Ion channels are proteins on the cell surface that open to allow ions to pass through. The lamprey is being used because the synapse is big. The neurotransmitter being studied is serotonin. Vesicles that are in the axon bulb contain the neurotransmitters that are released when the signal is sent. Serotonin is a neurotransmitter that controls behavior.
Low amounts increase aggressive behavior and high amounts lower aggressive behavior.