Purpose
Brain expansion during ontogeny has been identified as a key factor for explaining the growth pattern of neurocranial bones. However, the dynamics of this relation are only partially ...understood and a detailed characterization of integrated morphological changes of the brain and the neurocranium along ontogeny is still lacking. The aim of this study was to model the effect of brain growth on cranial bones by means of finite-element analysis (FEA) and geometric morphometric techniques.
Methods
First, we described the postnatal changes in brain size and shape by digitizing coordinates of 3D semilandmarks on cranial endocasts, as a proxy of brain, segmented from CT-scans of an ontogenetic sample. Then, two scenarios of brain growth were simulated: one in which brain volume increases with the same magnitude in all directions, and other that includes the information on the relative expansion of brain regions obtained from morphometric analysis.
Results
Results indicate that in the first model, in which a uniform pressure is applied, the largest displacements were localized in the sutures, especially in the anterior and posterior fontanels, as well as the metopic suture. When information of brain relative growth was introduced into the model, displacements were also concentrated in the lambda region although the values along both sides of the neurocranium (parietal and temporal bones) were larger than under the first scenario.
Conclusion
In sum, we propose a realistic approach to the use of FEA based on morphometric data that offered different results to more simplified models.
El estudio de las propiedades estructurales y funcionales del cerebro en Homo sapiens, así como en otros primates no-humanos, constituye un tema fundante en la tradición de investigación de la ...antropología biológica. Sin embargo, el cuestionamiento temprano a la perspectiva tipológico-racial condujo al abandono de los análisis intraespecíficos, limitando fuertemente su integración a las neurociencias. En este trabajo se realiza un análisis histórico crítico de las investigaciones sobre el cerebro, enfatizando en las poblaciones humanas actuales, realizadas desde la antropología biológica y las neurociencias -particularmente en biomedicina-. Finalmente, se discuten líneas de diálogo que podrían fortalecer a ambas áreas. Se concluye que el corpus ontológico y teórico-metodológico empleado por la antropología biológica para la generación de conocimientos sobre los patrones de variación espaciotemporal en rasgos fenotípicos y genéticos, así como de los procesos evolutivos y factores ambientales que los modelaron resulta un aporte significativo para los estudios desarrollados por las neurociencias.
El comportamiento alimentario comprende el conjunto de acciones que llevan al consumo de determinados alimentos, y está modelado por aspectos biológicos, psicológicos y socio-culturales. En ese ...sentido, el acceso a diferentes nutrientes en todas las etapas de la vida, incluyendo la prenatal, es variable y dependiente del contexto. La exposición a condiciones ambientales adversas, como una ingesta inadecuada de nutrientes, puede impactar en la salud materna, y en el crecimiento y desarrollo prenatal. El objetivo del presente trabajo es describir los patrones alimentarios y la composición nutricional de la dieta de mujeres gestantes residentes en Florencio Varela, Buenos Aires, Argentina. Se entrevistaron 150 mujeres que asistieron a controles prenatales entre julio del 2021 y marzo del 2022 y se estimó el índice de masa corporal (IMC) como medida del estado nutricional. Se realizó un cuestionario de frecuencia de consumo de alimentos y recordatorio de 24 horas. Los resultados indicaron la coexistencia de bajo peso, sobrepeso y obesidad junto con un elevado consumo de cereales refinados, azúcares y proteínas de origen animal, y un menor consumo de lácteos, pescados y frutos secos. Los datos obtenidos en este trabajo aportan a la discusión sobre el impacto de los comportamientos alimentarios en el estado nutricional de gestantes en contextos de vulnerabilidad.
The morphological changes of the brain and the skull are highly integrated as a result of shared developmental pathways and different types of interactions between them. Shared developmental ...trajectories between these two structures might be influenced by genetic and environmental factors. Although the effect of environmental factors on neural and craniofacial traits has been extensively studied, less is known about the specific impact of stressful conditions on the coordinated variation between these structures. Here, we test the effect of early nutrient restriction on morphological correspondence between the brain and the endocast. For this purpose, mice exposed to protein or calorie‐protein restriction during gestation and lactation were compared with a control group in which dams were fed standard food ad libitum. High‐resolution images were obtained after weaning to describe brain and endocranial morphology. By magnetic resonance imaging (MRI), brain volumes were obtained and endocasts were segmented from skull reconstructions derived from micro‐computed tomography (microCT). Brain and endocranial volumes were compared to assess the correspondence in size. Shape changes were analyzed using a set of landmarks and semilandmarks on 3D surfaces. Results indicated that brain volume is relatively less affected by undernutrition during development than endocast volume. Shape covariation between the brain and the endocast was found to be quite singular for protein‐restricted animals. Procrustes distances were larger between the brain and the endocast of the same specimens than between brains or endocasts of different animals, which means that the greatest similarity is by type of structure and suggests that the use of the endocast as a direct proxy of the brain at this intraspecific scale could have some limitations. In the same line, patterns of brain shape asymmetry were not directly estimated from endocranial surfaces. In sum, our findings indicate that morphological variation and association between the brain and the endocast is modulated by environmental factors and support the idea that head morphogenesis results from complex processes that are sensitive to the pervasive influence of nutrient intake.
Size and shape variation was studied in brain and endocranial surfaces of mice exposed to different diets with the purpose to determine the effect of early nutrient restriction on morphological correspondence between both structures. 3D reconstructions were obtained from micro‐computed tomography and magnetic resonance imaging. Results suggest that morphological variation and association between the brain and the endocast is modulated by maternal nutrient intake.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
El comportamiento alimentario comprende el conjunto de acciones que llevan al consumo de determinados alimentos, y está modelado por aspectos biológicos, psicológicos y socio-culturales. En ese ...sentido, el acceso a diferentes nutrientes en todas las etapas de la vida, incluyendo la prenatal, es variable y dependiente del contexto. La exposición a condiciones ambientales adversas, como una ingesta inadecuada de nutrientes, puede impactar en la salud materna, y en el crecimiento y desarrollo prenatal. El objetivo del presente trabajo es describir los patrones alimentarios y la composición nutricional de la dieta de mujeres gestantes residentes en Florencio Varela, Buenos Aires, Argentina. Se entrevistaron 150 mujeres que asistieron a controles prenatales entre julio del 2021 y marzo del 2022 y se estimó el Ãndice de masa corporal (IMC) como medida del estado nutricional. Se realizó un cuestionario de frecuencia de consumo de alimentos y recordatorio de 24 horas. Los resultados indicaron la coexistencia de bajo peso, sobrepeso y obesidad junto con un elevado consumo de cereales refinados, azúcares y proteÃnas de origen animal, y un menor consumo de lácteos, pescados y frutos secos. Los datos obtenidos en este trabajo aportan a la discusión sobre el impacto de los comportamientos alimentarios en el estado nutricional de gestantes en contextos de vulnerabilidad.
To investigate the association between the anthropometric status at birth and brain and bone growth during the first year of life. According to the brain-sparing hypothesis, we expect catch-up to be ...faster in head circumference (HC) than in body length.
This is a longitudinal design that included Argentinian infants under 12 months of age with at least three anthropometric records. We classified study participants into four growth status categories according to z-scores for HC (HCZ) and length (LAZ) at birth, with z-score = -2 as a threshold. We used the Count model to describe growth trajectories in HC and length in the first year of life according to the growth status at birth. Recovery indicator for HC and length was taken as the time until the predicted growth trajectory surpassed the threshold curve predicted by z-score = -2 for age.
Growth models included 3399 infants. There were significant differences in the growth parameters between groups in all cases (p < 0.05). Within the group with a low HCZ and a low LAZ at birth, HC recovery was faster than length. In the case of a low z-score for only one of the variables, newborns with a low HCZ recovered faster than individuals born with a low LAZ.
The postnatal growth pattern in HC and length is associated with the growth status of HC and length at birth. As we hypothesized, the fastest postnatal recovery occurs for HC in cases of intrauterine delayed growth.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The development of techniques for the acquisition of high-resolution 3D images, such as computed tomography and magnetic resonance imaging, has opened new avenues to the study of complex ...morphologies. Detailed descriptions of internal and external traits can be now obtained, allowing the intensive sampling of surface points. In this paper, we introduce a morphometric and statistical framework, grounded on Procrustes and Procrustes-like techniques as well as standard spatial statistics, to explicitly describe and incorporate the spatial pattern of these surface points into the analyses. We exemplified this approach by analyzing ontogenetic changes in a sample of human brain endocasts and inter-specific differences between primate skulls. An intensive sampling of points on 3D surfaces was performed by automatic techniques and the morphometric variation among specimens was measured by the residuals obtained after the alignment of points. Our results showed that shape changes in both examples are spatially structured. Different results were attained by using methods that incorporate or not the spatial structure in the evaluation of the effect of specific biological factors on shape variation. Particularly, these analyses indicated that the effect of biological factors acting at local scales can be confounded with more systemic factors (by example, the effect of the diet on the facial skeleton) if the spatial structure is not taken into account. Overall, our results suggest that the intensive description of shape differences among structures using densely sampled points on 3D surfaces combined with spatial statistical methods can be used to explore problems not widely addressed in morphological studies.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
PDF