The prefrontal areas and cerebralhemispheres of the neotropicalCebus apella and their correlationswith cognitive processes

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.(AU) A organizacao do cortex pre-frontal pode conter dados importantes para a compreensao de seu funcionamento. Os Cebus apella apresentam particularidades cerebrais e flexibilidade comportamental e cognitiva, possuindo habilidades que demonstram destacada sobreposicao sobre grandes primatas. Objetivos: Fornecer subsidios para realizacao de correlacoes entre particularidades anatomicas das regioes encefalicas analisadas e algumas habilidades cognitivas ja descritas nestes simios. Metodos: Analisamos o tamanho relativo dos hemisferios cerebrais e da regiao pre-frontal (RPF), utilizando paquimetro universal, em 24 hemisferios cerebrais de C. apella fixados em formol a 10% e conservados em solucao alcoolica a 70%. Resultados: Os dados obtidos permitiram-nos calcular o volume (cm3) aproximado das areas estudadas: antimero direito 35,2 cm3 (±5,3), antimero esquerdo 31,3 cm3 (±5,4) e das RPF esquerda 6,0 cm3 (±1,5) e a direita 6,9 cm3 (±1,7). Conclusoes: Concluimos que a RPF representa aproximadamente 20% do volume cerebral deste primata. Nao constatamos diferencas significativas nos antimeros em relacao aos volumes e as areas tanto dos hemisferios cerebrais como das RPF. Estes animais apresentaram tamanho cerebral proporcionalmente maior que os demais primatas neotropicais quando comparamos nossos achados com a literatura disponivel, permitindo-nos inclusive inferir que ha uma grande amplitude do lobo frontal em C. apella; possivelmente relacionada a maturidade e as funcoes cognitivas elaboradas indicativas de transferencia de cultura caracteristicas deste animal.(AU)