This action potential travels to the spinal cord, via a sensory axon which chemically communicates by releasing glutamate (see synapse) onto a motor nerve.

It may also provide a signal to alter glial cell metabolism when neurons release glutamate at a high rate.

Supporting evidence was obtained from experiments in which the ability of a depolarizing stimulus to release radiolabelled glutamate was shown to be elevated in potentiated hippocampal tissue.

Adult SVZ astrocytes also appear to release glutamate to regulate the survival of neuroblasts.

Bradykinin raises internal calcium levels in neocortical astrocytes causing them to release glutamate.

These receptors are densely located in cornu ammonis pyramidal cells, which are known to release glutamate.

For some of their communication needs, neurons release glutamate (which is an amino acid and the stuff of monosodium glutamate that cooks use).

More recently, astrocytes were shown to release glutamate or ATP in a vesicular, Ca-dependent manner.

As a result the transmembrane ion gradients run down, and glutamate transporters reverse their direction, releasing glutamate into the extracellular space.

It also initiates an electrical signal that travels down the length of the stimulated neuron, which itself releases glutamate, and the process is repeated.