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neuroscience

The brain in action

Experiment on patients with Parkinson's disease suggests that the electrical activity of neurons could move prostheses

DUKE UNIVERSITY PHOTOGRAPHYNicolelis with a mechanical arm: The use of electrical brain signals to move prosthesesDUKE UNIVERSITY PHOTOGRAPHY

Established for more than a decade and a half in the United States, where he has distinguished himself as one of the exponents of the creation of interfaces for the control of prostheses and machines via brain signals, the Miguel Nicolelis, 43 years of age, born in the city of São Paulo, last month saw two of his major dreams take a step forward towards reality.

At the beginning of March, the scientist promoted a highly successful symposium on neurosciences in Natal, which brought together close to 700 participants, from here and abroad, among them the German Erwin Neher, from the Max Planck Institute of Chemistry Biophysics, the winner of the Nobel Prize for Medicine and Physiology in 1991. In practice, the event served to officially launch his project for the building of an international neurosciences institute in the capital of the state of Rio Grande do Norte.

On the 23rd of the month, already back at Duke University in North Carolina, where he runs a laboratory with forty researchers, the neurologist announced the results of an experiment recently carried out by his team on human beings. It is the theme of a scientific paper to be published in July in the magazine Neurosurgery. The study indicates that in theory man, in the same way as had been concretely demonstrated with monkeys, could control robots and prostheses by way of the electrical activity of his neurons, or as a layman might say, “by force of thought.”

Thanks to 32 microelectrodes temporarily implanted in a region of the brain of eleven individuals with Parkinson’s disease that had been submitted to a type of neurosurgery aimed to reduce the symptoms of the disease, the researchers managed to register, during a five-minute period for each patient, signals emitted by up to fifty nerve cells while the patients played with one of his hands on the control of a very elementary video game. “We made use of this routine operation, in which the patients remain awake and conscious, to carry out our experiment”, Nicolelis tells.

The group of signals recorded is the electrical signature that precedes and directs the movements carried out by the patient’s hand in order to carry out the task in question. In non-scientific terms, this could be described as the order or orders that a portion of the nervous system sends when it wants to move a determined part of the body.

According to the Brazilian scientist, this is good news: the recording of the electrical activity of this half a hundred neurons, situated in a deep region of the brain called the nucleus of the base, carries sufficient information for a computer, set up with mathematical programs created by the Duke team, to be able to anticipate the type of mechanical movement ordered by the brain. “In this manner we demonstrated that our methodology can also work on human beings”, Nicolelis says.

There is an infinitely small time difference, of some milliseconds, between the moment at which the order leaves the central nervous system and the motor gesture – requested by the brain – is effectively carried out. For a prosthesis implanted in a human, say a mechanical arm, in order to function in a manner similar to that of the substituted organ, the interface between the brain and the machine would have to exactly predict the requested movements and almost instantaneously send the order.

Apparently, the experiment with the patients suffering from Parkinson’s disease showed that the quantity of information provided by the electrical activity of fifty human neurons, captured by the arrangement of microelectrodes, is sufficient for the system to work happily. The next step will be to repeat in humans that which has already been achieved with monkeys: to move, in real time, a mechanical arm using only the electrical activity of a group of nerve cells.

In the animals, the microelectrodes of Duke captured the signals from 300 neurons of the cortex motor, which showed themselves efficient in moving the electrical arm needed to play a videogame. Authorization for carrying out a similar experiment with human volunteers should be finalized at the end of this year. Optimist and enthusiastic by nature, Nicolelis believes that, in less than a decade, paraplegics or people with paralysis coming from health problems such as a stroke, could benefit from prostheses and machines that would be moved by brain signals.

“Two years ago it was believed that this was only going to occur ten years from now. Now this time scale is estimated at five”, the brazilian researcher says. In his vision, the major difficulties in the near future for man to begin to command machines with his brain resides more in the field of bioengineering than in neurology itself. The even greater miniaturizing of microelectrodes and the creation of interfaces “machine/man” without wires are points to be attacked with greater emphasis from here onwards.

After all, nobody is imagining that patients making use of hypothetical artifacts moved by brain signals will be condemned to go out into the streets with a head full of wires on show. The implantation of arrangements of microelectrodes in regions of the brain, an invasive procedure in a delicate area of the human body, could bring about some type of adverse reaction, infection or damage some nerve function. Even at that, Nicolelis is convinced that this problem will also be overcome. “The implants (electrodes) will be considered as invasive as pacemakers were in the past”, the neurologist argues.

Neuroscience in Natal
It may appear that the dream of moving machines through the electrical activity of neurons, an objective equally pursued by other research groups in the United States, outside of Duke University, has nothing to do with the idea of establishing an international neuroscience institute in the capital of Rio Grande do Norte, a more personal dream from Nicolelis. The researcher Idan Segev, from the Hebrew University of Jerusalem, who participated in the neurosciences symposium that took place last month in Natal, believes that one thing has everything to do with the other.

“People only took the project of establishing an institute here seriously because they respect and admire Miguel’s work”, said Dr. Segev, during his stay in the Northeast. “At just over forty, he is a fantastic scientist. Nobody would pay much attention to him if his research weren’t so brilliant.” Segev’s opinion is that of a renowned colleague in the profession and also that of a very close friend of the Brazilian.

Besides showing contagious eloquence, Nicolelis has many connections. Not just those of the brain, but also in his social life. He knows how to make friends and to influence people, to use a worn out phrase. The Israeli Segev, for example, was the person who convinced Erwin Neher, the German Nobel Prize winner, who did not personally know the Brazilian, to take the plane to Natal in order to participate in the symposium and to lend his support to the project for the neuroscience institute. “It’s a daring idea”, Neher stated.

“I’ve already seen a similar project in Chile, but there they didn’t have all of this social aspect.” The social side is the school for public school children and the mental health center, planned to function in the same area that will house the neuroscience research center. That is if the project gets off the drawing table three years from now as its creator forecasts. According to Nicolelis, the cost for the implementation of the enterprise revolves around US$ 30 million, a considerable sum in the world of Brazilian science.

For the time being the Brazilian has already managed some weighty support for the initiative, which aims to decentralize scientific production in the area of neurosciences from the South-Southeast. The government of Rio Grande do Norte has promised to implant the necessary infrastructure (light, water and road) in the location where the institute should function. The University of Rio Grande do Norte (UFRN), which has a neuroscience research center is ceding 100 hectares of land next to its agricultural school.

The location is not situated exactly in front of the sea. It is in the municipality of Macaíba, in the metropolitan region of Natal, half an hour from it. Counting up all the money obtained through development agencies and federal government ministries, Nicolelis can use R$ 4.5 million for the institute project. Certainly influenced by examples of American research foundations, which obtain fat donations from private companies and individuals for their coffers, the Brazilian founded the Alberto Santos Dumont Foundation, a private non-profit entity, and is wagering on securing non-public resources for his project. Up until now, the major private donation managed was from Duke University, Nicolelis’s employer, which donated US$ 50,000.

The president of the Central Bank of Brazil, Henrique Meirelles, is a member of the Foundation’s Council. Henrique Meirelles is a friend of the Brazilian neuroscientist Claudio Mello, from Oregon’s University of Health and Science. Settled some fifteen years in the United States, Mello is a kind of right hand man of Nicolelis in the project for establishing the international institute in Natal, along with another Brazilian Sidarta Ribeiro, from Duke University. The proof of Nicolelis’s prestige lies in the fact that president Meirelles attended the neurosciences symposium in Natal.

The minister of Science and Technology, Eduardo Campos, also showed up at the event. A few days after the symposium, Nicolelis was received by Brazilian president Luiz Inácio Lula da Silva at the Planalto Palace, in Brasilia. As well as science, they must have spoken about a common passion: football. The researcher is an avid supporter of Palmeiras. Lula is a devout Corinthian fan, but this must not have been a reason for any serious divergence.

For his undeniable scientific competence, involving personality and excellent connections, inside and outside of the laboratory, the Brazilian, who makes monkeys play on videogames with the force of thought, is unconditionally wagering on the concrete realization of his dream of building an international neuroscience institute on the soil of Natal.

Sometimes he speaks as if the project was already a reality. He even announced that he intends establishing a network of institutes in the North-Northeast specializing in other scientific areas. However, before this some details concerning the (possible) working of neurosciences in Natal will have to be debated and clarified within the scientific community.

What will be their line of research? Who will work at the institute? What will be the relationship with the UFRN, which will be there right beside it, and with other research centers in Brazil and abroad? “Nicolelis is very persistent and we support his project”, says Maria Bernadete de Sousa, assistant pro-rector of research at UFRN. “But we still need to discuss a lot about how the institute will function.”

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