ABL1 is a novel regulator in the laminated olfactory bulb structure formation during the early development

Abstract

Interneurons in the olfactory bulb(OB) are continuously generated and migrated from subventricular zone(SVZ) in the brain during the postnatal stage, while mitral and tufted cells in the OB are mainly formed during the embryonic stage. These neurons in the OB have their determined positions, and which makes lamination structures, similarly in the cortex or hippocampus. Abnormality of this structure leads to functional deficits, but how this process is induced and controlled has been little studied. We here report that the expression and activation of ABL1, a non-receptor type kinase in interneurons showed strong correlations to the early development of OB interneurons. Active ABL1 expressed in progenitors of interneurons massively entered into the OB until the first week after birth. Furthermore, when the ABL1 expression was inhibited by the injection of virus containing ABL1 shRNA and GFP during the first week of the birth, the distributed ratio of GFP+ cells were about 20% accumulated in deep granule cell layer(dGCL) compared to CTL group. It suggests that ABL1 may play a critical role in formation of proper OB organization during the early OB postnatal development, such as in migration and integration. In summary, the expression and activation of ABL1 at the specific stage appeared crucial for proper neuronal migration and laminated OB structure formation during the early OB development.