RESUMO
We have previously described the use of microchannels (µChannels) as substrate-integrated equivalents of micropipettes and advantageous neuron-electrode interface enhancers. The use of µChannels to establish stable recording and stimulation of threading axons results in a high signal-to-noise ratio (SNR), potentially high-throughput and low-cost alternative to conventional substrate-embedded microelectrodes. Here we confirm the consistent achievement of high SNRs with µChannels and systematically characterize the impact of µChannel geometry on the measured signals via numerical simulations and in vitro experiments. We demonstrate and rationalize how channels with a length of ≤300 µm and channel cross section of ≤12 µm(2) support spontaneous formation of seals and yield spike sizes in the millivolt range. Despite the low degree of complexity involved in their fabrication and use, µChannel devices provide a single-unit mean SNR of 101 ± 76, which compares favourably with the SNR obtained from typical microelectrode arrays.
