PMPI Calibration with [K+]ec steps and known [K+]ic and known kP ( IAPMPIKstepsKnownKi )

Parameters:

Name	Short Name	Type	Description
Range definitions in time courses:	rangedef	string	Defines whether the ranges given below refer to frames or seconds in the recordings
Baseline Range:	BaselineRange	string	Defines the range of the baseline (in the above defined time units). Longer baseline results more accurate calibration.
K+ Steps Ranges:	KStepsRanges	string	Enter a list of range definitions for the duration of the K+-steps (in the above defined time units), including the MDC treatment.
[K+]ec Steps (mM;mM):	KStepsConcentrations	string	Extracellular (ec) K+ concentrations corresponding to the above defined steps, including MDC, in mM. Use the Wizard tab to calculate concentrations from added volumes.
kP:	kP	real	Previously measured value of kp
[K+]ic (mM):	Kic	real	Intracellular K+ concentration (activity) in mM, considered to be stable for the duration of calibration. If PN is non-zero, this is the value of [K+]ic+PD, determined previously by K-steps - Zero calibration.
PN (permeability of plasma membrane to ions other than K+):	PN	real	Summed relative permeability of the plasma membrane to ions other than K+ during * concentration, shown in the numerator of the GHK equation. Use -1 for automatic determination.
fP0-fPX Allowed Range:	fP0MinusfPXRange	string	Trace selection criterion: the minimum and maximum allowed value of fP0-fPX
fPX r^2 Min:	fpXr2Min	real	Trace selection criterion: the minimum allowed value of r^2 for the PMPI-regression.
Quality control by propagated error of baseline:	QCPMPrest	boolean	Removes traces where the estimated SE of baseline is greater than the threshold below. Requires error propagation.
Maximum SE of baseline (mV):	QCPMPrestMaxSE	real	Traces where the SE of resting ΔψP parameter is larger than this number are removed.

Description:

This method calculates plasma membrane potential (ΔψP) time course using calibration parameters from a single time lapse with the exception of kp using the knowledge of [K+]ic. In turn, this calibration does not require establishment of zero potential at the end of the time lapse. If the plasma membrane is significantly permeable to ions other than K+ the value of [K+]ic is [K+]ic+PD, where the PD is the sum of permeability times concentration of all other ions in the denominator of the GHK equation.
Required experimental protocol: any time lapse followed by establishment of K-equilibrium potential, and at least one addition of high K+-medium. Typically use 3-4 steps.
The cells have to be able to maintain a constant hyperpolarized ΔψP before starting K+-steps. Do not use this method if ΔψP depolarizes substantially when adding MDC.