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Neuroscience

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Excitatory/Inhibitory Postsynaptic Potential

NEURO-BE9O13

In chemical synaptic transmission, neurotransmitter binding to postsynaptic receptors ultimately opens or closes postsynaptic ion channels, resulting in a graded potential in the postsynaptic neuron called a postsynaptic potential (PSP).

The PSP will be called an excitatory PSP, or EPSP, if it brings the membrane potential toward the threshold. Inhibitory PSPs or IPSPs bring the membrane potential away from threshold.

Read the following statements carefully, and select ALL that apply.

A

Postsynaptic potentials increase or decrease the probability for a postsynaptic neuron to fire an action potential.

B

A postsynaptic potential is an EPSP if its reversal potential is more positive than the action potential threshold.

C

Whether a postsynaptic potential is an EPSP or IPSP has little to do with its reversal potential.

D

EPSPs always depolarize the postsynaptic cell while IPSPs can produce both hyperpolarization and depolarization.