Yamamori T
Laboratory for Neural Networks, Frontier Research Program, RIKEN, Wako, Japan.
Neurosci Res. 1992 Jan;12(5):545-82. doi: 10.1016/0168-0102(92)90064-j.
Development of postmitotic neurons is influenced by two groups of polypeptide factors. Neurotrophic factors promote neuronal survival both in vivo and in vitro. Neuronal differentiation factors influence transmitter phenotypes without affecting neuronal survival. The list of neurotrophic factors is increasing partly because certain growth factors and cytokines have been shown to possess neurotrophic activities and also because new neurotrophic factors including new members of the nerve growth factor (NGF) family have been identified at the molecular level. In vitro assays using recombinant neurotrophic factors and distributions of their mRNAs and proteins have indicated that members of a neurotrophic gene family may play sequential and complementary roles during development and in the adult nervous system. Most of the receptors for neurotrophic factors contain tyrosine kinase domains, suggesting the importance of tyrosine phosphorylation and subsequent signal transduction for their effects. Molecules such as LIF (leukemia inhibitory factor) and CNTF (ciliary neurotrophic factor) have been identified as neuronal differentiation factors in vitro. At the moment, however, it remains to be determined whether or not the receptors for a group of neuronal differentiation factors constitute a gene family or contain domains of kinase or phosphatase activity. Synergetic combinations of neurotrophic and neuronal differentiation factors as well as their receptors may contribute to the generation of neural specificity and diversity.
有丝分裂后神经元的发育受到两类多肽因子的影响。神经营养因子在体内和体外均可促进神经元存活。神经元分化因子影响递质表型，但不影响神经元存活。神经营养因子的种类正在增加，部分原因是某些生长因子和细胞因子已被证明具有神经营养活性，还因为在分子水平上已鉴定出包括神经生长因子（NGF）家族新成员在内的新的神经营养因子。使用重组神经营养因子的体外试验及其mRNA和蛋白质的分布表明，一个神经营养基因家族的成员在发育过程中和成年神经系统中可能发挥着相继且互补的作用。大多数神经营养因子的受体含有酪氨酸激酶结构域，这表明酪氨酸磷酸化及随后的信号转导对其作用的重要性。诸如白血病抑制因子（LIF）和睫状神经营养因子（CNTF）等分子在体外已被鉴定为神经元分化因子。然而，目前仍有待确定一组神经元分化因子的受体是否构成一个基因家族，或者是否含有激酶或磷酸酶活性结构域。神经营养因子和神经元分化因子及其受体的协同组合可能有助于产生神经特异性和多样性。
