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Experimental Investigation on Spontaneously Active Hippocampal Cultures Recorded by Means of High-Density MEAs: Analysis of the Spatial Resolution Effects.

Maccione A, Gandolfo M, Tedesco M, Nieus T, Imfeld K, Martinoia S, Berdondini L - Front Neuroeng (2010)

Bottom Line: Then, the full resolution dataset is spatially downsampled in order to evaluate the effects on raster plot representation, array-wide spike rate (AWSR), mean firing rate (MFR) and mean bursting rate (MBR).Furthermore, the effects of the array-to-network relative position are evaluated by shifting a subset of equally spaced electrodes on the entire recorded area.Results highlight that MFR and MBR are particularly influenced by the spatial resolution provided by the neuroelectronic interface.

View Article: PubMed Central - PubMed

Affiliation: Neuroscience and Brain Technologies, Italian Institute of Technology Genova, Italy.

ABSTRACT
Based on experiments performed with high-resolution Active Pixel Sensor microelectrode arrays (APS-MEAs) coupled with spontaneously active hippocampal cultures, this work investigates the spatial resolution effects of the neuroelectronic interface on the analysis of the recorded electrophysiological signals. The adopted methodology consists, first, in recording the spontaneous activity at the highest spatial resolution (interelectrode separation of 21 mum) from the whole array of 4096 microelectrodes. Then, the full resolution dataset is spatially downsampled in order to evaluate the effects on raster plot representation, array-wide spike rate (AWSR), mean firing rate (MFR) and mean bursting rate (MBR). Furthermore, the effects of the array-to-network relative position are evaluated by shifting a subset of equally spaced electrodes on the entire recorded area. Results highlight that MFR and MBR are particularly influenced by the spatial resolution provided by the neuroelectronic interface. On high-resolution large MEAs, such analysis better represent the time-based parameterization of the network dynamics. Finally, this work suggest interesting capabilities of high-resolution MEAs for spatial-based analysis in dense and low-dense neuronal preparation for investigating signaling at both local and global neuronal circuitries.

No MeSH data available.


Related in: MedlinePlus

(A) Mean Firing Rate (MFR) and (B) Mean Bursting Rate (MBR) obtained by varying the array electrode density on 7 experiments at different DIVs. Instable values in the MFR for the some experiments (2–3–7) are observed for electrode densities lower than 151 electrode/mm2 (480 electrodes on the active area of 1.7 × 1.7 mm2). This instability is more evident for the MBR where almost all experiments are stable for a density higher than 151 electrode/mm2. (C) Box-plots representation of the firing rate distribution (left axis) superimposed to the StdDev (right axis) at different electrode densities and layout positions. First and third quartile, median and standard deviation, are almost identical for electrode density of 289 and 580 el/mm2. At the same values StdDev shows a stable plateau. (D) Logarithmic representation of the Kullbach-Leibler distances of pair-wise firing rate distribution. Distributions, whose distance fall below the threshold (gray dashed line), are close to each other. This holds true from the firing rate distributions at 289 and 580 el/mm2.
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Figure 4: (A) Mean Firing Rate (MFR) and (B) Mean Bursting Rate (MBR) obtained by varying the array electrode density on 7 experiments at different DIVs. Instable values in the MFR for the some experiments (2–3–7) are observed for electrode densities lower than 151 electrode/mm2 (480 electrodes on the active area of 1.7 × 1.7 mm2). This instability is more evident for the MBR where almost all experiments are stable for a density higher than 151 electrode/mm2. (C) Box-plots representation of the firing rate distribution (left axis) superimposed to the StdDev (right axis) at different electrode densities and layout positions. First and third quartile, median and standard deviation, are almost identical for electrode density of 289 and 580 el/mm2. At the same values StdDev shows a stable plateau. (D) Logarithmic representation of the Kullbach-Leibler distances of pair-wise firing rate distribution. Distributions, whose distance fall below the threshold (gray dashed line), are close to each other. This holds true from the firing rate distributions at 289 and 580 el/mm2.

Mentions: Differences between the different array layouts can be observed for the MFR and for the MBR. This is shown in Figure 4 reporting the MFR (Figure 4A) and MBR (Figure 4B) calculated for 7 preparations on subsets of electrodes featuring an increasing electrode density. As shown by these plots, by increasing the electrode density a stable MFR and MBR is reached especially for experiments 2, 3 and 7. The achievement of a refined statistics of global parameters such as MFR and MBR is particularly important for experiments involving dissociated cultures that generally present a high variability both inter and intra-cultures. However, the extrapolation of a general quantification of the minimum electrode density required for reaching stable values is rather difficult since the steady-state stability depends also on the time-window of observation. Here, to evaluate the threshold at least at our experimental conditions we further analyzed the data as described in Section “Statistical and stability tests”.


Experimental Investigation on Spontaneously Active Hippocampal Cultures Recorded by Means of High-Density MEAs: Analysis of the Spatial Resolution Effects.

Maccione A, Gandolfo M, Tedesco M, Nieus T, Imfeld K, Martinoia S, Berdondini L - Front Neuroeng (2010)

(A) Mean Firing Rate (MFR) and (B) Mean Bursting Rate (MBR) obtained by varying the array electrode density on 7 experiments at different DIVs. Instable values in the MFR for the some experiments (2–3–7) are observed for electrode densities lower than 151 electrode/mm2 (480 electrodes on the active area of 1.7 × 1.7 mm2). This instability is more evident for the MBR where almost all experiments are stable for a density higher than 151 electrode/mm2. (C) Box-plots representation of the firing rate distribution (left axis) superimposed to the StdDev (right axis) at different electrode densities and layout positions. First and third quartile, median and standard deviation, are almost identical for electrode density of 289 and 580 el/mm2. At the same values StdDev shows a stable plateau. (D) Logarithmic representation of the Kullbach-Leibler distances of pair-wise firing rate distribution. Distributions, whose distance fall below the threshold (gray dashed line), are close to each other. This holds true from the firing rate distributions at 289 and 580 el/mm2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2871691&req=5

Figure 4: (A) Mean Firing Rate (MFR) and (B) Mean Bursting Rate (MBR) obtained by varying the array electrode density on 7 experiments at different DIVs. Instable values in the MFR for the some experiments (2–3–7) are observed for electrode densities lower than 151 electrode/mm2 (480 electrodes on the active area of 1.7 × 1.7 mm2). This instability is more evident for the MBR where almost all experiments are stable for a density higher than 151 electrode/mm2. (C) Box-plots representation of the firing rate distribution (left axis) superimposed to the StdDev (right axis) at different electrode densities and layout positions. First and third quartile, median and standard deviation, are almost identical for electrode density of 289 and 580 el/mm2. At the same values StdDev shows a stable plateau. (D) Logarithmic representation of the Kullbach-Leibler distances of pair-wise firing rate distribution. Distributions, whose distance fall below the threshold (gray dashed line), are close to each other. This holds true from the firing rate distributions at 289 and 580 el/mm2.
Mentions: Differences between the different array layouts can be observed for the MFR and for the MBR. This is shown in Figure 4 reporting the MFR (Figure 4A) and MBR (Figure 4B) calculated for 7 preparations on subsets of electrodes featuring an increasing electrode density. As shown by these plots, by increasing the electrode density a stable MFR and MBR is reached especially for experiments 2, 3 and 7. The achievement of a refined statistics of global parameters such as MFR and MBR is particularly important for experiments involving dissociated cultures that generally present a high variability both inter and intra-cultures. However, the extrapolation of a general quantification of the minimum electrode density required for reaching stable values is rather difficult since the steady-state stability depends also on the time-window of observation. Here, to evaluate the threshold at least at our experimental conditions we further analyzed the data as described in Section “Statistical and stability tests”.

Bottom Line: Then, the full resolution dataset is spatially downsampled in order to evaluate the effects on raster plot representation, array-wide spike rate (AWSR), mean firing rate (MFR) and mean bursting rate (MBR).Furthermore, the effects of the array-to-network relative position are evaluated by shifting a subset of equally spaced electrodes on the entire recorded area.Results highlight that MFR and MBR are particularly influenced by the spatial resolution provided by the neuroelectronic interface.

View Article: PubMed Central - PubMed

Affiliation: Neuroscience and Brain Technologies, Italian Institute of Technology Genova, Italy.

ABSTRACT
Based on experiments performed with high-resolution Active Pixel Sensor microelectrode arrays (APS-MEAs) coupled with spontaneously active hippocampal cultures, this work investigates the spatial resolution effects of the neuroelectronic interface on the analysis of the recorded electrophysiological signals. The adopted methodology consists, first, in recording the spontaneous activity at the highest spatial resolution (interelectrode separation of 21 mum) from the whole array of 4096 microelectrodes. Then, the full resolution dataset is spatially downsampled in order to evaluate the effects on raster plot representation, array-wide spike rate (AWSR), mean firing rate (MFR) and mean bursting rate (MBR). Furthermore, the effects of the array-to-network relative position are evaluated by shifting a subset of equally spaced electrodes on the entire recorded area. Results highlight that MFR and MBR are particularly influenced by the spatial resolution provided by the neuroelectronic interface. On high-resolution large MEAs, such analysis better represent the time-based parameterization of the network dynamics. Finally, this work suggest interesting capabilities of high-resolution MEAs for spatial-based analysis in dense and low-dense neuronal preparation for investigating signaling at both local and global neuronal circuitries.

No MeSH data available.


Related in: MedlinePlus