Exploring the Intricacies of Neurogenic Niches: Unraveling the Anatomy and Neural Microenvironments

Neurogenesis is the process of forming new neurons from neural stem cells (NSCs). In adults, this process takes place in specific areas of the brain, known as neurogenic niches. These regions have unique anatomical features that have been studied in animal models and in the human brain; however, there are differences between these models that need to be addressed. The most studied areas are the subventricular zone, the lateral and latero-dorsal walls of the lateral ventricles, and the dentate gyrus of the hippocampus (Hp), which are known as the canonical areas. Other, less-studied niches, such as the hypothalamus, the cerebellum, and the amygdala, are known as non-canonical areas. Anatomy occupies a relevant place in adult neurogenesis, in which the tissue architecture and cellular location are necessities for the interaction and release of diverse molecules that allow this phenomenon. The cell arrangement within the niche and the location of the niche itself are of particular relevance to the state in which the NSCs are found. Consequently, the majority of previous discoveries have been related to pathology. While many studies are based on animal models, discoveries related to neurogenesis in humans have also been made; however, in this case, opinions vary, leading to extensive controversy in recent years. In this review, we address the anatomical characteristics of the different brain regions to better understand their relationships within neurogenesis

Chimpanzees organize their social relationships like humans

Human relationships are structured in a set of layers, ordered from higher (intimate relationships) to lower (acquaintances) emotional and cognitive intensity. This structure arises from the limits of our cognitive capacity and the different amounts of resources required by different relationships. However, it is unknown whether nonhuman primate species organize their affiliative relationships following the same pattern. We here show that the time chimpanzees devote to grooming other individuals is well described by the same model used for human relationships, supporting the existence of similar social signatures for both humans and chimpanzees. Furthermore, the relationship structure depends on group size as predicted by the model, the proportion of high-intensity connections being larger for smaller groups

Accidente vascular isquémico por disección de la arteria vertebral

El accidente vascular en los niños no es un evento muy raro, motivo por el cual, el pediatra debería pensar en el mismo ante un déficit neurológico de origen inexplicable. Se presenta el caso clínico de un niño de 7 años de edad con antecedente de traumatismos mínimos que inicia el cuadro con déficit motor progresivo en las 4 extremidades, cefalea intensa y posteriormente, hipertensión arterial severa refractaria al tratamiento. La terapéutica fue conservadora por la cantidad de tiempo transcurrido entre el debut del cuadro y el ingreso a la UTI. Recibió megadosis de corticoides por 3 días, antiagregantes plaquetarios y medicación antihipertensiva múltiple hasta el control de la presión arterial con clonidina. Mediante estudios por imágenes y arteriografía, se diagnosticó: disección de la arteria vertebral derecha y lesión isquémica de la porción superior de la medula e inferior de la protuberancia, descartándose las etiologías cardiaca, vascular, renal, autoinmune, hematológica, e infecciosa, entre otras. El niño egresó del hospital a los 19 días en proceso de recuperación neurológica y a los 30 días ya no presentaba ningún déficit motor. En el presente trabajo se discute la importancia del diagnóstico precoz para instituir la terapéutica adecuada, así como los factores pronósticos

Bioethanol production using high density Eucalyptus crops in Uruguay [Research article]

Experimental scale crops for Eucalyptus grandis, Eucalyptus benthamii, Eucalyptus dunnii and Eucalyptus tereticornis, at 2,220, 4,440 and 6,660 trees ha?1 were established in two soil units, at Paysandú and Tacuarembó, Uruguay. Wood samples were taken from twenty-two-months-old trees, and were used to produce bioethanol by pre-hydrolysis simultaneous saccharyfication and fermentation process (PSSF). Cellulose and lignin content was analyzed. Species and planting density affected biomass production at both sites; the highest value was obtained with E. dunnii at 6,660 trees ha?1 at Paysandú. Cellulose content of wood varied between species at both sites, but only between planting densities at Tacuarembó. The site effect showed that the highest amount of cellulose (14.7 Mg ha?1) was produced at Paysandú. E. benthamii and E. tereticornis wood showed higher lignin contents, conversely, the PSSF yields showed no differences, which led to a bioethanol average of 97 L Mg?1. Bioethanol productivity was associated to the biomass productivity. It was possible to obtain 2,650 L ha?1 of bioethanol using wood from E. benthamii, E. dunnii and E. grandis at 4,440 and 6,660 trees ha?1 at Paysandú, and with E. benthamii at 4,440 and 6,660 trees ha?1, and E. dunnii at 6,660 trees ha?1 at Tacuarembó

Near room temperature dielectric transition in the perovskite formate framework [(CH(3))(2)NH(2)][Mg(HCOO)(3)].

We report that the hybrid organic-inorganic compound [(CH(3))(2)NH(2)][Mg(HCOO)(3)] shows a marked dielectric transition around T(t) ∼ 270 K, associated to a structural phase transition from SG R3[combining macron]c (centrosymmetric) to Cc (non-centrosymmetric). This is the highest T(t) reported so far for a perovskite-like formate that is thus a promising candidate to display electric order very close to room temperature

Chimpanzees organize their social relationships like humans

Human relationships are structured in a set of layers, ordered from higher (intimate relationships) to lower (acquaintances) emotional and cognitive intensity. This structure arises from the limits of our cognitive capacity and the different amounts of resources required by different relationships. However, it is unknown whether nonhuman primate species organize their affiliative relationships following the same pattern. We here show that the time chimpanzees devote to grooming other individuals is well described by the same model used for human relationships, supporting the existence of similar social signatures for both humans and chimpanzees. Furthermore, the relationship structure depends on group size as predicted by the model, the proportion of high-intensity connections being larger for smaller groups