Final answer:
An excitatory postsynaptic potential (EPSP) depolarizes the postsynaptic membrane, making a neuron more likely to fire, while an inhibitory postsynaptic potential (IPSP) hyperpolarizes the membrane, making a neuron less likely to fire. These potentials are based on the movement of specific ions across the membrane.
Step-by-step explanation:
Label each statement as either excitatory postsynaptic potential (EPSP), inhibitory postsynaptic potential (IPSP), or both.
- Hyperpolarizes the postsynaptic membrane - IPSP
- Results from the movement of Na+ ions into the postsynaptic cell - EPSP
- Moves the postsynaptic membrane potential farther away from threshold - IPSP
- Is a graded potential - Both EPSP and IPSP
- Results from the movement of K+ ions out of the postsynaptic cell - IPSP
- Depolarizes the postsynaptic membrane - EPSP
- Brings the postsynaptic membrane potential closer to threshold - EPSP
Postsynaptic potentials, whether depolarizing or hyperpolarizing, are graded potentials that either increase (EPSP) or decrease (IPSP) the likelihood of a neuron firing an action potential. The movement of specific ions across the postsynaptic membrane, like Na+ for EPSPs and K+ for IPSPs, dictates these changes in membrane potential.