Ion Channels - L2

What is hyperkalemia?

What does hyperkalemia result in?

What are the different configurations an ion channel (eg Na+) can exist in? At what voltages would you expect to see this?

What cell is a two-electrode voltage clamp used on? Why? What electrodes are used?

What type of recording does a whole-cell voltage clamp perform? How does the cytoplasm relate to the interior of the pipette?

What can the recording pipette be used to do in a whole-cell voltage clamp?

How does a single-channel patch clamp differ to whole-cell voltage clamp? What are the different possible configurations?

What is a more modern method of observing cell/channel activity? When is this particularly useful?

What does the permeability of a cell membrane mainly depend on? What is the conductance of the cell membrane and that ion?

What are the reversal values of Na+ and K+? Why are they rectifiers at physiological values?

How do inner hair cell currents change with maturation? What does this suggest?

What can be used to block K+ currents when dissecting whole cell currents?

What can be used to block Na+ currents? (2)

What is Ic?

What does the shape of a single-channel recording tell you?

What are transient openings described in terms of?

What is the conductance of a Cl- channel?

Give 2 examples of channels which are gated by voltage and ligands?

How do Ik(Ca) channels work? What are they important for and on what type of cell?

What evidence is there for the combined gating of Ik(Ca) channels?

What does the function of BK cells relate to?

Why do different VG K+ channels show different current traces?

Why are many K+ channels known as 'delayed rectifiers'?

What are the 6 main features you might expect to see in a voltage gated ion channel?