Scientists in the US and elsewhere are studying the effects of sleep deprivation and diet on the brains of people suffering from dementia.
The research, published in The Lancet Neurology, is looking at the effects that different kinds of deprivation can have on the brain.
The findings could have implications for treatment for people who have Alzheimer’s disease and others who suffer from dementia, the journal said.
Sleep deprivation in the brain is thought to affect how the brain works, allowing the body to regulate sleep, sleep quality and mood, the authors said.
“In the current study, we observed that brain-derived neurotrophic factor (BDNF) levels in the hippocampus, which is a region that is implicated in cognition, memory and learning, decreased in the brains brains of patients with early-stage dementia compared with healthy controls,” the authors wrote.
The authors said the study was an “important first step towards understanding the brain-dependent and cognitive-behavioral mechanisms that underlie sleep-deprivation-induced cognitive dysfunction.”
BDNF is a protein found in the blood that is known to have positive effects on brain development and functioning.
Sleep, as well as a lack of exercise, have been shown to lower BDNF levels.
“Although the mechanisms underlying the brain’s sleep-wake cycles remain to be elucidated, the results highlight the importance of investigating sleep deprivation as a novel mechanism of cognition-related neurodegeneration,” the study authors wrote in their study.
“Sleep deprivation, in particular, may represent an important target for early- and late-stage neurodegenesis in the aging brain.”
“BDNF is also a crucial regulator of sleep-induced neuronal plasticity, which may underlie the beneficial neuroprotective effects of neuroinflammation,” they added.
The study was led by a team at the University of Arizona and was published in the journal Neurobiology of Aging.
The researchers said their research showed that the changes in BDNF that they observed in the rats’ brains were the result of sleep restriction.
The rats that had been given just a single hour of uninterrupted sleep showed no changes in the number of neurons or in the overall number of synapses in the hippocampal formation, but the amount of activity in those synapses decreased.
This suggests that sleep deprivation may not be enough to produce the effects the authors were looking for, they said.
The results suggest that the mechanism of sleep loss in the animals’ brains may be a result of increased BDNF activity in the region, but that the impact of sleep on the neurons may be less potent than that observed in people with dementia, said lead author Dr. Ravi Srinivasan.
The scientists said their findings were preliminary and preliminary data could be refined.
“However, these findings suggest that sleep-related brain dysfunction may have a neuroprotrophic role in the onset and progression of cognitive impairment in older adults, and the implications for prevention and treatment are still under investigation,” the team wrote.
“The results also highlight the value of investigating the effects on the hippocampi of sleep and other lifestyle factors as possible therapeutic targets.”
Researchers also found that the amount and type of sleep the animals received were associated with their brain’s response to stress.
For example, the rats that were given just two hours of uninterrupted sleeping had a higher level of BDNF than the ones who received two hours.
They also had higher levels of a protein called c-Jun N-terminal kinase, which binds to the protein that activates BDNF.
In addition, the hippocampus and cortex showed a greater number of synaptic connections when sleep was reduced, the researchers noted.
The BDNF-signaling pathway also increased when the animals were deprived of sleep, the team said.
This means that the researchers believe the reduced amount of sleep may contribute to the increased activity in synapses that are important for the brain to function normally.
The team also noted that the increased level of activity was associated with a reduction in the amount, size and density of white matter, which contains the nerve cells that connect to neurons.
The white matter is thought be a critical component of the brain and is crucial to memory and cognition.
“It’s not clear yet how sleep deprivation leads to a reduction of BDN-signal pathways, but it is possible that reduced sleep may increase the activity of BDNP-containing synapses,” the researchers said.
In fact, one of the findings that the team made was that the BDNF signalling pathway itself decreased in rats given only two hours sleep, which indicates that the reduced sleep had a positive effect on the activity in that pathway, the scientists wrote.
However, the sleep deprivation also did not affect the activity or the density of neurons in the dentate gyrus, a region involved in the processing of sensory information, which scientists think is crucial for memory formation.
“These findings may also be relevant for the development of novel therapeutic strategies to slow cognitive decline,” the investigators wrote.
Other studies have shown that sleep and cognitive decline in