Ultrastructural features and synaptic connections of hilar ectopic granule cells in the rat dentate gyrus are different from those of granule cells in the granule cell layer.

Several investigators have shown the existence of dentate granule cells in ectopic locations within the hilus and molecular layer using both Golgi and retrograde tracing studies but the ultrastructural features and synaptic connections of ectopic granule cells were not previously examined. In the present study, the biocytin retrograde tracing technique was used to label ectopic granule cells following injections into stratum lucidum of CA3b of hippocampal slices obtained from epileptic rats. Electron microscopy was used to study hilar ectopic granule cells that were located 20-40 microm from the granule cell layer (GCL). They had ultrastructural features similar to those of granule cells in the GCL but showed differences, including nuclei that often displayed infoldings and thicker apical dendrites. At their origin, these dendrites were 6 microm in diameter and they tapered down to 2 microm at the border with the GCL. Both biocytin-labeled and unlabeled axon terminals formed exclusively asymmetric synapses with the somata and proximal dendrites of hilar ectopic granule cells. The mean number of axosomatic synapses for these cells was three times that for granule cells in the GCL. Together, these data indicate that hilar ectopic granule cells are postsynaptic to mossy fibers and have less inhibitory input on their somata and proximal dendrites than granule cells in the GCL. This finding is consistent with recent physiological results showing that hilar ectopic granule cells from epileptic rats are more hyperexcitable than granule cells in the GCL

Avaliação do efeito da expansão rápida da maxila no padrão respiratório, por meio da rinomanometria anterior ativa: descrição da técnica e relato de caso Evaluation of the effect of rapid maxillary expansion on the respiratory pattern using active anterior rhinomanometry: case report and description of the technique

A finalidade deste artigo é avaliar o efeito da expansão rápida da maxila (ERM) no padrão respiratório. Por intermédio de um caso clínico, será relatado como indivíduos com atresia da maxila e problemas respiratórios podem se beneficiar com a expansão rápida da maxila. Outro aspecto que deve-se salientar é como profissionais da área da saúde, principalmente ortodontistas e otorrinolaringologistas, têm à sua disposição exames complementares para o diagnóstico do paciente com "Respiração Bucal"<br>The aim of the present investigation is to evaluate the effect of rapid maxillary expansion (RME) on the respiratory pattern. A clinical case is presented to describe how patients with atresic maxilla and respiratory problems can benefit from rapid maxillary expansion. The article highlights that the health professional, mainly the Orthodontist and the Otorhinolaryngologist, may use complementary exams to diagnose a mouth breather patien

Seizure-Induced Axonal Sprouting: Assessing Connections Between Injury, Local Circuits, and Epileptogenesis

Neurons and neural circuits undergo extensive structural and functional remodeling in response to seizures. Sprouting of axons in the mossy fiber pathway of the hippocampus is a prominent example of a seizure-induced structural alteration which has received particular attention because it is easily detected, is induced by intense or repeated brief seizures in focal chronic models of epilepsy, and is also observed in the human epileptic hippocampus. During the last decade the association of mossy fiber sprouting with seizures and epilepsy has been firmly established. Many anatomical features of mossy fiber sprouting have been described in considerable detail, and there is evidence that sprouting occurs in a variety of other pathways in association with seizures and injury. There is uncertainty, however, about how or when mossy fiber sprouting may contribute to hippocampal dysfunction and generation of seizures. Study of mossy fiber sprouting has provided a strong theoretical and conceptual framework for efforts to understand how seizures and injury may contribute to epileptogenesis and its consequences. It is likely that investigation of mossy fiber sprouting will continure to offer significant opportunities for insights into seizure-induced plasticity of neural circuits at molecular, cellular, and systems levels

Percutaneous fixation of selected scaphoid fractures by dorsal approach

The aim of our study was to evaluate clinical, radiological and functional outcomes of selected cases of percutaneous fixation of scaphoid fractures via a dorsal approach. Percutaneous fixation by dorsal approach was done in 32 patients (mean age 32.2 years) involving both fresh and late scaphoid fracture presentations (mean 17 days). Fourteen cases of B1 type, ten cases of B2 and eight cases of C type (Herbert’s classification) were treated. The patients were prospectively followed up clinically and radiologically for a minimum follow-up of 14 months (mean 16 months), and functional outcome and complications were assessed. All fractures united over an average of nine weeks. There was no avascular necrosis or screw cutout with preservation of wrist movement and grip strength. There were no injuries to any at risk anatomical structures. Percutaneous fixation of scaphoid fractures through dorsal approach gives good clinical and functional outcome in acute and chronic scaphoid fractures of B1, B2 and C types (Herbert’s classification)

Is Plasticity of GABAergic Mechanisms Relevant to Epileptogenesis?

Numerous changes in GABAergic neurons, receptors, and inhibitory mechanisms have been described in temporal lobe epilepsy (TLE), either in humans or in animal models. Nevertheless, there remains a common assumption that epilepsy can be explained by simply an insufficiency of GABAergic inhibition. Alternatively, investigators have suggested that there is hyperinhibition that masks an underlying hyperexcitability. Here we examine the status epilepticus (SE) models of TLE and focus on the dentate gyrus of the hippocampus, where a great deal of data have been collected. The types of GABAergic neurons and GABAA receptors are summarized under normal conditions and after SE. The role of GABA in development and in adult neurogenesis is discussed. We suggest that instead of "too little or too much" GABA there is a complexity of changes after SE that makes the emergence of chronic seizures (epileptogenesis) difficult to understand mechanistically, and difficult to treat. We also suggest that this complexity arises, at least in part, because of the remarkable plasticity of GABAergic neurons and GABAA receptors in response to insult or injury