Attractive action of FGF‐signaling contributes to the postnatal developing hippocampus

Abstract

During brain development neural cell migration is a crucial, well-orchestrated, process, which leads to the proper whole brain structural organization. As development proceeds, new neurons are continuously produced, and this protracted neurogenesis is maintained throughout life in specialized germinative areas inside the telencephalon: the subventricular zone (SVZ) and the dentate gyrus (DG) of the hippocampus. In the anterior SVZ, newly generated neurons migrate through long distances, along the rostral migratory stream (RMS), before reaching their final destinations in the olfactory bulb (OB). Intriguingly, recent observations pointed out the existence of other postnatal tangential routes of migration alternative to the RMS but still starting from the SVZ. The presence of such dynamic and heterogeneous cell movements contributes to important features in the postnatal brain such as neural cell replacement and plasticity in cortical regions. In this work, we asked whether a caudal migratory pathway starting from the caudal SVZ continues through life. Strikingly, in vivo analysis of this caudal migration revealed the presence of a postnatal contribution of SVZ to the hippocampus. In vitro studies of the caudal migratory stream revealed the role of FGF signaling in attracting caudally the migrating neuroblasts during postnatal stages. Our findings demonstrate a postnatal neuronal contribution from the caudal ganglionic eminence (CGE) CGE-SVZ to the hippocampus through an FGF-dependent migrating mechanism. All together our data emphasizes the emerging idea that a developmental program is still operating in discrete domains of the postnatal brain and may contribute to the regulation of neural cell replacement processes in physiological plasticity and/or pathological circumstances.

Neuronal progenitors of the dentate gyrus express the SARS-CoV-2 cell receptor during migration in the developing human hippocampus

“…Moreover, positive sensitivity and specificity of immunostaining have been proved by detection of expression in lungs and kidneys, corroborating the reported expression of ACE2 in adult human tissues [ 28 ]. In addition, we have described the presence of the caudal migratory stream expressing TBR2 along the GFAP + radial glia fibers, from the fimbria hippocampus angle to the marginal layer of the DG, which generates intermediate DG progenitors during the first two postnatal weeks of brain development [ 59 ], and corroborated the data published by Ciprinai et al [ 29 ]. Moreover, we have also demonstrated the close interaction between blood vessel development and migratory neural progenitors in mouse DG development at these early postnatal stages [ 60 ].…”

Neuronal progenitors of the dentate gyrus express the SARS-CoV-2 cell receptor during migration in the developing human hippocampus

“…Tbr2 along the GFAP + radial glia bers, from the mbria-hippocampal angle to the marginal layer of the DG, that generates intermediate DG progenitors during the rst two postnatal weeks of brain development [53]. Moreover, we have also demonstrated the close interaction between blood vessel development and migratory neural progenitors in mouse DG development at these early postnatal stages [54].…”

Nissl Granules, Axonal Regeneration, and Regenerative Therapeutics: A Comprehensive Review

“…Additionally, knowledge of plasticity mechanisms aids in the creation of therapeutic treatments for mental illnesses and neurodegenerative diseases. A foundation for improving patient care and neurological research is laid by embracing the idea of neural plasticity, which emphasizes the dynamic nature of the brain and the potential for recovery, adaptation, and development [17][18][19][20][21][22][23][24][25].…”