Researchers in the United States have identified a substance in brain that could adversely affect memory and learning.

The compound called kynurenic acid can impede cognitive abilities by inhibiting brain receptors that stimulate learning and memory, according to a new study compiled by researchers at the University Of Maryland School Of Medicine.

Kynurenic acid is produced after consuming foods containing tryptophan. Tryptophan is an amino acid essential to produce serotonin, which promotes sleep. The Maryland scientists, who have been studying the link for more than a decade, have found that mice genetically engineered to produce 70 percent less kynurenic acid had markedly improved cognition.

Abnormally high levels of kynurenic acid are found in people with brain disorders such as schizophrenia, Alzheimer’s and Huntington’s, which may contribute to cognitive problems. Kynurenic acid is also produced in excess as people age.

Now the researchers are looking for ways to reduce the acid and interrupt the process of declining memory and other abilities. They need to also ensure that in the process of blocking kynurenic acid, the action of other crucial brain chemicals like serotonin and another neurotransmitter, dopamine are not getting affected.

The researchers found that serotonin is made within the nerve cells in the brain, and kynurenic acid is made in glial cells. Even though it was known earlier that kynurenic acid is produced in glial cells, scientists considered their primary role to be support and protection of the nerve cells.

“We know where we want to go. We’ll see who gets the chemical right with no side effects,” says Robert Schwarcz, professor of psychiatry, pediatrics’ and pharmacology and experimental therapeutics at the University Of Maryland School Of Medicine.

The new findings could potentially open the door to development of a drug that could aid learning in healthy people and perhaps for those affected with disorders such as Alzheimer’s disease.

“Workers might want to take a pill so they can work harder, and college students would be interested because they already are taking amphetamine-type pills so they will be sharper. What happens with diseases would be a major add-on,'' says Schwarcz, who published the study in the medical journal Neuropsychopharmacology.