Lindholm D, Castrén E, Berzaghi M, Blöchl A, Thoenen H
Department of Neurochemistry, Max Planck Institute for Psychiatry, Martinsried, Germany.
J Neurobiol. 1994 Nov;25(11):1362-72. doi: 10.1002/neu.480251105.
The neurotrophins exhibit neurotrophic effects on specific, partially overlapping populations of neurons both in the peripheral and the central nervous system (CNS). In the periphery, they are synthesized by a variety of nonneuronal cells, and their synthesis seems to be independent of the neuronal input. In contrast, in the CNS all neurotrophins are expressed under physiological conditions primarily by neurons. The production of NGF and BDNF is controlled by neuronal activity: up-regulation by glutamate and acetylcholine, down-regulation by gamma-aminobutyric acid. In contrast, NT-3 regulation is independent of neuronal activity, but it is up-regulated by thyroid hormones and BDNF. The latter observation suggests that NT-3 might be controlled indirectly by neuronal activity via BDNF. In peripheral nonneuronal tissues, glucocorticoid hormones down-regulate NGF mRNA levels both in vitro and in vivo. In contrast, in the CNS, neuronal production of NGF is enhanced by glucocorticoids. The rapid regulation of NGF and BDNF by subtle physiological stimuli together with the recent demonstration that the neurotrophins release neurotransmitters such as acetylcholine opens up interesting perspectives for the function of neurotrophins as mediators of neuronal plasticity.
神经营养因子对周围神经系统和中枢神经系统（CNS）中特定的、部分重叠的神经元群体具有神经营养作用。在周围神经系统中，它们由多种非神经元细胞合成，其合成似乎独立于神经元输入。相比之下，在中枢神经系统中，所有神经营养因子在生理条件下主要由神经元表达。NGF和BDNF的产生受神经元活动控制：由谷氨酸和乙酰胆碱上调，由γ-氨基丁酸下调。相比之下，NT-3的调节独立于神经元活动，但受甲状腺激素和BDNF上调。后一观察结果表明，NT-3可能通过BDNF间接受神经元活动控制。在周围非神经元组织中，糖皮质激素在体外和体内均下调NGF mRNA水平。相比之下，在中枢神经系统中，糖皮质激素增强神经元产生NGF。NGF和BDNF受细微生理刺激的快速调节，以及最近关于神经营养因子释放乙酰胆碱等神经递质的证明，为神经营养因子作为神经元可塑性介质的功能开辟了有趣的前景。
