[Campbell Biology P.1128] Which of the following statements accurately describes the differen... | Practice Question
Which of the following statements accurately describes the difference between temporal and spatial summation of postsynaptic potentials?
A: Temporal summation involves multiple synapses firing simultaneously, while spatial summation involves a single synapse firing rapidly.
B: Temporal summation results from a single presynaptic neuron firing repeatedly in quick succession, whereas spatial summation results from multiple presynaptic neurons firing at the same time.
C: Both temporal and spatial summation refer to the summing of inhibitory postsynaptic potentials (IPSPs) only.
D: Spatial summation always leads to an action potential, but temporal summation never does.
Explanation
Temporal summation occurs when a single presynaptic neuron fires rapidly, causing successive EPSPs to add up. Spatial summation occurs when multiple presynaptic neurons fire simultaneously at different locations, and their EPSPs sum together. Both can lead to an action potential if the threshold is reached.