The Fifth Sense

Do you know what Anosmia is? It’s a disorder in which the patient loses the sense of smell. Medical science and society hasn’t paid much attention to this disorder. The lack of awareness and support for the sufferers of anosmia is so much, that a patient in UK started an organization called Fifth Sense to promote awareness and offer support to anosmiacs.

It is easy to understand why society does not pay much attention to anosmia. After all, losing the ability to smell does not sound like a big disaster, right? People should be able to get on with life, with a little inconvenience. We all experience this when we get bad cold. Smell seems to be the least important of the five senses, after taste.

Nothing is further from truth. The ability to smell, called Olfaction, has a very important place in our life. It is true that it does not seem to have much significance is our daily routine. But it is because we take it for granted. Let’s see the place olfaction plays in our life.

Smell bonds us to our close family. A newborn baby gets locked to the smell of the breast of its mother. This smell has a soothing effect on the baby. This might be the reason why crying babies calm down when held by their mother. The odor of close relatives, like parents, children or siblings, does not appear to us as smell. Brain processes these odors differently to create a feeling of familiarity and comfort in us.

Olfaction helps us in choosing our food. We detect the quality of our food from its smell. Remember how we feel disgusted if the food has gone a little bad? It is a built in mechanism to protect us from dangerous food, triggered by smell. It seems we can also detect the content of the food by smelling it. In an interesting piece of research, scientists have found that people can detect which food has more fat in it by its smell.

Thus in important matters of family bonding and food, olfaction is vital. But apart from this, it has a strong connection with emotions and mental health. Anxiety and fear can be triggered by disagreeable smells, and pleasant smells can trigger a sense of well being. Smells have a special memory facility in the brain, called Olfactory Memory. This memory gets linked to other memories, both good and bad. This is the reason why certain smells invoke past memories and strong emotions. A smell sometimes fills us with joy or moves us to tears, seemingly without reason. We have forgotten the incident but have retained the olfactory memory.

Researchers have found that the ability to smell gets affected in mental diseases like Schizophrenia. On the other side, losing ability to smell affects mental health adversely. We have seen above the disorder anosmia. The patients of anosmia experience depression and difficulty in social bonding. Most of the flavour of food comes from the sense of smell. Thus these patients lose interest in food, lose weight and even become anorexic.

Such is the important but neglected fifth sense – smell. So far, the research on this sense has been very limited. In 2004, a Nobel prize was awarded to two scientists for finding out how sense of smell works. A lot of research is now going on. I am sure it will bring up a lot of sweet smelling surprises.

Mood Repair

Scientists have found that passing ultrasound waves through the brain can improve mood of a person.

Last July, researchers conducted trials on 31 chronic pain patients. The ultrasound probe was held to their heads so as to pass the sound waves for about 30 seconds through the brain. The patients experienced improved mood for up to 40 minutes. This technique can be very useful for those suffering from mood disorders, such as Depression.

Depression is quite common in the world today. About 8 percent of the world population (60 crore people!) are suffering from depression. It is one of the major causes of suicide.

But even for those of us not suffering from any mood disorder, mood plays a very important part. Most of us find ourselves in a bad mood now and then. This negative mood affects our daily life in many ways. It changes our perception of the world. People in negative mood tend to label most things as negative. If you get an email when you are in a bad mood, you will find yourself thinking more about the sender than the mail. The negative mood makes us less energetic, stressed and can interfere with sleep.

Doctors use Mood Repair Strategies to treat mood disorder patients. The name may sound impressive, but the strategies are really common sense, and we can adapt them for our own use. Some useful strategies are:

Recalling positive memories: Usually bad mood makes us remember bad memories. You have to force yourselves to retrieve good memories, such as that first prize you won in school.

Music: Listening to music that you normally listen when you are happy can trigger change in mood.

Social connect: Talking to family and friends can be a great way of getting out of bad mood.

Meditation: If you have learned to meditate, it’s a powerful technique for repairing mood.

Exercise or play: Physical activity releases chemicals called endorphins in the brain, which induce a nice feeling. This can provide the right trigger for improving mood.

Sleep: If you are not getting enough sleep lately, that will be the first thing to correct. A peaceful 7-8 hours of sleep can do wonders.

Humor: Laughter is the best medicine for mood improvement. It increases levels of a chemical called Serotonin, which bring a feeling of contentment. So, an hour of Comedy Nights with Kapil can be useful.

Disclaimer: The Mood Repair Strategies part of this article gives a few recommendations. Please use your own judgement while using them. Also, if you do not want to take recommendations from a non-doctor, please ignore this part.

Black Silicon: a violent nanotechnology

In the month of September 1928, a scientist called Alexander Fleming returned home after enjoying a holiday with his family. Fleming was a brilliant but untidy researcher. Before going on holiday in August, he had stacked his experiment material carelessly on a bench. In the material were some dishes in which Fleming was growing a bacteria of the weighty name Staphylococcus aureus.

Fresh from vacation, he pulled out the culture dishes. In one of the dishes, a mould was growing, just like what we see sometimes growing on a piece of bread forgotten in a corner. Before throwing it out, Fleming had a good look at the dish, and was rewarded with a wonderful sight. The bacteria around the mould had vanished. The mould had killed it. This was the discovery of penicillin, and beginning of the antibiotics industry. Man had won, bacteria had lost.

But Staph aureus, the bacteria that causes diseases like pneumonia and meningitis was not going to give up so easily. By 1960, it developed resistance and could no longer be killed by penicillin. More and more powerful antibiotics with cracking names were discovered – Methicillin, Oxacillin, Streptomycin. But Staph kept on developing resistance. Today, Staph infections is a major menace in Hospitals, and most infections require expensive and risky treatment.

It has happened not only with Staphylococcus aureus, but with many other bacteria. The most famous example is the TB bacteria, Mycobacterium tuberculosis. These bacteria are no longer responding to common antibiotics. Antibiotic resistance is one of the major problems for public health in 21st Century. We are going to need alternate ways of fighting bacteria.

One ray of hope has arrived in form of a interesting research story. It’s a thrilling case of nature teaching us a thing or two.

Scientists found that the wings of Wandering Percher dragonfly (‘Chatur’ in Hindi - do a google search and see the images) can kill bacteria. They examined the wings and found something unique. The wings of dragonfly have very small needle-like structures. The needles are only 250 nanometre long. These knives actually stab the bacteria and leave them harmless!

(To understand what a nanometre is, take a one millimetre long needle and cut it into 1000 parts. Now, grab hold of one of those invisible parts, and again cut into 1000 parts. One of the parts that you are now holding is a nanometre long.)

Researchers got an excellent idea to work with. They identified a material called Black Silicon. This material is made by processing the surface of normal silicon in a certain way. It has nano-needles on its surface that are even longer than the dragonfly.

Black Silicon was tried on the Staph aureus bacteria, and it came out victorious. A one centimetre by one centimetre piece of Black Silicon can kill 4,50,000 bacteria per minute!

Even though the cost of this material is high today, this gives us a whole new weapon in our battle with bacteria. In future, we may be able to protect ourselves from the oldest enemy of mankind with antibacterial clothes!

The green network

Somewhere in Canada, a little maple plant is under attack. It’s attackers are the greenflies, also called plant lice. The insects have bitten into the maple’s stem and are drinking the sap, it’s life juice. There is not much the plant can do for itself. But already, it has started sending signals that are going to save many of its friends around.

The signals are molecules of certain chemicals. They will reach the plants around the one that is under attack. As soon as the surrounding plants receive the signals, they will start preparing their defense. They will emit chemicals that will repel the greenflies. They also have in stock scents that attract wasps who eat the greenflies. The plants even know a method to make an insecticide. All these defenses are going to come handy against the attackers. Even though some little maples will be damaged, many are going to survive the attack.

No, this is not a science fiction tale. Researchers have found that plants actually communicate and alert each other of dangers like attack of herbivores, the plant eaters. They do so with the help of chemicals called volatile organic compounds, or VOC. VOCs are nothing but chemicals that can produce smells, like the perfumes that we use.

These signals are transmitted between plants in two ways – one is through air as we have seen. Another is through the soil. The roots of plants are in touch with each other, through which the chemical signals travel. But there is another interesting network under soil.

Some types of fungi make long threads that connect the roots of various trees and plants, making a vast underground network. The fungi get sugar from the roots, and give nutrients like nitrogen and phosphorous. This network is used to carry the plant messages too.

To ignorant observers like us, the plants appear to be just sitting quietly. Only now we are beginning to understand that they have a solid social network to exchange gossip, rumors and news. Remember that next time you pluck a casual flower from the bush.