Lobotomy- the notorious procedure unveiled

Yesterday I watched a Horizon episode detailing the traumas of living with OCD. One of the opening scenes revealed that the infamous lobotomy was previously used to treat patients with OCD. Firstly, I feel compelled to dismiss common misconceptions regarding OCD; merely maintaining tidiness or alphabetising a CD collection wouldn’t label you as OCD. OCD is a disorder that has a neurobiological basis.  People who have OCD are driven by obsessions (persistent, uncontrollable thoughts, impulses, or images that are intrusive, unwanted and disturbing) to perform compulsions (repetitive behaviors often called rituals) in an attempt to reduce anxiety, fear, worry, doubt and distress created by the obsessions.  These rituals may work, but the relief is only temporary.  Unfortunately, getting even momentary relief from obsessions makes it more likely that individuals will perform rituals whenever they experience obsessions.  Over time, the cycle continues, and OCD frequently gets worse. This self perpetuating cycle of ritualistic behaviour often leads to suicidal thoughts and severely diminished quality of life.

It consists of cutting or scraping away most of the connections to and from the prefrontal cortex, the anterior part of the frontal lobes of the brain. While some patients experienced symptomatic improvement with the operation, this was achieved at the cost of creating other impairments, and this balance between benefits and risks contributed to the controversial nature of the procedure.  For Moniz, the lobotomy’s curator, “to cure these patients,” it was necessary to “destroy the more or less fixed arrangements of cellular connections that exist in the brain, and particularly those which are related to the frontal lobes,” thus removing their fixed pathological brain circuits. Moniz believed the brain would functionally adapt to such injury, thus resulting in a rectification of the prior mental disorder.  As aforementioned, the purpose of the operation was to reduce the symptoms of mental disorder, and it was recognized that this was accomplished at the expense of a person’s personality and intellect. Following the operation, spontaneity, responsiveness, self-awareness and self-control were reduced. Activity was replaced by inertia, and people were left emotionally blunted and restricted in their intellectual range. These observations were noted by British psychiatrist Maurice Partridge, among a study group of 300 patients.

The first prefrontal leucotomy on American soil was performed at the George Washington University Hospital on 14 September 1936 by the neuropsychiatrist Walter Freeman and his friend and colleague, the neurosurgeon, James W. Watts. Freeman proceeded to develop the idea of approaching the frontal lobes through the eye sockets instead of through drilled holes in the skull. In 1945 he took an icepick from his own kitchen and began testing the idea on grapefruit initially, then cadavers. This new “transorbital” lobotomy involved lifting the upper eyelid and placing the point of a thin surgical instrument (often called an orbitoclast or leucotome) under the eyelid and against the top of the eyesocket. A mallet was used to drive the orbitoclast through the thin layer of bone and into the brain along the plane of the bridge of the nose. The orbitoclast was malleted five centimetres into the frontal lobes, and then pivoted forty degrees so the tip cut toward the opposite side of the head (toward the nose). The instrument was returned to the neutral position and sent a further two centimetres  into the brain, before being pivoted around twenty-eight degrees each side, to cut outwards and again inwards. All cuts were designed to transect the white fibrous matter connecting the cortical tissue of the prefrontal cortex to the thalamus. The leucotome was then withdrawn and the procedure repeated on the other side.

The lobotomy’s apparent brutality and contradiction of a person’s human rights is why the USSR headed the ban of the lobotomy in 1950. This procedure completely fascinates me; partially due to it permittivity, partially due to its occasional success and partially due to the fact people were willing to undergo such a treatment. If anything, patient’s willingness to accept an infantile existence to rid themselves of their mental disease, elucidates the power mental diseases can exert.

Natural limits of bodybuilding

This week’s article aims to address the increasing expectations of young people commencing their fitness journey. Immersed in a world of ever growing, leaner athletes, natural limits to the body must be understood and realised in order to manage expectations. Over the past three years I have been weight training; the most recent of which has been taken very seriously. Through tracking macro nutrients and progressive overload training, vast developments in both strength and conditioning have been attained, however, through extensive research, I have come to realise that genetic potential can lead you only so far.

Recently numerous studies have been conducted into the physiological limits of the natural body builder. Let’s begin by looking at the most important study ever performed on the subject of natural bodybuilding.

Dr. Casey Butt analysed the numbers of 300 natural bodybuilding champions who competed between the years of 1947 and 2010. It should be emphasized that this data pool is comprised of champions; what would logically be considered the elite in the genetics pool.  Numerous factors were analysed: weight, body fat percentage, lean body mass, height, bone structure, wrist size, ankle size, etc. After compiling the data, Dr. Butt was able to develop a formula capable of predicting the natural bodybuilding limits.

Here is the formula:

Dr. Casey Butt's formula

The variables in the formula are as follows:

H = Height in inches
A = Ankle circumference at the smallest point
W = Wrist circumference measured on the hand side of the styloid process.
(The styloid process is the bony lump on the outside of your wrist.)
%bf = The body fat percentage at which you want to predict your maximum lean body mass

In order to provide some perspective to the formula above, let’s look at a typical scenario…a 19 year old male, 5’10” in height, 68kg body weight, 15% body fat, and perhaps naturally small boned with wrists approximately 6.5″ and ankles at 9″. Lean body mass will be provided, along with a look at scale weight while at 12% body fat. Using Dr. Casey Butt’s Formula the male described could attain a 81.9kg lean body mass potential, 93kg scale weight at 12% body fat.

The result of this formula realises the extreme steroid use of Mr. Olympia competitors today, with contest weights of around 127kg!

 

 

Visiting Evolutionary biologist

Having organised an evolutionary biologist from Plymouth University to speak to the biology society, today I was introduced to the concept of sperm competition in males of various species. The topic of evolutionary biology is rapidly becoming a growing interest of mine, and today we were also enlightened to the fact species, such as the peacock, have evolved to prioritise attraction of mates over increased survival chance. This idea was explored in Dawkin’s ‘The selfish gene’, as propagation of genes is the ultimate priority of any organism. Perhaps a more humorous development of this idea is expressed the stalk eyes fly. The impracticality of having its eyes situated on relatively huge stalks vs the increased chance of mating with ludicrous head extensions, is balanced in favour of the attraction to females. The result of the course of natural selection for this aptly named fly is revealed in the picture below.

Returning to the original premise of this article; what is sperm competition? Sperm competition is the physical competition between the sperm of two separate males to fertilize the eggs of a lone female. A male’s fitness is usually measured as a function of the number of females inseminated, however in many animal species fertile females mate with many male partners. When this happens, whose sperm will fertilise her eggs? This actually improves the genes inherited by the females offspring thus increasing the probability of the female’s genes being propagated in future generations. Males in many species have evolved mechanisms to give their own sperm a special advantage after deposition in the female reproductive regions. In addition to super powered sperm, some males of species have developed rather more brutal mechanisms of ensuring their sperm fertilises the egg. Spiked penises of many species dissuade females from copulating more than once, thus are only inseminated once.

Some males, instead of or in addition to their own mechanisms of sperm competition, will guard their female partners from more copulation even after sperm deposition. These postcopulatory interactions do produce fertilization benefits for the guarding male. Mate guarding exists in a variety of forms including prolonged copulations, mating plugs, mate grasping, and mate mounting. In the parasitic wasp Cotesia rubecula competition for mates is intense and there is a short window of time immediately following copulation in which a second male may induce a mated female to copulate again. In order to distract rival males, a recently mated male will mimic a female long enough for the mated female to become unreceptive. Female mimicry in this species acts as a post-copulatory mate guarding tactic employed by males to increase paternal reproductive success.

Interestingly, in primates, there is a direct correlation between the prevalence of sperm competition in the species and testes size. Bearing large testes is a significant burden due to the fact mitotic division is so frequent in testes; large amounts of energy are consequently expended in maintaining large testes. Chimpanzees experience a considerable level of sperm competition due to their promiscuous nature. In accordance with the correlation aforementioned, Chimps have testes around 150g. This can be compared to the 20g testes of Gorillas, a species to which sperm competition isn’t factor.

Having received some recommended reading from today’s speaker, hopefully I can further my knowledge into natural selection.

Shadowing a Consultant Oncologist

This week I was privileged to spend two days shadowing a consultant oncologist in Derriford hospital. This was a brilliant opportunity to gain a more pertinent insight into medicine’s palliative endeavours. Oncology is often an avenue for the provision of end of life care; this was fully exemplified to me today when a middle aged man’s prognosis was estimated at three weeks. Previously healthy and in full possession of his mental faculties; within the space of a few weeks his malignant brain tumour had progressed from a stage 1 to a stage 4 tumour.

  • grade I – cancer cells that resemble normal cells and aren’t growing rapidly.
  • grade II – cancer cells that don’t look like normal cells and are growing faster than normal cells.
  • grade III –  cancer cells that look abnormal and may grow or spread more aggressively.

I was able to spend time observing various clinicians during their consultations with cancer patients. Prior to numerous consultations I spoke to patients in the absence of a doctor in order to gain privy into their perspective on cancer. One specific occasion elucidated the stark difference in doctor patient perspective. One patient, with a brain tumour, was offered one radiosurgery course around 6 months ago, however instead opted to have to tumour removed surgically. Having discharged herself on the day of surgery, this patient now required a course of 28 radiotherapy treatments. Having spoken to the patient about her situation, she said making a decision was difficult and thus causing her current, unfortunate situation.

However, when talking to the consultant about the very same situation, it was apparent that the patient was advised clearly to have to single radiosurgery treatment previously. Her self discharge was a major inconvenience to the surgeon and her subsequent requirement for the 28 treatments will be difficult to book.  Both sides of the story seemed completely justified from each perspective consequently placing me in an uneasy state of confusion as to whose was more important. Perhaps both were as significant as each other.

To conclude, this experience has allowed me to gain better insight into patients receiving long term, life changing treatment. My mother’s current breast cancer treatment, coupled with my shadowing experience, has made me realise that the future is completely unpredictable. To quote the consultant I shadowed, “you wouldn’t get out of bed if you knew what was around the corner”. How very optimistic!

The Selfish Gene

Having finished ‘The Selfish Gene’ a few months ago, I have finally gotten around to publishing a review. Dawkins coined the term selfish gene as a way of expressing the gene-centred view of evolution, which holds that evolution is best viewed as acting on genes and that selection at the level of organisms or populations almost never overrides selection based on genes. In chapter three, he explains:

“Genes are competing directly with their alleles for survival, since their alleles in the gene pool are rivals for their slot on the chromosomes of future generations. Any gene that behaves in such a way as to increase its own survival chances in the gene pool at the expense of its alleles will, by definition, tautologously, tend to survive. The gene is the basic unit of selfishness.”

This way of looking at selection, from the perspective of the gene, gets extended to such emergent behaviors as kin selection and altruism, by way of the fact that an allele not only gets propogated through the gene pool by helping the immediate organism survive, it also helps other copies of itself survive in other members of its species. Meaning, altruistic behavior is a natural outcome of selection, even if it is bad for the individual organism, because the genes themselves are acting selfishly by protecting other copies of themselves. Dawkins uses numerous clever analogies in order to establish a tangible image of these processes. Of course most genes don’t directly influence behavior, meaning that most genes are, at best, indirectly selfish – but in the case of parochial altruism (within a family or other inbreeding group), most organisms benefiting from altruism likely carry copies of the same non-behavioral genes anyway.

At a time when the idea of group selection was being shown not to be a stable evolutionary strategy, this model provided one way of explaining why kin selection was a much better description of sociality in animals.

For these reasons, The Selfish Gene has rightfully received wide acclaim. But, it is just a metaphor, and no gene is an island. Each gene must act in concert with the rest of an organisms’ genome, which in turn must act to cooperate and compete with other members of its species and within a given ecosystem. As a result, tradeoffs get made. Many times, it is not the allele that is most effective at performing its usual task that is propogated in the gene pool, but the allele that works best with the rest of its genome to generate a successful phenotype that survives.

Obesity implant

I again revert to obesity treatment methods for this week’s post. From crash diets to stomach-stapling and jaw-wiring, it seems there’s nothing people won’t try to lose weight. Soon you may even be able to have an implant, one that works by blocking signals between the stomach and the brain.

The device, called the Maestro Rechargeable System, has just been approved by the US Food and Drug Administration for people who are both severely obese – defined as those with a body mass index over 35 – and have a weight-related condition such as diabetes. Once fitted, it is recharged and adjusted wirelessly using an external controller. It is due to go on sale in the US later this year, with sales in other countries to follow. The premise behind the treatment is that it is a less invasive option that gastric bypass surgery. The device doesn’t seem to be the long-sought cure for obesity, though, as it leads to only modest weight loss – about 9 per cent.

The signals blocked by the device travel along the vagus nerve, an important line of communication between the brain and several major organs. The electrodes wrap around the branch of the nerve connecting to the stomach. This contains both the neurons going from the stomach to the brain and those going back down to the stomach.

According to EnteroMedics, blocking this signalling pathway reduces stomach expansion and contraction, as well as the secretion of digestive enzymes. The net result is that people feel less hungry and their calorie intake is reduced. This may fill the treatment gap between diet and exercise, and conventional weight loss surgeries.

Personality of the immune system

Our personality literally shapes our world. It helps determine how many friends we have, which jobs we excel in and how we cope with adversity. Now it seems it may even play a role in our health – and not just in terms of any hypochondriac tendencies we harbour, but also how prone our bodies are to getting sick in the first place. It is a provocative idea but one that has been steadily gaining traction.

We think of conscientiousness, for example, as a positive trait because it suggests caution, careful planning and an aversion to potential danger. But could it also be a symptom of underlying weakness in the immune system?

That’s one interpretation of a study published last month that sought to pick apart the links between personality traits and the immune system. It found that highly conscientious people had lower levels of inflammation; an immune response that helps the body fight infection and recover from injury. Highly extrovert people had higher levels.

This may mean that extroverts are more physically robust – at least while they’re young. While this sounds like good news, there’s also a downside since sustained inflammation over a lifetime may leave you vulnerable to diabetes, atherosclerosis and cancer.

Past studies have hinted at a link between personality and the immune system. However, the current one is the first to assess personality across a range of people, and connect it to the activity of a suite of genes that control how the immune system works. “They are looking at the immune system in a much more cohesive and comprehensive way,” says a professor of biological psychiatry at King’s College London.

In the latest study at the University of Nottingham, UK, 121 healthy students filled in personality questionnaires to assess the so-called big five personality traits – conscientiousness, extraversion, neuroticism, openness and agreeableness. They also asked them about other behaviours such as smoking, drinking or exercise that might be associated with certain personality types. They took blood samples to assess the activity of 19 genes involved in the inflammatory response, as well as genes involved in the production of antibodies and viral defence.

Even after controlling for behaviour such as alcohol consumption, they found that on average, the genes that trigger inflammation are 17 per cent more active in extroverts than in introverts. In students who scored high for conscientiousness the activation of these genes was 16 per cent lower compared with less conscientious people. There was no apparent difference in the other immune system genes

“The idea that a huge amount of who and what we are is influenced by the way our species fights disease is a powerful and emerging theme across lots of different areas,” says Daniel Davis, an immunologist at the University of Manchester, UK. “A link with personality is not outside the world of what should be looked at,” he adds. However, he cautions that it will take more work to confirm the extraversion, conscientiousness and inflammation link. And if it does exist, do the observed differences translate into meaningful differences in health?

Assuming it does hold, the next question is whether the immune system shapes personality, or vice versa. We know that factors such as stress can boost the activity of inflammatory genes, triggering a short-term boost against infection. Conscientious people might have less inflammation simply because they take better care of themselves than extroverts do – so are less likely to get injured or be around other sick people who could potentially pass on germs. It would be a terrific idea to boost inflammation genes if you’re running around meeting new people, says Cole.

However, it’s also becoming clear that the immune system can influence your mood. A good example of this is “sickness behaviour”; the tendency to become lethargic and withdrawn in response to infection. Possibly, it’s a two-way street. “The mechanisms don’t have to be mutually exclusive,” says Damian Murray, a psychologist at UCLA.

So how might the immune system influence behaviour? In the short term, immune cells release chemicals called cytokines that seem able to cross the blood-brain barrier and interfere with brain cell activity. For example, the release of gamma interferon reduces serotonin production and makes people feel less sociable.

But some think the immune system might also affect the evolution of personality traits like conscientiousness. “In the course of evolution, humans have faced adaptive challenges caused by infectious diseases,” says Napolioni at the Stanford University School of Medicine. “In addition to the immune system, human behaviour may also act as an anti-pathogen defence [by enhancing the survival of people with weaker immune systems].” Last year, Napolioni showed that Americans who carry a variant of the ACP1gene, which boosts susceptibility to infections, are more introverted and less open to new experiences.

Even if conscientious and introverted people do have weaker inflammatory responses, other areas of their immune defence may be stronger, says Davis. As for extroverts, if they really are at greater risk of diseases linked to inflammation, exercise and weight loss can help.

COPD- my first diagnosis

This week, as part of my volunteering at Derriford Hospital, I was given the opportunity to take the case history of an already diagnosed patient. This was a brilliant chance to implement the protocols I had learnt whilst shadowing Dr Lambert. Prior to meeting the patient I was provided with a final run through of all the necessary information I should have acquired. Firstly I was to ask about the presenting complaint, then enquire further as to determine the history of the presenting complaint. Having established this, the past medical history and allergies needed to be established, as well as any regular drugs that have been prescribed. To conclude my investigation, I was to proceed to find out about the patient’s social situation, including factors such as alcohol intake and the extent to which the patient has smoked.

image (8)image (7)

Above are the photos of the notes I was able to take; from these I made an educated guess that emphysema was the likely cause of the described wheezing and coughing of sputum. Upon looking further into what I believed was causing the patient’s presenting complaints, COPD (Chronic Obstructive Pulmonary Disease). To my great surprise the doctor with me confirmed that my suspicions were correct!

The main cause of COPD is smoking. The likelihood of developing COPD increases the more you smoke and the longer you’ve been smoking; the patient I had questioned had in fact been smoking for 40 years. Smoking irritates and inflames the lungs, which results in scarring. Over many years, the inflammation leads to permanent changes in the lung. The walls of the airways thicken and more mucus is produced, this explains the sputum in the patient’s cough. Damage to the delicate walls of the air sacs (elastic fibres in particular) in the lungs causes emphysema and the lungs lose their normal elasticity. When there is high pressure in the lungs during exhalation, the weakened elastic fibres don’t force air out of the lungs. This air is compressed and under high pressure causes the alveoli to burst. This reduces the surface area:volume ratio of the lungs, thus reducing their efficiency as an exchange system. The smaller airways also become scarred and narrowed. These changes cause the symptoms of breathlessness, cough and phlegm associated with COPD.

Cough

A chronic cough is usually the first symptom to occur. When it exists for more than three months a year for more than two years, in combination with sputum production and without another explanation, there is by definition chronic bronchitis. This condition can occur before COPD fully develops. The amount of sputum produced can change over hours to days. In some cases the cough may not be present or only occurs occasionally and may not be productive. Some people with COPD attribute the symptoms to a “smoker’s cough”. Sputum may be swallowed or spat out, depending often on social and cultural factors. Vigorous coughing may lead to rib fractures or a brief loss of confidence. 

Shortness of breath

Shortness of breath is often the symptom that bothers people the most. It is commonly described as: “my breathing requires effort,” “I feel out of breath,” or “I can’t get enough air in”. Different terms, however, may be used in different cultures. Typically the shortness of breath is worse on exertion of a prolonged duration and worsens over time. In the advanced stages it occurs during rest and may be always present. It is a source of both anxiety and a poor quality of life in those with COPD. Many people with more advanced COPD breathe through pursed lips and this action can improve shortness of breath in some.

Other features

In COPD, it may take longer to breathe out than to breathe in. Chest tightness may occur but is not common and may be caused by another problem. Those with obstructed airflow may have wheezing or decreased sounds with air entry on examination of the chest with a stethoscope. A barrel is a characteristic sign of COPD, but is relatively uncommon. 

Advanced COPD leads to high pressure on the lung arteries, which strains the right ventricle. This situation is referred to as cor pulmonale, and leads to symptoms including leg swelling and bulging neck veins. COPD is more common than any other lung disease as a cause of cor pulmonale. Cor pulmonale has become less common since the use of supplemental oxygen.

To conclude, this brief encounter with practising diagnosis has made me realise the enormous room for error; so many diseases present such similar symptoms. Attempting to deduce the fine details of a patient’s case is also very difficult when the patient them-self is both confused and exasperated. This experience has revealed the importance of blood tests, particularly arterial blood-gas tests, when attempting to determine the diagnosis of a lung disease.

Surgical On Call Experience

For the past four days I have had the pleasure of shadowing general surgeon Commander Anthony Lambert; I was able to observe a take and post take period over the extended weekend. The team of people I spent most of my team with consisted of a consultant, a first year surgical registrar, a senior house officer (F2 doctor) and an F1 doctor. However, during my time I was able to spend time with several anaesthetists, ODPs, nurses and  radiographers. In order to reveal the extent of the 55 hours I spent in these people’s company, below is a list of some of the procedures I was able to observe:

  1. Investigatory laparoscopic procedure
  2. Trauma laparotomy proceeding a self inflicted stab wound
  3. 3 appendicectomys
  4. Colectomy
  5. Abdominal wound debridement
  6. Splenectomy
  7. Perianal abscess removal
  8. Pilonidal cyst removal
  9. Cronh’s stricture (laparotomy)
  10. Female catheterisation
  11. Epididymitis discovery on demand of torsions correction surgery by patient

Without a doubt my favourite experience of the weekend, besides the sixteen hour days of course, was being able to observe a trauma case from start to finish. Barely had I heard the surgical reg’s bleeper sound before we were all walking, with great haste, to A&E. I asked what was going on and was told ‘be prepared, this one’s going to be good’. These words took me aback slightly, I realised that I had been hoping for something dramatic to occur so that I could observe something ‘cool’. But for me to tick off my bucket list for the weekend, real lives had to be affected. I didn’t realise it then but I was about to witness a life changing laparotomy proceeding a self inflicted stab wound.

Being ushered into the corner of the trauma bay, I felt very much in the way of things, Doctors and nurses busied themselves preparing x-ray machines and allocating jobs. Then a paramedic’s voice sounded, detailing the case of the woman being wheeled in behind him. For someone who had just stabbed herself in the lower abdomen with a six inch kitchen knife, I was amazed at how coherent this woman was.

Within just 7 minutes I found myself following the woman to theatre. There was absolutely no humility to the procedure, and as Dr Lambert opened her up I couldn’t help but note the irony in her relatively small puncture wound. The irony was made explicitly poignant when Dr Lambert said she’d missed her inferior vena cava by just 2mm. Other than piercing her large intestine, this woman had gotten away with it (so to speak).

The next morning I was able to see the patient on the morning ward round. Dr Lambert remarked that she’d remember him, litotes at its best. The woman had a scar reaching from her pubis to her sternum; I’m sure she’d struggle to forget!

To conclude this brief overview of my experience, I would like to state that I was also able to observe the less dramatic side of medicine. The ‘take’ of patients in the first three days was done predominantly by the F1 doctor. I was able to spend a lot of time observing how the junior doctor approached patients. He showed what the order of proceedings was in order to determine the diagnosis of the patient. Overall I can honestly say that there was nothing I didn’t enjoy about my four day experience, it has provided me with a surge of motivation to continue down the path to medical school.

Sleep; what is it, and why do we do it?

Every night, nearly every person undergoes a remarkable change: we leave waking consciousness and for hours lay immersed in dreams and deep sleep. When we wake, we typically remember little or nothing about the hours that have just passed. However, lately I contemplated just what sleep is and wondered just why we actually need to do it? Surely by sleeping we expose ourself to more danger as a consequence of our vacancy. Surely sleep is an uneconomical way to spend time. Although everyone sleeps, I believe most people would be hard-pressed to precisely define sleep. All organisms exhibit daily patterns of rest and activity that resemble the daily sleep and wakefulness patterns seen in humans. From observing changes in behaviour and responsiveness, scientists have noted the following characteristics that accompany and in many ways define sleep:

  • Sleep is a period of reduced activity.
  • Sleep is associated with a typical posture, such as lying down with eyes closed in humans.
  • Sleep results in a decreased responsiveness to external stimuli.
  • Sleep is a state that is relatively easy to reverse (this distinguishes sleep from other states of reduced consciousness, such as hibernation and coma).

Many physiological variables are controlled during wakefulness at levels that are optimal for the body’s functioning. Our temperature, blood pressure, and levels of oxygen, carbon dioxide, and glucose in the blood remain quite constant during wakefulness and change only to accommodate shifts in metabolic demands. During sleep, however, physiological demands are reduced and temperature and blood pressure drop. In general, many of our physiological functions such as brain wave activity, breathing, and heart rate are quite variable when we are awake or during REM sleep, but are extremely regular when we are in non-REM sleep. REM (rapid eye movement) sleep is when the body is in resting state but has high levels of cortical activity, this often results in vivid dreams. In order to prevent us from acting out our subconscious roll plays, all skeletal muscles are paralysed during REM. Non-REM sleep is defined by much lower cortical activity in which we have very little consciousness of our environments. Non-REM sleep is divided into three subsections; N1 (light sleep), N2 and N3 (deep sleep).

For centuries, physicians believed that sleep was a period of brain inactivity, yet research over the last 60 years has shown that the brain remains, at least partially, active during sleep. There is a progressive decrease in the activation or “firing” rate of most neurons throughout the brain as sleep progresses from wakefulness to non-REM sleep. Also, the patterns of neuron firing change from a seemingly random and variable activity pattern during wakefulness, to a much more coordinated and synchronous pattern during non-REM sleep.  However, during REM sleep the firing of neurones once again becomes random and much more frequent; this is believed to be the cause of dreaming. In all mammals and many other animals, sleep can be defined in much the same way as sleep is defined for humans. However, there are some notable differences among species. When humans sleep, the entire brain is involved. Dolphins and whales, on the other hand, need to maintain consciousness while they sleep so they can occasionally surface to breathe. In these marine mammals, sleep occurs in only one hemisphere of their brain at a time—allowing for some degree of consciousness and vigilance to be maintained at all times.

One of the possible functions of sleep is to give the heart a chance to rest from the constant demands of waking life. As compared to wakefulness, during non-REM sleep there is an overall reduction in heart rate and blood pressure. During REM sleep, however, there is a more pronounced variation in cardiovascular activity, with overall increases in blood pressure and heart rate. Additionally, changes in blood flow that cause erections to occur in males or swelling of the clitoris in females is characteristic of REM sleep The underlying reason for these considerable neural and physiological variations in REM sleep is currently unknown, and may be a by-product of REM-related changes in nervous system activity or related to dream content.

I personally have only just started to contemplate the true obscurity of sleep, and now find the topic completely fascinating. To think that every night we send our bodies into a temporary state of unconsciousness is amazing, whether it be to conserve energy by reduced body temperature, to give our hearts a slight rest or for an as yet unknown reason, all I know for sure is without it, both the physiological and psychological implications are horrific.