Neuronal death in the spinal ganglia of the chick embryo and its reduction by nerve growth factor.

摘要: In the spinal ganglia of chick embryo, two neuronal populations can be distinguished: large, early differentiating ventrolateral (VL) cells and small, late dorsomedial (DM) cells. It was found that, beginning with stage 25, DM originate from a narrow band immature at medial border ganglion, extending to dorsolateral border. We have designated this as inner outer marginal zone. Neuronal death investigated in thoracic ganglion 18 brachial 15 by counting degenerating cells, separately for VL populations, every 24 (4% days) 38 (12 days). both ganglia, separate degeneration periods were which do not overlap. The peaks are: 27 (5% population 18, 30 (6% 7 16, 35 (8% ganglia. Daily injections 6 pg nerve growth factor, (NGF) 12 ~1 0.9% sterile salt solution into yolk sac 21 (3% day sacrifice resulted significant reduction rescue practically all neurons normally would died. This is first demonstration an NGF effect on neurons. analysis multiple effects factor (NGF), sympathetic played dominant role; sensory are other target attracted much less attention. Yet, if one entertains notion that might natural trophic maintenance agent these neuron types (i.e., actually produced their organs), then approach testing hypothesis engage viva experiments. For