Feb. 7 (UPI) -- Researchers at the University of Maryland School of Medicine have discovered that adjusting levels of kynurenic acid, or KYNA, can have significant effects on schizophrenia symptoms.
People with schizophrenia, a long-term mental disorder that involves a breakdown in the relation between thought, emotion and behavior leading to inappropriate actions and withdrawal from reality, have higher than normal levels of kynurenic acid in their brain.
KYNA is a metabolite of the amino acid tryptophan and decreases glutamate, which is lower in people with schizophrenia.
Researchers have found that people with schizophrenia have lower glutamate activity, and higher KYNA may be the driving force behind symptoms of schizophrenia including cognitive issues.
For the study, researchers studied mice who were deficient in an enzyme vital for determining levels of KYNA known as kynurenine 3-monoxygenase, or KMO. The mice with lower levels of KMO had impairments in contextual memory and spent less time interacting with unfamiliar mice in a social setting than the control group.
The mice with low KMO also had increased anxiety-like behavior when placed in a maze.
"This study provides crucial new support for our longstanding hypothesis," Robert Schwarcz, Ph.D., a professor in the Department of Psychiatry at the University of Maryland School of Medicine and author of the study, said in a press release. "It explains how the KYNA system may become dysfunctional in schizophrenia."
Results show the potential to modify KYNA to adjust glutamate more precisely to decrease symptoms of schizophrenia.
The study was published in Biological Psychiatry.