Synapses that pass signals between individual neurons are tiny morphologically as well as functionally, as the electrical signals that pass through them are very weak. Measuring their activity has proven to be difficult, and only limited methods have come into laboratory practice.
Researchers at Queen Mary University of London have reported in journal Neuron the development of a new technique that allows for accurate measurement of current within cultured synapses of the central nervous system.
From the study abstract in Neuron:
Here we report a method based on superresolution scanning ion conductance imaging of small synapses in culture at approximately 100–150 nm 3D resolution, which allows presynaptic patch-clamp recordings in all four configurations (cell-attached, inside-out, outside-out, and whole-cell). Using this technique, we report presynaptic recordings of K+, Na+, Cl−, and Ca2+ channels. This semiautomated approach allows direct investigation of the distribution and properties of presynaptic ion channels at small central synapses.
Queen Mary University of London: Nanoscale neuronal activity measured for the first time