Final answer:
The main difference between EPSP and IPSP is that EPSP depolarizes the neuron, making it more likely to fire an action potential, while IPSP hyperpolarizes the neuron, making it less likely to fire. EPSPs are associated with Na+ influx, whereas IPSPs typically involve Cl- influx or K+ efflux.
Step-by-step explanation:
The key difference between an excitatory postsynaptic potential (EPSP) and an inhibitory postsynaptic potential (IPSP) lies in the change in membrane potential they induce. An EPSP moves the membrane potential closer to the threshold necessary to trigger an action potential by depolarizing the neuron. T
his is usually a result of Na+ ions flowing into the neuron. On the other hand, an IPSP moves the membrane potential further away from this threshold, thereby hyperpolarizing the cell and making an action potential less likely. The inhibitory effect typically involves the influx of Cl- ions or the efflux of K+ ions.
To address the specifics in the student's question, option A) EPSP increases membrane potential, while IPSP decreases it, is the most accurate statement. An EPSP causes depolarization, which is an increase in membrane potential, whereas an IPSP results in hyperpolarization, a decrease in membrane potential.