How is a nerve impulse propagated across a synapse?
1) Through the release of the neurotransmitter acetylcholine from the pre-synaptic membrane and diffusion across the synaptic cleft to the post-synaptic membrane
2) Through the release of the neurotransmitter dopamine from the pre-synaptic membrane and diffusion across the synaptic cleft to the post-synaptic membrane
3) Through the release of the neurotransmitter serotonin from the pre-synaptic membrane and diffusion across the synaptic cleft to the post-synaptic membrane
4) Through the release of the neurotransmitter GABA from the pre-synaptic membrane and diffusion across the synaptic cleft to the post-synaptic membrane
