gcse synapse define
1 An electrical impulse travels along an axon. 2  This triggers the nerve-ending of a neuron to release chemical messengers called neurotransmitters. 3  These chemicals diffuse across the synapse (the gap) and bind with receptor molecules on the membrane of the next neuron. These chemicals diffuse across the synapse (the gap) and bind with receptor molecules on the membrane of the next neuron. 2  The receptor molecules on the second neuron bind only to the specific chemicals released from the first neuron.