<prompt> ___ is the major excitatory neurotransmitter in the brain.AchAspaateGABAGlutamate  <response>: 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. 