| Description |
Encephalization refers to the disproportionate growth in brain size relative to body size. While the brain-to-body ratio has been extensively studied in Drosophila species, prior research has largely focused on whole-brain metrics. There is a notable gap in understanding how specific neural subpopulations and circuits scale with overall brain size. This study examines the relationship between encephalization and the size of two subpopulations in the dopaminergic learning pathway-the PAM and PPL1 complexes- across a range of Drosophila species. Using dissection, immunostaining, and a combination of automated and manual cell counting techniques, neural data was collected and analyzed for multiple species within the Drosophila genus. Statistical analysis of this data revealed no consistent correlation between overall brain size and the number of cells within these subpopulations. These findings suggest that encephalization in Drosophila- and potentially in other organisms due to inherent analogy in neural structures-may not be strongly influenced by dopaminergic circuits involved in associative learning, but instead by other cognitive domains such as spatial estimation or problem-solving. |
