Question

9. Consider a neuron whose intra- and extracellular ion concentrations are such that EK = -70 mV and ENa = +50 mV a) Plot an action potential IN THIS CELL (label graph axes, values matter), and indicate the refractory period on your drawing. (Cell 1) b) On the same graph, plot another action potential for a different cell that is the same as cell 1 but has 25% as many non-gated (passive) potassium channels. (Cell 2) c) Would the action potential threshold for cell 2 be more positive, the same, or more negative than the action potential threshold for cell 1? In other words, would it be any easier to elicit an action potential in cell 2 compared to cell 1? In one sentence explain why.

Answer 1

In cell 2, 25 percent ​​​​​K+ channel are non gated so they might be leaky channels . This will make the intracellular more negative compared to cell 1 .

Threshold potential for a neuron is fixed that's why all or non rule occurs for the transmission of neural signal.

It will be little bit diificult for cell 2 for signal transmission as more Na influx will be required to generate action potential by depolarizing the membrane.