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Optogenetic Manipulation of Neural Circuits During Monitoring Sleep/wakefulness States in Mice
Published on: June 19, 2019
Eye movements and abducens motoneuron behavior during cholinergically induced REM sleep
Javier Márquez-Ruiz1, Miguel Escudero
1Neurociencia y Comportamiento, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain.
Sleep
|May 6, 2009
Summary
Cholinergic drug injections in the pons induce REM sleep, mimicking natural sleep patterns. This research validates carbachol microinjections as a model for studying REM sleep eye movements and motoneuron activity.
Area of Science:
- Neuroscience
- Sleep Research
- Oculomotor Systems
Background:
- Cholinergic drug injections into the pons are a common method for inducing Rapid Eye Movement (REM) sleep.
- Studying REM sleep is crucial for understanding various neurological processes occurring during this sleep stage.
Purpose of the Study:
- To test if eye movements and extraocular motoneuron behavior during carbachol-induced REM sleep mirror those during spontaneous REM sleep.
- To validate the use of carbachol microinjections in the nucleus reticularis pontis oralis (NRPO) as a model for REM sleep research.
Main Methods:
- Adult female cats underwent chronic recordings of eye movements, electroencephalography, electromyography, and abducens motoneuron activity.
- Microinjections of the cholinergic agonist carbachol were administered into the NRPO.
- Ponto-geniculo-occipital (PGO) waves were recorded at the lateral geniculate nucleus.
Main Results:
- Carbachol microinjections in the NRPO successfully induced REM sleep-like periods.
- Induced REM sleep featured eye convergence, downward rotation, and phasic rapid eye movements associated with PGO waves.
- Abducens motoneurons lost tonic activity and eye position coding but retained eye velocity coding during movement bursts.
Conclusions:
- Eye movements and abducens motoneuron activity during carbachol-induced REM sleep closely resemble those during natural REM sleep.
- Carbachol microinjections effectively activate REM sleep oculomotor pathways, validating the pharmacological model.
- This model facilitates efficient exploration of the tonic and phasic phenomena governing eye movements in REM sleep.
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