XPP | Unlocking the Secrets of Brain Signals

This video describes the function and 3-D structure of a protein complex that provides the ultrafast trigger for chemical messages sent between nerve cells in our brains. The details of this structure, brought to light in an experiment at SLAC’s Linac Coherent Light Source X-ray laser, provide a new understanding of the molecular machinery driving brain function.



inside each of our brains there are

roughly 100 billion highly specialized

cells called neurons that make about 500

trillion connections called synapses

these unique cells transmit important

information allowing us to sense and

interact with the world around us if you

were to take a closer look you would see

that this information is transmitted

between neurons using chemicals called

neurotransmitters where tiny structures

called synaptic vesicles fuse with the

membrane of one neuron and release

chemical signals into the gap where the

second neuron can receive them

scientists already knew some about how

this neurotransmission process works but

now thanks in part to over 10 years of

collaborative research between Stanford

University and SLAC National Accelerator

Laboratory along with the ultra-bright

x-rays of slack's Stanford synchrotron

radiation light source and linic

coherent light source scientists now

have a better idea of exactly how these

tiny vesicles might fuse with the

membrane of one neuron to transmit their

signals the key to this fusion is a

cooperation between special proteins

called snares and synaptotagmin one that

are then triggered by calcium to cause

the vesicle to fuse with the membrane of

the neuron when a synaptic vesicle comes

close enough to the membrane the

proteins connect with the two and enter

a pre fusion state next when the neuron

fires calcium arrives and triggers the

proteins which bend the neuronal

membrane toward the vesicle membrane and

draw the two together this finally

triggers fusion allowing the

neurotransmitters to leave the neuron

this experiment represents the first

time that scientists have seen how

synaptotagmin one interacts with the

snares at the atomic scale and

scientists are now also more confident

that this protein group is assembled

before calcium arrives allowing the

fusion process and resulting

neurotransmission to happen very quickly

getting information from point A to

point B in less than a millisecond the

end result is that our nervous system

can work at incredible speeds enabling

us to sense react to and interact with

the world around us and now that

scientists have been able to use the

bright x-rays of s srl the LCLs and the

ANL aps light source to see how this

particular process works it opens the

door to better understand our nervous

system in ways that even our brains

can't yet

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