ENat +54.5 mV [X]out [X]in P Ext -94.8 mV Nat 250 mM 30 mM 1 Eca2+ +85.6 mV K+ 8 mM 320 mM 10 EMP2+ +52.4 mV Ca2+ 8 mM 0.01 mM N/A Eci- -59.2 mV Mg2+...

Hello. I'm struggling to formulate a hypothesis based on a scenario given to me for a neuroscience question

. Lets say hypothetically speaking, I'm doing research that involves working with isolated neurons that are kept in cell culture at 25 degrees. I have my calculations for equilibrium potentials as well as the expected membrane resting potential Vm. The first "drug" is expected to increase K+ permeability of the resting membrane tenfold by binding to ligand-gated K+ channeled in the membrane. Another drug tetrodotoxin is added to avoid the influence of voltage-gated channels to the result. What should I predict will happen and why? What will happen to the Vm as we apply drug and why? Could we predict a new Vm after the drug has been applied? And why do we expect the outcome? What parameters have changed after drug 1 has been added?

Please help direct me!

I know that increasing the permeability of K+ ions in the rested membrane tenfold would only affect the duration of the action potential. If there is an increase in the rate, wouldn't there maybe a minimal decrease in the amplitude of the action potential but no change in the resting potential?

.Because an action potential is generated when the membrane is depolarized, that is potassium moves out and sodium moves in cause a change in charge. So if potassium is allowed to exit tenfold, the magnitude of the action potential will increase, can I hypothesize that after adding drug 1, the Vm will remain the same?

For drug two when expected to

Wouldn't there be a change in the membrane potential Vm when there another drug added that is expected to open all ligand-gated Magnesium and Chloride channels in the membrane with still both Na+ and K+ voltage channels being blocked by Tetrodotoxin? That is drug 2 is used to block the potassium and sodium gates? Chlorine is negatively charged and magnesium is positive. Can I hypothesize that It will not affect the membrane potential? The potential can still be generated as chlorine can move in and Magnesium out?

There is a difference in Chlorine and Magnesium compared to sodium and potassium therefore the action potential will increase the Vm with the use of drug 2?

ENat+54.5 mV[X]out[X]inPExt-94.8 mVNat250 mM30 mM1Eca2++85.6 mVK+8 mM320 mM10EMP2++52.4 mVCa2+8 mM0.01 mMN/AEci--59.2 mVMg2+12 mM0.2 mMN/AVM-58.6 mVCI-600 mM60 mM0.01Table 1: Results from Assignment #1.Table 2: lon concentrations and membrane permeabilitiesIn a resting, non-drugged neuron.