Circadian

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What does Circadian mean?

The newly formed Circadian Magazine is quickly becoming a part of student life at Barts and The London. It finally provides students and societies alike the opportunity to voice their opinions, share new and upcoming research, and practise their satire all in one place. However, many have questions regarding the name; Circadian. What does it mean? Is it a medical term? If so, how does it all relate?

The origin of the word Circadian is derived from the Latin words circa meaning around or approximately and diem as in day, which quickly evolved into Circadian. However, it is most commonly seen in reference to the term ‘Circadian Rhythm,’ which can be used to describe our internal body rhythm/clock. It includes the analysis of daily, weekly, or seasonal rhythms found throughout our environment. Cycles with 24-hour oscillations are typically called diurnal rhythms. Hence, humans are generally described as being diurnal, as we are a species that are predominantly active during daytime and inactive at night

Looking at our sleep cycles, let’s ask ourselves this question; ‘Why do we feel tired at certain times during the day?’ The control centre of our circadian rhythm is located in the suprachiasmatic nucleus (SCN), which are a pair of cells found in the hypothalamus. Studies have shown that destruction of this nucleus has led to the absence of regular sleep-wake cycles. Normally, the SCN receives the information from the retina. Rod and cone (i.e. light sensitive cells) inhibit the activity of SCN. In the dark, the SCN relays signals down to the pineal gland. The pineal gland is an important structure in the brain that is responsible for regulating a number of endocrine processes, and one of its main function is to release melatonin. Melatonin is believed to be the main neurotransmitter contributing to our feeling of sleepiness.Consequently, our circadian rhythm is controlled by melatonin and the presence of light. In a dark environment, there is an increase of melatonin. In the presence of light, melatonin release is inhibited. This can explain why everyone around the world sleeps at different times. Inhabitants of Los Angeles for example, will be asleep while for those living in London, the day has just begun.

With all that being said, what is the relationship between the circadian rhythm and Circadian Magazine? Circadian Magazine provides a platform for students at Barts and The London to have a voice. The more voices there are, the more people become inspired, and the more people are willing to share their stories and ideas. This cycle continues and eventually, a rhythm is established. Every term an issue of Circadian is released. Much like the light that is perceived by our retina to activate the SCN in our circadian rhythm, Circadian will relay its messages throughout the different nuclei scattered around Barts therefore stimulating our thoughts and encouraging us to speak up. Circadian Magazine aims to be the light that prevents us from feeling tired of not having a voice.