| Abstract: | Maturation of the cerebellar influence on rubral cells was studied in70 young rabbits aged from 3 to 17 days. Extracellular spike potentials of 187 neurons belonging to the magnocellular part of the red nucleus were recorded with glass microelectrodes. The differences observed between young and old animals are quantitative and particularly striking. Out of 107 cells in animals less than 8 days old, only 7 were facilitated or inhibited by cerebellar stimulation, whereas in older animals, out of 80 cells, 76 were facilitated or inhibited. Similar results were obtained for 273 perirubral cells and 72 oculomotor cells. The present results suggest that cerebello-interposital or interposito-rubral connections are not yet functional during the first postnatal week. |
