Hello, I am your brain

Hmm... this is tough. How do I list the ways in which I help you? Even as you are reading this, it’s me who is really processing the words and reading them back to you. Think about it (but really, it’s me, again, who’s asking you to hink about it). Is that complicated or what? But then, that’s me, the brain. I am the most perplexing creation ever and many a scientist has stated that if he could solve the mystery of how I function, it would be greatest breakthrough for mankind.

Every idea, experience, dream (and nightmare), memory, or the lack of it, every smart thought, and all the dumb ones, everything you think about in your life is all due to me. I have certain functions and how I perform them is what determines if you will be the next Einstein or just a garden-variety thinker. Truth is, I am willful, but scientists will tell you that you can train me to do your bidding. Can you? That’s debate is for another day. Today, let’s look at my physical entity

Ancient civilisations thought of my presence as nothing more than a stuffing for the cranium (your skull) or as a radiator to cool off the body. What were they thinking?!

Let me give you my address

I am housed inside your skull, also referred to as the cranium. Your skull, though it looks like one big round structure, is actually made up of 8 flattened, irregular smaller bones - frontal, occipital, sphenoid, ethmoid and 2 each of the parietal and temporal. The bones meet at the sutures which, though technically joints, are rigid with little movement between them.

MY vital statistics (and they are impressive!)

When you were born, there were 44 bony pieces which later fused to form your skull. At that stage, the sutures are soft and filled by fibrous tissue (fontanelles) to make the skull soft and pliable enough to journey through the birth canal and also to allow brain growth during the initial years. But by the time you were two years old, the bones united to form a rigid structure.

Your skull is one of the least deformable structures in nature and it is estimated that a force of 1 ton is required to reduce the diameter of the human skull by 1 cm.

If your cranium were a vessel, what would be its capacity? Between 1000 to 1900 ml.

When you step on to the weighing scale, set aside about 3 pounds for me, because that’s my weight.

What do I look like? Next time you eat a walnut, take a good look at it. I have a similar structure. I am covered with a fibrous protective membrane called the meninges. The membrane itself is composed of 3 layers:

1) The piamater in contact with the brain substance.

2) The duramater, on the outside, and

3) The arachnoidmater, in between.

A clear fluid called the cerebrospinal fluid (CSF) between the arachnoid and pia maters supplies some nutrition and provides a liquid medium in which I am perpetually immersed and floating, to cushion me from harm. The CSF also combats infection by rushing the requisite type of protective blood cells to the area of the brain affected by the infection.

Incidentally, the same fluid also fills the hollow cavities inside me called the ventricles. The fluid is in continuous circulation, forming and being absorbed in a perpetual cycle.

Now to a confession: I am terribly calorie conscious. I use 0.18 calories per minute at rest which jumps to 1.5 calories per minute when I am making you think hard. I burn more calories when you are in hyper metabolic states like fever, meningitis, encephalitis and hyperthyroidism.

I mainly live on glucose and get it directly from the blood flowing in my numerous small arteries. The CSF is also rich in glucose and serves to nourish me well. If the level of blood glucose decreases (hypoglycemia), I make an instant fuss and the result is you feel giddy, things swim in front of your eyes and you see two of everything. Over a period, if the low blood sugar persists, as during prolonged fasting, I reprogramme myself and learn to survive on other substances like ketone bodies.

One of my most important aspects is that I maintain what is called a Blood Brain Barrier (BBB). I don’t allow everything in the blood to enter my premises. Bacteria, large antibiotic and other drugs molecules are kept out while the smaller oxygen, glucose and carbon dioxide molecules are invited in. (Which is why meningitis is such a dangerous illness. My BBB is breached and bacteria and other nasties sort of barge in, deranging me..

I make up just 2% of the body weight but I recieve 15% of all the blood pumped by my friend, the heart, gobble up 20% of all the oxygen made available by my other friend, the lung, and use 25% of the total glucose utilised by the body.

MY JOB DESCRIPTION (this is just the tip of the iceberg)

I am the most complex of organs in structure and function, engaging in activities of such complexity, that scientists are still in the process of unravelling my mysteries. They do not know for sure, for example, how memory can be stored and retrieved inside my substance, or what processes are involved.

I am made up of 100 billion neurons, each connected to 10,000 others! At a given time, only 10% of the neurons are firing, while the other 90% are dormant.

What’s a neuron: A neuron is the basic structural entity of the nervous system. It is an electrically excitable cell that processes and transmits information through electrical signals.

How does a neuron work? Each neuron is made of a central cell body called the soma. The soma sends out small filaments in all directions called the dendrites, which catch signals. Soma then transmits these signals to the axon, a large prolongation that ends in contact with the dendrite of another neuron. But between the axon of one neuron and the dendrite of another is a small gap called a synapse which is filled with a fluid. Into this fluid (in the synapse), when an impulse arrives it is filled with chemicals called neurotransmitters (of which there are several types).

The neurotransmitters, or different types of chemicals then diffuse through the synapse and lock onto specific receptors in the dendrite on the other side. These dendrites take the signal into their soma. A signal transmission is thus completed.

The transmission of a signal (or impulse) is part physical and part chemical. Some common neurotransmitters (or chemicals that fill the fluid in the synapse) are Acetyl choline, Serotonin and Dopamine. Some neurotransmitters like GABA actually impede the transmission of the impulse rather than facilitate it. It serves to prevent too many impulses reaching the target at the same time and for inhibition rather than stimulation of the target tissue all the time.

A neuron may be sensory (carrying sensation of light, sound, pain) or motor (for muscle movements and gland secretion).

People have this notion that the bigger the size of the brain, the brainier the species. While this is generally true, it does not explain why the Neanderthals had bigger brains than you, or why the brain of a certain gentleman who went by the name of Prof Albert Einstein was smaller than the average Joe’s.

I may be roughly divided into 4 parts:

1) The cerebrum: This forms my bulk and comprises the parietal, temporal, frontal, and occipital regions. This is involved in storing memory, retrieving it, deleting it, controlling emotions, taste, smell, movement of the various organs, thought processes, rational thinking, intelligence and indeed for most of the items one associates with me. The two hemispheres of the cerebrum are joined together by a thick bundle of neurons called the corpus callosum. This serves to transmit information from one side to the other so that the two hemispheres do not have to work in isolation.

Below the corpus callosum and in front of the cerebellum lies the limbic system comprising the thalamus, hypothalamus, amygdala and hippocampus. Briefly, the limbic system concerns thirst, hunger, maintenance of the biological clock, internal environment of the body, emotions, memory and control of the pituitary, besides being an important relay centre of sensory neurons.

Frontal lobe is mainly concerned with decision making, processing of information, planning, reasoning, parts of speech, movement, emotions, problem solving.

Occipital lobe with vision, colour recognition.

Parietal lobe deals with processing sensory information, movements, orientation, recognition, perception of stimuli.

Temporal lobe is involved with emotions, memory and speech.

2) The cerebellum: in the back of the head. The cerebellum is responsible for co-ordination of movements, gait, posture and balance.

3 & 4) The Pons and medulla: these parts contain the centre for temperature control (much like a thermostat of the fridge) and the centres responsible for breathing, circulation, control of the heart and other autonomous functions. Pons is responsible for consciousness, sleep, movement, posture, and also transmits motor and sensory axons.

The various areas of the brain each have specific jobs. These have been mapped out and given arbitrary numbers. For example, the Broca’s area (Area 44 and 45 of the brain) situated in the frontal lobe on the left side in right-handed people, for example, is responsible for speech.

My wish list (it’s less ambitious than the ones you constantly draw up with my help)

• Exercise: By now, you must have learned to live with this truth. You’ve heard the heart, liver and kidney say it and now I say it too. A brisk walk, aerobic activity or a run gets the blood cruising through me and some light bulb moments can also occur. The fresh oxygen and glucose that I feed on is a real treat. It helps me get rid of carbon dioxide and urea from my vicinity, leaving me clean, healthy and thinking clear.

Exercise also cajoles me to release some super neurotransmitters called endorphins. Yes, every time you have run around Safa Park, that feeling of being on top of the world? That’s thanks to the endorphins.

• Use me. The more you use me, the stronger I get. Don’t just sit in front of the telly and watch mindless blow-them-up-cars movies. Solve puzzles, do the sudoko; read intelligent articles; learn a language; practice playing a new instrument; read books on history and science; know how the galaxies work. Such mental gymnastics will work wonders for me, and you. They may even prevent me from falling victim Alzheimer’s and dementia.

• Eat a balanced diet. Don’t be a carnivore all the time. Try being a flexitarian and include vegetables, fruits, nuts and whole grains in your daily meals. While I do subsist on glucose, the fact is, that glucose is better derived if you eat nutritious foods. This is essential for my well-being.

• Quit smoking: No, I am not having an identity crisis. Neither am I speaking on my behalf of my friends, the lungs. I hate it when you smoke. I will explain how and why it affects me. Every time you smoke, I unwillingly end up penalizing my friend, the heart, by increasing his beat and your blood pressure. Why? Because the ‘mid-brain’ activity increases due to chemical intake.

• Be happy: Happiness is a wonder tonic for me. Yes, this is a conundrum. When you do things that make you happy, in a way, they are the things that I am asking you to do so you can be happy. You see, I have a storage of evidence of what makes you smile, what makes your heart sing, etc. So spend time with loved ones and friends, be generous, compassionate; give of your time to the less privileged. Do things that make you happy.

• Stay off alcohol: Every time you drink, I feel I am trapped in a house of mirrors. Everything looks confusing, crazy…. I get disoriented and if I am so, how can you be any different? (After alcohol intake, the thought process, judgment, behaviour and emotions are all affected due to changes in the level of neurotransmitters present in the brain. Motor functions are also affected resulting in a jerky gait, loss of balance, stumbling and falling over chairs and all the other regrettable things associated with those drunk silly!)

My nemesis (when the mighty fall!)

1) Brain infection (encephalitis or meningitis). This is thankfully rare in the UAE due to a high level of public hygiene and sanitation. Meningitis may be bacterial, viral or fungal and is spread by throat and nasal secretions when, for example someone sneezes or coughs in you face. It can also spread by sharing cups and glasses, cigarettes (another reason smoking is injurious to health!), infected faeces and through mosquitoes.

2) Psychiatric disorders. Including mental depression signify some chemical imbalances inside me =. (Psychiatric illnesses may be genetic and hereditary). There are numerous chemicals to control my activities in addition to the minute electrical circuits. Some of these chemicals are Acetylcholine, Dopamine and GABA.

3) Stroke. This is a large range of fatal or debilitating conditions giving rise to paralysis as a result of blockage of a blood vessel in me or by its rupture. If a vessel on my left side is affected, usually the right side of the body is paralysed.

4) Physical injury: A common condition worldwide where the brain is brought to grief is an accidental injury as a work related or automobile mishap. I am cased inside a tough skull but there are limits to even the strength of the cranial bones. The brain tissue may be damaged by a direct hit from a hard surface like the road or a falling brick. Alternatively, the force may rupture an artery in me - notably the middle meningeal artery situated above and in front of the ear on either side of your head and the blood leaking out of the artery may compress me against the rigid skull. The surgeon in this case often gets enough time to open up the skull, stop the leak and repair the damage.

5) Brain tumour. A tumour may be benign or malignant. Unlike tumours of most other organs, even the benign ones may be life threatening, because the rigid skull gives little room for expansion and the growth impinges on the normal brain tissue to affect its functioning. The malignant ones may be local or be brought by blood from a distant source (metastatic). The success of brain surgery to remove the tumour depends a great deal on the location of the growth. Gama ray knife surgery is a recent addition in the arsenal of neurosurgeons. It is a misnomer as it involves no knife and no surgery. The radiation is focused with precision at the tumour to destroy it without even opening up the skull.

6) Aneurysms. These can be often present since birth and are small areas of weakness in the wall of the artery resulting in a balloon-like dilatation which may rupture suddenly, leading to bleeding, paralysis and death. If detected in time, it can be treated with varying degrees of success.

7) Alzheimer disease. It affects memory (especially recent memory), judgment, and learning, language and reasoning.

8) Parkinson’s disease. This causes tremors, walking difficulties, and a mask like non-expressive face.

9) Epilepsy. Causes uncontrolled jerky movements of the limbs for a period of time which usually stops as suddenly as it began.

10) Hydrocephalus. There is accumulation of CSF (Cerebro Spinal Fluid) in me due to improper circulation leading to a big head in babies. It is a grotesque but curable condition if reported in time.

11) Migraine. This is a severe headache, typically on one side of the head and accompanied by vomiting.

CHECK LIST: RECURRING SYMPTOMS THAT YOU NEED TO PAY ATTENTION TO

1. Unconsciousness.

2. Memory loss.

3. Convulsions.

4. Loss of judgment.

5. Tremors.

6. Dizziness.

7. Fatigue.

8. Numbness .

9. Vomiting.

10. Confusion.