A research team led by Ana Domingos of Portugal, the Institute has developed a new genetic technique that eliminates specific neurons of the peripheral nervous system, without affecting the brain. Using a new technique in rodents, we studied the function of the neurons that innervate adipose tissue, and saw that their removal leads to rapid weight gain. Published April 3 in Nature Communications, this method opens up new ways of studying diseases related to the peripheral nervous system and the other outside the brain cells.
Intrigued by the study of the neurobiological mechanisms underlying obesity, laboratory A. Domingos found a set of neurons that innervate adipose tissue, and showed that the direct activation of these neurons to burn fat. Then the researchers analyzed whether the mice gained weight in the absence of peripheral neurons.
In order to develop a method Domingos laboratory worked with a chemist Gonzalo Bernardes from the Institute of Molecular Medicine of Portugal. The research team modified molecular tool based on diphtheria toxin. The toxin kills only cells that contain its receptor. He has been artificially introduced into the cells that need to be studied. Scientists injected the rodents receptor of diphtheria toxin (including neurons of the brain that scientists do not want to remove). "The problem is that we could not use this molecular tool for the elimination of peripheral neurons without affecting similar to neurons, which are also in the brain," - explains Ana Domingos.
To solve this problem, the research group is chemically modified diphtheria toxin, increasing its size, thereby limiting access to the brain. "Large molecules can not penetrate into the brain, so we made the toxin more," - says Ana Domingos.
Ines Mach from Domingos laboratory, author of the study, described the results: "We have removed the neurons from the adipose tissue of mice without affecting the brain. By comparing mice with peripheral neurons, and without them, we observed similar behavior in the food. However, mice that lacked the sympathetic neurons, to quickly gain weight. " According to A. Domingos, the new method makes it possible to check the operation of neurons that innervate adipose tissue to maintain normal weight gain.