EEG-fMRI in awake rat and whole-brain simulations show decreased brain responsiveness to sensory stimulations during absence seizures
- University Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, France
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Finland
- Paris-Saclay University, CNRS, Institut des Neurosciences (NeuroPSI), France, France
- University Grenoble Alpes, Inserm, US17, CNRS, UAR 3552, CHU Grenoble Alpes, IRMaGe, France
- Aix Marseille University, INSERM, INS, Inst Neurosci Syst, France
Figures
Figure 1 with 2 supplements
Sensory stimulation, EEG setup, and example EEG traces.
For visual stimulation, optical fiber cables were positioned bilaterally close to the eyes (A1) .For whisker stimulation, plastic tips guided air flow bilaterally to whiskers (A2). For EEG, carbon …
Figure 1—figure supplement 1
Example of EEG trace and illustration of stimulation and seizure block paradigms used as statistical parametric mapping (SPM) inputs.
Inputs (A) were convolved with third-order gamma functions (B), which was selected as basis functions, accounting for temporal and dispersion differences in hemodynamic responses. Example of …
Figure 1—figure supplement 2
Habituation and imaging schedules for three illustrative rats.
After 8 days of habituation, three to five functional magnetic resonance imaging (fMRI) experiment were conducted within a 1–3 week period for each rat. In case rats were re-imaged more than 1 week …
Figure 2 with 1 supplement
EEG-functional magnetic resonance imaging (fMRI) setup and illustration of MRI data quality.
MRI transmit-receive loop coil placed around the implant (A), spatial signal-to-noise ratios of an illustrative high-resolution T1-FLASH (B), and low-resolution zero echo time (ZTE) image (C), …
Figure 2—figure supplement 1
Zero echo time (ZTE) and gradient-echo-echo-planar imaging (GE-EPI) data collected during visual stimulus experiment (15s ON, 30s OFF paradigm), and EEG trace illustrating MRI gradient artifacts, from an example rat in preliminary study.
Illustration of image quality, and statistical t-contrast maps to visual stimulation (A), functional contrast (B), and effect of EEG artifact (C) for both imaging sequences. Although ZTE exhibits …
Figure 3
Activation F-contrast maps of stimulation responses during interictal and ictal states and difference maps between these two states for the visual (A) and the whisker (B) stimulation experiments.
Parameter estimates of regressors were calculated for every voxel, and contrasts were added to parameter estimates of interictal stimulation, ictal stimulation, and to compare interictal versus …
Figure 4 with 1 supplement
Hemodynamic response functions (HRFs) to stimulations performed during an interictal and ictal period: visual stimulation (A) and whisker stimulation (B) groups.
HRFs were calculated in selected ROI, belonging to visual or somatosensory area, by multiplying gamma basis functions (Figure 1—figure supplement 1B) with its corresponding average beta-value over a …
Figure 4—figure supplement 1
Hemodynamic response functions (HRFs) to stimulation during an ictal period and during a condition when stimulation ended a seizure, for visual stimulation (A) and whisker stimulation (B) groups.
HRF was calculated in selected ROI, belonging to visual or somatosensory area, by multiplying gamma basis functions (Figure 1—figure supplement 1B) with their corresponding average beta-values over …
Figure 5
Activation F-contrast map (A) and hemodynamic response functions (HRFs) to seizure (B).
Parameter estimates of regressors were calculated for every voxel, and contrasts were added to parameter estimates of seizure in absence of stimulation. For statistical significance, F-contrast (p<0.…
Figure 6 with 2 supplements
Simulation of sensory stimulation during ictal and interictal periods.
(A–B) Asynchronous irregular (AI) and spike-and-wave discharge (SWD) type of dynamics obtained from the mean-field model, representing interictal and ictal periods respectively. The change between …
Figure 6—figure supplement 1
Single region activity during stimulation in whole-brain simulation.
We show the results of the simulations during interictal (A, B, C) and ictal periods (D, E, F). The stimulus is applied in the primary visual cortex (A, D) and propagates to the connected regions. …
Figure 6—figure supplement 2
Comparison of the spike-and-wave discharge (SWD) dynamics in the mean-field model and a spiking-neural network of adaptive exponential LIF neurons (AdEx) neurons.
(A) Raster plot (top) and mean firing rate (bottom) from an SWD type of dynamics obtained from the spiking network simulations. The network is made of 8000 excitatory neurons and 2000 inhibitory …
Tables
Table 1
Characteristics of the stimulations and seizures during a 45 min functional magnetic resonance imaging (fMRI) scanning period.
Occurrences (numbers/45 min) of each stimulation type during scanning period are presented, as well as occurrences and duration of seizures.
| Visual stimulation group | Whisker stimulation group | ||||
|---|---|---|---|---|---|
| Stimulations (nr/45 min) | Stimulations (nr/45 min) | ||||
| Mean | SD | Mean | SD | ||
| Stimulation during baseline | 32.4 | 12.3 | Stimulation during baseline | 22.2 | 8.8 |
| Stimulation fully inside seizure | 11.4 | 8.2 | Stimulation fully inside seizure | 9.9 | 9.5 |
| Stimulation started during seizure, >50% inside of seizure | 2.9 | 3.0 | Stimulation started during seizure, >50% inside of seizure | 2.1 | 2.2 |
| Stimulation started during seizure, >50% outside of seizure | 3.9 | 2.5 | Stimulation started during seizure, >50% outside of seizure | 3.5 | 4.0 |
| Stimulation started before seizure, >50% inside of seizure | 1.5 | 1.6 | Stimulation started before seizure, >50% inside of seizure | 0.1 | 0.3 |
| Stimulation started before seizure, >50% outside of seizure | 1.3 | 1.5 | Stimulation started before seizure, >50% outside of seizure | 0.5 | 0.8 |
| Stimulation ended seizure | 3.1 | 2.8 | Stimulation ended seizure | 12 | 8.1 |
| Stimulation right after seizure | 1.1 | 0.8 | Stimulation right after seizure | 1.8 | 1.6 |
| Seizures | Seizures | ||||
| Total number of seizures | 40.2 | 28.3 | Total number of seizures | 49.6 | 34.6 |
| Seizures without a stimulation | 15 | 7.8 | Seizures without a stimulation | 19.8 | 8.2 |
| Duration of seizures (s) | 6.1 | 5.2 | Duration of seizures (s) | 5.1 | 4.0 |
