Preparation of carbon-fibre microelectrode for extracellular recording of synaptic potentials.

A method is proposed for rapid and effective forming of the recording tips of carbon-fibre microelectrodes by trimming and treating the tip with electric current pulses. The tip is trimmed to the required length. The signal-to-noise ratio of carbon-fibre microelectrodes is improved at low-frequency range (less than 100 Hz) after the treatment. The same microelectrode may be used for several experiments because of the possibility to trim and treat the tips repeatedly. This method also allows one to readily fabricate 2- or multi-channel carbon-fibre microelectrodes with the vertical distance between recording tips from few tens to hundreds of micrometres. As an example, the process of fabrication of a 2-channel microelectrode is described.