Article Figures & Data
Figures
- Figure 1.
Schematic of multianimal chronic video-LFP recording and analysis pipeline. A, Components for chronic LFP recordings. Custom-made electrodes (bottom left, scalebar: 3 mm) were implanted into CA1 of the hippocampus. Custom-made cables (top left) were soldered to an Intan adapter board (middle) and further protected with 10 mm heat shrink tubing (right). B, Timeline of experiment. Red rectangles represent 48 h of continuous monitoring. C, Experimental setup. Recordings were performed from four mice simultaneously. Video-LFP data were acquired and controlled in a custom-made Bonsai workflow. Seizure analysis was performed with a custom-made seizure analysis GUI, written in MATLAB. D, LFP and video were acquired and synchronized by merging timestamps (left). Timestamp, video, and voltage data were streamed to time-dependent loops (nodes labeled with X and *X) that enabled data saving once per hour.
- Figure 2.
LFP signals simultaneously recorded from different mice are independent. A, Five-second-long clips of LFP recorded simultaneously from two mice during hour 1 of monitoring (left) or hour 2 of monitoring (right). For each mouse two traces are shown corresponding to electrodes located in left (L) and right (R) hippocampus. Red lines indicate a period in which signals from both hemispheres showed synchronous signal within mouse 1. B, A matrix to visualize comparisons made to create distributions shown in C. Correlations between hour-long traces were made for comparisons that fell into three categories: (1) left versus right same mouse, same hour (gray); (2) different mice, same hour (purple); (3) different mice, different hours (cyan). Black represents self-comparisons, which were not included. White represents comparisons between the same mouse, but different hours, which were also not included. For actual distributions shown in C, comparisons were made across four mice, and for each hour across 24 h of recording. C, Cumulative density functions (CDFs) of correlations obtained from comparisons described in B. ***p < 0.001, one-way ANOVA, post hoc Tukey’s test
- Figure 3.
Seizure analysis GUI. A, Schematic of the GUI. A working directory is selected and recording date and mouse are chosen to be analyzed (top, right). Channels to show and duration of LFP traces are set by the user in Plot settings (top, left). Video lag, allows the user to set playback speed. Pressing “Seizure Detection” opens a pop-up window where the user may filter and/or flip signals before applying a threshold. When the user accepts the detection results, video and filtered LFP of the first event is loaded into the Video Playback and LFP Viewer. Detected seizure events are toggled through by the user using the “Next” button. Questions regarding the LFP signal and behavior are answered for each event (left). After performing scoring, annotations are saved by pressing the “Save” button. B, Seizure detection sequence. The user selects a channel on which the detection will occur (blue box). LFP is down-sampled, bandpass-filtered, and possibly flipped according to user input. An amplitude threshold is set by inputting an integer value (green line). Finally, detected events are displayed (magenta). User can expand view to look at several individual events and then choose to accept all results and start scoring or adjust the threshold and repeat the detection. C, Example of detected subclinical seizure. Detected seizure is indicated by the red bar and additional 60 s preseizure and postseizure baseline are shown. Gray lines indicate the range of the zoomed in 2-s-long gray trace. In this example, the seizure is only observed on the right hemisphere (bottom). D, Example of Stage V seizure. Seizure can be observed on both hemispheres. Notations are the same as in C.
- Figure 4.
Examples of subclinical seizures and behavioral seizures detected by the GUI. A, Segments of data from 1 h of recording that have been passed through the spectral method of seizure detection using the GUI. Early in the hour, a cluster of three subclinical seizures were detected and later in the hour, one Stage V seizure was detected. Classification as subclinical or behavioral was done by three independent scorers using the GUI. B, Enlarged versions of the events shown in A. For events s1 and s4, the first 3 s are enlarged on the right.
Tables
Timestamp Time (ms) LFP samples Video frame LFP sampling rate set at 2 kHz 1 1–128 1–256 1 2 129–256 257–512 5 3 257–384 513–768 8 4 385–512 769–1024 12 5 513–640 1025–1280 16 … 15 1793–1920 3585–3840 55 16 1921–2048 3841–4096 59 Timestamp Time (ms) LFP samples Video frame Frame interpolation LFP sampling rate set at 30 kHz 1 0–9 1–256 1 1 2 9–17 257–512 1 1 3 17–26 513–768 1 1 4 26–34 769–1024 1 1 5 34–43 1025–1280 1 2 … 15 120–128 3585–3840 1 3 16 128–137 3841–4096 4 4 Linear frame interpolation was done offline after data were acquired to assign unassigned frames.
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