1) You voltage-clamp axons from a wild-type squid and from a series of a genetically modified...

 

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1) You voltage-clamp axons from a wild-type squid and from a series of a genetically modified squid. In all cases the response to a step from -100 mV to 0 mV is shown, and the ion concentrations are such that Ena = +60 mV and Ek= -100 mV. You can get the amplitude value of current from the right figure. a) Wild-type currents are shown to the right. The rise of the potassium current does not begin until 3 ms after the step begins. What do you estimate the peak sodium conductance to be in this axon? b) What is the steady state sodium conductance (i.e. 20 ms after the start of the step)? c) What is the steady state potassium conductance (i.e. 20 ms after the start of the step)? d) What is the peak potassium conductance? Explain. Membrane Current (A) 400 200- 0 -200 -400 0 Wild-type squid 5 10 Time (ms) 15 20 1) You voltage-clamp axons from a wild-type squid and from a series of a genetically modified squid. In all cases the response to a step from -100 mV to 0 mV is shown, and the ion concentrations are such that Ena = +60 mV and Ek= -100 mV. You can get the amplitude value of current from the right figure. a) Wild-type currents are shown to the right. The rise of the potassium current does not begin until 3 ms after the step begins. What do you estimate the peak sodium conductance to be in this axon? b) What is the steady state sodium conductance (i.e. 20 ms after the start of the step)? c) What is the steady state potassium conductance (i.e. 20 ms after the start of the step)? d) What is the peak potassium conductance? Explain. Membrane Current (A) 400 200- 0 -200 -400 0 Wild-type squid 5 10 Time (ms) 15 20