Jackie Eng is a middle-aged man who is transported to the emergency department unconscious and accompanied by a nurse from the medical floor. The nurse states that the patient was in line in front of her in the hospital cafeteria when he suddenly fell to the floor. He then had a "generalized tonic-clonic seizure." She called for assistance and accompanied him to the emergency department. No other historical information is available. On physical examination, Jackie is confused and unresponsive to commands. What is the pathophysiology of generalized seizures? (include the role of neurotransmitters).