Electrode resistance values can reflect DRG neurite contact with electrode.

<p>In a single experiment resistance values from electrodes were averaged by classification (DRG neurite, UNCLEAR, or CLEAN). The soma in this experiment was not placed in contact with any electrodes. (A) The change in resistance for electrodes in contact with a DRG neurite (-0.24 ± 0.02 MΩ; n = 16; p < 0.001; F = 69.685) were significantly less than for electrodes classified as UNCLEAR (-0.42 ± 0.02 MΩ; n = 19; p < 0.001) or CLEAN (-0.53 ± 0.01 MΩ; n = 31 electrodes). (B) The distribution of the change in electrode resistances for CLEAN electrodes, UNCLEAR electrodes and electrodes contacted by a DRG neurite were plotted in a frequency curve (0.5 MΩ bins). (C) The average change in resistance of UNCLEAR electrodes was background subtracted across all electrodes in a single experiment. This did not change the relationship between resistance values of electrodes contacted by DRG neurites and CLEAN electrodes. However it allowed for a comparison of resistance values across experiments.</p

The average change in resistance (MΩ) of each classified electrode after background subtraction for all six experiments (SEM in brackets).

<p>The average change in resistance (MΩ) of each classified electrode after background subtraction for all six experiments (SEM in brackets).</p

High resolution phase contrast photomicrograph of DRG tissue seeded on a microelectrode array after a 2 day culture.

<p>(A). 59 extracellular electrodes were visually classified as having contact with a DRG soma (B) or a DRG neurite (C). For some electrodes it was unclear if there was DRG neurite contact (D) and electrodes devoid of contact with DRG tissue were classified as CLEAN (E). The majority of electrodes classified as CLEAN were located on the opposite side of the array from where the DRG tissue was located (left side of A; scale bar = 200 μm).</p