Cell interactions and the regulation of cholinergic enzymes during neural differentiation in vitro

ADLER, RUBEN; TEITELMAN, GLADYS; SUBURO, ANGELA MARÍA

DEVELOPMENTAL BIOLOGY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 1976 vol. 50 p. 48 - 57

0012-1606

Seven-day-old chick embryo neural retina (NR), telencephalon (T), optic lobe (OL), and rombencephalon (Ro) were dissociated, and the resulting cell suspensions were allowed to reaggregate in vitro during 3 days either independently or in different binary combinations.Interactions could be detected by the comparison of the activity of the enzymes of the cholinergic system, choline acetyltransferase (CAT) and acetylcholinesterase (ACE), in ?pure? and ?combined? aggregates. The results clearly show that the activity of both enzymes in embryonic neural cells can be modified selectively by interactions between different cell populations. Thus, combined NR-OL aggregates show an increase in CAT without changes in ACE, NR-T an increase in CAT and a decrease in ACE, T-Ro a decrease in both CAT and ACE, and OL-T no changes at all. Experiments in which NR and OL cells were combined in different proportions indicate that the interactions require the presence of defined numbers of cells from each kind. Isochronousand heterochronous combinations of 7- and lo-day-old NR and OL cells show that the interactive capacities of the cells change with development.