Why do we want to have what we like, like food, sex, drugs, or any art form, that makes us happy?
The French philosopher Denis Diderot pointed to a central puzzle—that it is the desire for something that creates the desire to have it, but it is also true that desire creates a desire.
Neuroscience has solved part of the mystery by identifying a system that drives desire in mammals through specific brain regions. The desire for something can help an animal survive, for example to experience pleasure from nutritious food.
Now, as we discuss in a paper in the journal Science, new research by Jingnan Huang and colleagues at the Fujian University of Agriculture and Forestry has found evidence of a similar desired system in bees.
General desire to get what you like
What do we mean when we talk about “like” and “want”? So, to neuroscientists, “liking” refers to the pleasurable feeling we get when we consume something. On the other hand, “to want” means to be motivated to reach for something.
We know a little about what happens in our brains when we seek a reward and what happens in other mammals like rats. This action involves dopamine, a type of chemical called a neurotransmitter that enables communication between neurons in our brains.
To understand how the process works for non-mammals, Huang and his colleagues looked at what happens in the brains of bees when they are likely to find something.
As the German scientist Karl von Frisch showed in the 1920s, bees use a symbolic dance language to tell hive mates about the location of desired flowers.
Other bees that observe this dance are prompted to leave the hive to collect the pollen needed to make honey.
Huang and his colleagues measured dopamine levels in the brains of bees who danced and watched them. They found that this chemical increases between the performers and the audience at the beginning of the dance, and decreases when the dance ends.
Dopamine levels were higher when watching the dance than when the bees were eating. These fluctuations suggest that it is the expected sweet reward of pollen that chemically drives the bees to work.
A desired system in the miniature brain
Despite having less than a million neurons in their tiny brains, bees exhibit complex behavior and have the ability to solve problems such as detecting the scent and color of flowers.