Monoamine Transporters as Ionotropic Receptors.

It is well established that glutamate and GABA signal through both ionotropic and metabotropic receptors. Conversely, it is thought that, with one exception, monoamines (dopamine, serotonin, and norepinephrine) signal via metabotropic receptors. Given their capacity to generate fast-acting currents, I suggest that the monoamine transporters should be considered as ionotropic receptors.