postsynaptic potential

postsynaptic potential (PSP), a temporary change in the electric polarization of the membrane of a nerve cell (neuron). The result of chemical transmission of a nerve impulse at the synapse (neuronal junction), the postsynaptic potential can lead to the firing of a new impulse. When an impulse arrives at a synapse from an activated neuron (presynaptic neuron), a chemical substance called a neurotransmitter is released causing the opening of channel-shaped molecules in the membrane of...