Adjusting the amount of a certain compound in your brain could improve schizophrenia symptoms. Scientists looked at mice with low levels of an enzyme called kynurenine 3-monooxygenase for their study, published in Biological Psychiatry, and have connected that deficiency with cognitive impairments.

The enzyme is one stop on a long chain of events, as the University of Maryland School of Medicine describes: It determines how much kynurenic acid is in your brain, which in turn drives your level of an amino acid called glutamate. Specifically, the mice with low levels of kynurenine 3-monooxygenase have too much kynurenic acid, and thus have too little glutamate. And the deficient mouse brains can tell scientists about humans with schizophrenia because those latter patients have imbalances that are similar to the mice.

It doesn’t stop there — “research has found that people with this illness tend to have less glutamate signaling than people without the disease,” the University of Maryland School of Medicine said in its statement. And that could be linked to their cognitive issues and other symptoms. The mice, for example, who were enzyme-deficient “showed impairments in contextual memory and spent less time than did a control group interacting with an unfamiliar mouse in a social setting.” They also showed higher anxiety levels.

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Understanding this mechanism could help experts design treatments for schizophrenia. Simply increasing levels of glutamate has “ serious side effects, including seizures and nerve cell death,” the university noted. But using the pathway the scientists uncovered could more precisely and safely change glutamate levels, and thus alleviate cognitive deficits. “Because this mechanism is indirect, it seems not to trigger the same side effects that directly boosting glutamate does.”

The new study is not the first to implicate this brain mechanism in human illness. Another recent study linked it to neurodegenerative diseases like multiple sclerosis, ALS, Alzheimer’s and Parkinson’s. That group of researchers found a way to diagnose MS using a blood test that measures substances that go through the kynurenine pathway, including the amino acid tryptophan.

Source: Schwarcz R, Rassoulpour A, Wu H, Medoff D, Tamminga CA, Roberts RC. Increased cortical kynurenate content in schizophrenia. Biological Psychiatry. 2017.

See also:

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Cigarettes Are Medication for People with Schizophrenia