Can recording dye something? Or I've misunderstood the meaning of the word via?
Context:
A direct patch-clamp recording from a dendrite of a pyramidal cell in mouse visual cortex in the intact brain. The neuron has been filled with a fluorescent dye via the dendritic recording and imaged using a two-photon microscope. These recordings directly reveal the computations performed by the dendrites during visual processing. (Credit: UCL)