PATHOLOGY

Detailed explanation-1: -Glutamate is the major excitatory neurotransmitter in the mammalian brain. Fast transmission mediated by this neurotransmitter accounts for synaptic excitation of most, if not all, brain neurons (Kandel et al. 2000), and thus glutamate is found throughout the brain.

Detailed explanation-2: -Neurons talk to each other across synapses. When an action potential reaches the presynaptic terminal, it causes neurotransmitter to be released from the neuron into the synaptic cleft, a 20–40nm gap between the presynaptic axon terminal and the postsynaptic dendrite (often a spine).