A new idea for treating brain injury doesn't involve fixing the damaged regions. Instead, researchers want to detour neural impulses around the damage.
Scientists used to think of the brain as an collection of discrete parts, with different regions taking charge of different neural functions. Today's emerging model of brain activity indicates that even a simple act of perception or cognition involves many different brain regions. Several projects are devoted to mapping those complex webs of interconnections, collectively known as the connectome.
The current experiment on brain injury banks on the idea that a lesion in the brain may be disruptive partially because it interrupts some neural circuit. The researchers, from Case Western Reserve University and the Kansas University Medical Center, thought that a little judicious rewiring could solve the problem.
In the study, researchers caused brain injuries in rats' caudal forelimb area, which is involved in the movement of the rats' front legs. That brain region typically processes information from a sensory area that provides information about the limbs' positions, and it sends on the command to the premotor cortex, which in turn conveys the command to the spinal cord. In these injured rats, though, the signal couldn't make it past the sensory area. A rat presented with food pellets will still try to grab them, but it will grope around almost at random, and will have little success in nabbing the food.
To restore function, researchers implanted a microdevice in the rats. One set of electrodes recorded and digitized the signals in the sensory area, then the signal was routed to another set of electrodes in the premotor cortex, where they delivered precise electrical pulses. When these cyborg rats were tested for their pellet-grabbing skills, they performed almost as well as uninjured animals.
The video below tells the tale. Warning: Don't watch if you don't want to look at post-brain-surgery rats. They have a somewhat Frankenstein-like appearance.
Such technology could one day help a broad swath of people who suffer from traumatic brain injury, including football players, war veterans, trauma victims, and stroke patients.
Image and video: David J. Guggenmos et al.
Eliza Strickland is a senior editor at IEEE Spectrum, where she covers AI, biomedical engineering, and other topics. She holds a master’s degree in journalism from Columbia University.