In vitro stimulation of neurons by a planar Ti–Au-electrode interface

We report on the realization of a planar large area electrode interface which reproducibly allows the global excitation of neurons and the generation of stimulated network activity. The interface is formed by two double finger-shaped Ti–Au-electrodes without any isolating coating deposited by electron beam evaporation on microscope cover slips. Dissociated nerve cells from embryonic rat cerebral cortex were cultured on these electrodes forming electrophysiologically active networks within seven days of culture. These networks were electrically excited by application of voltage pulses, resulting either in an activity of single neurons or in a stimulated synchronous network activity in dependence on the pulse parameters. The impact of these parameters, such as the number of pulses, the pulse amplitude and the delay between distinct pulse events, on the stimulation success was systematically investigated. We found threshold values for the voltage pulse amplitude of 1.8–2.2 V and for the voltage pulse duratio...