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You are investigating a genetic mutation in KIR channels which is preventing the passage of K+ across the membrane while voltage clamped at a membrane potential of -90 mV. Which of the following regions could be mutated and affecting the normal function?

In a voltage clamp experiment, when does the HERG channel inactivate, and when is a current for K+ seen with this channel?

Which of the following is FALSE regarding the K+ inward rectifying channel?

A voltage-gated sodium channel has more alpha subunits than a KV4.1 channel.

Tetraethyl ammonium (TEA) is applied to a neuron to block voltage gated potassium channels. The neuron is then voltage clamped above threshold and CURRENT is recorded. Compared to a recording at the same voltage clamp, but without TEA, which part of the current will change? HINT – think about how current and voltage plotted

You have isolated a channel during an experiment you conducted in lab. This channel allows for the passage of K+ and is NOT voltage sensitive, but only exhibits a high K+ conductance in 8.0 pH solution. Which channel might you have isolated?

If you applied scorpion beta toxin and voltage clamped a typical voltage-gated sodium channel, what might occur?

A neuron is treated with TEA to inhibit voltage-gated K+ channel and is voltage clamped at +10 mV and then at +50 mV. Which of the following would you expect to observe? Assume normal physiological conditions.

____________ channels do NOT have an inactivation domain.

A neuron is voltage clamped above threshold and the induced currents are recorded. Then the experiment is repeated: the neuron is voltage clamped to above threshold, and the currents are recorded, but this time the experimenter has applied Tetraethyl ammonium (TEA) to block voltage gated potassium channels. Compared to the first recording (without TEA), which part of the current will change in the second recording?