Mapping the cellular expression patterns of vascular endothelial growth factor aa and bb genes and their receptors in the adult zebrafish brain during constitutive and regenerative neurogenesis

The complex interplay between vascular signaling and neurogenesis in the adult brain remains a subject of intense
research. By exploiting the unique advantages of the zebrafish model, in particular the persistent activity of neural
stem cells (NSCs) and the remarkable ability to repair brain lesions, we investigated the links between NSCs and cerebral
blood vessels. In this study, we first examined the gene expression profiles of vascular endothelial growth factors
aa and bb (vegfaa and vegfbb), under physiological and regenerative conditions. Employing fluorescence in situ
hybridization combined with immunostaining and histology techniques, we demonstrated the widespread expression
of vegfaa and vegfbb across the brain, and showed their presence in neurons, microglia/immune cells, endothelial
cells and NSCs. At 1 day post-lesion (dpl), both vegfaa and vegfbb were up-regulated in neurons and microglia/
peripheral immune cells (macrophages). Analysis of vegf receptors (vegfr) revealed high expression throughout
the brain under homeostatic conditions, with vegfr predominantly expressed in neurons and NSCs and to a lower
extent in microglia/immune cells and endothelial cells. ... mehrThese findings were further validated by Vegfr3 and Vegfr4
immunostainings, which showed significant expression in neurogenic radial glial cells.
Following brain lesion (1 dpl), while vegfr gene expression remained stable, vegfr transcripts were detected in proliferative
cells within the injured parenchyma. Collectively, our results provide a first overview of Vegf/