Long Term Cognition via a strong, robust Circadian Oscillation

Circadian rhythms are physical, mental, and behavioral changes that follow a 24-hour cycle. These natural processes respond primarily to light and dark and affect most living things, including animals, plants, and microbes.

The internal body clock sets the timing for many circadian rhythms, which regulate processes such as

  • Sleep/wake cycles
  • Hormonal activity
  • Body temperature rhythm
  • Eating and digesting

“If your circadian clock is not quite right for years and years — you routinely suffer from disrupted sleep at night and napping during the day — the cumulative effect of chronic dysregulation could influence inflammatory pathways such that you accumulate more amyloid plaques”.

 A weak or misaligned circadian rhythm, can, over time, be causative of cognitive decline.

Circadian derangements/disturbed sleep feed the risk of developing AD.

Circadian dysfunction injures via poor sleep efficiency.

Circadian dysfunction injures via altered gene expression.

Proper circadian protein function is important in the maintenance of neuronal integrity.

Circadian dysfunction precedes Alzheimer’s symptoms. Demonstrated in mice.

Rats in which the circadian rhythm was messed up with continuous light for four months showed disrupted metabolic profiles, suggestive that their digestive systems may also have been adversely affected by the disrupted circadian rhythms. The level of soluble Aβ in the brain was also significantly higher in these rats compared to the controls, and they experienced down-regulation of anti-aging gene Sirt1 and up-regulation of the neuronal damage markers. Circadian rhythm disruption due to chronic light exposure caused memory and cognitive deficits in the rats. Collectively, these findings were suggestive of an AD-like phenotype.

There is a daily oscillation in Aβ42 clearance that was lost in cells without a circadian rhythm. We established the underlying cause of this oscillation was the circadian control of cell surface molecules, heparan sulfate proteoglycans, which have previously been shown to play a role in the regulation of Aβ42 clearance. We further showed that this regulation was specific to Aβ42, demonstrating a mechanistic link underlying the connection between the disruption of circadian rhythms and AD.

In addition to being a key regulator of the diurnal cycle, the circadian clock might also suppress oxidative stress and synaptic damage. For example, a reduced level of BMAL1, one of the circadian regulating factors, is thought to cause neurodegeneration, as evidenced by the astrogliosis, oxidative damage, and synaptic damage in Bmal1 knockout mice.

Dissociation between the output of the circadian clock and external environmental cues is a major cause of human cognitive dysfunction.

In animal models of Alzheimer’s disease, a basal circadian rhythm that controls macroautophagy may be necessary to limit cognitive decline and amyloid deposition. Neurodegenerative disorders such as Alzheimer’s disease and Parkinson’s disease may progress in the setting of altered circadian rhythm dysfunction.

Synchronizing rhythms may delay the onset of neurodegenerative disease such as AD.

In patients with Alzheimer’s disease, rhythmic methylation of BMAL1 has been found to be changed in the brains of patients with Alzheimer’s disease, suggesting that alterations in the DNA methylation of clock genes may contribute to cognitive loss and behavior changes in individuals with Alzheimer’s disease

Other brain disorders are linked to a dysfunctional circadian system.

Minimizing blue light in the evening will maximize endogenous melatonin.

A robust circadian oscillation may minimize neuroinflammation.

Shift work, especially rotating shift work, confuses our body clocks and that has important ramifications in terms of our health and well-being and connection to human disease,” said David Earnest, professor in the Department of Neuroscience and Experimental Therapeutics at the Texas A&M University College of Medicine. “When our internal body clocks are synchronized properly, they coordinate all our biological processes to occur at the right time of day or night. When our body clocks are misaligned, whether through shift work or other disruptions, that provides for changes in physiology, biochemical processes and various behaviors.”

 

By Otto

I am a health enthusiast, engineer, and maker.

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