Eating sweets is always a pleasurable experience but different brain circuits may have different ideas on how to define pleasure.
In a study published in the journal Nature Neuroscience, researchers found that different brain circuits respond differently when activated by pleasure derived from eating sweets and the corresponding calories they provide.
Ivan de Araújo, lead investigator of the study, and colleagues carried out a series of experiments involving mice. During these experiments, they observed neural circuits located in the striatum, a major part of the basal ganglia and a subcortical portion of the forebrain.
Specifically, the researchers noted that ventral striatum circuits recognize pleasure in sweet taste while dorsal striatum circuits perceive pleasure in the presence of sweet food's nutritional and caloric value.
Previous studies have pointed out that striatum circuits and dopaminergic neurons may be involved in identifying taste and nutritional value. However, it wasn't until now that specific striatum circuits were shown to be equally responsible for identifying the two characteristics.
When mice were given sweeteners and administered stomach injections containing either sugar or non-caloric sweetener solutions. In response to both sugar and sweetener, the ventral striatum released a lot of dopamine, meaning it doesn't distinguish between caloric and non-caloric food but rather focuses on taste.
Dorsal striatum circuits, on the other hand, showed a huge release of dopamine only when sweetener consumption was paired with intragastric sugar infusions, meaning the neural circuits were more attuned to caloric value.
"The conclusion may be that if you have a ‘sweet tooth,' this is due to your brain's craving for calories rather than an addiction to sweetness as such," said Tatiana Lima Ferreira, one of the researchers.
Researchers from Brazil's Center for Mathematics, Computation & Cognition at the Federal University of the ABC and the Biomedical Science Institute at the University of São Paulo, and the United States' Yale University participated in the study.
Alongside lead investigator De Araujo and Ferreira, Luis Tellez, Anthony van den Pol, Wenfei Han, Sara Shammah-Lagnado, Xiaobing Zhang and Isaac Perez were also part of the research.
Photo: Ashley Linh Trann | Flickr