A. sodium ion, into, positive B. potassium ion, into, positive C. sodium ion, out of, negative D. potassium ion, out of, negative E. potassium ion, out of, positive 23. A. True B. False 24. A. dopamine and norepinephrine B. acetylcholine and serotonin C. caffeine and dopamine D. alcohol and nicotine E. transmissin and excitin 25. 1.Receptors open ion gates. Neurotransmitters diffuse across the synaptic cleft.
Action potential causes the release of neurotransmitter.
A postsynaptic potential is formed. Neurotransmitters are detected by receptors. To prevent continuous stimulation of the postsynaptic neuron, neurotransmitters released into the synaptic cleft A. self-destruct after a short time. B. are inactivated by enzymes on the postsynaptic membrane. C. are inactivated by calcium ions.