Signal Transduction: The process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly involving changes in the activity of proteins.
Neurotransmitter:A chemical substance released at the end of a nerve fiber by the arrival of a nerve impulse and, by diffusing across the synapse or junction, causes the transfer of the impulse to another nerve fiber, muscle fiber, or some other structure.
Ion Channel: A pore-forming membrane protein whose functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ions across the cell membrane