The Epigenetic Link between Memory Loss and Epilepsy

Researchers have discovered a potential epigenetic explanation for why individuals with epilepsy, particularly temporal lobe epilepsy, usually experience memory loss. The scientists progress our understanding of numerous other disorders involving memory loss and could lead to a therapeutic approach for restoring proper memory function via epigenetic mechanisms. Patients that suffer from temporal lobe epilepsy experience recurrent and unprovoked epileptic seizures that originate from the temporal lobe, one of the four major lobes of the mammalian brain that is involved in processing sensory input, specifically auditory information. Memory loss is a common occurrence for patients who are diagnosed with temporal lobe epilepsy, even if the seizures are controlled effectively with medication.

The link between DNA methylation and memory loss which occurs as a result of epileptic seizures. DNA methylation is a well-studied epigenetic mechanism known to affect gene expression by turning genes off or on by adding a methyl (CH3) group onto DNA. When a gene is turned off, its specific protein is no longer produced by that gene. When a gene is turned on, the protein is produced as normal. This epigenetic mark can therefore impact how much a particular protein is produced. This disrupts the gene and prevents it from turning off at the right time.

Facts on Epilepsy:

People with epilepsy experience recurrent seizures, because a sudden surge of electrical activity in the brain causes a temporary disturbance in the messaging systems between brain cells. Every function in the human body is triggered by messaging systems in our brain. Epilepsy results when this system is disrupted due to faulty electrical activity. There are three diagnoses a doctor might make when treating a patient with epileptic seizures:

Idiopathic: There is no apparent cause.

Cryptogenic: The doctor thinks there is most probably a cause, but cannot pinpoint it.

Symptomatic: The doctor knows what the cause is.

There are three descriptions of seizures, depending on where in the brain the activity started. Gene expression then increases and amounts of messenger RNA (mRNA), which carries the instructions of the gene to the brain. This causes the BDNF protein to be over-expressed, which seems to severely impair the formation of memories in those with temporal lobe epilepsy.