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What makes our bodyclock tick

Introduction

My name is Adam and I am a first-year Neuroscience PhD student, studying how our bodies measure the passage of time. In fact, nearly every cell in our body contains a clock. However, it is the brain that keeps our cells in sync with the environment. Think of the body like an orchestra; each musician (cell) has the ability to create music (measure time), however without the conductor (brain), the musicians will play out of time with each other.  

An important feature of our natural environment is the 24-hour changes in solar conditions, which we can divide into day and night. The brain receives natural light information through the eyes that tells it how much light is available at different times of the day. Then, it adjusts its internal clock to the correct time of day and coordinates the rest of the body. The resulting ‘circadian’ rhythms in our behaviour and physiology, for example sleep/wake and body temperature patterns, last approximately (circa) a day (dian). Without a circadian system, we would be unable to partition our phasic biology to the day and night.

In-depth

In 1972, scientists found the location of the ‘master’ circadian clock in an area of the hypothalamus, called the suprachiasmatic nucleus (SCN). Many SCN cells contain a network of genes, including the Period and Cryptochrome, that function like the cogs of a wristwatch; the time between switching them on and off is equal to around 24 hours. This genetic rhythm is detected in many different organs and tissues however in the SCN it is self-sustained and reset by light. We can detect these genes to identify other brain areas that may function as a self-sustained clock. As a result, our understanding of the circadian system has progressed towards a multi-clock model in which different brain regions combine circadian timekeeping with different physiological processes. One such region is the mediobasal nucleus of the hypothalamus (MBH) which has an established role in the regulation of metabolism (energy intake and expenditure).

One issue with modern life is that our daily schedules no longer correlate with sunrise and sunset, but with our working hours/social hours. Recent evidence suggests that this misalignment increases the risk of a range of diseases from obesity and diabetes to depression and dementia. The MBH, being both a clock and a metabolic controller, may play a role in this relationship between circadian disruption and metabolic disease.

My project aims to develop an understanding of how the clockwork in the MBH influences how it controls metabolism under normal conditions and with different diets. A detailed understanding of this interaction may help us develop clock-targeted treatments for metabolic diseases. 

4 tips for a healthy circadian system-

·  Expose yourself to as much natural light as possible

·  Make your bedroom dark – seal up the windows and avoid light at all costs!

·  Avoid artificial light before bedtime – that means no phones, laptops, tablets folks.

·  Sleep/wake at regular times – While a lie in at the weekend is good for catching up on ‘sleep-debt’ accumulated during the week, try not to overdo it. 

Going further

The website for the faculty of life sciences at the University of Manchester - http://www.ls.manchester.ac.uk/

At the University of Manchester we have the largest group of chronobiologists in Europe! Information about this research can be found here- http://www.manchester.ac.uk/collaborate/expertise/neuroscience/biological-clocks/

How the circadian clock affects sleep – The sleep foundation http://sleepfoundation.org/sleep-topics/sleep-drive-and-your-body-clock