Epilepsy is a chronic noncommunicable disease of the brain that affects people of all ages and causes frequent seizures. It is one of the most common neurological diseases, affecting around 50 million people globally.
In epilepsy, the electrical firing of the brain becomes deregulated often presenting as sudden bursts of neuronal spikes, ultimately causing seizure activity. The mechanism of epileptogenesis remains unclear.
Seizures caused by epilepsy can occur at any time, usually lasting from a few seconds to a few minutes. It can affect people in different ways with varying types of symptom manifestations. Seizures can be classified based on their onset location and propagation: focal seizures begin on one side of the brain and generalized seizures involve both sides of the brain.
Possible symptoms of epilepsy include:
- Uncontrollable jerking and shaking, called a “fit”
- Losing awareness and staring blankly into space
- Becoming stiff
- Strange sensations, such as a “rising” feeling in the tummy, unusual smells or tastes, and a tingling feeling in your arms or legs
- Collapsing
- Patients with epilepsy might pass out and not remember what happened.
Up to 70% of epilepsy patients can control their epileptic episodes with antiseizure medication. While 20% of patients develop treatment-resistant epilepsy (TDR) and they must resort to more invasive methods, such as surgical removal of the brain region involved in seizure onset or deep brain stimulation.
Animal Models for Epilepsy – PTZ Model
Pentylenetetrazol(PTZ), a GABA-A receptor antagonist, is used to generate a common chemically-induces seizure model. The PTZ model are categorized as a model of generalized seizure.
PTZ induces all four behavioural phenomena: freezing, myoclonic twitches, clonic seizures, and tonic-clonic seizures. The PTZ-induced kindling model has become a widely applicable technique for studying seizure mechanisms and to investigate the pathophysiology of epilepsy and neuronal damage after epileptic seizures.
Animal Models for Epilepsy – KA Model
Kainic acid (KA) is a potent glutamate analog that is used to induce neurodegeneration and model temporal lobe epilepsy(TLE) in rodents. The model presents with neuropathological and electroencephalographic features that are seen in patients with TLE.
KA reliably induces severe, prolonged seizures, which are convulsive status epilepticus. The kainic acid model is widely used in the study of epilepsy and is a reliable model for understanding TLE.