Researchers who fed a cocktail of key amino acids to mice improved sleep disturbances caused by brain injuries in the animals. These new findings published in Science Translational Medicine provide a proof-of-principle for investigating this dietary intervention as a potential treatment for millions of people affected by traumatic brain injury (TBI).
While physicians can relieve the dangerous swelling that occurs after TBI, no treatments exist that address the underlying brain damage associated with neurobehavioral problems such as impaired memory, learning, and sleep patterns.
“If this type of dietary treatment is proved to help patients recover function after traumatic brain injury, it could become an important public health benefit,” said CHOP neuroscientist Akiva S. Cohen, PhD, the study’s co-leader.
Comparing mice with experimentally induced mild TBI to uninjured mice, the scientists found the injured mice were unable to stay awake for long periods of time. The injured mice had lower activity among orexin neurons, which help to maintain the animals’ wakefulness. This is similar to results in human studies showing decreased orexin levels in the spinal fluid after TBI.
The researchers investigated the use of selected branched chain amino acids (BCAA) —precursors of the neurotransmitters glutamate and GABA — which are involved in communication among neurons and help to maintain a normal balance in brain activity. The dietary therapy restored the orexin neurons to a normal activity level and improved wakefulness in the brain-injured mice. EEG recordings also showed improved brain wave patterns among the mice that consumed the BCAA diet.
Current evidence does not support TBI patients medicating themselves with commercially available amino acids, Dr. Cohen cautioned.
Dr. Cohen collaborated with two experts in sleep medicine: the University of Pennsylvania’s Allan I. Pack, MD, PhD, and Miranda M. Lim, MD, PhD, of the Portland VA Medical Center and Oregon Health and Science University.