Glutamatergic neuron is a nerve cell which sends messages by using the neurotransmitter glutamate. Glutamate serves as both the mammalian brain's primary excitatory neurotransmitter and as a key neuromodulator to control synapse and circuit function over a wide range of spatial and temporal scales. Glutamate pathways are linked to many other neurotransmitter pathways, and glutamate receptors are found throughout the brain and spinal cord in neurons and glia.