New thin-film surface electrode array enables brain mapping with high spatial acuity in rodents

Abstract

In neuroscience, single-shank penetrating multi-electrode arrays are standard for sequentially sampling several cortical sites with high spatial and temporal resolution, with the disadvantage of neuronal damage. Non-penetrating surface grids used in electrocorticography (ECoG) permit simultaneous recording of multiple cortical sites, with limited spatial resolution, due to distance to neuronal tissue, large contact size and high impedances. Here we compared new thin-film parylene C ECoG grids, covering the guinea pig primary auditory cortex, with simultaneous recordings from penetrating electrode array (PEAs), inserted through openings in the grid material. ECoG grid local field potentials (LFP) showed higher response thresholds and amplitudes compared to PEAs. They enabled, however, fast and reliable tonotopic mapping of the auditory cortex (place-frequency slope: 0.7 mm/octave), with tuning widths similar to PEAs. The ECoG signal correlated best with supragranular layers, exponentially decreasing with cortical depth. The grids also enabled recording of multi-unit activity (MUA), yielding several advantages over LFP recordings, including sharper frequency tunings. ECoG first spike latency showed highest similarity to superficial PEA contacts and MUA traces maximally correlated with PEA recordings from the granular layer. These results confirm high quality of the ECoG grid recordings and the possibility to collect LFP and MUA simultaneously.

Analysis and Model of Cortical Slow Waves Acquired with Optical Techniques

“…On the other hand, we only have this information for the discrete points corresponding to the pixels. For this reason, the partial derivatives that appear in (2) have been calculated as finite differences, with the distance between two pixels denoted as d: 9 MATLAB R , The MathWorks, Inc., Natick, Massachusetts, United States, https://www.mathworks.com/products/matlab. html (accessed on Dec. 2018).…”

Advances in Carbon-Based Microfiber Electrodes for Neural Interfacing

“…To interface with neurons, microelectrodes are implanted in the nervous system to monitor and/or modulate neural activity (Kita and Wightman, 2008;Jacobs et al, 2014;Thompson et al, 2016). Compared to non-penetrating surface electrodes, such as in electrocorticography (ECoG) and electroencephalogram (EEG), penetrating microelectrodes can communicate with neurons with higher spatial and temporal resolution due to the closer distance between the electrodes and target neural tissue (Wang et al, 2017;Konerding et al, 2018).…”

Stimulus Driven Single Unit Activity From Micro-Electrocorticography

“…For example, penetrating laminar shank style probes provide excellent resolution and are commonly used in neurophysiology studies (e.g., Fukushima et al, 2015;Kozlov and Gentner, 2016;Vyssotski et al, 2016), but lack broad spatial coverage. These PEAs, which can sample spatially at varying depth, could be combined with micro-ECoG electrode arrays that have broad coverage over the surface of the brain to gain new insights into neural dynamics as well as the physiological origin of local field potentials sensed at the surface (Suzuki and Larkum, 2017;Konerding et al, 2018). Micro-ECoG can also provide high spatial resolution.…”