Problem
i. Imagine that a toxin creates pores that are permeable to Ca2+, Describe its immediate effect on the resting potential of a neuron: identify which ions diffuse across the membrane, which direction they diffuse (and why), and whether this brings the neuron closer to or further from threshold potential.
ii. Imagine that a toxin makes K+leak channels more permeable to K+ ions. Describe its immediate effect on the resting potential: identify which ions diffuse across the membrane, which direction they diffuse (and why), and whether this depolarizes or hyperpolarizes the neuron.
iii. Imagine that in a different neuron, voltage-gated K+ channels open quickly, only 0.3ms after voltage-gated Na+ channels. Predict changes in timing, amplitude and shape of an AP by drawing one labeled diagram comparing a normal AP (solid line) to this AP (dashed line), and explaining why these changes occur. Label the axes, depolarization and repolarization phases, and threshold potential.