Page "Neuron" Paragraph 46

The two most common neurotransmitters in the brain, glutamate and GABA, have actions that are largely consistent.

Glutamate acts on several different types of receptors, and have effects that are excitatory at ionotropic receptors and a modulatory effect at metabotropic receptors.

Similarly GABA acts on several different types of receptors, but all of them have effects ( in adult animals, at least ) that are inhibitory.

Because of this consistency, it is common for neuroscientists to simplify the terminology by referring to cells that release glutamate as " excitatory neurons ," and cells that release GABA as " inhibitory neurons.

" Since over 90 % of the neurons in the brain release either glutamate or GABA, these labels encompass the great majority of neurons.

There are also other types of neurons that have consistent effects on their targets, for example " excitatory " motor neurons in the spinal cord that release acetylcholine, and " inhibitory " spinal neurons that release glycine.