Temporal lope epilepsy (TLE) is one of the most common forms of epilepsy. 30 million people worldwide suffer from TLE, but a third of them are not receptive to the available forms of treatment. Now researchers at the Faculty of Health and Medical Sciences at the University of Copenhagen have made a discovery that may be used to treat these patients.

Just like earthquakes have an epicenter, TLE also has a starting point. The subiculum is a part of the temporal lope of the brain, and this is where TLE originates. The flow of calcium contributes to the formation of so–called bursts of activity by neurons in the subiculum. When the activity of the neurons becomes overly synchronous, it results in abnormal electrical fluctuations, which lead to epileptic seizures. But it can be controlled using serotonin, Anders Victor Petersen, PhD, explains.

‘We have discovered a specific serotonin receptor (5–HT2C), which can control the neurons by lowering the activity of a calcium channel. Serotonin hampers the flow of calcium and thereby prevents the neurons from creating bursts causing epileptic seizures’, he says.

A TLE seizure can take various forms – from visual disorders to anxiety, clumsiness, nausea and reduced consciousness. In time, it can lead to reduced short–term memory and further damage to the temporal lope. Therefore, it is important to find a form of treatment for the third who are currently unreceptive to treatment.

Knowledge of serotonin’s antiepileptic effect is not new. Still, professionals have been reticent about using it, because medicinal products affecting the serotonin system can have a broad range of both intended and unintended side effects. So the problem has been that we have lacked a specific form of treatment, Associate Professor at Center for Neuro Science Jean–Francois Perrier explains.

’Our discovery makes it possible to target the treatment specifically at the receptor we have found. You can thus avoid the side effects that used to be a consequence of treatment with serotonin’, he elaborates.

Tests have been conducted on mice and rats, and now the researchers hope someone will be able to subject their results to clinical testing.

The study ’Serotonin Regulates the Firing of Principal Cells of the Subiculum by Inhibiting a T–type Ca2+ Current’ was published in the journal Frontiers.