker; tetrodotoxin. Messenger RNA for trkB, a receptor for brain-derived neurotrophic factor, was found in the retinal ganglion cells expressing brain-derived neurotrophic factor showing that certain retinal ganglion cells express messenger RNA both for brain-derived neurotrophic factor and trkB. Furthermore, trkB messenger RNA was found in tectum, in the same layers as the brain-derived neurotrophic factor messenger RNA. These findings suggest that brain-derived neurotrophic factor expression is regulated in an activity-dependent manner during the phase of development when neuronal activity plays an important role.
越来越多的证据表明神经营养因子作为发育中的视觉系统中神经元衍生的营养信号具有重要性，尽管它们的确切作用仍不明确。在此我们表明，脑源性神经营养因子信使核糖核酸在胚胎发育后期同时在一部分视网膜神经节细胞及其靶标中表达。此外，光以及兴奋性毒素—— kainic 酸，可诱导脑源性神经营养因子信使核糖核酸增加，而这可被钠通道阻滞剂——河豚毒素所阻断。在表达脑源性神经营养因子的视网膜神经节细胞中发现了trkB（脑源性神经营养因子的一种受体）的信使核糖核酸，这表明某些视网膜神经节细胞同时表达脑源性神经营养因子和trkB的信使核糖核酸。此外，在顶盖中与脑源性神经营养因子信使核糖核酸相同的层中发现了trkB信使核糖核酸。这些发现表明，在神经元活动起重要作用的发育阶段，脑源性神经营养因子的表达是以活动依赖的方式进行调节的。
