A new strategy that has the potential to improve cognition has been developed by US researchers.
For the first time, scientists at the University of Maryland School of Medicine have linked a brain compound called kynurenic acid to cognition, possibly open doors for new ways to enhance memory function and treat catastrophic brain diseases.
When researchers decreased the levels of kynurenic acid in the brains of mice, their cognition was shown to improve markedly, according to the study.
The study is the result of decades of pioneering research in the lab of Robert Schwarcz, a professor of psychiatry, pediatrics and pharmacology and experimental therapeutics at the University of Maryland School of Medicine.
"We believe that interventions 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," says Dr. Schwarcz.
Kynurenic acid is a substance with unique biological properties and is produced when the brain metabolizes the amino acid L-tryptophan. The compound is related to another breakdown product of tryptophan known as quinolinic acid.
In 1983, Dr. Schwarz published a paper in the journal Science identifying the critical role excessive quinolinic acid plays in the neurodegenerative disorder Huntington's disease. He has since designed a therapeutic strategy targeting quinolinic acid for the treatment of Huntington's disease.
Dr. Schwarcz and his colleagues at the Maryland Psychiatric Research Center examined mice that had been genetically engineered to have more than 70 percent lower kynurenic acid levels than ordinary mice.
These mice were found to perform significantly better than their normal peers on several widely used tests that specifically measure function in the hippocampus. The hippocampus is a critical area of the brain for memory and spatial navigation.
The mice were clearly superior in their ability to explore and recognize objects, to remember unpleasant experiences and to navigate a maze.
The engineered animals also showed increased hippocampal plasticity, meaning they had a greatly improved ability to convert electrical stimuli into long-lasting memories.
The study was published in the July issue of the journal Neuropsychopharmacology.