Final answer:
Neurotransmitters, not action potentials, are the chemicals that travel across the synapse. Action potentials trigger the release of these neurotransmitters, which then bind to receptors on the next neuron to continue the signal transmission.
Step-by-step explanation:
The chemicals that travel across the synapse are not action potentials; instead, they are neurotransmitters. An action potential is an electrical signal that travels along the membrane of a neuron. When the action potential reaches the axon terminal, it triggers a complex sequence of events leading to the release of neurotransmitters into the synaptic cleft. Neurotransmitters are the actual chemical messengers that bridge the gap between neurons at a chemical synapse, allowing for the transmission of information to the next neuron.
Neurotransmitters carry signals across synapses, initiating a response in another neuron once they bind to postsynaptic receptors. This interaction can result in either excitatory or inhibitory postsynaptic potentials, depending on the type of neurotransmitter and the receptor involved. It is through these chemical signals, rather than electrical ones, that neurons communicate across synaptic gaps.