Neuronal communication depends on electrical and chemical signals. A neuron generates an electrical signal (action potential) that is conducted down its axon. When that nerve impulse arrives at the axon terminus, it is converted into a chemical signal (neurotransmitter) that is released from the presynaptic membrane into the synapse. Neurotransmitter binds to receptors on the postsynaptic membrane, causing a change in the voltage across that membrane. As a result, the postsynaptic cell may fire its own action potential.