[Realization of systemic relations in the behavior of early neuroblasts in nerve tissue cultures]

When cultivating the nervous tissue of newborn rats, rabbit embryos and tadpoles (as whole fragments or dissociated cells), 3 groups of neuroblasts are distinguished: differentiating, migrating and with growing processes. These groups correspond to different stages of neuroblast development in vivo and their presence in the tissue cultures of different brain regions reflects the heterochrony of cell development in these regions. The neuroblasts realize their morphogenetic potential within several days of cultivation irrespective of the contact with the other cells but the subsequent differentiation (dendrite branching, nuclear clearance etc.) proceeds only in cells united in aggregates.