Biochemical and cytochemical studies of the development of choline acetyltransferase and acetylcholinesterase in organotypic cultures of chick neural tube

Choline acetyltransferase (ChAc) and acetylcholinesterase (AChE) activities have been studied in organotypic cultures of early chick neural tube. During the first week in culture the ChAc activity remains extremely low at which time it can not be demonstrated histochemically in early neurons. It increases rapidly during the second and third weeks in culture, as demonstrated biochemically and histochemically. AChE activity rises rapidly during the first week, and then more gradually for the remainder of the culture period; it can be demonstrated histochemically in early neurons and well differentiated multipolar neurons throughout this period. In our culture system biochemical differentiation (ChAc and AChE activity) occurs concomitantly with morphological differentiation.