New study takes a 'deep dive' into brain infections that magnify epilepsy

SA has high rates of epilepsy, with one in every 100 South Africans living with the brain disorder, mainly caused by parasitic infections that affect the brain.

In SA most of the seizure-causing brain infections in adults are caused by pig tapeworm larvae, Taenia solium, which is acquired by either eating undercooked pork or living near pigs such as on farms or in rural areas.

In an effort to understand even better how this tapeworm affects the human brain, scientists at the University of Cape Town’s (UCT's) Nuroscience Institute have embarked on a five-year study using ethically sourced brain tissue that is ordinarily discarded during brain surgery, and are investigating whether the tapeworm larvae could have any benefits for the treatment of brain infections.

Dr Joseph Raimondo, a senior lecturer at UCT’s department of human biology, who recently got awarded the Wellcome Trust international intermediate fellowship to conduct the research, said while animal models had been used in the past to understand parasitic brain infection, animal models don’t always work well in simulating what’s going on in the human body.

“The epilepsy-causing larvae can’t be studied in any kind of detail in live humans. Animal models aren't ideal as they don't fully recapitulate the disease in humans.

 “We’re getting the tapeworm that infects humans by harvesting them from pigs. We’re getting human brain tissue from people having surgery to treat epilepsy or other disorders. The tissue is normally discarded once removed, and instead can now help contribute to understanding how to manage brain conditions in the future. We can then treat the brain tissue with the tapeworm larvae and see what they do to the brain. This is all made possible by this important collaboration,” he said.

The discarded brain tissue is kept alive in a special solution before it’s moved into an incubator.

Raimondo, a member of the Neuroscience Institute who is conducting this research with his colleagues, including neurosurgeons from Red Cross Children's Hospital, said while the use of the pig tapeworm larvae is to see what they do to the human brain, “we hope to learn from what the pig tapeworm larvae do to the brain to develop new treatments for epilepsy and inflammation”.

“Let’s say the tapeworm larvae make a particular molecule that is anti-inflammatory, perhaps we can use that as a treatment. If we find an active molecule (which) the larvae make, either we can purify that from the larvae, or we synthesise it.”

Raimondo said this is a completely new experiment that has never been done anywhere.

Lack of access to human brain tissue had been one of the limitations in Africa, despite the high prevalence of  brain infections. “This is because it is difficult having access to human brain tissue, and in places where it is available scientists aren't interested in an infectious disease that primarily affects developing-world countries.”

Among the things that the researchers will investigate include:

• determining how tapeworm larvae affect inflammation and cell death
• exploring how these larvae affect networks of nerve cells to cause seizures
• using new genetic techniques to measure changes in the expression of genes in individual brain cells after exposure to the larvae.

“The combination of these investigations will result in substantial gains in the study of inflammation, nerve cell networks and genes in the human brain.” Through the grant, Raimondo will pursue his dual passions for investigating the basic mechanisms of how the brain works, while growing the understanding of a condition that affects the health of South Africans — ultimately to help improve their quality of life.

 Raimondo’s lab, which works with hi-tech microscopic equipment, will record the brain’s electrical signalling and observe how brain cells talk to each other.

 “It’s a unique opportunity that couldn’t be done anywhere else. You have to have sophisticated neurosurgery, where you can get the brain samples; access to rural areas, where proximity to pigs can increase the chances of exposure to infection; and people who care about a disorder that doesn’t really occur in the global north, and who have the expertise to study it at a very detailed level,” Raimondo said.