Suppose both excitatory and inhibitory neurons synapse with a single postsynaptic neuron. What determines if an action potential is initiated in the postsynaptic neuron?

A) The kind of neuron involved
B) The size of the neuron involved
C) Whether the neuron is myelinated or non-myelinated
D) The number of EPSPs in relation to the number of IPSPs
E) This situation is not possible in humans.

EPSPs

Excitatory Post-Synaptic Potentials, which are temporary depolarizations of postsynaptic cells that make it more likely for a neuron to fire an action potential.

IPSPs

Inhibitory post-synaptic potentials, which decrease the likelihood of a post-synaptic neuron firing an action potential.

Action Potential

A rapid change in electrical potential across the membrane of a nerve cell as a nerve impulse is transmitted.