The intensity of brain activity during the day, notwithstanding how long we've been awake, appears to increase our need for sleep, according to a new study in zebrafish.
The research, published in Neuron, found a gene that responds to brain activity in order to coordinate the need for sleep. It helps shed new light on how sleep is regulated in the brain.
"There are two systems regulating sleep: the circadian and homeostatic systems. We understand the circadian system pretty well - our built-in 24-hour clock that times our biological rhythms, including sleep cycles, and we know where in the brain this rhythm is generated," explained lead author.
"But the homeostatic system, which causes us to feel increasingly tired after a very long day or sleepless night, is not well understood. What we've found is that it appears to be driven not just by how long you've been awake for, but how intensive your brain activity has been since you last slept."
To understand what processes in the brain drive homeostatic sleep regulation - independent of time of day - the research team studied zebrafish larvae.
Zebrafish are commonly used in biomedical research, partly due to their near-transparent bodies that facilitate imaging, in addition to similarities to humans such as sleeping every night.
The researchers facilitated an increase in brain activity of the zebrafish using various stimulants including caffeine.
Those zebrafish which had drug-induced increased brain activity slept for longer after the drugs had worn off, confirming that the increase in brain activity contributed to a greater need for sleep.
The researchers found that one specific area of the zebrafish brain was central to the effect on sleep pressure: a brain area that is comparable to a human brain area found in the hypothalamus, known to be active during sleep. In the zebrafish brain area, one specific brain signalling molecule called galanin was particularly active during recovery sleep, but did not play as big a role in regular overnight sleep.
To confirm that the drug-induced findings were relevant to actual sleep deprivation, the researchers conducted a test where they kept the young zebrafish awake all night on a 'treadmill' where the fish were shown moving stripes - by imitating fast-flowing water, this gives the fish the impression that they need to keep swimming. The zebrafish that were kept awake slept more the next day, and their brains showed an increase in galanin activity during recovery sleep.
The findings suggest that galanin neurons may be tracking total brain activity, but further research is needed to clarify how they detect what's going on across the whole brain.
The researchers say their finding that excess brain activity can increase the need for sleep might explain why people often feel exhausted after a seizure.
"Our findings may also shed light on how some animals can avoid sleep under certain conditions such as starvation or mating season - it may be that their brains are able to minimise brain activity to limit the need for sleep," said the study's first author.
The researchers say that by discovering a gene that plays a central role in homeostatic sleep regulation, their findings may help to understand sleep disorders and conditions that impair sleep, such as Alzheimer's disease.
"We may have identified a good drug target for sleep disorders, as it may be possible to develop therapies that act on galanin," added the lead and senior author.
https://www.cell.com/neuron/fulltext/S0896-6273(19)30694-4
Sleep rebound following increased neuronal activity is linked to a neuropeptide, galanin
- 1,007 views
- Added
Edited
Latest News
Brain hormone regulate both…
By newseditor
Posted 17 Mar
Blocking long non-coding RN…
By newseditor
Posted 17 Mar
Artificial intelligence and…
By newseditor
Posted 17 Mar
Blood-brain barrier protein…
By newseditor
Posted 17 Mar
Preventing heart attacks an…
By newseditor
Posted 17 Mar
Other Top Stories
Linking La Niņa climate cycle to increased diarrhea
Read more
Lead exposure linked to decreased brain volume in adolescents
Read more
How psychedelics may enhance mood at mass gatherings
Read more
New insights into neurobiology of decision-making and imagination
Read more
The pheromone darcin drives a circuit for innate and reinforced beh…
Read more
Protocols
Integration of Kupffer cell…
By newseditor
Posted 18 Mar
A mouse DRG genetic toolkit…
By newseditor
Posted 17 Mar
An optogenetic method for t…
By newseditor
Posted 13 Mar
Profiling native pulmonary…
By newseditor
Posted 08 Mar
Neuromuscular organoids mod…
By newseditor
Posted 06 Mar
Publications
Synaptopathy: presynaptic c…
By newseditor
Posted 18 Mar
Allergic Rhinitis
By newseditor
Posted 18 Mar
ALK upregulates POSTN and W…
By newseditor
Posted 18 Mar
PRODH safeguards human naiv…
By newseditor
Posted 18 Mar
Secretin-dependent signals…
By newseditor
Posted 17 Mar
Presentations
Hydrogels in Drug Delivery
By newseditor
Posted 12 Apr
Lipids
By newseditor
Posted 31 Dec
Cell biology of carbohydrat…
By newseditor
Posted 29 Nov
RNA interference (RNAi)
By newseditor
Posted 23 Oct
RNA structure and functions
By newseditor
Posted 19 Oct
Posters
A chemical biology/modular…
By newseditor
Posted 22 Aug
Single-molecule covalent ma…
By newseditor
Posted 04 Jul
ASCO-2020-HEALTH SERVICES R…
By newseditor
Posted 23 Mar
ASCO-2020-HEAD AND NECK CANCER
By newseditor
Posted 23 Mar
ASCO-2020-GENITOURINARY CAN…
By newseditor
Posted 23 Mar