How does the hippocampal LTP experiment work?
The hippocampal LTP experiment described on the final page of the handout is notoriously hard to understand without spending large amounts of time figuring out exactly what’s being done where. With reference to the graph (which I’ve not put here because I’m assuming the notes are copyright), this page explains how the experiment shows that LTP exists. The idea behind the experiment is that CA1 pyramidal cells in the hippocampus receive two main sets of inputs – Schaffer collaterals coming from the CA3 cell field, and commissural fibres from the contralateral hippocampus. These synapse on the pyramidal cells at seperate points. In the experiment, stimulating electrodes are introduced into the commissural fibres and Schaffer collaterals (see diagram on handout). Recordings are made from the CA1 cells themselves. The Schaffer collaterals are always stimulated strongly in the experiment, whilst the commissural fibres are stimulated weakly. As a result, the synapses of these fibres will hav
