An interneuron may receive multiple stimuli from the same sensory neuron over a very short period of time. The firing rate of the receiving neuron is proportional to the number of signals received from the sensory neuron over time.

The basic objective of temporal summation is to merge the amplitudes of individual pre- synaptic potential with the post synaptic potential. so that the sum amplitude of the potential produced can be greater than individual amplitudes. The merged amplitudes will enable the membrane potential to reach the threshold level for generation of post synaptic action potential.

Generally, the post synaptic membrane stores charges.Thus it stores in quick succession the amplitude of the first action potential, and as this is falling, it stores that of the second , third and fourth and merged this together to reach the threshold.

Temporal summation depends on the ''time frame' between the first and second pre-synaptic potential. Because the closer they are(pre-synsptic potential) the higher the chances of storing charges in the post-synaptic membrane for Post-synaptic potential. Thus if the duration is long, membrane potential of the post -synaptic neuron will be reduce, threshold will be be reached and PSP will not be achieved

In summary temporal summation depends on the time frame of the occurrence of post-synaptic potential.