Final answer:
The correct term for the buildup of depolarization due to rapid succession of EPSPs is temporal summation, involving multiple signals at the same location on a neuron over time.
Step-by-step explanation:
The buildup of depolarization when EPSPs (excitatory postsynaptic potentials) arrive in rapid succession is called temporal summation. This type of summation involves the combination of multiple signals at the same location on a neuron resulting in a significant change in the membrane potential over time. Temporal summation often requires several EPSPs to occur closely in time in order for the postsynaptic cell to reach the threshold for an action potential. By contrast, spatial summation refers to the accumulative effect of EPSPs generated at different locations across the cell’s membrane, which can occur simultaneously or at slightly different times.
These processes are crucial for the neuron to reach the threshold of excitation, which is necessary to generate an action potential. Signal summation ensures that only the strongest signals—those that represent significant inputs—are likely to result in an action potential, thus acting as a filter to reduce random noise within the neuronal signaling system.