0:00
Hi, my name is Dr.
Marie-Eve Tremblay.
I am an associate professor at
the Division of Medical Sciences,
at the University of Victoria
and Canada Research Chair
in Neurobiology of
Aging and Cognition.
This presentation will
provide an overview of
the physiological roles of
microglia in the healthy brain,
with a technical and
historical perspective.
0:27
As the provocative title
of this review suggests,
we are experiencing an
important paradigm shift
in the microglia field.
Microglia are not
neurotoxic cells
that should be eradicated.
Instead, they are beneficial
immune cells that actively
contribute through their
many physiological roles
in order to maintain
brain health.
0:52
Over the past decade,
the beneficial roles
of microglia in
the healthy brain have
started to unravel,
as shown by a PubMed
search with microglia
in the title in all fields.
There were only few
papers published on
the topic before the 1990s,
and then a steady increase
until the beginning
of our century,
leading to an exponential
growth of microglial research.
There is the first
inflection point in 2005,
with the seminal discovery using
non-invasive two-photon
in vivo imaging,
that microglia, which used
to be called resting or
quiescent in the healthy
brain, are extremely dynamic.
Continuously surveying
the parenchyma
with their highly
motile processes.
There is a second
inflection point in 2010,
coinciding with the
discovery of their
exclusive origin from
the embryonic yolk site.
Microglia infiltrate
the brain during
embryonic development and they
stayed there throughout life,
maintaining their numbers
through self-renewal.
For more information regarding
the first description
of microglia,
I invite you to read
the Translation,
by Amanda Sierra,
published in the journal, Glia,
of the original work by
Pio del Rio-Hortega,
considered the Big-Bang
of Modern Glial Biology
Also, this recent review
on Microglial History
in Trends in Neurosciences.
