Effects of clozapine-N-oxide and compound 21 on sleep in laboratory mice
- Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Germany
- Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom
- Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of Oxford, United Kingdom
- The Kavli Institute for Nanoscience Discovery, United Kingdom
- Department of Pharmacology, University of Oxford, United Kingdom
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, United States
- Geneva University Hospitals (HUG), Division of Psychiatric Specialties, Switzerland
- University Hospital of Psychiatry and Psychotherapy, University of Bern, Switzerland
- Centre for Experimental Neurology, University of Bern, Switzerland
Figures
Figure 1 with 1 supplement
Suppression of REM sleep following CNO injection.
(a) Time course of wakefulness, NREM, and REM sleep in the 6 hr following intraperitoneal injections of CNO or saline at light onset (ZT 0). (b) Percentage of time spent in the three vigilance …
Figure 1—figure supplement 1
Reduced REM/NREM ratio following CNO injections.
(a) Time course of REM sleep expressed as ratio between REM and NREM sleep over the 6 hr following intraperitoneal injections of CNO or saline at light onset (ZT 0). (b) REM/NREM ratio during the …
Figure 2
Altered sleep architecture following CNO injections.
(a) Representative hypnograms and EEG slow wave activity (0.5–4.0 Hz, 4 s epochs) from one individual mouse after injection of saline (left panel) and 5 mg/kg CNO (right panel). Note the reduced …
Figure 3 with 3 supplements
EEG spectral changes, increased sleep state stability, and sleep continuity following CNO injections.
(a) Frontal EEG spectra during NREM sleep following CNO injections relative to saline injections for the acute (first 2 hr, left column) and prolonged (6 hr, right column) observation period. Note …
Figure 3—figure supplement 1
EEG power spectra of wakefulness, NREM, and REM sleep following injections of saline and 1 mg/kg CNO.
Frontal EEG spectra in 0.25 Hz bins between 0.5 and 30 Hz arranged by vigilance state and time window. Two-way ANOVAs revealed a significant interaction effect between ‘frequency’ and ‘condition’ …
Figure 3—figure supplement 2
EEG power spectra of wakefulness, NREM, and REM sleep following injections of saline and 5 mg/kg CNO.
Frontal EEG spectra in 0.25 Hz bins between 0.5 and 30 Hz arranged by vigilance state and time window. Two-way ANOVAs for NREM sleep spectra revealed a significant interaction effect between …
Figure 3—figure supplement 3
EEG power spectra of wakefulness, NREM, and REM sleep following injections of saline and 10 mg/kg CNO.
Frontal EEG spectra in 0.25 Hz bins between 0.5 and 30 Hz arranged by vigilance state and time window. Two-way ANOVAs for NREM sleep spectra revealed a significant interaction effect between …
Figure 4 with 1 supplement
Suppression of REM sleep following C21 injections.
(a) Time course of wakefulness, NREM, and REM sleep in the 6 hr following injection of C21 or saline at light onset (ZT 0). (b) Percentage of time spent in the three vigilance states during the …
Figure 4—figure supplement 1
Reduced REM/NREM ratio following C21 injections.
(a) Time course of REM sleep expressed as the ratio between REM and NREM sleep over the 6 hr following intraperitoneal injections of C21 or saline at light onset (ZT 0). (b) REM/NREM ratio during …
Figure 5 with 2 supplements
Effects of C21 on sleep architecture, NREM sleep spectra, sleep state stability, and sleep continuity resemble the effects of CNO.
(a) NREM sleep architecture and (b) REM sleep architecture for the 6 hr observation period following C21 injections. (c) Frontal EEG spectra during NREM sleep relative to saline injections for the …
Figure 5—figure supplement 1
EEG spectral analysis of NREM sleep following injections of saline and 3 mg/kg C21.
(a) Frontal EEG spectra in 0.25 Hz bins between 0.5 and 30 Hz for the acute (first 2 hr, left) and full (first 6 hr, right) observation time window. For the 2 hr time window, the two-way ANOVA …
Figure 5—figure supplement 2
EEG power spectra of wakefulness, NREM, and REM sleep following injections of saline and 3 mg/kg C21.
Frontal EEG spectra in 0.25 Hz bins between 0.5 and 30 Hz arranged by vigilance state and time window. Note that due to the low number of suitable animals n=3 for the wake condition (because of …
Figure 6
Implant configurations.
(a) LED anchor screw, bilateral frontal and occipital EEG screws, and cerebellar reference screw. Implant configuration of n=5 mice. (b) Microinfusion cannula, right frontal and occipital EEG …
Author response image 1
Benjamini-Hochberg correction for multiple comparisons confirms the robustness of CNO effects on NREM sleep EEG spectra. Note that the stringent α error threshold of p<0.01 (black asterisks) largely …
Author response image 2
Frontal EEG spectra in comparison between 1 mg/kg CNO and saline injections.
Author response image 3
Frontal EEG spectra in comparison between 5 mg/kg CNO and saline injections.
Author response image 4
Frontal EEG spectra in comparison between 10 mg/kg CNO and saline injections.
Author response image 5
Absolute and relative frontal EEG spectra of NREM sleep in comparison between 3 mg/kg C21 and saline injections in n=6 animals.
a) absolute and b) relative EEG spectra. Note that this analysis performed on n=6 animals with artefact-free NREM sleep resembles the EEG spectral changes observed in the 5 and 10 mg/kg CNO condition.
Author response image 6
NREM sleep architecture over the first 2 hours following saline and CNO injections.
Author response image 7
NREM sleep architecture over the first 2 hours following saline and C21 injections.
Tables
Author response table 1
Comparison of CNO effects for all animals (n=16) and for the subgroup of animals (n=11) that received all four injections (saline and 3 doses of CNO).
Note that despite the considerably reduced power, all but two previously significant analysis still approach significance (p < 0.1). Further note that the effect sizes are very similar between n=11 …
| null-hypothesistesting (mixedeffect models)p-value | effect sizes1 mg/kg CNO | effect sizes5 mg/kg CNO | effect sizes10 mg/kg CNO | |||||
|---|---|---|---|---|---|---|---|---|
| Analysis | ||||||||
| n=16 | n=11 | n=16 | n=11 | n=16 | n=11 | n=16 | n=11 | |
| Wake (%, 0-2 h) | 0.2504 | 0.4114 | -0.0234 | -0.0489 | -0.3393 | -0.3890 | -0.4815 | -0.3793 |
| Wake (%, 0-6 h) | 0.4928 | 0.5702 | 0.1467 | 0.1059 | -0.1715 | -0.2587 | -0.2633 | -0.2145 |
| NREM (%, 0-2 h) | 0.0682 | 0.2085 | 0.1157 | 0.1389 | 0.4941 | 0.4915 | 0.6961 | 0.5389 |
| NREM (%, 0-6 h) | 0.1661 | 0.3039 | -0.0361 | -0.0416 | 0.4130 | 0.4214 | 0.4630 | 0.3328 |
| REM (% of TST, 0-2 h) | 0.0019 | 0.0211 | -0.5802 | -0.6207 | -0.5594 | -0.4037 | -1.2743 | -1.3152 |
| REM (% of TST, 0-6 h) | 0.0038 | 0.0863 | -0.4697 | -0.3743 | -0.7724 | -0.5301 | -0.9333 | -0.8488 |
| Longest NREM ep. | 0.0001 | 0.0005 | 0.3562 | 0.3616 | 0.9438 | 0.9599 | 1.5129 | 1.2811 |
| Av. NREM ep. Dur. | 0.0001 | 0.0028 | 0.1810 | 0.0356 | 1.1430 | 1.1181 | 1.1883 | 0.9655 |
| Number of NREM ep. | 0.0010 | 0.0181 | -0.2938 | -0.1339 | -1.0628 | -1.0981 | -1.1989 | -1.0248 |
| NREM latency | 0.0463 | 0.1068 | -1.2021 | -1.1337 | -0.3744 | -0.4198 | -0.2424 | -0.1689 |
| Longest REM ep. | 0.6266 | 0.7213 | -0.0083 | -0.2382 | 0.1710 | 0.0684 | 0.2450 | 0.0163 |
| Av. REM ep. | 0.0232 | 0.0631 | -0.3757 | -0.5302 | 0.5463 | 0.4006 | 0.4111 | 0.1842 |
| Number of REM ep. | 0.0047 | 0.0741 | -0.0892 | 0.0870 | -0.7456 | -0.5453 | -0.8710 | -0.5829 |
| REM latency | 0.0220 | 0.0532 | 0.8061 | 0.7955 | 0.3202 | 0.3279 | 0.9213 | 0.7851 |
| Brief awakenings | 0.0006 | 0.0106 | -0.6271 | -0.4125 | -1.0691 | -0.8290 | -1.5760 | -1.4014 |
| NREM before REM | 0.0137 | 0.0577 | 0.7996 | 0.8960 | 0.5317 | 0.6101 | 1.8239 | 1.6994 |
Additional files
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Supplementary file 1
Time spent in wakefulness, non-rapid eye movement (NREM), and rapid eye movement (REM) sleep after clozapine-N-oxide (CNO) and saline injections.
- https://cdn.elifesciences.org/articles/84740/elife-84740-supp1-v1.docx
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Supplementary file 2
Sleep architecture after clozapine-N-oxide (CNO) and saline injections.
- https://cdn.elifesciences.org/articles/84740/elife-84740-supp2-v1.docx
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Supplementary file 3
Non-rapid eye movement (NREM) sleep architecture for the first 2 hr after clozapine-N-oxide (CNO) and saline injections.
- https://cdn.elifesciences.org/articles/84740/elife-84740-supp3-v1.docx
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Supplementary file 4
Analysis of variance (ANOVA) results for electroencephalography (EEG) spectra following clozapine-N-oxide (CNO) and saline injections.
- https://cdn.elifesciences.org/articles/84740/elife-84740-supp4-v1.docx
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Supplementary file 5
Sleep parameters after saline and compound 21 (C21) injections.
- https://cdn.elifesciences.org/articles/84740/elife-84740-supp5-v1.docx
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Supplementary file 6
Non-rapid eye movement (NREM) sleep architecture for the first 2 hr after compound 21 (C21) and saline injections.
- https://cdn.elifesciences.org/articles/84740/elife-84740-supp6-v1.docx
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MDAR checklist
- https://cdn.elifesciences.org/articles/84740/elife-84740-mdarchecklist1-v1.docx
