system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
_______________ is the major excitatory neurotransmitter in the brain.
assistant
The correct answer is  Glutamate is the major excitatory neurotransmitter; 60% of brain synapses are glutamatergic. GABA is the major inhibitory neurotransmitter and can be localized by using glutamic acid decarboxylase as a marker. A delta fibers which carry sharp pricking pain also release Glutamate.