Another type of glial cell, the astrocyte, provides motor neurons with nutrients, ion buffering and recycling of the neurotransmitter glutamate.

The other, guanfacine, is currently used to treat high blood pressure and is thought to keep sensory neurons from releasing glutamate into the spinal cord.

Many people think ketamine affects the action of a common neurotransmitter called glutamate, by blocking the activity of receptors for this molecule.