If you ever ate a bite of your favorite food and suddenly felt better about your day, you may be interested to know that a recent study suggests we share this feeling with bees.
The explanation is not that out of this world, since dopamine, the hormone responsible for the neurotransmission of different states, is actually found to be present in the brains of invertebrates.
The study found that bumblebees express dopamine-induced positive emotion-like behaviors. However, their nature and their association with emotions remain uncertain. The experiment trained some bumblebees with rewarding cues and the others with unrewarding ones. In comparison, the ones given a positive sucrose stimulus responded with a positive behavior.
"The finding that bees exhibit not just surprising levels of intelligence, but also emotion-like states, indicates that we should respect their needs when testing them in experiments, and do more for their conservation," stated Lars Chittka, senior professor and author of the research.
A second experiment was also conducted, and the subjects given a sucrose-based stimulus took a shorter time to reinitiate foraging in the aftermath of a simulated predator attack caused by a spider. The changes were reversed, stimulating fluphenazine, the dopamine's reversed hormone.
Other experiments suggested that the sucrose doesn't just work as an incentive for bees to be more curious and active, but it also opened a new set of possibilities in comprehending the anatomy of emotions when it comes to their natural manifestations as well as their impact on animals' decision-making processes.
"Sweet food can improve negative moods in human adults and reduce crying of new-borns in response to negative events. Our results suggest that similar cognitive responses are occurring in bees," declared Luigi Baciadonna, Ph.D. candidate and co-author.
This cognitive similarity could reinforce the idea that cognitive processes and brain wirings are similar due to the evolutionary processes' contributions.
The bees were trained to find food at a blue flower and none at a green one, then subjected to tests in the case of a blue-green flower. The ones that had drunk the sucrose prior to the experiment landed on the blue-green flower at a faster rate than their counterparts. Other experiments managed to rule out the possibility of parasitic variables to have contributed to the results. Consequently, this means that the dopamine-induced states similar to the emotions humans experience are actually genuinely the result of the external, artificial stimulus.
Conservation efforts are made in the case of bumblebees, as their dramatic population decline strongly suggests a highly probable numeric shrinking toward being an endangered species.