A team of researchers has developed a wireless device the width of a human hair that can be implanted in the brain and activated by remote control to deliver drugs. The study was published in the journal Cell.
The technology, demonstrated for the first time in mice, one day may be used to treat pain, depression, epilepsy and other neurological disorders in people by targeting therapies to specific brain circuits, according to the researchers.
The research is a major step forward in pharmacology and builds on earlier work in optogenetics, a technology that makes individual brain cells sensitive to light and then activates those targeted populations of cells with flashes of light. Because it's not yet practical to re-engineer human neurons, the researchers made the tiny wireless devices capable of delivering drugs directly into the brain, with the remote push of a button.
Previous attempts to deliver drugs or other agents, such as enzymes or other compounds, to experimental animals have required the animals to be tethered to pumps and tubes that restricted their movement. But the new devices were built with four chambers to carry drugs directly into the brain. By activating brain cells with drugs and with light, the scientists are getting an unprecedented look at the inner workings of the brain.
As part of the study, the researchers showed that by delivering a drug to one side of an animal's brain, they could stimulate neurons involved in movement, which caused the mouse to move in a circle.
In other mice, shining a light directly onto brain cells expressing a light-sensitive protein prompted the release of dopamine, a neurotransmitter that rewarded the mice by making them feel good. The mice then returned to the same location in a maze to seek another reward. But the researchers were able to interfere with that light-activated pursuit by remotely controlling the release of a drug that blocks the action of dopamine on its receptors.
The researchers also believe that similar, more flexible devices could have applications in areas of the body other than the brain, including peripheral organs.
For now, the devices contain only four chambers for drugs, but in the future, the researchers hope to incorporate a design much like a printer's ink cartridge so that drugs can continue to be delivered to specific cells in the brain, or elsewhere in the body, for as long as required without the need to replace the entire device.
Based on material originally posted by Washington University School of Medicine.