Researchers from UT Dallas explained how specific experiences, like sounds or movements, paired with nerve stimulation can reorganize the brain. This new technology could be the beginning of new treatments for tinnitus, autism, stroke, and other disorders.
The speed, at which the brain works in laboratory animals, could be altered by pairing stimulation of the vagus nerve with fast or slow sounds, according to UT Dallas neuroscientists in a related paper.
Dr. Robert Rennaker and Dr. Michael Kilgard led a group of researchers to examine if neural activity within the laboratory rats' primary motor cortex would change if it were repeatedly paired with vagus nerve stimulation with a specific movement. They used two groups of rats, pairing the vagus nerve stimulation with movements of the forelimb. The team published their findings in Cerebral Cortex.
The team analyzed the brain activity in response to the stimulation after 5 days of stimulation and movement pairing. They found that the rats that received the stimulation and the training displayed large changes in the organization of the brain's movement control system. Those that received identical motor training without stimulation pairing did not experience any brain changes, or plasticity.
Attempting to regain motor skills, people who suffer brain trauma or strokes may undergo rehabilitation that involves repeated movement of the affected limb. Experts believe that frequent use of the affected limb leads to reorganization of the brain vital to recovery.
This new research implies that pairing standard therapy with vagus nerve stimulation could result in a faster and more extensive reorganization of the brain. According to Rennaker, associate professor in The University of Texas at Dallas' School of Behavioral and Brain Sciences, this finding offers the potential to improve and speed up the recovery of a stroke victim.
"Our goal is to use the brain's natural neuromodulatory systems to enhance treatments for neurological conditions ranging from chronic pain to motor disorders. Future studies will investigate its effectiveness in treating cognitive impairments."
Vagus nerve stimulation is known to have an outstanding safety record in epilepsy patients. Knowing this, the technique can provide a new method to treat brain conditions in which the timing of brain responses is abnormal, such as dyslexia and schizophrenia.
Kilgard led another team that paired vagus nerve stimulation with audio tones of speeds at different variations in order to alter the rate of activity within the rats' brains. Their research, published in the journal Experimental Neurology, showed that this technique induced neural plasticity within the auditory cortex (controls hearing).
MicroTransponder, a biotechnology firm associated with the University, developed a device that the UT Dallas research team is currently working with. MicroTransponder has been testing people in Europe with a vagus nerve stimulation therapy. They hope to eliminate, or reduce, the symptoms of tinnitus, the incapacitated disorder that is often described as "ringing in the ears."
"Understanding how brain networks self-organize themselves is vitally important to developing new ways to rehabilitate patients diagnosed with autism, dyslexia, stroke, schizophrenia, and Alzheimer's disease."
Unfortunately, treating a neurological disease is currently limited to interventions such as behavioral, surgical, or pharmacological. With the discoveries in this research, it may be possible to effectively manipulate the plasticity of the human brain for a variety of reasons. People could benefit from activity in their brain intentionally directed toward rebuilding their lost abilities.
If further research is done that confirms the UT Dallas findings, patients could be treated better with more efficient therapies that are less invasive while avoiding long-term use of drugs.