July 15th, 2015 Text by WebContent
Neural probes are widely used today in neuroscience research and have many applications. These small needles, when inserted into the brain, allow the stimulation of specific regions and the recording of electrical activity. However, they are not yet produced in Brazil. With that in mind, one of BRAINN’s projects is to develop neural probes in the country for the first time.
“In 2010, researcher Hercules Neves invited me to be part of an European project of which he was coordinator, called Neuroprobes” says Roberto Panepucci, one of the researchers in BRAINN’s neural probes project. “The following year I came in contact with BRAINN, and we realized that developing neural probes here would be an interesting project.”
The activities began in 2012 with two master projects, supervised by Panepucci. Students André Malavazi and Jesus Arbey developed prototypes of the probes in the Renato Archer Information Technology Center (CTI), which have been tested with promising results.
PROBES MADE IN BRAZIL
“During electrical activity recording tests stimulated by light pulses in live animals, our probes proved to be better than the ones already available on the market,” says Panepucci. “The silicon used in neural probes being sold today absorbs light and generates an electrical interference in the neural signal. Our probes are made from polymers, so this effect was significantly reduced, caused only by interaction with the metal”.
Besides their usefulness to scientific research, neural probes produced in the country could also bring economic advantages and might be easier to obtain.
“Currently, researchers working with neural probes in Brazil need to import them,” says Roberto Covolan, one of the project’s coordinators. “By producing these devices in the country, bureaucracies related to the importing process would be avoided. The cost of the probes would also be reduced”.
TECHNOLOGICAL INNOVATION AND CUSTOMIZATION
One of the challenges related to neural probes is data transfer. Since the probes have many electrodes, they need to be connected to many wires. This could make it difficult to carry out experiments and may limit the minimum size of the apparatus. “For these reasons, we are now working on the development of probes that can transmit information wirelessly,” says Covolan.
The next steps of the project involve making the neural probes available to several research groups that have shown interest in the equipment.
“One of the main advantages of developing probes here is the possibility of customization,” says Panepucci. “We created a software that lets you easily draw the probes and build a prototype from it. This way the probe can be made according to the demands of the researcher“.
André Vieira, postdoctoral student at FCM/Unicamp, is one of the scientists already interested in the neural probes. Vieira works with the molecular mechanisms of epilepsy, and part of his research involves the stimulation and the recording of brain activity in animals, particularly in the hippocampus area.
Vieira has conducted tests of mechanical nature with the equipment and noticed, for instance, that in order to use them it is necessary to remove the dura-mater, the outermost layer of meninges that surround the brain. According to Vieira, this procedure might bring advantages to the experiments, as the probe would be better fixed in the brain and would thus reduce the chances of tissue injury. And the advantages of the probes go on and on.
“With neural probes it is also possible to simultaneously record activities in different regions of the hippocampus, which is not possible with an electrode,” he says. “In addition, we can isolate the activity of individual neurons”.
The next step in Vieira’s project is to carry out electrical activity recording tests. For these he will use a custom-made neural probe, which will have a greater length I order to reach the hippocampus. “We intend to conduct these tests in the upcoming months,” he says.