The present report compares the morphology of callosal axon arbors projecting from and to the hind- or forelimb representations in the primary somatosensory cortex (SI) of the agouti (Dasyprocta primnolopha), a large, lisencephlic Brazilian rodent that uses forelimb coordination for feeding. Callosal axons were labeled after single pressure (n = 6) or iontophoretic injections (n = 2) of the neuronal tracer biotinylated dextran amine (BDA, 10 kD), either into the hind- (n = 4) or forelimb (n = 4) representations of SI, as identified by electrophysiological recording. Sixty-nine labeled axon fragments located across all layers of contralateral SI representations of the hindlimb (n = 35) and forelimb (n = 34) were analyzed. Quantitative morphometric features such as densities of branching points and boutons, segments length, branching angles, and terminal field areas were measured. Cluster analysis of these values revealed the existence of two types of axon terminals: Type I (46.4%), less branched and more widespread, and Type II (53.6%), more branched and compact. Both axon types were asymmetrically distributed; Type I axonal fragments being more frequent in hindlimb (71.9%) vs. forelimb (28.13%) representation, while most of Type II axonal arbors were found in the forelimb representation (67.56%). We concluded that the sets of callosal axon connecting fore- and hindlimb regions in SI are morphometrically distinct from each other. As callosal projections in somatosensory and motor cortices seem to be essential for bimanual interaction, we suggest that the morphological specialization of callosal axons in SI of the agouti may be correlated with this particular function.

Rodentia is the largest mammalian order, with more than 2,000 species displaying a great diversity of morphological characteristics and living in different ecological niches (terrestrial, semi-aquatic, arboreal and fossorial). Analysis of the organization of the somatosensory areas in six species of rodents allowed us to demonstrate that although these species share a similar neocortical blueprint with other eutherian mammals, important differences exist between homologous areas across different species, probably as a function of both lifestyle and peripheral sensory specializations typical of each species. We based this generalization on a phylogenetic comparison of the intrinsic organization of the primary somatosensory area (SI) across representatives of different rodent suborders. This analysis revealed considerable structural variability, including the differential expansion of cortical representation of specific body parts (cortical amplification) as well as the parcellation of areas into processing modules.

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We analyzed the organization of the somatosensory and visual cortices of the agouti, a diurnal rodent with a relatively big brain, using a combination of multiunit microelectrode recordings and histological techniques including myelin and cytochrome oxidase staining. We found multiple representations of the sensory periphery in the parietal, temporal, and occipital lobes. While the agouti's primary (V1) and secondary visual areas seemed to lack any obvious modular arrangement, such as blobs or stripes, which are found in some primates and carnivores, the primary somatosensory area (S1) was internally subdivided in discrete regions, isomorphically associated with peripheral structures. Our results confirm and extend previous reports on this species, and provide additional data to understand how variations in lifestyle can influence brain organization in rodents.

The National School Feeding Program (PNAE) is a policy that aims to contribute to the improvement of school feeding. Therefore, the goal of this study was to analyze the menus offered in the year 2014 in public schools of the municipal and state educational network in the municipality of Abaetetuba, Pará, according to the recommendations of the PNAE. For nutritional adequacy, the average energy consumption (Kcal), carbohydrate (g), protein (g), lipid (g), fiber (g), calcium (mg), iron (mg), magnesium (mg), zinc (mg), vitamin A (μg) and vitamin C (mg) of all the menus by educational category, were compared with the values established in Resolution No.26/2013. Nutrient values above or below the recommendation by the PNAE were considered inadequate. The analyzed menus were nutritionally inadequate, which may contribute to the reduction of school performance and student growth, in addition to dietary uncertainty. The elaborate menus were not nutritionally adequate, demonstrating the need to readjust the recommendations and thus guarantee the Human Right to Adequate Food and consequently the improvement of the learning and school performance.

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Este artigo objetiva analisar a importância do Programa Nacional de Alimentação Escolar (PNAE) como instrumento de garantia de segurança alimentar e nutricional e de resiliência social também no rural, sobretudo no atual contexto de pandemia da Covid-19 na Amazônia brasileira. Para atender a este objetivo, as escolhas metodológicas abarcam pesquisas bibliográfica e documental, além de reuniões remotas com atores sociais envolvidos com a operacionalização do PNAE em contexto de pandemia, no estado do Pará. O texto inicia por discutir sucintamente o conceito de políticas públicas, principalmente direcionadas ao Desenvolvimento Rural, e o papel histórico do PNAE no contexto brasileiro, até chegar nas alterações da legislação que guia o Programa, em cenários de pandemia. Posteriormente são descritas as experiências de municípios no Estado do Pará, relacionadas à execução de ações do PNAE durante o período da pandemia. Esse percurso ressalta a importância e potencialidade de expansão das compras públicas de alimentos produzidos localmente e, sobretudo, a necessidade de traçar estratégias de desenvolvimento, que possibilitem a famílias em vulnerabilidade socioeconômica o acesso à alimentação de qualidade, por um lado, e a consolidação de mercados construídos socialmente, com e pela agricultura familiar amazônica.

The plasticity of the central nervous system (CNS) allows the change of neuronal organization and function after environmental stimuli or adaptation after sensory deprivation. The so-called critical period (CP) for neuroplasticity is the time window when each sensory brain region is more sensitive to changes and adaptations. This time window is usually different for each primary sensory area: somatosensory (S1), visual (V1), and auditory (A1). Several intrinsic mechanisms are also involved in the start and end of the CP for neuroplasticity; however, which is its duration in S1, VI, and A1? This systematic review evaluated studies on the determination of these time windows in small rodents. The careful study selection and methodological quality assessment indicated that the CP for neuroplasticity is different among the sensory areas, and the brain maps are influenced by environmental stimuli. Moreover, there is an overlap between the time windows of some sensory areas. Finally, the time window duration of the CP for neuroplasticity is predominant in S1.