synapse

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As Virginia Hughes noted in a recent piece for National Geographic’s Phenomena blog, the most common depiction of a synapse (that communicating junction between two neurons) is pretty simple:

External image

Signal molecules leave one neuron from that bulby thing, float across a gap, and are picked up by receptors on the other neuron. In this way, information is transmitted from cell to cell … and thinking is possible.

But thanks to a bunch of German scientists - we now have a much more complete and accurate picture. They’ve created the first scientifically accurate 3D model of a synaptic bouton (that bulby bit) complete with every protein and cytoskeletal element.

This effort has been made possible only by a collaboration of specialists in electron microscopy, super-resolution light microscopy (STED), mass spectrometry, and quantitative biochemistry.

says the press release. The model reveals a whole world of neuroscience waiting to be explored. Exciting stuff!

You can access the full video of their 3D model here.

Credit: Benjamin G. Wilhelm, Sunit Mandad, Sven Truckenbrodt, Katharina Kröhnert, Christina Schäfer, Burkhard Rammner, Seong Joo Koo, Gala A. Claßen, Michael Krauss, Volker Haucke, Henning Urlaub, Silvio O. Rizzoli

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The emotional sensitivity gene

Serotonin is one of the major neurotransmitters (i.e. chemicals) in the brain. It’s very connected to our emotions and so it’s not a coincidence that a lot of the drugs that are used to treat depression and anxiety act on the serotonin system in the brain. This is clearly a very important chemical for determining the nature of our emotional lives.

The serotonin transporter gene regulates serotonin in the brain. People are born with variations of this gene. The long variation clears serotonin out of the neural synapse more efficiently. The short variation is less efficient, which lets the serotonin hang around a little bit longer in the synapse. 

The short variation was originally considered a risk gene — but it’s now being thought of as a sensitivity gene.

Learn more about how the gene impacts our emotional responses →

Incredible and rare micrograph of a synapse 

Neuron cell body (purple) with numerous synapses (blue) magnified 80,000x under a scanning electron microscope.

Everone talks about synapses even though some seem to use it to sound cool without actually knowing what it is. So for those persons (and everyone willing to become a bit more educated), here’s a simple explanation.

Information from one neuron flows to another neuron across a synapse. The synapse contains a small gap separating neurons. 

The synapse consists of:

a presynaptic ending that contains neurotransmitters, mitochondria and other cell organelles,

a postsynaptic ending that contains receptor sites for neurotransmitters,

a synaptic cleft or space between the presynaptic and postsynaptic endings.

At the synaptic terminal (the presynaptic ending), an electrical impulse will trigger the migration of vesicles containing neurotransmitters toward the presynaptic membrane. The vesicle membrane will fuse with the presynaptic membrane releasing the neurotransmitters into the synaptic cleft. 

read more from Neurons Want Food 

Scientists to simulate human brain inside a supercomputer

Scientists at its forerunner, the Switzerland-based Blue Brain Project, have been working since 2005 to feed a computer with vast quantities of data and algorithms produced from studying tiny slivers of rodent gray matter.

Last month they announced a significant advancement when they were able to use their simulator to accurately predict the location of synapses in the neocortex, effectively mapping out the complex electrical brain circuitry through which thoughts travel.

Henry Markram, the South African-born neuroscientist who heads the project, said the breakthrough would have taken “decades, if not centuries” to chart using a real neocortex. He said it was proof their concept, dubbed “brain in a box” by Nature magazine, would work.

Now the team are joining forces with other scientists to create the Human Brain Project. As its name suggests, they aim to scale up their model to recreate an entire human brain.

It is a step that will need both a huge increase in funding and access to computers so advanced that they have yet to be built.

If their current bid for €1 billion ($1.3 billion) of European Commission funding over the next 10 years is successful, Markram predicts that his computer neuroscientists are a decade away from producing a synthetic mind that could, in theory, talk and interact in the same way humans do.

Unutarnji pismonose / Internal letter-carriers
by ~strybor  [Croatia]

ALLEGORICAL SCIENTIFIC ILLUSTRATION
SYNAPSES & NEUROTRANSMITTERS

  • The cages are pre-synaptic vesicles,
  • freeing the bird-neurotransmitters, which,
  • when they position themselves on the branches - receptors,
    activate the trees which then
  • make their roots transfer more messages into the neuron’s body.
One synapse, by itself, is more like a microprocessor–with both memory-storage and information-processing elements–than a mere on/off switch. In fact, one synapse may contain on the order of 1,000 molecular-scale switches. A single human brain has more switches than all the computers and routers and Internet connections on Earth.
—  Stephen Smith
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Tiny chip mimics brain, delivers supercomputer speed

Researchers Thursday unveiled a powerful new postage-stamp size chip delivering supercomputer performance using a process that mimics the human brain.

The so-called “neurosynaptic” chip is a breakthrough that opens a wide new range of computing possibilities from self-driving cars to artificial intelligence systems that can installed on a smartphone, the scientists say.

The researchers from IBM, Cornell Tech and collaborators from around the world said they took an entirely new approach in design compared with previous computer architecture, moving toward a system called “cognitive computing.”

“We have taken inspiration from the cerebral cortex to design this chip,” said IBM chief scientist for brain-inspired computing, Dharmendra Modha, referring to the command center of the brain.

Read more