A gene called ANK3, which is associated with bipolar disorder (formerly known as manic depression) could also be linked to epilepsy, according to a study published in the scientific journal Molecular Psychology.This new finding means that ANK3 could be targeted and opens new potential avenues for the treatment of epilepsy.Research led by Dr Edward Cooper, at Baylor College of Medicine in Houston, Texas, has shown that reduced expression of one variant of the ANK3 gene causes an imbalance between nerve cell excitation and inhibition.The team found that a protein encoded by a variant of the ANK3 gene, which is reduced in people with bipolar disorder, is selectively lost from inhibitory neurons, or neurons that block firing, meaning that the excitation/inhibition balance is shifted towards excessive excitation.In a press release from Baylor, Dr Cooper said: “We found that reduced expression of one type of ANK3 removes a brake on the output of brain neurons, leading to excesses in firing in circuits for emotions, memory and epilepsy”.In order to test the effect of this imbalance, researchers created a mouse model lacking the inhibitory form of the ANK3 gene. They found that the animals had frequent epileptic seizures and a high risk of sudden death.“This showed us that imbalance in ANK3 function can result not only in excessive circuit sensitivity and output leading to bipolar disorder, but also severe epilepsy,” Dr Cooper said.Dr Cooper and his team discovered, around ten years ago, that ANK3 interacts with two other genes that are mutated in some people with epilepsy. Soon after, genetic testing on a large number of psychiatric patients across the world revealed that ANK3 is linked to bipolar disorder but the connection with epilepsy remained unclear. Through this work the connection between ANK3 and epilepsy has been unravelled for the first time.Author: Dr Özge ÖzkayaClick here for more articles about brain science including genetics.