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.ObjectivesTo provide evidence of correlations between anatomical particularities of the brain areas analyzed and some cognitive abilities previously described in these simians.MethodsThe 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.ResultsData gathered allowed the calculation of the approximate volume (cm3) of the areas under study: right antimere 35.2cm3 (±5.3), left antimere 31.3cm3 (±5.4) and of the left PFA 6.0cm3 (±1.5) and right PFA 6.9cm3 (±1.7).ConclusionsWe 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.

Anatomical Study of Intrahemispheric Association Fibers in the Brains of Capuchin Monkeys (Sapajussp.)

“…The present study reported similar size and amount of association fibers originating from the frontal lobe in Sapajus to those in Macaca and Homo . The frontal cortex in Sapajus keeps high percentage in its brain [ 47 ]. Extensive studies reported that Sapajus monkeys have similar relative neocortical size as in big apes and are highly encephalized [ 8 , 15 , 20 , 48 – 50 ].…”

Gross anatomy of the longitudinal fascicle of Sapajus sp.

“…Indeed, there has been no such research on this topic involving Neotropical primates of the genus Sapajus. Species of this genus, interestingly and unexpectedly, have abilities for memory, cognition, social behavior and tool use that are similar to those of apes [18,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]. They also have large brains relative to their body mass [29,40] and high motor development [41].…”

Comparative anatomical study of the leg's nerves of Cebus (barbed capuchins) with baboons, chimpanzees and modern humans

“…Previous studies reported, using Cebus, 1) anatomy of the thoracic members in the shoulder, arm (Aversi-Ferreira et al 2007a, 2007b, 2007c, and forearm (Aversi-Ferreira et al 2005a, 2005b, 2006, 2011b, Marin et al 2009, 2) anatomy of the pelvic members, thigh's nerves (Aversi-Ferreira et al 2011a), retus femoralis muscle (Amado et al 2011), 3) neuroanatomy (Watanabe 1982, Watanabe & Madeira 1982, Borges, Ferreira & Caixeta 2010, Pereira-de-Paula et al 2010, 4) behavior and tool use (Aversi-Ferreira et al 2011a, Resende & Ottoni 2002, 5) cortical physiology (Lima, Fiorani & Gattass 2003), 6) cephalization index (Areia 1995, Byrne 2000, and 7) memory capability (Tavares & Tomaz 2002). Recently wild capuchins were observed to fish for termites using twigs, which is a behavior that have been reported until now only in chimpanzees (Souto et al 2011).…”