This new technique is just too cool not to blog about.
|Novak et al. 2013 Figure 1A pre-synaptic patch clamp|
The synapse is the connection between two neurons. The pre-synaptic part is from the neuron sending a signal and the post-synaptic part is from the neuron receiving the signal.
If you want to learn about the connection between the two neurons, you want to know what is happening on both sides of the synapse. It's relatively easy to record signals from the post-synaptic side using patch clamp or sharp electrode recording, but it is much much harder (basically impossible until now) to record from the pre-synaptic side.