Related Experiment Videos
From waking to sleeping: neuronal and chemical substrates
1Department of Neurology and Neurosurgery, McGill University, Montreal Neurological Institute, Montreal, Quebec H3A 2B4, Canada. barbara.jones@mcgill.ca
Trends in Pharmacological Sciences
|September 27, 2005
Summary
Neurotransmitter systems regulate sleep-wake cycles. Noradrenaline, histamine, and orexin neurons promote wakefulness, while acetylcholine and GABA neurons exhibit reciprocal activity, controlling sleep and arousal states.
Area of Science:
- Neuroscience
- Sleep Science
- Neuropharmacology
Background:
- Waking is maintained by chemical neurotransmitters released from widespread nerve terminals.
- Specific neurotransmitter systems, including noradrenaline, histamine, and orexin, are active during waking and decrease activity during sleep stages.
Purpose of the Study:
- To elucidate the roles of different neurotransmitter systems in regulating sleep-wake states.
- To understand the reciprocal interactions between wake-active and sleep-active neuronal groups.
Main Methods:
- The study reviews the firing patterns of neurons containing noradrenaline, histamine, orexin, acetylcholine (ACh), and GABA during different sleep-wake states.
- It examines the reciprocal activities of these neuronal populations.
Main Results:
- Noradrenaline, histamine, and orexin neurons fire during waking, decrease firing during slow-wave sleep (SWS), and cease firing during paradoxical sleep (PS).
- Acetylcholine (ACh)-containing neurons fire during waking and PS, with decreased firing during SWS.
- GABA-containing neurons show reciprocal activity, with one group active during SWS and another during quiescence in SWS and PS.
Conclusions:
- The interplay between wake-active and sleep-active neuronal groups dictates the alternation between waking and sleeping.
- Modulation of these neuronal systems and their transmitters forms the basis for stimulant and hypnotic drugs.