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Development of REM sleep drive and clinical implications
T Kobayashi1, C Good, K Mamiya
1Center for Translational Neuroscience, Department of Anatomy and Neurobiology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
Journal of Applied Physiology (Bethesda, Md. : 1985)
|October 7, 2003
Summary
Rapid eye movement (REM) sleep decreases significantly during development. This study investigates changes in brainstem neurons, finding that altered excitatory and inhibitory responses may underlie REM sleep regulation.
Area of Science:
- Neuroscience
- Sleep Science
- Developmental Biology
Background:
- Human Rapid Eye Movement (REM) sleep declines from 50% in newborns to 15% in adults, primarily between birth and puberty.
- A failure in this developmental decrease in REM sleep drive could lead to lifelong increases in REM sleep.
- In rats, REM sleep decreases from over 70% to 15% between 10-30 days postpartum.
Purpose of the Study:
- To investigate the neurobiological mechanisms underlying the developmental decrease in REM sleep.
- To examine changes in pedunculopontine nucleus (PPN) neuronal responses during a critical developmental period in rats.
Main Methods:
- Intracellular recordings were performed on brainstem slices from rats aged 12-21 days.
- Neuronal responses to N-methyl-D-aspartic acid (NMDA), kainic acid, and serotonergic agonists were measured.
- Modulation of PPN projections to ascending and descending targets was examined.
Main Results:
- Excitatory responses of PPN neurons to NMDA decreased, while responses to kainic acid increased during development.
- Inhibitory responses to serotonergic type 1 agonists increased, but not to serotonergic type 2 agonists.
- PPN projections showed common signals modulating arousal and postural/locomotor functions.
Conclusions:
- Developing PPN neurons become increasingly activated by kainic acid and inhibited by serotonergic type 1 receptors.
- These neurochemical and receptor changes are potentially linked to the developmental reduction in REM sleep.
- Disturbances in these developmental processes may contribute to disorders characterized by increased REM sleep drive.