This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Axon Membrane Zoo/Psych/Neuro 523 Problem Set 4 (due Friday Oct 3 rd ) 2008 1. In a voltage clamp experiment, when the membrane potential is depolarized, draw a diagram showing the net current flow across the membrane. Describe two ways in which you could distinguish the current carried by sodium ions from that carried by potassium ions. Voltage = 0 Net current = 0 = Ik+INa+Ifeedback to voltage clamp amplifier Feedback current in Na+ current in K+ current out saline external fluid Using a voltage clamp, one way to distinguish the sodium current from the potassium current is by blocking sodium channels with tetrodotoxin (TTX). If this is done while membrane voltage is clamped to 0, then the resulting measurable current will be from potassium only. Similarly, if potassium channels are blocked with tetraethylammonium (TEA) under the same voltage conditions, then the potassium current will be blocked and the sodium current alone can be...
View Full Document
- Fall '08