| Abstract: | Explants of the ganglion trigeminale from chick embryos were cultivated in Maximow chambers in the presence of 10-6...10-8 M substance P (SP . 3CH3COOH.4H2O). 1. In SP-treated cultures the index of areas covered by the explants was increased in shorttime tests. 2. The density of cells was related to the type of medio-dorsal (MD) and ventro-lateral (VL) neuroblasts. The density of SP-treated VL cells was not altered. The density of MD cells decreased. 3. The percentage of dark neuroblasts was decreased under the influence of SP. 4. A stimulation of VL neuroblasts did not take place. 5. The diameters of MD pericarya and the areas of MD cell nuclei and the areas of nuclei from nonneuronal cells increased. 6. The possible role of SP as a factor controlling In-vitro-processes is discussed. |
