Neurotransmitters affect postsynaptic cells by (select all that apply)I. initiating signal transduction pathways in the cells. II. causing molecular changes in the cells. III. affecting ion-channel proteins. IV. altering the permeability of the cells.

Neurotransmitter can affect postsynaptic cells by causing molecular changes in the cell and initiating signal transduction pathways in the cell.

Explanation:

When stimuli is strong enough then neurotransmitter which is chemical messenger transfer into the nerve impulse. If it is strong enough then it pass on to the postsynaptic cell which cause changes in the structure of neuron. And is all above is carried out when signal transduction occur.