Question

If neuron A fires an action potential after simultaneously receiving an EPSP input in dendrite 1 and dendrite 4, what is this an example of?

1) Spatial summation
2) Temporal summation
3) Inhibitory postsynaptic potential
4) Excitatory postsynaptic potential

Answer 1

Neuron A's firing of an action potential due to receiving EPSP inputs at different dendrites simultaneously exemplifies spatial summation, where multiple signals combine to reach the action potential threshold.

Step-by-step explanation:

When neuron A fires an action potential after simultaneously receiving an excitatory postsynaptic potential (EPSP) input in dendrite 1 and dendrite 4, this is an example of spatial summation. Spatial summation refers to the process where multiple graded potentials occurring at different locations on a neuron's membrane add up to reach the threshold for an action potential. The summation occurs at the axon hillock of the neuron where the depolarizing influences of various EPSPs are combined. If the net effect of these EPSPs is sufficiently depolarizing, the neuron's membrane potential reaches the threshold, thus triggering an action potential.