Sonic hedgehog signaling regulates mode of cell division of early cerebral cortex progenitors and increases

The morphogen Sonic Hedgehog (SHH) plays a critical role in the development of different tissues. In the central nervous system, SHH is well known to contribute to the patterning of the spinal cord and separation of the brain hemispheres. In addition, it has recently been shown that SHH signaling also contributes to the patterning of the telencephalon and establishment of adult neurogenic niches. In this work, we investigated whether SHH signaling influences the behavior of neural progenitors isolated from the dorsal telencephalon, which generate excitatory neurons and macroglial cells in vitro. We observed that SHH increases proliferation of cortical progenitors and generation of astrocytes, whereas blocking SHH signaling with cyclopamine has opposite effects. In both cases, generation of neurons did not seem to be affected. However, cell survival was broadly affected by blockade of SHH signaling. SHH effects were related to three different cell phenomena: mode of cell division, cell cycle length and cell growth. Together, our data in vitro demonstrate that SHH signaling controls cell behaviors that are important for proliferation of cerebral cortex progenitors, as well as differentiation and survival of neurons and astroglial cells.

ANÁLISE COMPARATIVA DO CONHECIMENTO, ATITUDES E PRECONCEITOS DE UNIVERSITÁRIOS DOS CURSOS DE PEDAGOGIA, EDUCAÇÃO FÍSICA E MEDICINA EM RELAÇÃO À EPILEPSIA

Epilepsy is a chronic disorder of the central nervous system, most frequently characterized by abnormal electrical impulses in the brain. It is the oldest recorded neurological disease and has been surrounded by myths, mistaken beliefs and preconceptions. Three professionals work with epileptic patients on a daily basis: teachers, physical educators and physicians . This study aimed to analyze and compare the level of knowledge, preconceptions and attitudes of undergraduate students in the courses of Pedagogy, Physical Education and Medicine, future professionals who will deal with epileptic patients. This descriptive observational study was conducted with 286 university undergraduates of both sexes (women 99/34.6% and men 187/65.4%) from the first to fourth year of Pedagogy, Physical Education and Medicine courses at the Universidade Estadual Rio Grande do Norte (UERN), with mean age of 23 years. A validated and adapted 17-question questionnaire, divided into nine knowledge-based questions, five related to preconceptions and three on attitudes, was applied. Results allowed elaboration of a manuscript entitled Comparative Analysis of Knowledge, Attitude and Preconceptions in University Undergraduates of Pedagogy, Physical Education and Medicine Courses in Relation to Epilepsy. The findings of this article show that knowledge of epilepsy in the three groups is very satisfactory. The low level of preconception indicates that educational or clarifying information is being transmitted, albeit by television, a layman s information vehicle, which has undoubtedly contributed to reducing the stigma of epilepsy through educational information. Results also suggest a lack of knowledge on how to act during a seizure, especially in education professionals. Although there are limitations in our sample, the relevance and contribution of this study is to call attention to the importance and need for these future professionals to be informed and learn correct attitudes with respect to epilepsy during their academic formation. This is essential at a time when the disease is being brought out of the shadows. This research was supported by the Office of the Dean of Teaching, and Deans of Pedagogy, Physical Education and Medicine at UERN. The research was made possible by the multidisciplinary interaction among a physical educator, child neurologist and statistician, all contributing to achieving the aims set out here

Um sistema inteligente de classificação de sinais de EEG para Interface Cérebro-Computador

The Brain-Computer Interfaces (BCI) have as main purpose to establish a communication path with the central nervous system (CNS) independently from the standard pathway (nervous, muscles), aiming to control a device. The main objective of the current research is to develop an off-line BCI that separates the different EEG patterns resulting from strictly mental tasks performed by an experimental subject, comparing the effectiveness of different signal-preprocessing approaches. We also tested different classification approaches: all versus all, one versus one and a hierarchic classification approach. No preprocessing techniques were found able to improve the system performance. Furthermore, the hierarchic approach proved to be capable to produce results above the expected by literature

Delimitação dos grupamentos serotoninérgicos/núcleos da rafe do mocó (kerodon rupestris): citoarquitetura e imunoistoquímica para serotonina

Serotonin or 5-hydroxytryptamine (5-HT) is a substance found in many tissues of the body, including as a neurotransmitter in the nervous system, in which may exert varied post-synaptic actions. Inside the neuro-axis, the location of 5-HT neurons is almost restricted to the raphe nuclei of the brainstem, such that 5-HT-immunoreactivity can be considered a marker of the raphe nuclei. The raphe nuclei are located in the brainstem, at or near the midline. The serotonergic groups were originally alphanumerically classified as B1 to B9 towards caudorrostral in rats and can be divided into upper and lower groups. In this study the distribution of serotonergic neurons was studied using immunohistochemistry in the brain of the rock cavy (Kerodon rupestris), a species of rodent endemic to Northeastern Brazil. The cytoarchitectonic location of serotonergic neurons was established in series of adjacent coronal and sagittal sections stained by the Nissl method and immunohistochemistry for 5-HT. Thus, we defined the raphe rostral linear, caudal linear, dorsal, median, and paramedian pontine raphe nuclei, and B9 cluster, constituting the rostral group, and the interpositus, magnus, obscure and palidus, constituting the caudal part of the group, comparable to which has been described for other mammalian species

Análise imunoistoquímica da distribuição de Serotonina, transportador de serotonina e receptores de serotonina no hipotálamo do sagui (callithrix jacchus)

The hypothalamus is a diencephalic portion located around the third ventricle below the hypothalamic sulcus, limited by the optic chiasm, and by the mammillary bodies, acting as a center that integrates behavioral and homeostatic functions. Serotonin is a neurotransmitter produced in limited sites in the midbrain and brain stem, but is distributed throughout the central nervous system and has many functions, acting through specific receptors that are also distributed throughout the nervous system. Using immunohistochemical techniques, the aim of this study was to delineate the hypothalamic nuclei of the marmoset (Callithrix jacchus) and study the distribution of serotonin transporter and serotonin receptors in the hypothalamus of this species. We used the Nissl method to determine the cytoarchitecture of the hypothalamic nuclei, and immunohistochemistry to reveal the presence of NeuN as a method to determine the contours of the hypothalamic nuclei. As a result, we found serotonin containing fibers and terminals throughout the rostrocaudal extent of the hypothalamus, more concentrated in some nuclei, and even absent in some. Like serotonin, serotonin transporter was observed between pre-optic area and tuberal region of the hypothalamus, in densities and distribution similar to serotonin. The 5-HT1A and 5-HT1B receptors were found with minor differences among itselves regarding the disposition and intensity of staining.

Investigação da capacidade intelectiva de pacientes pediátricos diagnosticados com tumores de fossa posterior

Central Nervous System are the most common pediatric solid tumors. 60% of these tumors arise in posterior fossa, mainly in cerebellum. The first therapeutic approach is surgical resection. Malignant tumors require additional strategies - chemotherapy and radiotherapy. The increasing survival evidences that childhood brain tumors result in academic and social difficulties that compromise the quality of life of the patients. This study investigated the intellectual functioning of children between 7 to 15 years diagnosed with posterior fossa tumors and treated at CEHOPE - Recife / PE. 21 children were eligible - including 13 children with pilocytic astrocytoma (G1) who underwent only surgery resection, and eight children with medulloblastoma (G2) - submitted to surgical resection, chemotherapy and craniospinal radiotherapy. Participants were evaluated by the Wechsler Intelligence Scale for Children - WISC-III. Children of G1 scored better than children of G2. Inferential tools (Mann-Whitney Ü Test) identified significant diferences (p ≤ 0.05) between the Performance IQ (PIQ) and Processing Speed Index (PSI) as a function of treatment modality; Full Scale IQ (FSIQ), PIQ and PSI as a function of parental educational level; PIQ, FSIQ, IVP and Freedom from Distractibility (FDI) as a function of time between diagnosis and evaluation. These results showed the late and progressive impact of radiotherapy on white matter and information processing speed. Furthermore, children whose parents have higher educational level showed better intellectual performance, indicating the influence of xxii socio-cultural variables on cognitive development. The impact of cancer and its treatment on cognitive development and learning should not be underestimated. These results support the need to increase the understanding of such effects in order to propose therapeutic strategies which ensure that, in addition to the cure, the full development of children with this pathology