[Role of the determinance factor in formation of systemic connections during ontogenesis].

Behaviour of differentiating neuroblasts was studied in the nervous tissue culture of the newborn rats cortex and medulla oblongata of the rabbit embryo. The phasic-contrast microscopy and study of fixated preparations revealed that distribution of the neuroblasts over the substrate, their mutual orientation, the character of their branches growth and formation of contacts occur in vitro involving certain stages of morphological forming of the brain systemic organization. The clear trend of the neuroblasts behaviour to formation of certain connections suggests their genetic determinance. The distribution of neuroblasts over the substrate from different brain areas has its own phenotypic features.