Yoohoo, happy molecule!

When you are in a bad mood, you either charge it to the regular ebb and flow of this enterprise called life (“to err is human” anyway) or as I have read somewhere before, you can blame it on someone else which is even more human. But consider another option — check yourself. This is a science column, so I mean a real blood check. After all, to err and have your serotonin checked (before blaming it on the other guy) is to be a scientific human.

Serotonin is mostly found in your gut and the rest, in your blood and in your brain. In your brain, it is a neurotransmitter — a chemical that enables the transmission of messages between brain cells. This is a chemical that has been known to contribute to many things about you — your moods, your sleep, your appetite, your temperature, your memory and learning, your muscle movements as well as working with other hormones to make you the (presumably) complex human being that you are.

Lower than normal levels of this chemical have been shown to manifest as depression in humans and just enough levels of it seems to keep humans in a good mood. That is why if it were a celebrity, paparazzi will whistle and summon it this way: “Yoohoo, Happy Molecule!” And then they will ask it intriguing questions like “can we just pop lots of you and keep ourselves happy?” or “can we eat lots of turkey or bananas known to increase serotonin so we could always be calm and smiling?” And serotonin will just shake its head and get inside its molecule limo and mutter to itself “these paparazzi, they always want simple yes and no answers which are not the case with celebrity molecules like me.”

Serotonin is not something you can just pop as a pill so easily when you feel depressed. Inside your head, when serotonin is released from one brain cell to the next, whatever is not used up will be taken back to the brain cell where it was before, like being re-deposited to one’s account. Drugs that treat depression caused by low serotonin levels block this “redeposit” so more of it can be used to keep you from being depressed. But beyond normal ranges, serotonin is a dangerous chemical which can cause serious damage or death.

Serotonin is also not instantly available as it has to be converted from an essential amino acid called tryptophan. Yes, tryptophan is known to be found in milk, eggs, bananas and turkey but in such miniscule amounts to cause a difference. To date, science could not sign off on these foods as a dietary strategy for happiness.

But serotonin is known to be produced by vigorous exercise and bright light. Scientists found this out when they examined the brains of corpses who died in the summer versus the ones who died during winter. In fact, in an experiment, when they gave bright light (3000 lux instead of dim light) to women whose tryptophan levels were depleted (thus, moods were lowered), their moods were neutralized.

In the April 7, 2011 issue of the journal Nature entitled “Molecular regulation of sexual preference revealed by genetic studies of 5-HT in the brains of male mice,” scientists found another power that serotonin possesses. It can swing sexual preference, at least for mouse. They manipulated levels of serotonin on mice and found that male mice who lacked serotonin wanted to have sex with male mice. In fact, as reported in Livescience.com, these serotonin-deficient male mice even serenaded their fellow male mice with the ultrasonic equivalent of the song “Let’s Get Crazy Tonight” — something that male mice do to female mice as part of the wooing process if their serotonin levels are “just right.”

So indeed, if serotonin were a character, it will be a big-time celebrity affecting your emotional state, specifically your moods and since you live with other humans, even your relationships. It can make you see a water-filled glass as half-empty or half-full, or if you are a mouse, swing you into preferring your own sex for sex. That is some power for this celebrity molecule. And you thought alcohol was pretty potent.

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