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Editorial

Astrocytes: everything but the glue

Oscar Gonzalez‑Perez , Veronica Lopez‑Virgen , Alfredo Quiñones‑Hinojosa 2
1
1
1 Laboratory of Neuroscience, School of Psychology, University of Colima, Colima, Col 28040, Mexico.
2 Department of Neurosurgery, Johns Hopkins School of Medicine, Baltimore, MD 21201, USA.

[2]
The current knowledge in neuroscience indicates that communication. Postnatal synapse refinement is
the neural tissue has two major cell populations: neurons also associated with astrocyte maturation suggesting
and glia (term derived from the Greek word for glue). that the astroglia is an important modulator of neuronal
Neuronal population is characterized by the capacity to plasticity. [3]
produce action potentials, whereas glial cells are typically
identified as the subordinate cell population of neurons. Astrocytes are ubiquitous brain cells that outnumber
Till date, this point of view has changed dramatically, and neuronal population in the proportion of 10:1 and
growing evidence indicates that glial cells play a crucial comprise approximately 50% of the neural tissue. Before
role in normal mental functions and the pathogenesis 1980’s, the role of astrocytes was basically associated
of neurological diseases. Classically, glial cells include with supporting and nourishing neurons (primarily
four major populations clearly discernible in the adult’s considered as a “real” functional cells). However,
brain: astrocytes, oligodendrocytes, microglia cells and current evidence indicates that this perspective is
NG2 glia. Astrocytes, also referred as to astroglia, are by quite limited and incorrect. Today, it is well accepted
far the most abundant cell lineage in the adult’s brain and that astrocytes have a more major role in neurological
display a very diverse morphology, which varies during functioning, neural homeostasis and pathogenesis than
neural development and adulthood [Figure 1]. These previously thought. [4]
cells are in close contact with several tissue components
of the brain parenchyma including neurons, vasculature, Astroglia is the main source of glycogen that
extracellular matrix and other glial populations. Hence, delivers energy to the brain interstitial tissue and
[5]
the number and strategic position of astrocytes provide nourishes neurons by providing lactate. Other
them with exceptional capacity for modulating multiple astrocytic functions include: the uptake or release
[6]
functions in the neural tissue. of neurotransmitters, modulation of synaptic
plasticity and neuronal transmission, regulation of
[3]
During neural development, the origin of astrocyte interstitial ions, cerebral regulation of blood flow
[7]
varies according to the anatomical region, but the and blood-brain barrier, myelin regulation, tissue
[9]
[8]
most accepted viewpoint suggests that astrocytic cells repair, [10] neuroprotection [11] and drug metabolism. [12]
originate from radial glial cells (in the ventricular zone)
and some progenitor cells located in the subventricular In addition, astrocytes have astonishing enzymatic
zone (SVZ). Therein, astrocyte lineage is directed by the machinery that includes cyclooxygenase, lipoxygenase
expression of notch receptors and their ligands (delta and cytochrome P450 epoxygenase pathways. [12]
and serrate-jagged) that efficiently repress neuronal Remarkably, these enzymes allow astrocytes to depurate
[1]
fate and promotes gliogenesis. At this developmental several drugs and alcohol, a property that was previously
stage, astrocytes are crucial for the synapse formation thought to be exclusive of hepatocytes (liver cells).
by improving the neuron’s ability to receive synaptic Astroglia can also produce metabolic intermediates
contacts, which consequently initiate neuronal of polyunsaturated fatty acid arachidonic acid and
epoxide metabolites that may help protect against
Access this article online stroke. Nevertheless, some gene mutations on astrocytes
Quick Response Code: produce defective proteins that upon accumulation
Website: may lead to neurodegenerative diseases. Besides, the
www.nnjournal.net
phospholipase-C (PLC) enzymatic family and the
DOI: phosphoinositide signaling system are essential for
10.4103/2347-8659.153979 molecule transduction from the cell membrane to
the nucleus. [12] This system appears to be involved

Corresponding Author: Dr. Oscar Gonzalez‑Perez, Laboratory of Neuroscience, School of Psychology, University of Colima, Av.
Universidad 333, Colima, Col 28040, Mexico. E‑mail: osglez@ucol.mx

Neuroimmunol Neuroinflammation | Volume 2 | Issue 2 | April 15, 2015 115