Riddle D R, Lo D C, Katz L C
Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Nature. 1995 Nov 9;378(6553):189-91. doi: 10.1038/378189a0.
Altering the balance of activity between the two eyes during the critical period for visual-system development profoundly affects competitive interactions among neurons in the lateral geniculate nucleus and primary visual cortex. Neurons in the lateral geniculate nucleus that are deprived of activity by closing or silencing one eye atrophy as a result of competition with non-deprived neurons for some critical factor(s) presumed to be present in the cortex. Based on their actions in the developing visual system, neurotrophins are attractive candidates for such factors. We tested whether neurotrophins mediate intracortical competition of afferents from the lateral geniculate nucleus by using monocular deprivation and a new method for highly localized, in vivo delivery of neurotrophins. This method allowed unambiguous identification of neurons that were exposed to neurotrophin. Here we report that only one neurotrophin, the TrkB ligand NT-4, rescued neurons in the lateral geniculate nucleus from the dystrophic effects of monocular deprivation.
在视觉系统发育的关键时期改变两眼之间的活动平衡，会深刻影响外侧膝状体核和初级视皮层中神经元之间的竞争性相互作用。通过闭合或使一只眼睛失活而被剥夺活动的外侧膝状体核中的神经元，由于与未被剥夺的神经元竞争假定存在于皮层中的某些关键因子而萎缩。基于神经营养因子在发育中的视觉系统中的作用，它们是这类因子的有力候选者。我们通过使用单眼剥夺和一种用于在体内高度局部递送神经营养因子的新方法，测试了神经营养因子是否介导来自外侧膝状体核的传入纤维的皮质内竞争。这种方法能够明确识别暴露于神经营养因子的神经元。在此我们报告，只有一种神经营养因子，即TrkB配体NT-4，能挽救外侧膝状体核中的神经元免受单眼剥夺的营养不良影响。
