By Pallab Ghosh
BBC News science correspondent
A rich experience, or just a bunch of chemicals?
It is said that love is a drug. But is it just a drug?
That is the contention of Larry Young, a professor of neuroscience at Emory University in Atlanta, Georgia.
Writing in the respected scientific journal Nature, Professor Young argues that love can be explained by a series of neurochemical events in specific brain areas.
If it is true, he says, people will no longer have to rely on oysters or chocolates to create a loving mood.
Instead, it will be possible for scientists to develop aphrodisiacs - chemicals that would make people fall in love with the first person they see.
And for those who have fallen in love with someone they shouldn't have, there could be an antidote to unrequited love.
There is even the prospect of a genetic "love test" to assess whether two potential love-birds are predisposed to a happy married life.
Poets would have us believe that love is one of those things that are beyond understanding.
But that concept is anathema to Professor Young.
"I'm not sure we'll be able to understand it fully," he said.
Oysters are known as one of the more traditional aphrodisiacs
"But my belief is that our emotions have evolved from behaviours and emotions that are in the animal kingdom.
"I don't think that the way a mother loves her baby is that different to a mother's love in a chimpanzee or a rhesus monkey - or even a rat."
In animals, scientists have observed that a chemical called oxytocin is involved in developing a bond between a mother and her young.
Professor Young believes it is very likely that a similar process is going on in humans.
"It's just that when we experience these emotions they are so rich we can't imagine that they are just a series of chemical events," he said.
But even if that is true of maternal love, is romantic love simply down to a squirt of oxytocin and a few other love chemicals at a timely moment?
Professor Young thinks it might be.
Researchers have found that oxytocin is involved in the bonding of male and the female prairie voles, which like humans, form an intense bond with each other that lasts for a very long time.
And there have been studies in humans that show that oxytocin increases trust - the ability to read the emotions of others.
So, Professor Young argues that it makes sense that the same sort of molecule might be involved in strengthening the bond between individuals.
He believes there are other chemicals involved too - it is just a matter of doing the research and finding out which ones they are.
"I'm sure that we are just beginning to tap the surface," he said.
"There are hundreds of signalling molecules in the brain - they all act in different brain areas.
"I think one day we will have a much better understanding of how all these chemicals interact and act in specific brain areas that have specific function that give rise to these complex emotions."
Other scientists argue that upbringing and psychology play a part.
Professor Nick Bostrom, director of Oxford University's Future of Humanity Institute, said: "We shouldn't think that this perspective on its own provides a full understanding of what love is.
"There are also evolutionary, psychological, sociological, phenomenological (a philosophical approach and method of qualitative research) and humanistic perspectives that offer important insights."
"Nurture has an important part to play," Professor Young conceeds.
"But the way nurture works is through changing neurochemistry.
"We know from studies in humans that women that have experienced abuse or neglect early in their life have decreased levels of oxytocin in their brain.
Some perfumes contain oxytocin, a chemical which helps human bonding
"So I totally agree that our experiences have a huge impact on our ability to form relationships - but that impact occurs through changes in neurochemistry and gene expression."
So, if love really is just a complex chemical reaction, could that most powerful of human emotions be manipulated?
"Oxytocin increases eye gaze, increases our ability to recognise emotions in others," Professor Young said.
"It may actually enhance our ability to form relationships, and so it is a very real possibility that something like oxytocin could be used in conjunction with marital therapies to bring back that spark."
There are already perfumes on the market containing oxytocin, but Professor Young believes the levels are too low for it to be an effective aphrodisiac.
"But I think in the future we can develop drugs that readily pass into the brain and can target certain brain areas that could do this," he said.
Professor Bostrom believes it will become increasingly possible to manipulate the neurological mechanisms that play a role in romantic attachment.
"Used wisely, such pharmacology could enhance human experience and mitigate unnecessary suffering.
"However, this kind of manipulation would raise a thicket of ethical and cultural issues, which would need to be carefully explored."