ANY AT ALL?
http://journal.frontiersin.org/article/10.3389/fnins.2015.00071/full?
Adult neurogenesis 20 years later: physiological function vs. brain repair
- 1Neuroscience Institute Cavalieri Ottolenghi, Orbassano, Italy
- 2Life Sciences and Systems Biology, University of Turin, Torino, Italy
- 3Department of Veterinary Sciences, University of Turin, Torino, Italy
Two decades of intense investigation in the field of
adult neurogenesis (AN) provided us with a fully renewed vision of brain
plasticity, involving stem/progenitor cells capable of generating new
neurons and glial cells throughout life. We know for sure that new
neurons produced within canonical stem cell niches do play a significant
role in cognitive tasks (learning/memory) operated by specific neural
systems (Lepousez et al., 2013; Aimone et al., 2014).
The fact that neural stem/progenitor cells (NSC) produce new elements
that can integrate within some regions of the mature brain, replacing
lost neurons/glial cells or adding to pre-existent neural circuits,
appears extremely fascinating in the perspective of regenerative
therapeutic approaches. Since the burst of investigations in AN/NSC
field in the nineties, many neurobiologists addressed their studies on
brain plasticity in the hope of brain repair, often discussing their
results in a translational context. Nevertheless, in spite of striking
efforts to clarify mechanisms/factors regulating AN and its
physiological function, the question whether it can be exploited for
healing neurologic diseases remains unsolved.(This is precisely why we need a strategy) More recent findings
revealed additional examples of “non-canonical” neurogenesis and
gliogenesis in various regions of the mammalian central nervous system
(CNS; reviewed in Bonfanti and Peretto, 2011).
These discoveries also open new hopes for brain repair, since the
occurrence of spontaneous neuro-gliogenesis within the parenchyma does
represent an endogenous source of progenitor cells even outside the
restricted environment of canonical neurogenic sites. Nevertheless,
parenchymal cell genesis remains substantially obscure as to its
functional meaning(s) and outcome(s), and not yet exploitable for brain
repair. Such an impasse largely resides on evolutionary discrepancies:
most vertebrates use AN for brain repair as a byproduct of evolution, in
addition to its physiological functions; mammals have lost such
capacity, mainly because of unfavorable environments for
repair/regeneration in their mature CNS (Bonfanti, 2011).
A scarce perception of these facts might have produced misconceptions
among scientists, sometimes leading to attitudes of unconditional
optimism.
This Editorial is part of a Frontiers' research topic
(and related e-book), gathering 18 articles which were intended to
explore the relationships between actual existence of NCSs in mammals
(playing homeostatic roles in AN and responding to pathological
conditions) and lack of effective reparative outcome in terms of
regenerative neurology.Much more at link.
No comments:
Post a Comment