Pheromones and other love compounds

In sync with the imminent peaking of the cherry blossoms, I am witnessing a lot of overt displays of affection that makes me avert my eyes in embarrassment. Ceiling, meet floor. Floor, meet ceiling.  Romantic is normally not the word I'd use to describe the metro train during early morning hours. But clearly, for this Spring-y month at least, some folks find it 'conducive' enough.  As these couples flaunt their love for the world to see, my wool-gathering ends in.... Pheromones!


Why, oh why, do we act so differently when we first fall in love? The glazed look, the clumsiness, the grin. No doubt, love is a real emotion.  But how does the emotion manifest? Surely there's a neurochemical basis for feelings? What causes that initial spark, that electricity, that... chemistry? You knew I was going there.


I first encountered the word Pheromones when I was preparing a talk on insect neuropeptides in college, and has been fascinated with it ever since. See? You do learn something in college!  Phero/Pherein means "to bear" and -mone, well obviously for hormone. These are excreted factors or vaporized "imprints" that triggers a social response, which can be a signal for alarm, sex, food or aggregation. As expected, this is a response that benefits most insect species.  Ever wonder how foraging bees orient themselves back to the colony?  Yup, these hardworking bees release pheromones in the air fanned by their fast little wings. How does one ant from your backyard lead the rest to your kitchen? Yep, pheromone trails. When marking territories, cats, dogs and other animals use what? Say it with me: Pheromones! Even some plants have been known to secrete tannic pheromones to make themselves less appealing to herbivores. Too bad they can't escape vegetarians.


What about people? Oddly, one theory of why humans kiss is because it helps us "sniff out a quality mate". Sounds a bit primal, right? This stems from the belief that the pheromone receptors in humans are found in the olfactory system. So when our faces are close together, we're able to exchange pheromones.  While human pheromones have been marketed as a sort of love potion, the ability of humans to detect pheromones have yet to be proven by science. That's why in this case, I'll believe it when I see it, not when I smell it.


Ok then, if pheromones are not to blame when you break out into Tears for Fears' "Head over heels" while browsing relics at the National Archives, then what is? After all, when teenagers enter the dating scene - a petrifying parental stage - we are quick to blame the rule of overactive testosterone and estrogen glands.  There has got to be some "molecular triggers of love" that humans physiologically respond to, right?


Right, indeed! Anyone who's ever been in love is probably familiar with the palpitations-pink-cheeks-sweaty-palms stage. For that giddy feeling, you can thank the feel-good compounds: Dopamine, Norepinephrine and Serotonin. Dopamine, the "pleasure chemical", gives you that blissful feeling, while what you're mistaking for adrenaline-like rush of  excitement is caused by Norepinephrine. These two chemicals alone produce  intense energy, sleeplessness, craving, loss of appetite and focused attention. Sounds like the first stage of "love" to me! In other words, at this attraction phase, people tend to focus on the relationship and little else... like the road they're walking on, or the pole in front of them. 


But what about after the attraction? You know, that time when you see your partner rationally, rather than through the raging hormones of infatuation? Well, thank goodness people are equipped with the "attachment" hormone too. Oxytocin helps us develop interpersonal relationships and healthy boundaries. Interestingly enough, it is also the compound associated with the mother-infant bond, and is called the "cuddle hormone". Oh, how many times have I come accross this compound when I read about contractions and breastfeeding during my pregnancy - which I will not elaborate on in this article. You're very welcome.


Last but not least, Endorphins, which are also the body's natural painkillers, gives us that sense of peace and security which contributes to "the long haul". So, instead of sniffing people out, I'd say indulge on a few bars of chocolates to boost your happy hormones instead!

And on that note, welcome Spring!

Robin's eggs in perfect nest - picture taken outside my house in Spring '10