Am J Stem Cell 2012;1(2):92-105

Original Article
Meninges: from protective membrane to stem cell niche

Ilaria Decimo, Guido Fumagalli, Valeria Berton, Mauro Krampera, Francesco Bifari

Department of Public Health and Community Medicine, Section of Pharmacology, University of Verona, Italy; Department of Medicine,
Stem Cell Laboratory, Section of Hematology, University of Verona, Italy

Received May 16, 2012; accepted May 23, 2012; Epub 28, 2012; Published June 30, 2012

Abstract: Meninges are a three tissue membranes primarily known as coverings of the brain. More in depth studies on meningeal
function and ultrastructure have recently changed the view of meninges as merely protective membrane. Accurate evaluation of the
anatomical distribution in the CNS reveals that meninges largely penetrate inside the neural tissue. Meninges enter the CNS by
projecting between structures, in the stroma of choroid plexus and form the perivascular space (Virchow-Robin) of every parenchymal
vessel. Thus, meninges may modulate most of the physiological and pathological events of the CNS throughout the life. Meninges are
present since the very early embryonic stages of cortical development and appear to be necessary for normal corticogenesis and brain
structures formation. In adulthood meninges contribute to neural tissue homeostasis by secreting several trophic factors including FGF2
and SDF-1. Recently, for the first time, we have identified the presence of a stem cell population with neural differentiation potential in
meninges. In addition, we and other groups have further described in meninges the presence of injury responsive neural precursors. In
this review we will give a comprehensive view of meninges and their multiple roles in the context of a functional network with the neural
tissue. We will highlight the current literature on the developmental feature of meninges and their role in cortical development. Moreover,
we will elucidate the anatomical distribution of the meninges and their trophic properties in adult CNS. Finally, we will emphasize recent
evidences suggesting the potential role of meninges as stem cell niche harbouring endogenous precursors that can be activated by
injury and are able to contribute to CNS parenchymal reaction. (AJSC1205003).

Keywords: Meninges, leptomeninges, arachnoid mater, pia mater, corticogenesis, neurogenesis, neural stem cells, neural progenitors,
stem cell niche

Address all correspondence to:
Dr. Ilaria Decimo
Department of Public Health and Community Medicine
Section of Pharmacology

Dr. Francesco Bifari
Department of Medicine, Stem Cell Research Laboratory
Section of Hematology, University of Verona, Italy
P.le Scuro 10, 37134 Verona, Italy.
Tel: 0039-045-8027621; Fax: 0039-045-8027452
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