What is "Temporal" and "Spatial summation"?

Question

* What is "Temporal" and "Spatial summation"?

* Is there a difference between them? If yes, what?

(OH - this is a question concerning Neuron's by the way -- so therefore its a Biology/Psychology question).

Answer 1

Spatial summation occurs when excitatory potentials from many different presynaptic neurons cause the postsynaptic neuron to reach its threshold and fire.

Temporal summation occurs when a single presynaptic neuron fires many times in succession, causing the postsynaptic neuron to reach its threshold and fire.

As an analogy, spatial summation is like using many shovels to fill up a hole all at once.  Temporal summation is like using a single shovel to fill up a hole over time.  Both methods work to fill up the whole (the postsynaptic neuron reaches its action potential threshold).