Cerebral Anatomy of the Spider Monkey Ateles Geoffroyi Studied Using Magnetic Resonance Imaging. First Report: a Comparative Study with the Human Brain Homo Sapiens

El objetivo del presente estudio cualitativo fue analizar los aspectos morfológicos de la anatomía cerebral interna utilizando imágenes de resonancia magnética (IRM) en dos especies de primates, El mono Araña (A. geoffroyi) y el humano (H. sapiens), tomando como base un estudio comparativo de las estructuras cerebrales de las dos especies, concentrándose primordialmente en el sistema límbico del cerebro del mono araña. Aunque es una especie común en el hemisferio occidental, es interesante para estudiar dada su organización social y funciones motoras, el mono araña (A. geoffroyi) ha sido poco estudiado en cuanto a su neuroanatomía. Las IRM fueron hechas a un mono araña utilizando un resonador General Electrics Signa 1.5 T. Esta investigación se llevo a cabo conforme a las leyes internacionales para la protección de animales en cautiverio y teniendo en cuenta todas las medidas de protección para el manejo experimental para evitar cualquier efecto residual de índole comportamental o fisiológico. Desde un punto de vista cualitativo, los cerebros del mono araña y el humano tenían estructuras similares. Con respecto a la forma, las estructuras más parecidas fueron encontradas en el sistema límbico, sin embargo la curvatura cervical, la amígdala, el hipocampo, la comisura anterior y el colículo fueron más grandes proporcionalmente en el mono araña que en el humano.The objective of the present qualitative study was to analyze the morphological aspects of the inner cerebral anatomy of two species of primates, using magnetic resonance images (MRI): spider monkey (A. geoffroyi) and human (H. sapiens), on the basis of a comparative study of the cerebral structures of the two species, focusing upon the brain of the spider monkey and, primarily, its limbic system. In spite of being an endemic Western hemisphere species, a fact which is by its own right interesting for research due to this animal’s social organization and motor functions, the spider monkey (A. geoffroyi) has hardly been studied in regard to its neuroanatomy. MRI was carried out, in one spider monkey, employing a General Electric Signa 1.5 T scanner. This investigation was carried in accordance to international regulations for the protection of animals in captivity, taking into account all protective means utilized in experimental handling, and not leaving behind any residual effects, either physiological or behavioral. From a qualitative point of view, the brains of the spider monkey and the human were found to have similar structures. In reference to shape, the most similar structures were found in the limbic system; proportionally, however, cervical curvature, amygdala, hippocampus, anterior commissure and the colliculi, were larger in the spider monkey than in the human

Breve introducción a la antropología cognitiva

El presente artículo tiene como objetivo realizar un acercamiento al tratamiento de algunos de los temas enmarcados en la intersección entre la antropología social o cultural y el estudio de la cognición. Para introducir el tema, las autoras nos dan una explicación de los antecedentes del campo de conocimiento que es la antropología, además de la importancia de la cultura dentro de esta disciplina. En particular, se hace referencia a la antropología cognitiva, un campo que comenzó a desarrollarse en Estados Unidos a mediados del siglo xx y que cobró fuerza y siguió nuevos derroteros en los años ochenta y noventa en Francia. Se realiza, por lo tanto, un recorrido por algunos conceptos que delimitaron las diferentes líneas de investigación en este campo de estudio. Uno de los factores más importantes dentro de la antropología cognitiva es el lenguaje que refleja la cultura de nativos en una región

Tractography of the Spider Monkey (<i>Ateles geoffroyi</i>) Corpus Callosum Using Diffusion Tensor Magnetic Resonance Imaging

<div><p>The objective of this research was to describe the organization, connectivity and microstructure of the corpus callosum of the spider monkey (<i>Ateles geoffroyi</i>). Non-invasive magnetic resonance imaging and diffusion-tensor imaging were obtained from three subjects using a 3T Philips scanner. We hypothesized that the arrangement of fibers in spider monkeys would be similar to that observed in other non-human primates. A repeated measure (n = 3) of fractional anisotropy values was obtained of each subject and for each callosal subdivision. Measurements of the diffusion properties of corpus callosum fibers exhibited a similar pattern to those reported in the literature for humans and chimpanzees. No statistical difference was reached when comparing this parameter between the different CC regions (p = 0.066). The highest fractional anisotropy values corresponded to regions projecting from the corpus callosum to the posterior cortical association areas, premotor and supplementary motor cortices. The lowest fractional anisotropy corresponded to projections to motor and sensory cortical areas. Analyses indicated that approximately 57% of the fibers projects to the frontal cortex and 43% to the post-central cortex. While this study had a small sample size, the results provided important information concerning the organization of the corpus callosum in spider monkeys.</p></div

Mean FA value comparison.

<p>Mean FA values were calculated from the three measurements of the three subjects in each region in which CC was divided.</p><p>Mean FA value comparison.</p

MR mid-sagittal image of the corpus callosum of an <i>Atles geoffroyi</i> monkey.

<p>Corpus callosum was divided in five regions according to the anatomic landmarks and Hofer ‘s method [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117367#pone.0117367.ref003" target="_blank">3</a>].</p

Inter-species tractography comparison.

<p>CC tractography results obtained in the literature for different species of primates (<i>H. sapiens</i> [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117367#pone.0117367.ref003" target="_blank">3</a>]; <i>P. troglodytes</i> [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117367#pone.0117367.ref011" target="_blank">11</a>]; <i>M. mulatta</i> [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117367#pone.0117367.ref003" target="_blank">3</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117367#pone.0117367.ref028" target="_blank">28</a>])</p><p>Inter-species tractography comparison.</p

Regional FA comparison.

<p>Mean FA values for each subject and region.</p

DTI results for n = 3 subjects.

<p>Reconstructed fibers traversing the corpus callosum are over-imposed on a mid-sagittal anatomical image (subject 1, 3A; subject 2, 3B; subject 3, 3C. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0117367#pone.0117367.g003" target="_blank">Fig. 3D</a>: The mean map of Axial Eigenvectors showing the principal diffusion tensor directions of CC in global orientation. Color codes: red: left to right, green: anterior to posterior, blue: superior to inferior.</p