Rice University scientists claim to have identified a potential clue to the roots of neurological disorders like epilepsy, autism and schizophrenia.
The research team led by Eric Howlett discovered an unanticipated connection between glutamate - an amino acid and neurotransmitter in much of the food we eat - and phosphoinositide 3-kinase (PI3K), an enzyme that, Howlett found, regulates the activity of neurons.
In the study conducted using a fruit fly, they found that negative feedback mediated by PI3K regulates the excitability of neurons, an issue in a number of ailments that include neurofibromatosis.
A mutation in a glutamate receptor gene common to both the fruit fly and humans has the ability to disrupt that regulatory mechanism.
Howlett found the fruit fly's metabotropic glutamate receptor (DmGluRA) gene, when mutated, increased the excitability of the neuron by preventing PI3K from doing its job.
"What we found was that glutamate, which is released due to neuronal activity, feeds back onto metabotropic glutamate receptors on the same neurons that released it in the first place," he said.
"This leads to the activation of PI3K and ultimately to the dampening of the amount of glutamate that is released." Without that regulation, he said, things inside the cell can go terribly wrong," he added.
Michael Stern, co-researcher and a professor of biochemistry and cell biology, said that discovering the negative feedback loop that keeps neurons stable was key, however further studies are required.
"We know that glutamate activates mGluR and PI3K, but we don't know how," he said.
"There are almost certainly a number of intermediates that remain to be identified, and we have several candidates we're looking into," he added.
The study is published online by the Public Library of Science Genetics.