Journal: bioRxiv

Article Title: GABAergic neurons can facilitate the propagation of cortical spreading depolarization: experiments in mouse neocortical slices and a novel neural field computational model

doi: 10.1101/2024.10.24.620012

Figure Lengend Snippet: A . Raw near infrared transmitted light image of a representative coronal brain slice in which a pipette for applying 130 mM KCl and two extracellular electrodes for LFP recordings were placed in the somatosensory cortex. The image shows the initiation of CSD induced by a puff of KCl; Scale bar 0.5 mm. The other panels ( B-E ) show the same slice after image processing (subtraction of the background, optimization of the contrast) to highlight the intrinsic optical signal (IOS) during CSD initiation (KCl puff application, B ) and propagation ( C-E ) at the indicated times; the white wave is the CSD that propagates in the cortex. Scale bar 0.5 mm. F . Comparison of the propagation speed measured in slices from WT mice and from VGAT_cre − ChR2_lox mice (without optogenetic illumination), showing that there is no difference. G . LFP recorded during CSD propagation at the two locations indicated in E (LFP1 and LFP2), showing the typical CSD DC shift (note the delay of CDS initiation at LFP2 compared to LFP1).

Article Snippet: Extracellular DC local field potential (LFP) was recorded with a Multiclamp 700B amplifier (CV-7B headstage), a Digidata 1440A acquisition board and pClamp 10.3 software (Molecular Devices, USA).

Techniques: Slice Preparation, Transferring, Comparison

Journal: Frontiers in Neuroimaging

Article Title: Probing hippocampal stimulation in experimental temporal lobe epilepsy with functional MRI

doi: 10.3389/fnimg.2024.1423770

Figure Lengend Snippet: FMRI responses in epileptic mice and sham controls stimulated at 10 Hz. (A) Experimental design. (Left) Representative T2-weighted anatomical reference image showing stimulation and recording electrodes implanted in the right and left hippocampus, respectively. Scale bar: 1 mm. (Right) Exemplary (unprocessed) fMRI time course (blue) showing the responses to the stimulation indicated by the electrical artifacts in the LFP trace (black). Scale bar: 60 s. (B) fMRI activation in chronically epileptic mice from caudal (top left) to rostral (bottom right) direction at stimulation parameters: 10 Hz, 10 s, 80 μA. The group-level ( n = 6) fMRI activations are shown as red-yellow overlays in the AMBMC reference space (gray background) with contours of the AMBMC mouse brain atlas (colors red to yellow represent z-scores from 4.6 to 15 of significant responses at a voxel-wise corrected threshold p < 0.05). (C) fMRI activation in sham controls stimulated at 10 Hz, for 10 s and 80 μA. Positive and negative responses are shown as red-yellow (z-scores from 4.6 to 15) and blue-light blue (z-scores from −4.6 to −15) overlays (group-level n = 4, voxel-wise corrected threshold p < 0.05). (D) Group-level differences between epileptic ( n = 6) and control ( n = 4) mice. Yellow and cyan colored areas represent areas with significantly stronger responses in epileptic mice or controls, respectively (two-sample unpaired T -test, voxel-wise corrected threshold p < 0.05, stimulation parameters 10 Hz, for 10 s and 80 μA). (E) Mean fMRI responses in selected regions (mean ± SEM). The black bars indicate the stimulation periods. Atlas regions: sHC, septal hippocampus; iHC, intermediate hippocampus; mEnt, medial entorhinal cortex; Cg-Rsp, cingulate region/retrosplenial area; Cg, cingulate region/anterior cingulate area. (F) Quantification of the entire activated volume on the ipsilateral and contralateral hemisphere (mean ± SEM). In epileptic mice, the activated volumes on the ipsilateral hemisphere were significantly larger than on the contralateral side, whereas no difference was found in sham controls ( * p < 0.05, one-sample t -tests between ipsi- and contralateral “Entire Activated Volumes”).

Article Snippet: During fMRI measurements, local field potential (LFP) signals were recorded (EGI, Electrical Geodesics, USA) in the left dorsal HC with a sampling rate of 1 kHz.

Techniques: Activation Assay, Control

Journal: Nature Communications

Article Title: Biomimetic computer-to-brain communication enhancing naturalistic touch sensations via peripheral nerve stimulation

doi: 10.1038/s41467-024-45190-6

Figure Lengend Snippet: The successful development of a somatosensory neuroprosthesis is based on three main pillars: (1) In-silico models of the biological sensory processing have to be exploited for emulating the natural neural activation of the nervous system to external tactile stimuli (blue segment); (2) animal proof of concept allows for experimental validation of the mechanisms behind the use of specific neurostimulation strategies defined with the use of modeling (orange segment); DRG—dorsal root ganglion. (3) A rigorous clinical validation of the biomimetic technology with implanted humans has to be performed in order to assess the functional outcomes in real-life scenarios (green segment). The results from the clinical trials will then allow us to collect relevant data exploitable for improving computational modeling. (Illustration credit: Giacomo Valle, ETH Zurich).

Article Snippet: Examples of spiking activity over time during each condition are presented using a peri-stimulus time histogram (PSTH) (right) with a time bin of 50 ms. Brown lines represent the envelope of neural activity. b Comparing local field potential (LFP) recorded in DRG resulting from natural touch in biomimetic and tonic stimulation.

Techniques: In Silico, Activation Assay, Biomarker Discovery, Functional Assay, Clinical Proteomics

Journal: Nature Communications

Article Title: Biomimetic computer-to-brain communication enhancing naturalistic touch sensations via peripheral nerve stimulation

doi: 10.1038/s41467-024-45190-6

Figure Lengend Snippet: a Decerebrated cat experimental setup. We stimulated the tibial nerve with a cuff electrode and recorded neural response on the spinal level; upper part: exposed L6 vertebrae and dorsal root ganglion (DRG) with examples of recorded neural spikes from spinal linear electrode probe and DRG UTAH array. b Obtaining multiunit neural activity. We filtered the signal to extract the spiking component and detect the neural action potentials using the thresholding algorithm. c left: Example of biomimetic stimulation paradigm and recorded response signal in one channel of the spinal cord and DRG electrodes. Neural activity is presented and quantified with a raster plot (black dots) and peri-stimulus time histogram (PSTH, yellow, bin length 10 ms). Each row of the raster plot represents the response to a single biomimetic pattern (2 s), while each dot corresponds to an action potential. Right: We compared the PSTHs from different conditions and presented them using cross-correlation (blue: L6 neural response and stimulation pattern; red: DRG neural response and stimulation pattern; black: L6 and DRG neural responses). Source data are provided as a Source Data file.

Article Snippet: Examples of spiking activity over time during each condition are presented using a peri-stimulus time histogram (PSTH) (right) with a time bin of 50 ms. Brown lines represent the envelope of neural activity. b Comparing local field potential (LFP) recorded in DRG resulting from natural touch in biomimetic and tonic stimulation.

Techniques: Activity Assay

Journal: Nature Communications

Article Title: Biomimetic computer-to-brain communication enhancing naturalistic touch sensations via peripheral nerve stimulation

doi: 10.1038/s41467-024-45190-6

Figure Lengend Snippet: a Comparing multiunit neural activity as a response to natural touch, biomimetic, or tonic (50 Hz) stimulation. We compared the signal recorded in DRG (dorsal root ganglion) and spinal cord (level L6). The overall amount of neural activity during each condition is summed, normalized, and presented with bars for comparison (left). Examples of spiking activity over time during each condition are presented using a peri-stimulus time histogram (PSTH) (right) with a time bin of 50 ms. Brown lines represent the envelope of neural activity. b Comparing local field potential (LFP) recorded in DRG resulting from natural touch in biomimetic and tonic stimulation. Another natural touch response, recorded in cat 2, was added to the analysis. We compared the distribution of LFP amplitude values using the Kullback–Leibler divergence metric. c Comparing current source density (CSD) calculated from LFP recorded in the spinal cord resulting from natural touch, biomimetic, or tonic stimulation. CSD is normalized for each condition and presented along the length of the electrode with 100 ms bin for electrical stimulation and 40 ms for natural touch condition. d Left: correlation of CSD between biomimetic/tonic and natural touch condition and biomimetic and tonic stimulation, channel by channel, color-coded. Right: Histogram and cumulative distribution function (cdf) of the correlation coefficient values resulting from comparing biomimetic/tonic stimulation and natural touch condition (top/middle) and biomimetic and tonic stimulation (bottom). The blue line represents the cdf when the recording channels are matched and compared. The red line corresponds to cdf when channels are randomly shuffled and compared. Source data are provided as a Source Data file.

Article Snippet: Examples of spiking activity over time during each condition are presented using a peri-stimulus time histogram (PSTH) (right) with a time bin of 50 ms. Brown lines represent the envelope of neural activity. b Comparing local field potential (LFP) recorded in DRG resulting from natural touch in biomimetic and tonic stimulation.

Techniques: Activity Assay, Comparison

Journal: Communications Engineering

Article Title: Towards automated sleep-stage classification for adaptive deep brain stimulation targeting sleep in patients with Parkinson’s disease

doi: 10.1038/s44172-023-00150-8

Figure Lengend Snippet: a Representative local field potential (LFP) spectrogram recorded from the subthalamic nucleus (STN) of a Parkinson’s disease (PD) subject during a single nocturnal sleep period. White line indicates the hypnogram. Colorbar denotates the local field potential power (LFP) magnitude. b A horizontal stacked bar chart depicting the occurrence and distribution of sleep stages (i.e., awake, NREM1, NREM2, NREM3 and REM) for all 10 PD subjects used in this study. Colors denote distinct sleep stages. c Preprocessing steps for LFP data used as input for NN sleep stage classification (LFP data in schematic were simulated and not subject data). (1) Individual LFP recordings from each deep brain stimulation contact (black squares = DBS recording contact), (2) bipolar referencing strategy; grey squares indicate two adjacent DBS contacts used for referencing and resulting grey LFP recording, (3) raw LFP is partitioned into 30 s epochs based on distinct sleep stages (defined by expert scored polysomnography), (4) time and frequency processing performed on each 30 s epoch of LFP, (5) each 30 second epoch of LFP was decomposed into canonical frequency band related information, (6) power contributions for each frequency band were normalized before input into neural network.

Article Snippet: Colorbar denotates the local field potential power (LFP) magnitude. b A horizontal stacked bar chart depicting the occurrence and distribution of sleep stages (i.e., awake, NREM1, NREM2, NREM3 and REM) for all 10 PD subjects used in this study.

Techniques: