SNAREs at the Synapse

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Using tiny lipid discs, scientists resolve contradictory evidence about how many proteins are required for neurotransmitter release.


EDITOR’S CHOICE IN NEUROSCIENCE

There is very little about membrane vesicle fusion that Yale University biochemist James Rothman doesn’t know—he codiscovered SNAREs, the proteins that orchestrate the process. But one unanswered question in the field of membrane fusion has been what happens during the first milliseconds of synaptic transmission between neurons—when a vesicle full of neurotransmitters inside a neuron fuses to the cell membrane, opening a pore to release its contents into the synapse.

A fusion pore, the opening that occurs when a vesicle binds to a cell membrane, is present for just hundreds of microseconds, a thousand times shorter than the blink of an eye. Immediately after it opens, the pore rapidly expands as the vesicle membrane melts into the surrounding cell membrane. That quick transition has made it extremely difficult to study the pore, says Rothman. “We thought that if we could find a way to artificially stabilize the fusion pore, without interfering with its opening, we might be able to gain some new insights into neurotransmission,” he said.

To do so, Rothman’s group, together with Frédéric Pincet’s team at CNRS in Paris, France, created fusion pores in nanodiscs—circular discs of lipid bilayers, held together by scaffold proteins wrapped around each lipid disc like a belt. Because of the nanodiscs’ small size and rigid structure, a fusion pore can form but does not expand beyond 2 nm, essentially freezing the pore in place for analysis.

Written By: Megan Scudellari
continue to source article at the-scientist.com

4 COMMENTS

  1. Please excuse my French but this stuff is fucking amazing.  If I could do my life over again there is absolutely no doubt I’d become involved in brain research.

    One could almost be pardoned for thinking an Intelligent Designer is responsible.  That is, until one recognizes that all the incredible mechanisms and biological widgets we see in biology are only the successful ones.  The vast majority of the other crazy, Rube Goldberg, non-intelligent schemes didn’t work and were ousted by Natural Selection.

    Nature discarded her many, many failures, in other words, and all we see are the showpieces.

  2. Good question, Susan.  A little experiment I performed might shed some light on the answer.

    On a different website, I read an article on athletes publicly praising God for their victories/successes.  I posted a couple of critical comments, and received the following reply:

    I dont believe one of the athletes said that God won for them or let them win.Im with you on that Christians, Jews, , Catholics, Buddists or athiests [sic] all have the same chance of winning. All they did was thank God for the knowledge and ability to be able to win. You may have all the ability in the world, but its up to the individual how they use it. They are just being humble and thanking the one they think is responsible.

    True believers apparently think they’re being “humble” when they attribute things to God.  I would think the same thing applies here.  Slapping one’s forehead and saying “Wow. The glory of God’s work! is simply how a good Christian expresses humility.  NFL quarterback Tim Tebow is the best modern example.

    This is a big problem, in my opinion, because when you’re critical of this practice, believers think you’re telling them to be arrogant and selfish.

    Once again, religion poisons everything.

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