COMPARATIVE ELECTRONMICROSCOPICAL INVESTIGATIONS OF CHOROID PLEXUS OF MOUSE IN VIVO AND IN VITRO

1. Choroid plexus of 1 to 15 day-old mice has been cultured and then examined electronmicroscopically. At the same time and in vivo a comparative electronmicroscopical study of the mouse choroid plexus, from the prenatal to the adult stage was made. 2. Some days after explantation foci of glycogen concentration are found in the plexus cells. These foci disappear gradually after the second week of incubation. 3. Simultaneously to the disappearance of the intracellular glycogen, the agranular endoplasmic reticulum undergoes a pronounced increase in size. At this stage the ultrastructure of the cells is similar to that of the adult plexus cells in vivo. This process can be accelerated by removal of glucose from the nutritive medium. © 1968 Springer-Verlag.