The daily routine of all creatures is rhythmic. All their daily activities happen at stipulated times. The rhythm at which the activities of life are moderated is called Circadian Rhythm. The term “circadian”, coined by Franz Hallberg, comes from the Latin circa, “around”, and diem or dies, “day”, meaning literally “approximately one day.” It means that the activities during the 24 hours of the day should be done at regular times. The science of studying this rhythm in activity periodically (e.g. over a week, month, year, etc,) is called Chronobiology. It is in this context that we hear about the biological clock. It is not just humans but all creatures live according to this biological clock. By transgressing this clock, we invite trouble and give way to many diseases and disorders.
The history of biological clock is not too ancient, but it is certainly interesting. A French scientist named Jean-Jaques d’Ortous de Mairan discovered this biological clock in 1700 when he observed the leaves of certain plants shrinking and opening during night and day. In 1751, a Swedish botanist Kerelis Linijas found this to be true in some flowering plants. According to his report, the flowers of Hawk’s Beard used to blossom at three in the morning, whereas the flowers of Hawkbit did not blossom before seven in the morning. After this initial phase, a research scientist of Moscow named A. Chizovski reported in 1924 that the entire cycle of human activities is controlled by the movement of Sun and Moon. In that context, he also tried to analyse using Astrobiology. His work was banned in Soviet Union in 1930 in connection with the spying of Stalin and he was banished to Siberia. However, his findings were published forty years later.
Franz Hallberg is considered to be the founder of ‘Circadian Rhythm’. He observed the human behaviour and analysed it in different phases. He found that some activities were controlled internally while some others were controlled by external circumstances. In plant kingdom, this behaviour is observed in opening up of leaves and during photosynthesis. In animals this rhythm is observed through activities like eating, sleeping, reproduction, hibernation, migration etc. This rhythm can be of three types: (i) Infradian Rhythm, (ii) Ultradian Rhythm and (iii) Tidal Rhythm. Infradian rhythm is a long-term cycle. The menstrual cycle among women falls into this category. Ultradian rhythm is of smaller duration. Rapid Eye Movement (REM) during sleep follows a 60-minute cycle; nasal cycle is of 4 hours; hormonal secretion cycle is of 3 hours. Tidal rhythms are seen in regions near the oceans and the ebbs and tides are seen in cycles of 12 hours each.
Biological clock is very important and largely influences our daily life. Just like other creatures, man cannot be untouched by the effect of biological clock. In day to day life, there comes a time during which we feel hungry, feel sleepy, sad or happy. From bodily perspective, all actions like maintaining body temperature, thought process, hormonal secretion, etc happen involuntarily. One cannot sleep when there is light. Hence, the moment night sets in, one begins to feel sleepy. Sleep during the night is much deeper and relaxing compared to the nap during the day. In this way, sleep also follows a cyclic pattern and comes in its own time. If one transgresses his sleeping schedule, then it proves to be troublesome. People who work in night shifts; pilots who fly the airplanes during the night, etc suffer from distorted sleep cycle because of light and other external factors. To preserve the sleep cycle of astronomers, light and darkness are controlled during regular intervals.
In Polar Regions, where daytime lasts for 6 months and night for another 6 months, the cycle of creatures living in those regions is adjusted accordingly. The latest research done by University of Troms revealed that the biological clock of animals like Ptarmigan, Reindeer etc living in Polar Regions is controlled by monsoons. Our biological clock is indirectly controlled by Sun and Moon. The time we wake up is linked to the time of sunrise. During winter, Sun rises at around 7.00 or 7.30 AM while in summer sunrise happens at 5.00 or 5.30 AM. All creatures begin their day with sunrise. The tender rays of the sun motivate the plants to open up their leaves and they shrink after sunset. Lotus also blooms at sunrise and closes during the night. Sunflower follows the movement of the Sun.
All the details discussed above go to prove that the biological clock of each being is controlled by the solar cycle. Plants obtain their nourishment through the process of photosynthesis that occurs only during the presence of Sun. This process cannot be launched during the night even if stipulated heat and light are provided to the plant artificially. Mind feels pleasant and enthusiastic during sunny days, whereas it begins to lose its zeal with the onset of evening. This is a cyclic phenomenon that influences us each day of our life. This is called the biological clock. Biologists talk of finding the location of this Bio clock. According to them, this clock is located in the Hypothalamus of our brain. This is called suprachiasmatic nucleus (SCN). A trace of melanopsin that is found in this nucleus is responsible for our sleep cycle. If this organ is affected or stops functioning, then we will not be able to sleep during the night and end up sleeping at odd hours.
Biological clock is also related to the regulation of body temperature. This is regulated by Melatonin that is secreted by Pineal gland. Scientists say that the temperature of the body reaches its minimum 2 hours before sun rise. During the day, the amount of Melatonin in the body decreases. Since it controls our sleep cycle, we tend to sleep less during the day. But, the secretion of Melatonin begins at around 9 in the night and hence we begin to feel sleepy. It is found in highest amount at midnight.
The suprachiasmatic nucleus found in Hypothalamus is called the master clock since it controls all the life activities in our body. Other bio-clocks that assist the master clock are present in various parts of our body like – intestines, kidneys, liver, pancreas, spleen, thymus, skin etc. The bio-clocks found in these organs regulate the activities related to these organs. The bio-clock present in the intestines controls the hunger cycle. In general, all these bio-clocks perform their functions, but the moment daily routine is disturbed, they fail to function properly.
In present times, people from all strata of society are largely living irregular lifestyles resulting in disturbed bio-clocks. The first consequence of this life style manifests as insomnia or sleeplessness. Once the sleep cycle is disturbed, only a person who has undergone the torture can explain the difficulties involved in regaining sleep. Research and analysis show that disturbance in sleep cycle is related to increased number of road accidents. The number of accidents during the day is much more pronounced than those during the night. Those who sleep well in the night are at their best awareness during the day. Those who remain awake during the night are prone to losing control on the road during the day which leads to accidents.
Disturbed biological clock leads to insomnia and bipolar diseases. Bipolar is a mental disease because of which a person undergoes depression during regular intervals. Because of this, a person becomes sad, depressed, angry due to guilty conscience, dejected, tired, ill-tempered; and suffers from disturbances in sleep and hunger. When others are enjoying life, these people are entangled in complex emotions and lack the desire to do any activity. No amount of inspiration induces the zeal to work. This disease, which has emerged because of modern life style, is affecting children too. The number of children suffering from this disease in 2003 was 40 times that of children afflicted in 1994. This number has increased much more in the current year.
Biological clock is disturbed with disturbances in life style. Initially, it starts off as a slow process, but once it establishes its grip on its victim, all the symptoms listed above begin to manifest. This not only affects our body, but our mind and emotions are also adversely affected. Just as there is a physical cycle, there are emotional and intellectual cycles too. Physical cycle is of 23 days duration. This is called psycho-visitation. This controls our capabilities, health and co-ordination. Emotional cycle is of 28 days duration. This regulates our creativity, emotions, moods and direct understanding. Intellectual cycle is of 33 days. This controls analysis, logic, memory and conversation.
If we observe these cycles, we will realize that a man experiences the same things during these regular cycles. When he is healthy he experiences these cycles, but when disorder in life style sets in, these experiences begin to become painful. For example, we can be in a worse mood than what we were 28 days before. We might not be able to exhibit the same intellectual expertise that we had 33 days before, because intellectual cycle repeats itself every 33 days. Ordinary man is so immersed in day to day activities and confusion that he does not realize these cycles.
The need of the hour is that we understand the rhythm of our biological clock which controls not only our body and mind but also our intellect. Not only can we resume the rhythm with right food habits, living habits and thinking habits, but we can also elevate and refine our life with each of the cycle. According to seers, the mystic scientists of yore, Brahma Muhurt is the period of transition. By sadhana and other activities, we can either enhance and make use of that time or waste it owing to our laziness. Biological clock is symbolic of how well we understand the cycles and get ready to welcome the next cycle. With self-restraint and sadhana we can reap the benefits or become prone to disease by lack of restraint. Hence, we have to organize our biological clock and enjoy the innumerable benefits that it offers.
Akhand Jyoti Magazine 2009 Mar-Apr