User manual

52
First, set the channel AD0 DataType to "mV".
Second, change the AD0 Gain to be equal to the total amplification gain from the electrode to the AD
board connection. For example, if an Axon Instruments AxoClamp is used in current clamp mode with an
internal x10 output gain, which then goes into an external x100 amplifier and then into channel AD0, the
AD0 Gain would be 1000.
Alternatively if an Axon Instruments AxoPatch 1D or 200B is used in whole cell voltage clamp mode (with
a CV-04 1/100 headstage where beta = 1), with an output gain of alpha = 10, and with the output going
channel AD0, the channel AD0 Gain would be the following:
V
out
Beta * Alpha mV 1 * 10 * 10
-3
AD0 Gain = ------ = ---------------------- = ----------------- = 10
10
= 10000000000
I
in
pA 10
-12
(Yes that's 10 0's!) If the output gain is changed to = 20, the AD0 Gain increases to 20000000000. Then
set the channel AD0 DataType to "pA".
Alternatively, the gain can be changed by entering it in Units/V (Fig. 2.13.1). While maybe it is clearer to
just type an AD Gain of 1000 for an extracellular or intracellular experiment in "mV", with a patch clamp
experiment in "pA" with enormous gain, a AD Units/V of 100 pA/V is much clearer than an AD Gain of
10000000000.
Furthermore, there is now also a mV/Unit field which as been added so that the patch-clamp gain can
now be set as mV/pA. This is to improve clarity of setting patch-clamp gain in mV/Unit (as in 10 mV/pA)
because many patch-clamps set gain in mV/pA. This gain is included with the normal strait gain (as in
Gain = 10000000000) and gain in Units/V (as in 100 pA/V).
Third, set the Train and PulseSweep Acquisition Sample Intervals to what you want, say 50 µsec (Fig.
2.13.1).
2.13.2 Set the Digital-to-Analog Output
Don’t worry about this for now. (Setting Digital-to-Analog output discussed in Section 4.8.1.)
2.13.3 Set the PulseSweep P0 Stimulation Values
Don’t worry about setting P0sweep stimulation values in the Sweep Stimulation Panel for now, just keep
the default values which are for single S0 pulse stimulation. (Setting sweep stimulation is discussed in
Section 4.9.1.)