Extracellular recording is a core method for recording the activity of individual neurons in vivo. To gather validation data, for which we know when a neuron nearby the extracellular probe is active, we developed in NeuroSeeker a new technique for "paired recordings". It uses high accuracy mechanical manipulators to position two probes, i.e. the extracellular device and a glass micro-pipette capable of isolating a single neuron, very close to one another. This ground truth dataset is made available through http://www.kampff-lab.org/validating-electrodes/ to validate new analysis-methods for the interpretation of high density neural recordings.