Epilepsy is the fourth most common neurological disease that approximately 3.4 million people in the world suffer from. It is predicted that about 1 in 26 people will be diagnosed with epilepsy during their lives.
Zebrafish research has been identified as an essential model in learning about epilepsy and its effects on the human body.
It is difficult to study epilepsy solely in human clinical trials due to the many different forms of the disease and the complexity of the human brain. The Zebrafish brain structure is similar to the human brain, making it a suitable model to test for the alterations in the function of the brain that epilepsy causes.
The Zebrafish model is used to study the effect of epilepsy drugs on the brain and how these drugs can be developed to combat this disease. Seizures can be chemically induced to monitor how the Zebrafish behaves and reacts.
Zebrafish are also a cost-effective solution as they are so small and can reproduce in their hundreds very rapidly and often. The model is almost completely transparent, allowing for in vivo (live) studies to take place. The live Zebrafish brain can be viewed easily due to its transparency, which gives more accurate research results.
It is possible to monitor the brain activity of the Zebrafish model once a test drug has been applied.
One of the main ways that Zebrafish are used to study epilepsy is through their swimming patterns. They are a reliable model as their normal patterns are predictable, so it is fairly easy to track any abnormalities following drug delivery.
The results show an alteration in the swimming movements, with erratic short swims that replicate an epileptic seizure. Another result is a repeated circular or spiral swim, as opposed to a smooth lengthways swim. Some Zebrafish also react by sinking to the bottom of the tank. The different patterns of reaction are important in studying various strengths of epilepsy drugs that can be applied.
Electroencephalography can also be used to monitor the Zebrafish brain. This is a test known as an EEG test, which records neural electrical activity.
Studies have been carried out on both Zebrafish larvae models and adult models to observe the brain’s activity when a seizure is taking place, or the effect anti-epilepsy medication has on the brain.
Zebrafish are also a useful model to expand science’s understanding of why epilepsy can be a genetic disease. Genetic research studying the biological activity of genes is essential to further understand epilepsy and its causes and treatment. The research includes the monitoring of epilepsy-related genes and how they behave.
The Zebrafish genome (the genetic material of an organism) structure is very similar to that of the human genome, although Zebrafish have more disease-causing genes than humans.
Genome modification is a scientific method to edit the genome sequence and can be used to monitor the functioning of the genes when subject to epilepsy. A common system that is used for this procedure in the Zebrafish model is the CRISPR (clusters of regularly interspaced short palindromic repeats) method. CRISPR technology allows scientists to genetically modify genes to reproduce those affected by epilepsy, giving wider potential for the study of this disease.
The Zebrafish model contributes greatly to science’s understanding of epilepsy and the behaviour of the brain. Over the last 20 years, this research has developed rapidly and will continue to do so in the quest for our comprehension of epilepsy.