Scientists from Russia have adapted «thermovisor» snakes to control mice brain

© Fotolia / ktsdesignНейрон brainScientists from Russia have adapted «thermovisor» snakes to control mice brain© Fotolia / ktsdesign

. Biochemists from Russia has created a new technique «on» and «off» nerve cells, which allows you to control individual neurons in the brain and other parts of the body, using the genes of snakes, «seeing» the heat said in an article published in the journal Nature Communications.

«Scientists have long been interested in the question of how we can point to control neurons. To carry out the idea was only in 2005 when a group of researchers from Stanford University under the direction of Karl Disserta could change the neurons genetic engineering methods and to excite nerve cells, showering them with light. This method called optogenetics – the combination of optics and genetics,» — says Yulia Ermakova of the Institute of Bioorganic chemistry in Moscow.

This technology is widely used today in experiments on animals in which scientists study the functions of the different chains of nerve cells of the brain and individual nerve cells. These experiments help neuroscientists and clinicians to find new ways to treat epilepsy, memory loss and other disorders associated with a failure in «communication» neurons and parts of brain with each other.

It tells Vsevolod Belousov, the head of research of the Institute of Bioorganic chemistry, the main problem of optogenetics is the light itself. Particles of visible light is extremely bad and pass through the tissues of a living body, which scientists have to implant fibers in the brain of animals, which prevents the study of the deepest layers of nerve cells within it and observations of the brain of fishes and other sea creatures. In addition, many animals see blue laser pulses used for irradiation of cells, and scare them, which also interferes with experiments.

Russian scientists managed to develop this idea to its logical end by creating a new version of optogenetics, which works with visible and infrared light, using genes that snakes used for his «imager». Reptiles use them to «see» heat sources, including mice and other potential victims, by converting infrared radiation into impulses of neurons.

Belousov and his colleagues have wondered whether it is possible to teach the nerve cells in the brain of mice and other animals to do the same, planting snakes genes in their DNA. They tested this idea by inserting the gene for TRPA1 that are responsible for this role in the genome promiscuousity, in the DNA of neurons, which they cultivated in vitro.

To implement this scheme, the biologists had to seek the assistance of physicists from Moscow state University, which created for them a special sensitive thermometer is able to measure the temperature at the level of single cells. This was necessary in order to prevent the irradiated cell literally «boil» when it is «turned on» by laser.

This operation, as shown by experiments on these cells, made the cells very sensitive to heat sources, they begin to emit pulses literally milliseconds after irradiation of an infrared laser. This allows the use of this method of brain stimulation to observe the rather complex and fast processes inside it.

Implementing this idea in practice, Belousov and his colleagues have tested it in experiments on real animals, TRPA1 built-in part of the neurons of the usual aquarium fish Danio rerio, which is responsible for touch recognition. After that, the researchers illuminated the body of a fish with a laser and watched their reaction.

As shown by these experiments, fish whose neurons were embedded «snake» genes «felt» invisible touch laser and tried to escape from an unseen enemy. Fish with a missing TRPA1 were not so themselves, which confirmed the efficiency of this technique, which Belousov and his team called «thermogenetic» by analogy with optogenetics.