part of part of regulation of postsynaptic membrane potential inhibitory postsynaptic potential A process that causes a temporary decrease in postsynaptic membrane potential due to the flow of negatively charged ions into the postsynaptic cell. The flow of ions that causes an IPSP is an inhibitory postsynaptic current (IPSC) and makes it more difficult for the neuron to fire an action potential. biological_process regulation of inhibitory post-synaptic membrane potential IPSP GO:0060080 chemical synaptic transmission, postsynaptic