Circadian Rhythms & Photobeam Activity Systems: How Environment Impacts Biological Clocks

Circadian rhythms are the biological clocks in humans and other organisms that run on a 24-hour period, which are reset by the sun’s light/dark cycle. They control many behavioral and physiological processes in our bodies and are strongly influenced by environmental factors such as light, noise, nutrition, sleep, temperature, and social cues. These environmental factors are fed into a complicated system of molecular feedback loops, which impact the circadian rhythm.

It is essential for scientists to understand and research circadian rhythms because any disruptions to them can have a severe impact on humans and animals. Consequences include impaired cognitive function, mental health problems, and an increased chance of cardiovascular and metabolic diseases. To reduce the risk of these health impacts, circadian rhythms must be optimized through planning and ensuring consistent sleep and nutrition are met, as well as timed light exposure. Understanding how the environment impacts biology and what can be done to maintain a healthy lifestyle is also essential.

This blog post will look at the relationship between circadian rhythms and the environment, focusing on the photobeam activity system and its importance in understanding circadian rhythms. We will also look at factors such as light, nutrition, and sleep and how these can impact our biological clock and overall health.

What are Photobeam Activity Systems

Photobeam activity systems are crucial devices. Scientists use them to monitor how living organisms respond to environmental cues that impact the circadian system and how the body is regulated in response. Light, social interactions, temperature, and some other factors are picked up by the photobeam activity system, with light exposure being the most important. Photosensitive cells are an essential part of monitoring with photobeam activity systems, as they detect light changes and transform their information into electrical signals for the biological clock to receive, located in the suprachiasmatic nucleus (SCN). The signals are then used to regulate the circadian rhythms and impact what response occurs. Typically, photobeam activity systems monitor rodent locomotor activity because they provide accurate qualitative data from rodents in an open or caged environment. Later in the blog, we will look at a caged PAS from San Diego Instruments.

Impact of Light Exposure, Nutrition, and Sleep on Circadian Rhythms

A range of environmental factors influence the body’s biological clock. They include light, nutrition, sleep, and temperature and can have positive or negative effects depending on how the body interacts with these factors. The biological clock is controlled by the suprachiasmatic nucleus (SCN) in the brain, which is formed of a group of cells that react to light and dark signals. The SCN receives signals from our retinas, which causes hormone production and suppression to control our bodily responses.

Light Exposure

It is crucial to monitor how light exposure, including its duration and timing, because it can significantly impact the regulation of circadian rhythms, which in turn can have multiple effects on the body, including mental health issues and certain diseases. When and how long we are exposed to light can impact our body and cognitive functions throughout the day. For example, exposure to bright morning light can support alertness during the day and reset the biological clock. However, being exposed to bright light in the evening could cause problems sleeping, resulting in fatigue and other health problems.

Sleep Patterns

Sleep is essential to positive health and cognitive functions. If a circadian rhythm is aligned correctly, this supports consistent and restorative sleep. However, if disrupted, it can lead to a range of health problems brought on by insomnia and fatigue. Sleeping patterns are primarily influenced by when exposure to light occurs and how long for. 

Nutrition

Circadian rhythms can also be impacted by food. Metabolic processes can disrupt the circadian rhythm if the wrong nutrients are absorbed, or insufficient nutrients are taken into the body. As a result of poor nutrition and an ill-aligned circadian rhythm, the body can suffer from metabolic disorders like diabetes and obesity. This is why it is necessary to eat regular, nutritional meals.

Implications For Human Health and Well-Being

Although light, sleep, and nutrition are key factors in optimizing the circadian rhythm, unhealthy habits or bodily disruption can also result in negative impacts, sometimes called circadian rhythm disorders. Body temperature, exercise, stress levels, working hours, age, and specific lifestyle choices can all affect circadian rhythms.

To summarize this blog post, circadian rhythms are required to regulate a healthy, functioning body and manage any environmental factors that may impact the body. To optimize cognitive function and positive mental health, it is important to maintain regular eating patterns and consistent sleep and be exposed to bright light in the morning and low light in the evenings. In the final section, we will look at how circadian rhythms are monitored in rodents and what systems are used to do so.

San Diego Instruments and Photobeam Activity Systems

San Diego Instruments offer a highly accurate qualitative analysis system to monitor the locomotor activities of rats and mice. The Photobeam Activity System-Home Cage (PAS-HC) offers flexibility and can accommodate up to 48 testing systems for up to seven days without human intervention. The PAS was designed for long-term testing of circadian rhythms in test subjects and is equipped with easy-to-use software, real-time beam break display, and the option to directly export results to Microsoft® Excel or a delimited file type.

Contact a team member today to learn more about analyzing circadian rhythms with photobeam activity systems.

References

  1. https://www.ncbi.nlm.nih.gov/books/NBK546664/#:~:text=The%20suprachiasmatic%20nucleus%20(SCN)%20is,circadian%20rhythms%20in%20the%20body
  2. https://www.cdc.gov/niosh/emres/longhourstraining/clock.html
  3. https://www.sleepfoundation.org/circadian-rhythm/sleep-drive-and-your-body-clock