Multichannel Systems MEA1060-Inv-BC Manual - Manual (Page 34)

MEA Amplifier with Blanking Circuit for Inverse Microscopes
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5.5 Stimulation
Recommended stimulus protocols for MEA electrodes
MCS recommends to use only biphasic voltage pulses with the negative phase first. The
duration of the pulse should be 100 μs for each phase and the amplitude between 100 mV
and 3000 mV. Make sure that the voltage level of the stimulating electrode is zero at the
end of the pulse. (See also Potter, S. M., Wagenaar, D. A. and DeMarse, T. B. (2005). Closing
the Loop: Stimulation Feedback Systems for Embodied MEA Cultures. Advances in Network
Electrophysiology Using Multi-Electrode Arrays. M. Taketani and M. Baudry, Springer;
Wagenaar, D. A., Madhavan, R., Pine, J. and Potter, S. M. (2005). "Controlling bursting
in cortical cultures with closed-loop multi-electrode stimulation." J Neurosci 25(3): 680-8.)
Stimulation with MEA electrodes
You can apply two different stimulus protocols to any selection of electrodes. Use the MEA_Select
program to select electrodes for recording and stimulation. The stimulation is triggered with a TTL
pulse, the so-called blanking signal. Please see "Blanking" for more information how to set up
and time the blanking signal.
You can also stimulate without blanking, for example, for testing your setup. Under Blanking,
deselect the Blanking option for disabling the blanking function.
Important: You can only stimulate during an active TTL pulse , which is used for triggering
the stimulation and the blanking (see illustration of switch positions below). You can switch off
the blanking for test purposes, but this is not considered a useful mode of operation, because
the amplifier will get saturated by the high stimulus input without blanking.
Important: The input voltage of the MEA1060-BC amplifier is limited to +/- 5 V . Exceeding
the voltage input range can result in unpredictable noise and artifacts. In rare cases, even damage
to the amplifier electronics might occur. For current driven stimulation, the voltage amplitude
depends on the electrode impedance. As the electrode impedance depends on several parameters,
for example, the electrode's degree of wear and its hydrophilicity, and therefore cannot be
predicted, it is generally recommended to use
only voltage driven stimulation . Current driven
stimulation may work with larger (30 μm) TiN electrodes that have a low impedance, but this
cannot be guaranteed by the manufacturer.
For more information on the setup, please see the chapter “Setting Up and Connecting
the MEA Amplifier”.