Automated multi-slice extracellular and patch-clamp experiments using the WinLTP data acquisition system with automated perfusion control

► Almost complete automation of synaptic plasticity and pharmacology experiments is achieved by adding automated perfusion to stimulation/acquisition protocol scripting. ► For multi-slice experiments, automated perfusion control is helpful when there is a need to change many solutions on many separately perfused slices. ► For single cell patch-clamp experiments, automated perfusion control is helpful when many solutions have to be rapidly changed with accurate timing. ► For slice and single cell, single-line automated perfusion, up to 16 different solutions can be delivered. ► For single cell, triple-line automated perfusion with stepper control, up to 48 different solutions can be delivered. WinLTP is a data acquisition program for studying long-term potentiation (LTP) and other aspects of synaptic function. Earlier versions of WinLTP (J. Neurosci. Methods, 162:346–356, 2007) provided automated electrical stimulation and data acquisition capable of running nearly an entire synaptic plasticity experiment, with the primary exception that perfusion solutions had to be changed manually. This automated stimulation and acquisition was done by using ‘Sweep’, ‘Loop’ and ‘Delay’ events to build scripts using the ‘Protocol Builder’. However, this did not allow automatic changing of many solutions while running multiple slice experiments, or solution changing when this had to be performed rapidly and with accurate timing during patch-clamp experiments. We report here the addition of automated perfusion control to WinLTP. First, perfusion change between sweeps is enabled by adding the ‘Perfuse’ event to Protocol Builder scripting and is used in slice experiments. Second, fast perfusion changes during as well as between sweeps is enabled by using the Perfuse event in the protocol scripts to control changes between sweeps, and also by changing digital or analog output during a sweep and is used for single cell single-line perfusion patch-clamp experiments. The addition of stepper control of tube placement allows dual- or triple-line perfusion patch-clamp experiments for up to 48 solutions. The ability to automate perfusion changes and fully integrate them with the already automated stimulation and data acquisition goes a long way toward complete automation of multi-slice extracellularly recorded and single cell patch-clamp experiments.