Answer: ion-channel-coupled receptors.
Explanation:
These channels are mainly involved with the fast transmission. These receptors are organized into the membrane and regulating or ion-flow channels according to their internal diameter and the predominant electrical charge of their constituent amino acids.
Ion channels can be activated either by membrane potential variation (VOC´S - tension-operated channels), as well as interaction with an agonist (ionotropic receptors), as well as mechanical stimulation or via intracellular agents such as calcium ions, cyclic nucleotides, inositol triphosphate, and G protein. This group includes the nicotinic cholinergic receptor, the GABA receptor, and the glutamate receptor.