NPI SEC-05LX, Operating Instructions Manual

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SEC/TEC SYSTEMS WITH DHC MODE
General Description
The “
D ynamic H ybrid C lamp” (DHC) mode is used for investigations of ionic conductances in
voltage clamp (VC) mode following action potentials in current clamp (CC) mode. In CC mode an
action potential is detected by a spike detector and triggers a timing unit. This timing unit sets a
delay for triggering the SEC/TEC (being in CC mode). The SEC switches from CC mode to VC
mode with the actual membrane potential as holding potential.
Operation
The DHC mode is set through the MODE OF OPERATION switch at the front panel. When the
switch is set to DHC, the amplifier is in CC mode and the membrane potential is fed into a sample-
and-hold electronic. If a TTL pulse (+5 V) is applied to the MODE SELECT TTL (
SEC-10LX:
DHC TTL ) BNC connector, the SEC/TEC is switched to VC mode. The COMMAND INPUT for
voltage clamp is disabled and the command potential is provided by the sample-and-hold electronic
e.g. the command potential represents the last membrane potential before switch to VC
mode.
In practice, the investigator needs additionally a spike detector and a timing unit. The spike detector
detects an action potential and triggers – with a delay set by the timing unit – the transition from CC
mode to VC mode.
Note : Please don’t use DHC and VCcCC mode simultaneously!!
Literature
Dietrich, D., Clusmann, H. & Kral, T. (2002). Improved hybrid clamp: resolution of tail currents
following single action potentials.
J.Neurosci Meth . 116 , 55-63.