Visualization of the electrode-surface.

<p>(A) SEM image of parylene coated Pt wire. (B) De-insulation with low power UV resulted in a smooth surface of the electrode. (C) Irradiation with high power UV resulted in an increment in the geographical surface area without increasing the physical area. (D) The electrode impedance as measured at 1 kHz was reduced after irradiation with high power UV (***p < 0.001). (Scale bar A = 11μm, B, C = 10 μm).</p

In-vivo characterization of electrode performance.

<p>(A) A 10 seconds long segment of an example recording made 8 weeks after implantation, illustrating the general characteristics of the recordings. (B) Distribution (median and interquartile range, IQR) of noise level across all recordings made within each week. Weekly noise level increased between weeks 1 and 2 (***p < 0.001), 2 and 3 (*p < 0.05) and 3 and 4 (**p < 0.01). After that, the weekly noise level remained stable (p > 0.05). N refers to the number of working channels recorded from each week. (C) Distribution (median and IQR) of SNR of recorded channels with identified single-units. SNR remained stable (p > 0.05) throughout the experiment. N refers to the number of working channels with identified single units within each week. (D) Distribution (median and IQR) of in-vivo impedance of recorded and working channels. Impedance remained stable (p > 0.05) throughout the experiment. N refers to the working channels on which an impedance measurement was performed each week. The variation in N (B-D) is mostly due to a varying number of animals recorded from each week.</p

Light field micrographs of track line and spreading of electrodes <i>in vivo</i>.

<p>(A) Electrode tip spread in with an average spread of approximately ≈ 500 μm in lateral direction. (B) Micrographs of electrically induced lesion in STN indicating the positions of separate electrode tips. Lesion marks induced by electrical stimulation of separate wires (6 wires/electrode, AC current, 1mA, 2 ms indicate the positions of the separate electrode tips in brain sections stained with cresyl violet.</p