Journal: Scientific Reports

Article Title: Dim light at night disturbs the daily sleep-wake cycle in the rat

doi: 10.1038/srep35662

Figure Lengend Snippet: Rats were exposed to LDim (n = 8) or LD (n = 5) and 24-h EEG/EMG recordings were performed on day 0 (baseline), day 1, day 7 and day 14. ( a ) LDim instantaneously decreased the amplitude of the daily rhythm in wakefulness (top), non-rapid eye movement (NREM) sleep (middle) and rapid eye movement (REM) sleep (bottom) with a further decrease over the following days. Control animals in LD showed no change in vigilance state distribution after 14 days. White bars: light phase, black bars: dark phase, grey bars: dim phase. ( b ) Percentage of time of 2-h intervals spent awake, in NREM sleep and in REM sleep. The baseline measurement at day 0 (open circles) is repeatedly plotted to facilitate comparison with subsequent days (closed circles). Registrations on day 0 and day 1 started at ZT12, recordings on day 7 and day 14 started at ZT0, but all data are plotted from ZT0 for convenience. Data are represented as mean ± SEM. If a significant main effect was detected, post hoc tests for differences from baseline were performed with student’s t -test and indicated by asterisks (P < 0.05) or double asterisks (P < 0.001).

Article Snippet: Rats (n = 13; bodyweight 283 ± 5 g) were anesthetized with Ketamine/Xylazine/Atropine, fixed in a stereotaxic frame and implanted with 2 electroencephalogram (EEG) screw electrodes (Plastics One, Roanoke, VA, USA; 1.4 mm diameter) and 2 electromyogram (EMG) patch electrodes (Plastics One; 0.35 mm diameter) as described previously .

Techniques: Control, Comparison

Journal: bioRxiv

Article Title: The relationship between fasting-induced torpor, sleep and wakefulness in the laboratory mouse

doi: 10.1101/2020.05.05.076570

Figure Lengend Snippet: a , Left: photograph showing the recording chamber with two Plexiglas cages for individually housed mice. Middle: A photograph of the thermal imaging camera and a representative thermal image of a mouse acquired with the camera. Right: schematic diagram showing the position of EEG electrodes. b , Experimental design illustrating the timing of feeding and fasting relative to the LD cycle. c , The time course of body weight across the experiment. Mean values (n=6, SEM). d , The time course of peripheral body temperature, shown separately for the maximum, mean and minimum daily temperature values, irrespective of the time of day or behavioural state. Mean values (n=6, SEM). e , The relationship between body weight and mean daily surface body temperature. The data points correspond to individual animals. Each animal contributes with three data points, corresponding to the days when body weight was measured (The data for Day 5 of fasting are depicted as large dark blue circles).

Article Snippet: – Each headmount consisted of three stainless steel screw EEG electrodes (SelfTapping Bone Screws, length 4 mm, shaft diameter 0.85 mm; InterFocus Ltd, Cambridge, UK) and two stainless steel EMG wires, all attached to an 8-pin surface mount connector (8415-SM, Pinnacle Technology Inc, Kansas, USA).

Techniques: Imaging

Journal: The Journal of Neuroscience

Article Title: Elevated TNF-α Leads to Neural Circuit Instability in the Absence of Interferon Regulatory Factor 8

doi: 10.1523/JNEUROSCI.0601-22.2022

Figure Lengend Snippet: Elevated activity of neurons on blockade of GABAergic transmission in Irf8 −/− mice. A , Location of nonpenetrating EEG electrodes over the 4-month-old cortex and hippocampus. B , Over a 24 h baseline, there is no significant change in the fraction of total power in the light and dark cycles for the δ (0.5-3.5 Hz) theta (3.5-7.5 Hz), α (7.5-12.5 Hz), β (12.5-30 Hz), and γ (30-50 Hz) power bands. C , Representative EEG traces from 4-month-old Irf8 +/+ and Irf8 −/− animals in response to 60 mg/kg PTZ. Red dotted line indicates when PTZ was injected. A lethal seizure is noted in a Irf8 −/− . D , The fraction of total power for δ, theta, α, β, and γ power bands in 1 min bins for Irf8 +/+ (top) and Irf8 −/− (bottom) animals before and after PTZ injection (black dotted line). E , Quantification reveals an increase in α, β, and γ power bands relative to Irf8 +/+ littermate controls in response to PTZ. Data are representative of one experiment; N = 4 mice per genotype. ** p ≤ 0.01 (two-way ANOVA with two-stage linear step-up procedure of Benjamini, Krieger, and Yekutieli multiple comparison post hoc test). Error bars indicate SEM. F , Whole-cell recordings from CA1 neurons (P24-P44). After 5 min baseline, the GABA A receptor antagonist (SR95531, 10 μ m ) was bath-applied to Irf8 +/+ and Irf8 −/− brain slices for 15 min. Bottom, Traces with synchronized activities. G , Quantification of the median number of synchronized events per animal. A greater number of synchronized events occurred in Irf8 −/− versus Irf8 +/+ slices. Data are mean ± SEM. Data are representative of 6 experiments/genotype; N = 6 or 7 animals per genotype. ** p ≤ 0.01 (Mann–Whitney test).

Article Snippet: Mice were implanted with four EEG screw electrodes (2 frontal [1 mm frontal, 1 mm lateral from bregma] and 2 parietal [mid-distance between bregma and λ and 1 mm lateral from the mid-line] electrodes; Pinnacle Technology) and two flexible EMG wire electrodes (in the neck muscles; Plastics One), previously soldered to a 6-pin connector (Heilind Electronics), and the assembly was secured with dental cement.

Techniques: Activity Assay, Transmission Assay, Injection, Comparison, MANN-WHITNEY