Biological process

negative regulation of excitatory post-synaptic membrane potential, reduction of excitatory postsynaptic membrane potential

Any process that prevents the establishment or decreases the extent of the excitatory postsynaptic potential (EPSP) which is a temporary increase in postsynaptic potential due to the flow of positively charged ions into the postsynaptic cell. The flow of ions that causes an EPSP is an excitatory postsynaptic current (EPSC) and makes it easier for the neuron to fire an action potential.

negative regulation of EPSP