Assignment
- Calculate the new resting potential by changing the gK to 0.090 Micro Siemens, verify your answer with the simulator?
- Calculate the new resting membrane potential, when only resting Na+ channels were present in the membrane? (Hint: By changing the conductance of K+ and Cl+ to zero in channel window)
- Calculate the new Vr by changing the ion concentration of inside and outside (by keeping the conductance constant/intial value)? Suppose we want to rise the resting membrane potential to -40 mV, Which ion’s concentration you will change?, What will be the new values?
- Calculate the outside Na+ concentration in order to achieve the Vr =55mV?
- Study the effect of temperature in Vr by changing the variable T in membrane window, change the temperature from the default value 6.3oC to 12.6 oC, what will be the new Vr ? , Why?
- Describe the parallel conductance equation and calculate the resting potential (Vr) from equilibrium potential given in the membrane window and conductance given in the channel window?
- Calculate the resting potential and reversal potential of Na+ ,K+ and Cl- ions in order to simulate different dynamics and properties of excitable cells from different species. The ionic concentrations inside and outside the cell membrane for ions (Na+ ,K+ and Cl) are given in the table below. Note to change temperature according to the value corresponds to the species given in the table before the you simulate the neuronal membrane model.
Hit the reset button at the right corner of the simulation control window, to reset all parameters to its initial/default values.While simulating all the assignment questions in this exercise please NOTE that, voltage gated channels are off (by changing its conductance to zero, in channels details sub window).
Solution for Question 2
1. Simulator was loaded by clicking the tab buttom "Simulator"
2.Switch off the voltage gated ion channels conductance (see the figure below)
3. "only resting Na+ channels were present in the membrane", making the conductance of resting K+ and Cl- ion channels to zero.
4. Newly updated resting membrane potential can be estimated from membrane window.