The prefrontal areas and cerebral hemispheres of the neotropical Cebus apella and their correlations with cognitive processes

Abstract The organization of the prefrontal cortex can hold important clues to understanding its functioning. The Cebus apella present cerebral particularities and behavioral and cognitive flexibility, possessing abilities that demonstrate an overlap with those of big primates. Objectives: To provide evidence of correlations between anatomical particularities of the brain areas analyzed and some cognitive abilities previously described in these simians. Methods: The relative size of the cerebral hemispheres and prefrontal areas (PFA) were measured using a Universal caliper, in 24 hemispheres of C. apella fixed with 10% formaldehyde and kept in 70% alcoholic solution. Results: Data gathered allowed the calculation of the approximate volume (cm3) of the areas under study: right antimere 35.2 cm3 (±5.3), left antimere 31.3 cm3 (±5.4) and of the left PFA 6.0 cm3 (±1.5) and right PFA 6.9 cm3 (±1.7). Conclusions: We concluded that the PFA represents about 20% of the cerebral volume of this primate. No significant differences were found in the antimeres in terms of volume and area of the hemispheres and likewise for the PFA. These animals have a proportionally bigger brain than that of other neotropical primates in the literature. This allows us to infer that the frontal lobe of C. apella is also larger; possibly related to its maturity and developed cognitive functions indicative of the culture transfers characteristic of this species.