Understanding How the Subcommissural Organ and Other Periventricular Secretory Structures Contribute via the Cerebrospinal Fluid to Neurogenesis.

Maria M Guerra,Maryoris Jara,Rosa I Muñoz,César González,Teresa Caprile,Karin Vío,Sara Rodríguez,Esteban M Rodríguez

doi:10.3389/fncel.2015.00480

Maria M Guerra, Maryoris Jara + Show 6 more

Open Access

https://doi.org/10.3389/fncel.2015.00480

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Abstract

The dynamic and molecular composition of the cerebrospinal fluid (CSF) and, consequently, the CSF physiology is much more complex and fascinating than the simplistic view held for decades. Signal molecules either transported from blood to CSF or secreted into the CSF by circumventricular organs and CSF-contacting neurons, use the CSF to reach their targets in the brain, including the pre- and postnatal neurogenic niche. The subcommissural organ (SCO), a highly conserved brain gland present throughout the vertebrate phylum, is one of the sources for signals, as well as the choroid plexus, tanycytes and CSF-contacting neurons. The SCO secretes into the fetal and adult CSF SCO-spondin, transthyretin, and basic fibroblast growth factor. These proteins participate in certain aspects of neurogenesis, such as cell cycle of neural stem cells, neuronal differentiation, and axon pathfinding. Through the CSF, the SCO-secretory proteins may reach virtually any target in the embryonic and adult central nervous system. Since the SCO continues to secrete throughout life span, it seems likely that the neurogenetic property of the SCO compounds would be targeted to the niches where neurogenesis continues in adulthood. This review is aimed to bring into discussion early and new evidence concerning the role(s) of the SCO, and the probable mechanisms by which SCO compounds can readily reach the neurogenic niche of the subventricular zone flowing with the CSF to participate in the regulation of the neurogenic niche. As we unfold the multiples trans-fluid talks between discrete brain domains we will have more tools to influence such talks.

Highlights

The identification of neural stem cells (NSCs) in the adult central nervous system closed down a long-held dogma that neurons are formed exclusively during brain development
What does control where and how adult neurogenesis occur? Which are the mechanisms and signals underlying neuronal migration, in-fate integration and function? Which are the sources of these signals? How do these signals reach their target?
A good body of evidence is revealing that the dynamic and molecular composition of the cerebrospinal fluid (CSF) and, the CSF physiology is much more complex and fascinating than the simplistic view held for decades

Summary

Introduction

The identification of neural stem cells (NSCs) in the adult central nervous system closed down a long-held dogma that neurons are formed exclusively during brain development. The mammalian brain retains the capacity to generate new neurons throughout life in two main locations, the subventricular zone (SVZ) of the lateral ventricles and the hippocampal dentate gyrus (AlvarezBuylla and Garcia-Verdugo, 2002; Gage, 2002). Compounds Secreted by the SCO Contribute to Neurogenesis. The cellular and molecular mechanisms that guide the progression from a dividing NSCs to a functional neuron are far from being understood. CSF-born signals have largely been overlooked (see below). What does control where and how adult neurogenesis occur? Which are the mechanisms and signals underlying neuronal migration, in-fate integration and function? Which are the sources of these signals? How do these signals reach their target? What does control where and how adult neurogenesis occur? Which are the mechanisms and signals underlying neuronal migration, in-fate integration and function? Which are the sources of these signals? How do these signals reach their target?

Objectives

Conclusion