This document discusses the mechanisms of seizures and antiseizure drugs for partial epilepsy. Over a century ago, it was proposed that seizures are caused by the excessive and rapid discharge of neurons in the brain. EEG studies later demonstrated that epilepsies are disorders of neuronal excitability. The major neurotransmitters in the brain, GABA and glutamate, play a role as the principal inhibitory and excitatory neurotransmitters, and microinjections of drugs targeting GABA or glutamate receptors can trigger seizures in experimental animals.