Journal: bioRxiv

Article Title: A role for thalamic projection GABAergic neurons in circadian responses to light

doi: 10.1101/2022.02.24.481804

Figure Lengend Snippet: Ablation of Sox14 + IGL/LGv neurons causes delayed vigilance state transitions at circadian light changes. A , B , spectrograms, EEG/EMG traces, and hypnograms over a one-hour period from a representative control mouse and an ablated mouse. C , over a 24-hour period control and Sox14 + IGL/LGv-ablated mice spend a similar percentage of time in Wake (48.24 % ± 1.96 % vs 48.22 % ± 1.71 %, p = 0.99), NREM (46.73 % ± 1.80 % vs 46.38 % ± 1.71 %, p = 0.89) and REM (5.03 % ± 0.20 % vs 5.39 % ± 0.17 %, p = 0.2). Values are mean ± s.e.m., t-test. D , E , distribution of Wake, NREM and REM in the two hours preceding and following each light transition. Light and dark hours are shaded in yellow and grey, respectively (see for comprehensive statistics). F , pairwise comparison in the content of Wake, NREM and REM between the hour preceding and each of the two hours following the light to dark transition. Control group: Wake -1 : 33.17 % ± 2.98 %, Wake 1 : 80.26 % ± 3.49 %, p < 0.0001, Wake 2 : 72.61 % ± 7.76 %, p = 0.001; NREM -1 : 60.08 % ± 2.65 %, NREM 1 : 18.39 % ± 3.29 %, p = 0.0001, NREM 2 : 25.17 % ± 7.04 %, p = 0.0015; REM -1 : 6.75 % ± 0.52 %, REM 1 : 1.35 % ± 0.45 % p = 0.0004, REM 2 : 2.18% ± 0.85 % p = 0.007. Ablated group: Wake -1 36.57 % ± 5.34 %, Wake 1 : 56.67 % ± 3.49 %, p = 0.093, Wake 2 : 75.23 % ± 7.24 %, p = 0.008; NREM -1 56.35 % ± 4.73 %, NREM 1 : 38.19 % ± 7.68 %, p = 0.093, NREM 2 : 22.36 % ± 6.64 %, p = 0.0081; REM -1 : 7.08 % ± 0.78 %, REM 1 : 5.10 % ± 1.16 %, p = 0.296, REM 2 : 2.41 % ± 0.90 %, p = 0.031. Values are mean ± s.e.m., t-test except Control REM -1 versus REM 2 , Ablated REM -1 versus REM 1 and REM 2 Wilcoxon test. G , pairwise comparison in the content of Wake, NREM and REM between the hour preceding and each of the two hours following the dark to light transition. Control group: Wake -1 : 94.77 % ± 3.48 %, Wake 1 : 63.47 % ± 9.42 %, p = 0.015, Wake 2 : 36.11 % ± 9.72 %, p = 0.015; NREM -1 : 5.22 % ± 3.48 %, NREM 1 : 34.87 % ± 8.82 % p = 0.015, NREM 2 : 57.51 % ± 8.86 % p = 0.015; REM -1 : 0.00 % ± 0.00 %, REM 1 : 1.66 % ± 0.64 %, p = 0.125, REM 2 : 6.37 % ± 1.09 %, p = 0.015. Ablated group: Wake -1 79.18 % ± 7.51 %, Wake 1 : 82.47 % ± 7.80 %, p = 0.812, Wake 2 : 39.37 % ± 8.09 %, p = 0.017; NREM -1 20.50 % ± 7.34 %, NREM 1 : 17.25 % ± 7.65 %, p = 0.848, NREM 2 : 56.31 % ± 7.22 %, p = 0.021; REM -1 : 0.31 % ± 0.21 %, REM 1 : 0.27 % ± 0.20 %, p > 0.999, REM 2 : 4.31 % ± 1.34 %, p = 0.0313. Values are mean ± s.e.m., Wilcoxon test except Ablated Wake -1 versus Wake 2 and NREM -1 versus NREM 2 t-test. H , fold change in distance travelled in the light phase (12 hours). Total distance in the dark phase (12 hours) was set at 1. Control group: 1.0 ± 0.14 (dark) versus 0.77 ± 0.26 (light); Ablated group: 1.0 ± 0.17 (dark) versus 0.52 ± 0.82 (light). I , Example trajectories for one control and one ablated mouse in the hour preceding and following the light change. Oval: ROI used for automated tracking; yellow: light, grey: dark. Histograms report the fold change in distance travelled in the hour preceding and following the light change. For the light to dark transition distance in the light was set at 1: Control group 1.0 ± 0.21 (light) 5.59 ± 1.36 (dark), p = 0.0078; Ablated group 1.0 ± 0.17 (light) 2.80 ± 0.68 (dark), p = 0.044. J , For the dark to light transition distance in the dark was set at 1: Control group 1.0 ± 0.15 vs 0.64 ± 0.31, p = 0.148; Ablated group 1.0 ± 0.28 vs 0.92 ± 0.29, p = 0.468. Values are mean ± s.e.m., Wilcoxon test except for Ablated light to dark transition t-test. A summary of statistical tests is available in .

Article Snippet: The EEG/EMG signals were sampled at 250 Hz, amplified 100× and low-pass filtered at 100 Hz using a two EEG channel, two EMG channel mouse pre-amplifier (Pinnacle Technology Inc).

Techniques: