Temporal summation is the type of summation that occurs when

Temporal summation is the type of summation that occurs when

• A. A number of subthreshold stimuli from the same axon are repeated
• B. Multiple subthreshold stimuli converge on a neuron at the same time
• C. A single suprathreshold stimulus triggers an action potential
• D. Stimulus below threshold

Answer: (A)

Temporal summation is the process by which successive subthreshold inputs from the same presynaptic neuron accumulate in time on the postsynaptic neuron. Each input creates a small depolarization, and if these depolarizations arrive quickly enough that they overlap before they decay, their effects add up to reach the threshold and trigger an action potential. This is different from spatial summation, where multiple subthreshold inputs from different neurons arrive at roughly the same time and sum to reach threshold. A single suprathreshold stimulus can trigger an action potential without summation, and a stimulus that remains below threshold will not.

Temporal summation is the process by which successive subthreshold inputs from the same presynaptic neuron accumulate in time on the postsynaptic neuron. Each input creates a small depolarization, and if these depolarizations arrive quickly enough that they overlap before they decay, their effects add up to reach the threshold and trigger an action potential. This is different from spatial summation, where multiple subthreshold inputs from different neurons arrive at roughly the same time and sum to reach threshold. A single suprathreshold stimulus can trigger an action potential without summation, and a stimulus that remains below threshold will not.