50. One way a neurotransmitter can cause an excitatory postsynaptic potential is by: A) opening chemically-gated calcium ion channels P closing chemically-gated sodium ion channels C) opening chemically-gated potassium ion channels D) opening chemically-gated chloride ion channels E) binding to anions trapped inside the cell 51. One way a neurotransmitter can cause an inhibitory postsynaptic potential is by: A) opening chemically-gated calcium ion channels Can B) opening chemically-gated sodium ion channels Nat C) opening chemically-gated potassium ion channels K+ D) closing chemically-gated chloride ion channels Cl E) binding to anions trapped inside the cell.