Reconstruction of brain tissue from cell suspensions. I. Aggregation patterns of cells dissociated from different regions of the developing brain

Abstract

Cells dissociated from different brain areas of chick and mouse embryos (cerebrum, diencephalon, optic tectum, or corpora quadrigemina, cerebellum, and medulla) reconstructed in vitro aggregates which were diagnostically characteristic in size and shape for their region of origin; in addition, cells from each area exhibited a distinctive age profile of aggregative behavior which reflected their developmental schedule. Mouse cell aggregates from all brain regions tested were consistently larger than aggregates of cells from corresponding chick brain regions; mouse cerebrum cells formed especially massive aggregates in contrast to small aggregates characteristic of chick cerebrum cells. Coaggregation of suspensions of mouse cerebrum cells with chick cells from various brain areas, or from nonnervous tissues resulted in bispecific aggregates which were generally intermediate in size between typical aggregates of each of the component cell populations. The size of these coaggregates and the extent of internal sorting out of cell types was closely related to the degree of homology between the commingled cell populations. The implications of the findings are discussed with reference to fundamental mechanisms governing regional brain differentiation and specificity of neuronal associations. © 1972.