Shelton D L, Reichardt L F
Proc Natl Acad Sci U S A. 1986 Apr;83(8):2714-8. doi: 10.1073/pnas.83.8.2714.
Beta nerve growth factor (NGF), a target-derived protein necessary for survival and development of sympathetic and sensory neurons, can also affect subpopulations of neurons in the central nervous system (CNS). Using a blot hybridization assay capable of detecting 10 fg of mRNA, we measured the levels of NGF mRNA in the major brain regions, including those innervated by NGF-responsive neurons. NGF mRNA was detected unambiguously in each major region of the CNS. The levels were comparable to those in sympathetic effector organs. Discrete areas contained very different amounts of NGF mRNA. Up to 40-fold differences were seen, a range comparable to the differences between richly and sparsely innervated sympathetic effector organs. The highest concentrations of NGF mRNA were found in the cortex and hippocampus, which are the major targets of the NGF-responsive cholinergic neurons of the basal forebrain nuclei. Significant amounts of NGF mRNA were also found in areas that contain the central processes of NGF-responsive sensory neurons, such as the pons, medulla, and spinal cord. The presence of NGF mRNA in these areas suggests that brain NGF may act as a target-derived trophic factor for both populations of neurons. NGF mRNA was also found in the striatum, suggesting that locally derived NGF may act there as a trophic factor for a recently identified population of NGF-responsive cholinergic local circuit neurons. However, high levels of NGF mRNA were also found in some regions, such as the diencephalon, that have no relation to any identified population of NGF-responsive neurons. This suggests that there may be additional populations of NGF-responsive neurons in the CNS that have not yet been discovered.
β神经生长因子（NGF）是交感神经元和感觉神经元存活及发育所必需的一种靶源性蛋白，它也能影响中枢神经系统（CNS）中的神经元亚群。我们使用一种能够检测10 fg mRNA的印迹杂交分析法，测量了包括那些受NGF反应性神经元支配的主要脑区中NGF mRNA的水平。在CNS的每个主要区域均明确检测到了NGF mRNA。其水平与交感效应器器官中的水平相当。不同区域所含的NGF mRNA量差异很大。可观察到高达40倍的差异，这一范围与富含神经支配和稀疏神经支配的交感效应器器官之间的差异相当。在皮质和海马中发现了最高浓度的NGF mRNA，皮质和海马是基底前脑核中对NGF有反应的胆碱能神经元的主要靶区。在含有对NGF有反应的感觉神经元中枢突的区域，如脑桥、延髓和脊髓中，也发现了大量的NGF mRNA。这些区域中存在NGF mRNA表明，脑源性NGF可能对这两类神经元都起到靶源性营养因子的作用。在纹状体中也发现了NGF mRNA，这表明局部产生的NGF可能在那里作为一种营养因子，作用于最近发现的一群对NGF有反应的胆碱能局部回路神经元。然而，在一些与任何已确定的对NGF有反应的神经元群体均无关联的区域，如间脑中，也发现了高水平的NGF mRNA。这表明在CNS中可能还存在尚未被发现的其他对NGF有反应的神经元群体。
