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Posted by on Oct 26, 2012 in Science |

DNA mapping Brain

Brain mapping DNA

In addition to technology, life sciences are the star of S. XXI. Among them, genetics plays an important role. Moreover called genetic engineering. A new approach tries to know the connection map of the brain, using DNA connectome. The project is witty, surprising and ambitious.

Advances in have allowed researchers are in an ideal location: manipulating a giant Lego pieces to create gene sequences using the computer without almost having to get their hands dirty in the lab. Using components of life, build bodies, or parts of them, which did not exist. The power that entails is now barely imagined. An incredible future is in your hands.

The human brain consists of 85 billion neurons connected by junctions called synapses. The map of these connections is called connectome . The manner in which neurons are connected is critical and largely determines behavior. Advance knowledge of the connectome is essential to know how the brain works.

So far there are two ways of knowing the connectome. One of them is based on the MRI . With this you can learn how water diffuses in major connecting roads, nerves or white matter. This method progresses gradually.

Another method is to go retail . We put a piece of brain under a microscope. Rebanamos a layer and take a picture. Rebanamos another layer and take the next picture. Then the computer build a 3D image of the shots taken. This microscopic method progresses very slowly.

Anthony Zador’s team has proposed another technique that is still under design with a little experimentation (the technique is not based on human brains). Regardless of the technique to be successful, reveals the tremendous imagination of genetic engineering. The method is called BOINC (barcoding of single neuronal connections or barcodes of individual neural connections). Let us see what so great audacity.

Firstly it is a barcode assigned to each individual neuron gene. The genetic code or DNA comprises a huge amount of four nitrogenous bases, four letters calls or calls Lego four parts A, T, C and G. The idea is to apply a recombinase enzymes called DNA part. If the part is sufficiently large and applies a sufficiently high number of recombination, the probability that each neuron has a different sequence from the rest is very high. That is, each neuron will have a different bar code (actually a sequence of letters in the DNA than the other neurons). Then other enzymes these barcodes separated from the rest of the genome and packaged into molecules called plasmids.

In the next step involves the virus, in particular herpes-like virus. The herpes virus can jump from one neuron to another through synapses. In its benign form, the herpes virus is hidden until, for example in a lowering of defenses or under stress may develop. Then follows a nerve and appears on the skin. This is the case of the common cold sores or fever.

Now than it is to get the DNA barcodes behave like a virus. Each barcode jumps a synapse and infect neighboring neurons. But yes, just one jump. Thus, each barcode infects the next neuron and stops. Thus each neuron containing barcode own of neurons and with which it is connected (but not all the neurons that are beyond a single hop synaptic).

With another enzyme packages created two barcodes: the neuron itself and the connected neuron. Suppose we have four neurons online. Their barcodes would be A, B, C and D. The neuron A would have the package AB, neuron B would have the AB and BC. The BC and C have the CD and CD D only.

Finally, crush the brain and extract all existing pairs. These pairs of bar codes indicate full connectivity of the brain.

Easy? Conceptually if experimentally is enough. Zador and his team have worked with a crop of several hundred neurons with promising results. It helps the tremendous cheapening of genome sequencing techniques and calculated that for less than 50,000 euros will map the connectome of the mouse brain.

Genetic engineering is a formidable technology and can scarcely imagine what it will be capable of.

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