Roback J D, Large T H, Otten U, Wainer B H
Department of Pathology, University of Chicago, Illinois 60637.
Dev Biol. 1990 Feb;137(2):451-5. doi: 10.1016/0012-1606(90)90270-s.
Nerve growth factor (NGF) is synthesized in the hippocampus and neocortex and provides trophic support for afferent cholinergic neurons of the basal forebrain. To determine the capacity of the developing hippocampus to express NGF in the absence of NGF-responsive afferents, embryonic hippocampal cells isolated prior to septal innervation were studied in reaggregating cell culture. The expression of NGF protein in vitro was qualitatively and quantitatively similar to that observed in situ. The expression of NGF mRNA exhibited an initial increase in vitro but then plateaued and was maintained at a steady level. This latter finding was in contrast to the steady rise in NGF mRNA levels observed in situ. These data suggest that (i) intrinsic hippocampal interactions regulate the onset of NGF expression, but that (ii) additional extrinsic developmental signals may be required for proper regulation of hippocampal NGF expression during ontogeny.
神经生长因子（NGF）在海马体和新皮质中合成，并为基底前脑的传入胆碱能神经元提供营养支持。为了确定在缺乏NGF反应性传入神经的情况下发育中的海马体表达NGF的能力，在重新聚集细胞培养中研究了在隔区神经支配之前分离的胚胎海马细胞。体外NGF蛋白的表达在定性和定量上与原位观察到的相似。NGF mRNA的表达在体外最初增加，但随后趋于平稳并维持在稳定水平。后一发现与原位观察到的NGF mRNA水平的稳定上升形成对比。这些数据表明：（i）海马体内部相互作用调节NGF表达的起始，但（ii）在个体发育过程中，可能需要额外的外部发育信号来适当调节海马体NGF的表达。
