抄録
Migration and apoptosis of selected neurons is essential for developing a properly arranged neural network. Although many migrate to the cortical regions, only those neurons that differentiate into a functional neural net are maintained while the others are eliminated through an apoptotic mechanism. As a model of this neuronal development, P19 embryonic carcinoma cells differentiate into neuronal cells when grown as aggregates in the presence of retinoic acid (RA). During RA-induced neuronal differentiation, the aggregated cells lose their malignant phenotype and many undergo apoptosis to provide a robust model of the apoptosis seen in the developing brain. On the other hand, reelin plays an important role in the migration of embryonic neurons. Even after neuronal migration is complete, reelin is expressed in all layers of the mature cerebral cortex and weak immunoreactivity of reelin is routinely detected in selected populations of cortical neurons throughout life. The persistence of reelin throughout life suggested to us that reelin may play a novel role in the maturing brain after neuronal migration is completed. In our study, reelin protected P19 embryonal cells from apoptosis during retinoic-acid induced neuronal differentiation. This protective effect of reelin included activating the Src-family kinases/PI3 kinase/Akt pathway. [Jpn J Physiol 54 Suppl:S211 (2004)]
