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It is near the millenium and there is great enthusiasm over the decoding of the code of life. We all had great expectations about the Human genome Project.
Our DNA is a code consisting of 4 letters: A, G, C, T. These letters produce myriads of proteins that are the building blocks of life. Nature uses a minimalistic approach is it’s code which leads to higher and higher complexity in the bottom up approach of building live creatures.
The majority of scientists believed that when we decode the human DNA we would have in our disposition all the necessary guidelines to treat genetic diseases!
Then came the first surprize… It was believed that organisms with higher complexity (e.g. human population) should have greater number of genes. In fact we have the same number of genes as mice: About 30.000. There are insects that have larger pool of genes.
The second surprize that came about is that it is not all about genes. The code is not linear. Is it the interaction of genes with molecular and geometrical switches that turn on and off the genes that leads to the expression of the genome.
We realized that the phenotype (the results of genes expression) is much more complex than the sole expression of genes. Genes are turned on and off with analogy to environment pressure and this leads to the same phenotype.
Result: Two organisms with exactly the same genome will express different phenotype in different environment. It has already been seen in monozygote (with exactly the same DNA) twins.
Some scientists expected that this would happen. Zygote, which is the ovary with the DNA of the spermatocyte, contains all the necessary information to build an organism. Every cell in the zygote has exactly the same DNA. But cells differentiate to give the tissues. Necessary genes are switched on during this procedure and others are turned off. There has to be switches.
Moreover, genetic diseases with the same depletion of a part of a chromosome lead to different manifestations of the disease. This means that some genes have to be regulated accordingly for this to happen.
Epigenetics (from the greek work epi- that means above) is the new science that studies the complex mechanisms of genes being turned on and off according to environmental ques. Genome is very stable. Mutations are seldom. On the other hand the environment is very volatile. In order for the species to survive the genome has mechanisms that respond to the volatile environment by turning on and off genes.
The way genes are regulated is not well understood. Methylation of same letters of a gene is one possible mechanism. Other possibility is a specific mechanical interaction between DNA and it’s interwinding proteins, histones. Heavy research is concentrated on how epigenetics work.
There are also indications that epigenetic changes are inherited to the ancestors. This is a radical change of our frame of mind. Our lifestyle and how the environment (or our choices, e.g. smoking) affects our genes, will be inherited to our ancestors!
Epigenetics should play crucial role in the manifestation of cancer and experiemental trials are already successful in MDS ( a type of cancer).
Neural activity produces electricity and vice versa, that is by applying electrical stimuli you can activate brain regions (you may activate brain regions by applying magnetic fields as per basic principles of electromagnetism, which is called TMS or Transcranial Magnetic Stimulation, google it for more…).
The problem of direct electrical stimuli to the brain is that due to high density of the neurons (brain is too evolved for this small scull) the stimuli diffuse. It is very difficult to localize the electrical stimuli with current technology. You need too thin electrodes, precision of the implanted device and many many other.
There is a way to go around the problem and this is a disruptive techology. It is called optogenetics and has only a few years that came into play. Optogenetics offers the potential to localize the external electrical stimuli to a single type of neurons or brain region.
It is achieved by inserting a gene responsible for the translation of channelrhodopsin 2 (ChR2) protein. This is a protein that is responsive to light and causes the neurons that produce it to react upon blue light stimuli.
The light does not have to be localized. The genetically altered neurons that respond to light are!
This technology has great importance for neuroscience. Medtronic scientists already work on it as a long term project. ( gene therapy has to be established prior optogenetics for human). Click here for more.
Animal testings have great success and provided great insight on the inner workings of brain. Google “optogenetics” to learn more about the history of this recent exciting discovery…
What is the advantage of this? Current implants diffure the stimuli to other brain regions causing side effects like nausea. Tissue response to brain implant which has to be in contact with brain leads to gradual rejection of the implant.
Optogenetic implants will provide the necessary brain region control to very localized and specific brain regions, without even having to be in contact with brain.
Moreover, if other proteins that react to other wavelenght of light are discovered then the damaged brain region may be controlled remotely…(for now science fiction of mind control only…)
Future has a lot of surprises in it’s pockets…
If you want some basic literature on optogenetics I suggest the following articles:
[1] Neuroscience: Controlling neural circuits with light, Michael Häusser & Spencer L. Smith, Nature446, 617-619 (5 April 2007) | doi:10.1038/446617a
[2] Ultrafast optogenetic control, Lisa A Gunaydin, Ofer Yizhar, André Berndt, Vikaas S Sohal, Karl Deisseroth & Peter Hegemann, Nature Neuroscience13, 387 – 392 (2010), doi:10.1038/nn.2495
Till later,
Nano L.A.>
Neuroscience: Controlling neural circuits with lightMichael Häusser1 & Spencer L. Smith1
Quantum mechanics seems to play a crucial role in the atomic world.
Great deal you might say. Quantum mechanics is for theorists that want to dig into the atomic world.
This is not true. If it wasn’t for quantum mechanics life would not even exist. Quantum mechanics is a model of how things in the atomic scale behave but these quantum mechanisms affect the macro scale from the bottom up.
The most impressive of all is that scientists are starting to realize that nature has used the quantum weird behavior and exlpoited it to create effective systems that are embedded in live creatures.
One great example is a model of our smell. Prior theories have proposed a key and lock mechanism (very common to theories in biology and medicine). This model suggests that if an odor molecule finds the correct receptor that has complementary shape then it ignites the smell. Look the image below. Nevertheless, there are some important features of smell that this model could not explain. For example, how molecules with the same shape smell very differently? This fact renders the model above useless.
In 1997 Luca Turin proposed a different model for the smell. He proposed that electrons from the odor receptor, tunnel through the molecule with the correct, analogous to the receptor, vibration. This tunneling causes the nerve attached to the receptor to ingite and produce the signal that brain interprets as smell.
Tunnelling effect is a quantum phenomenon where an electron due to its wave matter properties can surpass an energy barrier that classically would not have the energy to pass over. The probability is low but the tunnelling is possible. It is like you passing through a wall! (of course you are not electron
This is a much more robust model that explains the phenomenon of almost same molecules producing different odor. We know that even an atom could cause a shift in the vibrational modes of a molecule and thus produce a different energy barrier. If a molecule differs in a single atom from another, then the tunneling will not happen in the receptor causing the receptor not to fire signals to the brain. This explains the selectivity of the receptors for almost the same molecules. The tunneling of the electrons depends on the interaction and the energy barrier created by the molecule and the receptor combined.
We see now how important is quantum mechanics to our everyday life. QM will play crucial role in the future as we explain more and more biological phenomena that quantum weirdness comes into play. In another article I will write about the quantum mechanics interpretation of consiousness and brain function as Prof. Nanopoulos has imagined it and the importance of quantum mechanics in photosynthesis which is the source of life in our planet.
If you want more technical details about the QM model of smell you may download the original article here
A guy at Google has created a 6 screen environment that uses Google Earth’s flight simulator machine to navigate.
The results are spectacular. An immersive environment. Imagine in a few years…
We will be using Google Earth to travel virtually anywhere in the world. More and more data will be available until this virtual travel will be more life like.
Our life is not enough to travel anywhere in our planet. I would like to have this virtual travelling option in the future.
For now let’s enjoy the video of this virtual spaceship like flight…
Take a look at the video the guys created.I liked it very much.
They will update the software with phone connection capability, GPS, emergency, connection to buddy, g force meter and many more. The possibilities are endless.
The HUD system keeps data on the performance of the skier and can create sheets and graphs upon connection to a PC.
I would like to see this type of techology for motorbike helmets also.
HUD is coming to commercial products (till now it was available only to military) and we will be seeing it more and more of these products in the future.
This trend is part of the augmented reality movement which is the precursor of virtual reality.
The problem with this technology now is the big dark lens needed to project the image. That is why the goggles seemed like a commercially viable product (nobody would wear this for sunglasses , even if it had Armani signature on it
There are some commercial glasses intended for watching movies or connection to your PC or iPhone but are not transparent so they cannot be considered HUD. (nevertheless with a minor hack, like connecting these Glasses to your iPhone and turning on your camera, these can be a good augmenting reality tool).
I have not tried yet these products but I am really temptated. See them here: http://www.myvu.com/
I created this blog because I want to share my passion in science and techology with other people. Hopefully this will bring me closer to people sharing the same interest.
I am going to give only exciting news about the state of the art in nanotechnology, nanomedicine and other technological advances, plus the latest technological Gadgets!
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Nevertheless, there are some important features of smell that this model could not explain. For example, how molecules with the same shape smell very differently? This fact renders the model above useless.
This is a much more robust model that explains the phenomenon of almost same molecules producing different odor. We know that even an atom could cause a shift in the vibrational modes of a molecule and thus produce a different energy barrier. If a molecule differs in a single atom from another, then the tunneling will not happen in the receptor causing the receptor not to fire signals to the brain. This explains the selectivity of the receptors for almost the same molecules. The tunneling of the electrons depends on the interaction and the energy barrier created by the molecule and the receptor combined.
Look what I’ve came across!
