- 30 Downloads
Rat fetuses between day 11 of gestation and birth and young rats between the day of birth and the fourteenth postnatal day were treated with a single dose of 6-aminonicotinamide (6-AN) (10 mg/kg body weight) and after different time intervals the resulting brain edema and the deviations from the normal development of the central nervous system were studied in different brain regions, as represented by the visual system. In the phase of production of future nerve cells (preneurons or neuroblasts) from day 11/2 to 20 of pregnancy the undifferentiated ventricular cells react to application of 6-AN by the formation of an intracellular edema, mostly in the form of severe swelling of the perinuclear cleft, 24 hours after treatment. The preneurons themselves usually are affected by these alterations only minimally or not at all. As a consequence of the distribution of the ventricular cells the brain regions studied in early stages of development are characterized by a spongy-state-like appearance of the whole neural wall, in later developmental stages of those parts of the neural wall near the ventricle, specifically the ventricular and subventricular zones.