Nice haircut.

I usually check out the hips first.

Honesty and passion.

Hips.

Eyes.

The eyes.

His hands.

His height.

Lips.

Hips.

Her humor.

And the smile.

The curves. Charisma. Energy.

And the smile.

Smile. Her lips.

And the hair

The whole thing.

What makes us drawn to a particular person?

Well, if you ask that question to a thousand people

you may get a thousand different answers.

But being in love is actually one of the strongest feelings possible,

and even though we typically think of love being in our heart,

the chemistry of love has actually a lot more to do with this, our brain.

Our brain..

And the reason we start to act all funny when we find someone special

can actually be explained chemically.

Let’s look at three different molecules that play a big role in human attraction,

adrenaline, dopamine and serotonin.

If you’ve ever wondered why people act so goofy when they bump in to someone

they are attracted to, it’s not entirely their fault.

When this happens adrenaline is released in the body by signals from the brain.

This is actually the body activating a stress response

and we feel our heart rate increase and we begin to sweat.

Even if sweating may not be something we really wish to do

when trying to impress someone we like.

Well, another molecule related to adrenaline is dopamine,

a natural feel-good substance released in the brain as we fall in love.

Dopamine is the reward-molecule, it makes us want to repeat things

that have made us feel good, but high dopamine concentrations are also connected to

focused attention, obsessive thinking, sleeplessness and loss of appetite.

Does this sound familiar?

When we fall in love there seems to not be a thing in the world

that could bring us down.

Life is just great and we can’t stop thinking of that special one...

Well, we can partly thank our third chemical for that, serotonin.

But what is really happening in our body when these molecules are released?

Well, I know just the person to ask.

I’m meeting up with Andrew Ewing, who is a professor in analytical chemistry.

These molecules, dopamine, serotonin and adrenaline,

they are neurotransmitters in the brain.

Neurotransmitters are molecules that signal between two nerve cells,

whether it's in the brain or in the nerve system in the body.

When a nerve signal is sent in the body, the neurotransmitters transfer the signal

across small gaps between the nerve cells.

Neurotransmitters then have specific receptors on the receiving nerve cells,

making sure that only the right nerve signal is passed on.

Kind of like a lock and key.

Only the right key will open the right door and continue the signal.

But what really happens in our body when we fall in love?

Well, that’s when your brain sends all the signals to your body for action.

And so that’s why you have the adrenaline rush.

Adrenaline comes out and your palms get sweaty

and your heart rate increases, you get tunnel vision and you zero in on that person.

That’s who you’re looking at.

And then after a little while you get this euphoria and that’s serotonin,

and that's also rewarding so you have some dopamine involved.

It's probably more a time again reward with dopamine.

Well, it turns out that the effects of these little chemicals in our brain

could be so strong that some scientists even recommend that we avoid

making big decisions during this stage!

We could be acting under the influence of love chemicals!

But these molecules are not just important in explaining

why we act and feel the way we do when we fall in love.

They also provide insight in many other physiological effects.

A rapid increase in adrenaline for example is our bodies’ way to prepare for

a fight-or-flight situation.

That is why our heart rate increases and we feel knee weak when doing something scary!

Hey, falling in love is pretty scary, isn’t it?

Understanding the effects of adrenaline has now lead to its use in treating

severe allergic reactions, asthma, and restoring the heartbeat of patients

suffering cardiac arrest!

And understanding the biochemistry of dopamine has improved treatment methods

for diseases such as Parkinson’s disease.

The discovery of dopamine’s role as a neurotransmitter gave Arvid Carlsson

from Gothenburg in Sweden the Nobel Prize in 2000.

And get this, serotonin has now been used to help treat for example depression.

Well, even though chemistry might not explain why we fall in love,

we have learned that being in love depends a lot more on chemistry than you may have thought.

So we have seen how the molecules of love have a lot more to do with this, than this.

And understanding how these molecules work in the brain is helping scientists

in many ways, such as treating certain diseases.

And remember,

Chemistry is all around You!