Brain`s master switch `verified`
Washington: Scientists claim to have
verified the protein that has long been suspected of being the
master switch allowing brains to function.
A team, led by Yeon-Kyun Shin at Iowa State University
in the US, has shown that the protein called synaptotagmin1 is
the sole trigger for the release of neurotransmitters in the
brain, the `Science` journal reported.
Prior to this research, the protein Syt1 was thought
to be a part of the protein structure (not the sole protein) that triggered the release of neurotransmitters at 10 parts
per million of calcium.
"Syt1 was a suspect previously, but people were not
able to pinpoint that it`s the real one, even though there
were lots and lots of different trials.
"In this case, we are trying to show in the laboratory
that it`s the real one. So we excluded everything else, and
included SNARE proteins - that`s the machinery of the release,
and the Syt1 is a calcium-sensing timer," Shin said.
Syt1 senses, at 10 ppm of calcium, and tells the SNARE
complex to open pore to allow movement of neurotransmitters.
Brain activity occurs when neurotransmitters move into fusion
"We are showing that this Syt1 senses the calcium at
10 ppm, and sends the signal to the SNARE complex to open the
fusion pore. That is the process that we are showing right
now," Shin said.
The team was able to pinpoint the protein using a
new technique called single vesicle fusion method. Using this
method, they were able to create and monitor a single fusion
"We are quite excited that for the first time
we are showing that Syt1 is really what triggers the signal
in the brain. This is a really important thing in terms of
neurosciences. This is the heart of the molecular part of the
brain function," Shin said.