Heterogeneous distribution of doublecortin‐expressing cells surrounding the rostral migratory stream in the juvenile mouse

Abstract

In the postnatal mammalian brain, neural stem cells of the ventricular-subventricular zone continue to generate doublecortin (Dcx)-expressing immature neurons. Throughout life, these immature neurons migrate to the olfactory bulb through the rostral migratory stream (RMS). In this study, we investigated the distribution of these putative immature neurons using enhanced green fluorescent protein (EGFP) expression in the area surrounding the RMS of the juvenile Dcx-EGFP mice. Through the combined use of an optical clearing reagent (a 2,2'-thiodiethanol solution) and two-photon microscopy, we visualized three-dimensionally the EGFP-positive cells in the entire RMS and its surroundings. The resulting wide-field and high-definition images along with computational image processing methods developed in this study were used to comprehensively determine the position of the EGFP-positive cells. Our findings revealed that the EGFP-positive cells were heterogeneously distributed in the area surrounding the RMS. In addition, the orientation patterns of the leading process of these cells, which displayed the morphology of migrating immature neurons, differed depending on their location. These novel results provide highly precise morphological information for immature neurons and suggest that a portion of immature neurons may be detached from the RMS and migrate in various directions.

Neuroblast migration along cellular substrates in the developing porcine brain

“…During early postnatal periods of development, the subventricular zone (SVZ), housing the largest pool of neural stem/progenitor cells (NSPCs), promotes cortical expansion ( Sanai et al., 2005 ). NSPCs give rise to immature neurons (neuroblasts) that migrate to their final destinations in various regions of the human brain, including the ventromedial prefrontal cortex (vPFC) and the anterior cingulate cortex ( Aoyagi et al., 2018 ; Lazarini and Lledo, 2011 ; Lois et al., 1996 ; Paredes et al., 2016a ; Sanai et al., 2011 ; Sawamoto et al., 2011 ). The journey from site of origin to final destination is largely influenced by the size and complexity of the brain, as neuroblasts must migrate significantly further through dense cellular networks in larger brains.…”

Neuroblast migration along cellular substrates in the developing porcine brain

“…During early postnatal periods of development a secondary proliferative area emerges, the subventricular zone (SVZ), housing the largest pool of neural stem/progenitor cells (NSPCs) further promoting cortical expansion (Sanai et al, 2005). These NSPCs give rise to immature neurons (neuroblasts) that migrate to their final destinations in various regions of the human brain, including the olfactory bulb (OB), the ventromedial prefrontal cortex (vPFC), and the anterior cingulate cortex (Aoyagi et al, 2018;Lazarini and Lledo, 2011;Lois et al, 1996;Paredes et al, 2016a;Sanai et al, 2011;Sawamoto et al, 2011). The journey from site of origin to final destination is largely influenced by the size and complexity of the brain, as neuroblasts must migrate significantly further through dense cellular networks in larger brains.…”