Too much zinc in the brain could trigger epileptic seizures, research suggests
Zinc may play a key role in memory - but too much of the mineral in the brain could trigger epileptic seizures, research suggests.
A new study has found that zinc is critical to communication between neurons in the hippocampus, the brain's learning and memory centre.
Scientists used a chemical that binds to zinc to remove it from circulation in the brains of mutant mice.
Without the mineral, communication between neurons was impaired.
Lead researcher Dr James McNamara, from Duke University Medical Centre in North Carolina, US, said: "We discovered that zinc is essential to control the efficiency between two critical populations of nerve cells in the hippocampus. This addresses a long-standing controversy in the field."
The findings were published online in the journal Neuron.
More than 50 years ago, scientists learned that high levels of zinc were contained in specialised compartments in nerve cells called vesicles. These package the transmitter chemicals that enable nerves to communicate.
However, evidence that zinc actually played a role in cell signalling was lacking.
Over-communication by the brain cells highlighted in the study was known to occur in epilepsy, pointing to a link between zinc and the condition.
Dr McNamara said people taking zinc supplements should exercise caution. "Carefully controlling zinc's regulation of communication between these nerve cells is critical to both formation of memories and perhaps to occurrence of epileptic seizures," he added.