Development of embryonic rat brain cells in aggregating cell cultures with special reference to cholinergic functions.

Mechanically dissociated cells from embryonic rat brain regions (telencephalon and metencephalon 15-16 days gestation) reassociate in a rotation culture to form aggregates. These reaggregate cultures show a variety of developmental phenomena, expression of specific cell types and the formation of synapses as the most prominent ultrastructural change. The biochemical maturation is evident in increasing specific activities of choline acetyltransferase (ChAT, EC 2.3.1.6.) and acetylcholinesterase (AChE, EC 3.1.1.7.). The binding of 3H-quinuclidinylbenzilate(3H-QNB) represents the presence of the muscarinic acetylcholine receptor (mAChR) in these cultures. The expression of the cholinergic character was also shown by histochemical demonstration of specific AChE activity in cryostat sections of reaggregates.