Brain Compound Kynurenic Acid May Improve Memory
A brain compound called kynurenic acid may hold a key to enhancing cognition, improving memory, and treating critical brain diseases. Scientists at the University of Maryland School of Medicine have, for the first time, discovered a link between an agent in the brain and cognitive functioning.
After decades of research, Robert Schwarcz, PhD, professor of psychiatry, pediatrics and pharmacology and experimental therapeutics at the University of Maryland School of Medicine, and his team have made a significant discovery regarding kynurenic acid. When Schwarcz reduced the levels of this substance in the brains of mice, the rodents’ cognition improved markedly.
Schwarcz notes that “We believe that intervention aimed specifically at reducing the level of kynurenic acid in the brain are a promising strategy for cognitive improvement in both healthy patients and in those suffering from a variety of brain diseases ranging from schizophrenia to Alzheimer’s disease.”
The implications of this discovery, therefore, could be enormous. Alzheimer’s disease, for example, affects 5.3 million people in the United States, according to the Alzheimer’s Association, and is projected to reach up to 16 million by 2050. Schizophrenia affects approximately 2.4 million American adults. People who have any one of dozens of other brain diseases also could benefit from the results of this finding.
Kynurenic acid is produced when the brain breaks down the amino acid L-tryptophan. The substance is related to quinolinic acid, another byproduct of the metabolism of tryptophan. In previous studies, Dr. Schwarcz reported that abnormally high levels of quinolinic acid has a role in the neurodegenerative disorder Huntington’s disease, and from that discovery he then developed a treatment approach that targets quinolinic acid in people with the disease.
In this new study, Schwarcz and his team evaluated mice that had been genetically altered to have abnormally low levels of kynurenic acid. These deficient mice performed significantly better than their normal peers on several tests that measure the function of the hippocampus, the brain center for long-term memory and spatial navigation.
The kynurenic-deficient mice were better able to recognize objects, navigate a maze, and remember unpleasant experiences. They also had a greatly improved ability to transform electrical impulses into long-lasting memories.
Schwarcz believes these findings “open up an entirely new way of thinking about the formation and retrieval of memories.” He notes that “new chemicals that specifically influence the production of kynurenic acid in the brain predictably affect cognition,” which has lead him to begin developing new compounds to enhance cognitive abilities in people.
Schwarcz’s discovery that kynurenic acid plays a significant role in memory and cognitive functioning is a significant one that could impact people suffering from disorders such as Alzheimer’s disease, Huntington’s disease, schizophrenia, and dozens of others. E. Albert Reece, MD, PhD, MBA, vice president of medical affairs, University of Maryland, and John Z. and Akiko K. Bowers Distinguished Professor and dean, University of Maryland School of Medicine, noted that Schwarcz’s work “creates hope for these patients and their families, and his findings are making a significant impact on the field of neuroscience and psychiatric medicine.”
National Institute of Mental Health
University of Maryland School of Medicine