Microencephaly induces a long lasting change in B-50 phosphorylation in rats

Administration of Methylazoxymethanol acetate (MAM, 25 mg/kg i.p.), a potent antimitotic agent, to pregnant rats at gestational day (GD) 15, ablates neuroepithelial cells entering their final mitosis and committed to form cortical interneurons and hippocampal pyramidal cells in the fetus. The offspring show a marked reduction in the weight of cortex and hippocampus 8 days after birth and a similar weight reduction is observed also in 2 and 9 month old treated rat brains. This anatomical disorganization results in a persistent alteration of the protein kinase C (PKC)-dependent phosphorylation of the neuron specific protein B-50: in a post-hoc phosphorylation assay, 32P incorporation into B-50 is reduced by about 50% in MAM-treated rats of all age groups when compared to their age-matched controls.