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0:00
ELEK MOLNAR: Hello, my
name is Elek Molnar.
I'm Professor of Neuroscience
at the School of Physiology
and Pharmacology, University
Bristol, in the United Kingdom.
In this talk, I'm going to discuss
different localization techniques
for the investigation
of ionotropic glutamate
receptors in the
central nervous system.
0:20
I will start with the introduction
of the molecular organization
and functional properties
of glutamate receptors,
then I will overview the
main strategies you will use
for the localization of
endogenous glutamate receptors
in the central nervous system.
I will also discussed
special challenges.
Then, I will overview the various
advantages and limitations
of glutamate receptor
localization strategies.
0:46
Glutamate is a single minus 8,
which is responsible for most fast
information transfer in
the central nervous system.
The excitatory neurotransmitter
role of glutamate
gradually emerged in
the '50s and '60s.
Early studies identified
that glutamate
was present in high
concentration throughout
the mammalian central
nervous system.
It Produced convulsions
and excited single neurons.
The development of increasingly
specific pharmacological tools
during the '70s started to reveal
considerable functional diversity.
The family of glutamate-activated
cation channels,
called ionotropic
glutamate receptors,
was classified into three
major pharmacological families,
defined by their most selective
agonist, AMPA, Kainate, and NMDA.
Radio ligands were
produced, based on some
of these subtype-specific
agonists, which enabled
the first ionotropic glutamate
receptor localization
studies, using gold radiography.
In the mid '80s, a different type of
glutamate receptor was identified.
This glutamate receptor was directly
couples to a second messenger
system by GTP binding proteins and
metabotropic glutamate receptors.
However, ionotropic and
metabotropic glutamate receptors
remained elusive
until the late '80s.
The application of the newly
emerging expression cloning
approach led to a breakthrough,
and provided original sequence
information for the first
ionotropic glutamate
receptors, GluA1 and GluN1.
Metabotrope Glutamate Receptor 1A,
the first member of this family,
was also discovered
by expression cloning.
Successive cloning by sequence
homology led to the identification
of additional ionotropic
glutamate receptor subunits
and various metabotropic
glutamate receptor
isoforms, plus various splice
variants, were identified.
The cloning of glutamate
receptors provided
a major stimulus for
localization studies.
In situ hybridization approach was
used to map the expression profile
of our messenger RNAs for various
glutamate receptor subunits.
The first antibodies
for glutamate receptors
started to appear in the early '90s.
Subsequent
immunolocalization studies
started to reveal the
subcellular distribution
of various glutamate
receptor proteins.
