TABLE 2.
Experiment | Species | Effect on wakefulness | Effect on NREM sleep | Effect on REM sleep | References | |
Acute ICV infusion of MCH | Rats (Sprague-Dawley) | Decreased in wake amounts | Increased in NREM amounts | Increased in REM amounts Increased in the number of REM bouts No change in the duration of REM bouts |
Verret et al., 2003 | |
Microinjection of MCH | DRN | Rats (Wistar) | Decreased in wake amounts | Moderate increase in the NREM amounts | Increased in REM amounts Increased in the number of REM bouts No change in the duration of REM bouts |
Lagos et al., 2009 |
MnR | Rats (Wistar) | Decreased in wake amounts | No significant change in NREM amounts | Increased in REM amounts Increased in the number of REM bouts No change in the duration of REM bouts |
Pascovich et al., 2021 | |
LC | Rats (Wistar) | No significant change in wake amounts | No significant change in NREM amounts | Increased in REM amounts Increased in the number of REM bouts No change in the duration of REM bouts |
Monti et al., 2015 | |
BF | Rats (Wistar) | Decreased in wake amounts during the first 2-h post-injection | No significant change in NREM amounts | Increased in REM amounts during the first 2-h post-injection Increased in the number of REM bouts No change in the duration of REM bouts |
Lagos et al., 2012 | |
NPO | Cats | Decreased in wake amounts during the first hour post-injection | No significant change in NREM amounts | Increased in REM amounts during the first hour post-injection No change in the number of REM bouts No change in the duration of REM bouts Decreased in the latency to REM |
Torterolo et al., 2009 | |
SLD | Rats (Wistar) | No significant changes in wake amounts | No significant change in NREM amounts | Decreased in REM amounts during the first and the second 2-h post-injection Decreased in the number of REM bouts No change in the duration of REM bouts Increased in the latency to REM |
Monti et al., 2016 | |
VLPO | Rats (Wistar) | Decreased in wake amounts during 4–5 h block post-injection Decreased in the duration of Wake bouts |
Increased in NREM amounts | No change in REM amounts | Benedetto et al., 2013 | |
Pharmacological blockade of MCH-R1 | Subcutaneous administration | Rats (Sprague Dawley) | Increased in wake amounts Increased in the number of wake bouts Moderate increase in the duration of Wake bouts at the higher dose |
Decreased in NREM amounts Decreased in the duration of NREM bouts |
Decreased in REM amounts Decreased in the number of REM bouts Decreased in the duration of REM bouts at the higher dose |
Ahnaou et al., 2008 |
Oral administration | No change in wake parameters | No change in NREM parameters | No change in REM parameters | Able et al., 2009 | ||
MCH1-receptors deletion | Transgenic mice (Mch1r–/–) | No change in wake parameters |
No change in NREM parameters |
Increased in REM amounts during light period Increased in the number of REM bouts during the light period |
Adamantidis et al., 2008 | |
Increased in wake amounts Increased in the duration of wake bouts No change in the number of wake bouts Increased in wake amounts under restraint stress condition |
Decreased in NREM amounts Decreased in the duration of NREM bouts No change in the number of NREM bouts Decreased in NREM amounts under restraint stress condition |
No change in REM parameters Decreased in REM amounts under restraint stress condition |
Ahnaou et al., 2011 | |||
Mch gene knockout | Transgenic mice (Mch–/–) | Increased in wake amounts Increased in the duration of wake bouts Increased in wake amounts under fasting condition during both light and dark phase Increased in the duration of wake bouts during both light and dark phase |
Decreased in NREM amounts Decreased in NREM amounts under fasting condition during both light and dark phase |
Decreased in REM amounts Massive decrease in REM amounts under fasting condition during both light and dark phase Decreased in the duration of REM bouts under fasting condition during both light and dark phase |
Willie et al., 2008 | |
In vivo electrophysiology (Unit recordings of MCHergic neurons) |
Rats (long-Evans) | MCHergic neurons not firing | MCHergic neurons fired occasionally | MCHergic neurons fired maximally | Hassani et al., 2009 | |
Optogenetic manipulation of MCH neurons | Acute activation of MCH neurons at the onset of NREM | Transgenic mice (Pmch-Cre) | – | No change in the duration of NREM bouts Increased in the transition from NREM-to-REM |
– | Jego et al., 2013 |
Acute activation of MCH neurons at the onset of REM | – | Increased in the duration of REM bouts | ||||
Inhibition of MCH neurons at the onset of REM | No changes | Decreased in the frequency and amplitude of REM theta power | ||||
Acute activation of MCH neurons |
MCH-tTA; TetO ChR2 bigenic mice |
No change in wake amounts Increased in the number of wake bouts |
Decreased in NREM amounts Decreased in the duration of NREM bouts Increased in the number of NREM bouts Increased in the transition from NREM-to-REM |
Increased in REM amounts Increased in the number of REM bouts |
Tsunematsu et al., 2014 | |
Acute inhibition of MCH neurons |
MCH-tTA; TetO ArchT bigenic mice |
No changes | No changes | No changes | ||
Chronic activation of MCH neurons | C57BL/6J mice | Decreased in wake amounts during dark phase Decreased in the duration of wake bouts |
Increased in NREM amounts during dark phase No change in the duration of NREM bouts Increased in NREM delta power |
Increased in REM amounts during dark phase No change in the duration of REM bouts No change in REM theta power |
Konadhode et al., 2013 | |
Rats (long-evans) | Deceased in wake amounts during dark phase Deceased in the number of wake long bouts (> 32 min) during both day and night phases |
Increased in NREM amounts during dark phase Increased in the number of NREM short bouts during both day and night phases Increased in NREM delta power during day phase |
Increased in REM amounts during both dark and day phases Increased in the number of REM short bouts during both day and night phases Increased in REM theta power during both night and day phases |
Blanco-Centurion et al., 2016 | ||
Pharmacogenetic manipulation of MCH neurons | Chemoactivation (0.3 mg/Kg CNO) | Transgenic mice (MCH-Cre) | No changes | No changes | Increased in REM amounts during both day and night phases Increased in the number of REM bouts during both day and night phases No change in the duration of REM bouts |
Vetrivelan et al., 2016 |
Chemoactivation (0.5 mg/Kg CNO) | Transgenic mice (Pmch-Cre) | – | Deceased in NREM amounts Decreased in the duration of NREM bouts |
Increased in REM amounts Increased in the duration of REM bouts |
Varin et al., 2018 | |
Chemoinhibition (5 mg/Kg CNO) |
– | Increased in NREM amounts Increased in the duration of NREM bouts |
Deceased in REM amounts No change in the duration of REM bouts |
|||
MCH neurons ablation | Transgenic mice (MCH-Cre/ + ; iDTR) | Decreased in the duration of wake bouts during the day phase | No changes | Increased in REM amounts Increased in the number of REM bouts during the day phase |
Vetrivelan et al., 2016 | |
MCH-tTA; TetO DTA bigenic mice |
Increased in wake amounts during both light and dark phases No change in the duration of wake bouts during both light and dark phases |
Decreased in NREM amounts during both light and dark phases Decreased in the duration of NREM bouts during the dark phase No change on EEG power during NREM |
No change in REM amounts in both light and dark phases No change on EEG power during REM |
Tsunematsu et al., 2014 | ||
Transgenic mice (MCH/ataxin-3) | No change in wake amounts | No change in NREM amounts | Increase in REM amounts only during the light phase | Varin et al., 2016 | ||
Deep brain imaging | Transgenic mice (MCH-Cre) | – | The activity of MCH neurons began to increase during the transition from NREM to REM | Dynamic activation of MCH neurons during REM sleep and exploratory behavior | Blanco-Centurion et al., 2019 | |
Fiber photometry | Transgenic mice (MCH-Cre) | Moderate increase in the activity of MCH neurons | The activity of MCH neurons significantly increased during transitions from NREM to REM and from NREM to Wake | Increased in the activity of MCH neurons The activity of MCH neurons deceased during the transition from REM to Wake |
Izawa et al., 2019 |