RESUMEN

PURPOSES: Demonstrate that transcranial ultrasonography (TUS) scanning is viable and useful as a diagnostic method in experimental hydrocephalus, as well as to compare measurements of cerebral and ventricular width obtained from TUS scans of hydrocephalic rats with post-mortem anatomical specimens, aiming for the development of accurate criteria to establish ventricular enlargement and progression of hydrocephalus subsequently. METHODS: Thirty-five male Wistar rats were used. Following hydrocephalus induction, they underwent a transcranial ultrasound scan to measure cerebral and ventricular dimensions, in the fourth and 21 post-induction days. By the end of the experiments, measurements obtained from TUS scans were compared with actual values as seen in the post-mortem specimens of each animal. RESULTS: Ventricular dilation could be clearly visualized in hydrocephalic animals. We performed intraclass correlation coefficient and linear regression analyses that have demonstrated a precise correlation between measurements of TUS scans and post-mortem specimens; we have found a similarity of 0,95 for the cerebral diameter and 0,97 for ventricular width. CONCLUSIONS: Transcranial ultrasonography is a useful and reliable diagnostic tool for experimental hydrocephalus; also, it can be used to assess the progression of ventriculomegaly in animal models of hydrocephalus.

Asunto(s)

Hidrocefalia , Animales , Ventrículos Cerebrales/diagnóstico por imagen , Hidrocefalia/diagnóstico por imagen , Masculino , Proyectos Piloto , Ratas , Ratas Wistar , Ultrasonografía

RESUMEN

The tuberous sclerosis complex (TSC), focal cortical dysplasia IIB (FCD IIB), and hemimegalencephaly (HME) exhibit similar molecular features that are dependent on the hyperactivation of the mTOR pathway. They are all associated with refractory epilepsy and the need for surgical resection with varying outcomes. The phosphorylated protein S6 (pS6) is a downstream target of mTOR, whose increased expression might indicate mTOR hyperactivation, but which is also present when there is no alteration in the pathway (such as in FCD type I). We have performed immunohistochemical marking and quantification of pS6 in resected brain specimens of 26 patients clinically and histologically diagnosed with TSC, FCD IIB, or HME and compared this data to a control group of 25 patients, to measure the extent of pS6 positivity and its correlation with clinical aspects. Our results suggest that pS6 may serve as a reliable biomarker in epilepsy and that a greater percentage of pS6 marking can relate to more severe forms of mTOR-dependent brain anomalies.

Asunto(s)

Biomarcadores/metabolismo , Epilepsia Refractaria/metabolismo , Proteína S6 Ribosómica/metabolismo , Adolescente , Niño , Preescolar , Epilepsia Refractaria/etiología , Epilepsia Refractaria/cirugía , Epilepsia/complicaciones , Epilepsia/metabolismo , Epilepsia/cirugía , Femenino , Hemimegalencefalia/complicaciones , Hemimegalencefalia/metabolismo , Hemimegalencefalia/cirugía , Humanos , Lactante , Masculino , Malformaciones del Desarrollo Cortical de Grupo I/complicaciones , Malformaciones del Desarrollo Cortical de Grupo I/metabolismo , Malformaciones del Desarrollo Cortical de Grupo I/cirugía , Fosforilación , Esclerosis Tuberosa/complicaciones , Esclerosis Tuberosa/metabolismo , Esclerosis Tuberosa/cirugía

RESUMEN

In hydrocephalus, the progressive accumulation of cerebrospinal fluid (CSF) causes dilatation of the lateral ventricles affecting the third ventricle and diencephalic structures such as the hypothalamus. These structures play a key role in the regulation of several neurovegetative functions by the production of the hormones. Since endocrine disturbances are commonly observed in hydrocephalic children, we investigated the impact of progressive ventricular dilation on the hypothalamus of infant rats submitted to kaolin-induced hydrocephalus. Seven-day-old infant rats were submitted to hydrocephalus induction by kaolin 20% injection method. After 14 days, the animals were decapitated and brain was collected to analyze mitochondrial function, neuronal activity by acetylcholinesterase (AChE) enzyme, oxidative damage, glial activation, and, neurotransmission-related proteins and anti-apoptotic processes in the hypothalamus. The hydrocephalic animals showed reduction in respiratory rates in the States of phosphorylation (P < 0.01) and non-phosphorylation (P < 0.05); increase in AChE activity in both the cytosol (P < 0.05) and the membrane (P < 0.01); decrease in synaptophysin (P < 0.05) and Bcl-2 (P < 0.05) contents and; increase in protein carbonyl (P < 0.01), GFAP (P < 0.01) and Iba-1 (P < 0.05) levels. The results demonstrate that ventricular dilation causes hypothalamic damage characterized by cholinergic dysfunction and suggests further investigation of the synthesis and secretion of hormones to generate new approaches and to assist in the treatment of hydrocephalic patients with hormonal alterations.

Asunto(s)

Acetilcolinesterasa/metabolismo , Hidrocefalia/metabolismo , Hipotálamo/fisiopatología , Acetilcolinesterasa/fisiología , Animales , Animales Recién Nacidos , Encéfalo/fisiopatología , Ventrículos Cerebrales/fisiopatología , Modelos Animales de Enfermedad , Hidrocefalia/fisiopatología , Hipotálamo/metabolismo , Caolín/efectos adversos , Caolín/farmacología , Ventrículos Laterales/fisiopatología , Masculino , Neuronas , Ratas , Ratas Wistar

RESUMEN

Background. As the survival of preterm infants has increased significantly, germinal matrix hemorrhage (GMH) has become an important public health issue. Nevertheless, treatment strategies for the direct neuronal injury are still scarce. The present study aims to analyze the neuroprotective properties of cannabidiol in germinal matrix hemorrhage. Methods. 112 Wistar rat pups (P7) were submitted to an experimental collagenase induced model of GMH. Inflammatory response and neuronal death were analyzed both at the perilesional area as at the distant ipsilateral CA1 hippocampal area. Immunohistochemistry for GFAP and caspase 3 was used. The ipsilateral free water content was assessed for stimation of cerebral edema, and neurodevelopment and neurofunctional tests were conducted. Results. Reduction of reactive astrocytosis was observed both in the perilesional area 24 hours and 14 days after the hemorrhage lesion (p < 0.001) and in the Stratum oriens of the ipsilateral hippocampal CA1 14 days after the hemorrhage lesion (p < 0.05) in the treated groups. Similarly, there was a reduction in the number of Caspase 3-positive astrocytes in the perilesional area in the treated groups 24 hours after the hemorrhage lesion (p < 0.001). Finally, we found a significant increase in the weight of the rats treated with cannabidiol. Conclusion. The treatment of GMH with cannabidiol significantly reduced the number of apoptotic cells and reactive astrocytes in the perilesional area and the ipsilateral hippocampus. In addition, this response was sustained 14 days after the hemorrhage. These results corroborate our hypothesis that cannabidiol is a potential neuroprotective agent in the treatment of germinal matrix hemorrhage.

Asunto(s)

Apoptosis/efectos de los fármacos , Cannabidiol/farmacología , Hemorragia Cerebral/tratamiento farmacológico , Hemorragias Intracraneales/tratamiento farmacológico , Animales , Animales Recién Nacidos , Encéfalo/efectos de los fármacos , Encéfalo/patología , Edema Encefálico/complicaciones , Edema Encefálico/patología , Cannabidiol/administración & dosificación , Hemorragia Cerebral/complicaciones , Hemorragia Cerebral/patología , Modelos Animales de Enfermedad , Hemorragias Intracraneales/complicaciones , Masculino , Fármacos Neuroprotectores/farmacología , Ratas Wistar

RESUMEN

PURPOSE: We investigated the possible beneficial effects that hyperbaric oxygen therapy could offer in different brain structures affected by ventriculomegaly in pup rats submitted to experimental hydrocephalus. METHODS: Seven-day-old Wistar rats were submitted to hydrocephalus by intracisternal injection of 10% kaolin into the cisterna magna. The animals were divided into four groups: control (n = 5); control with HBOT (3ATA/2 h/day) (n = 5); untreated hydrocephalic (n = 10); hydrocephalic treated with HBOT (3ATA/2 h/day) (n = 10). The treatment with HBOT was performed daily for 14 days post-induction of hydrocephalus. To evaluate the response to treatment, behavioral tests (open field, Morris water maze, and activity monitor) were performed. After 14 days, the animals were euthanized, and the brain was removed for histological (hematoxylin-eosin and solochrome-cyanine) and immunohistochemical (GFAP and Ki-67) studies. RESULTS: The hyperbaric treatment, although not causing changes in ventricular enlargement, resulted in a significant improvement in the behavioral performance (p = 0.0001), with greater agility and exploration of the environment, preservation of spatial memory, and greater learning capacity (p = 0.0001). Through the immunohistochemical study, the astrocytic activity (glial fibrillary acidic protein) in the corpus callosum (p = 0.0001) and in the germinative matrix (p = 0.0033) was significantly reduced as compared to that in the H group. CONCLUSION: The results suggest that hyperbaric treatment bettered the behavioral performance and offered benefits to the structures affected by the ventricular increase helping to recover the brain damages. In this way, the HBOT it can be considered an adjuvant therapy for the treatment of hydrocephalus.

Asunto(s)

Lesiones Encefálicas/patología , Gliosis/patología , Hidrocefalia/patología , Oxigenoterapia Hiperbárica/métodos , Animales , Lesiones Encefálicas/etiología , Hidrocefalia/complicaciones , Masculino , Ratas , Ratas Wistar

RESUMEN

PURPOSE: We investigate the effects of environmental enrichment (EE) on morphological alterations in different brain structures of pup rats submitted to hydrocephalus condition. METHODS: Hydrocephalus was induced in 7-day-old pup rats by injection of 20% kaolin into the cisterna magna. Ventricular dilatation and magnetization transfer to analyze myelin were assessed by magnetic resonance. Hydrocephalic and control rats exposed to EE (n = 10 per group) were housed in cages with a tunnel, ramp, and colored plastic balls that would emit sound when touched. The walls of the housing were decorated with colored adhesive tape. Moreover, tactile and auditory stimulation was performed daily throughout the experiment. Hydrocephalic and control rats not exposed to EE (n = 10 per group) were allocated singly in standard cages. All animals were weighed daily and exposed to open-field conditions every 2 days until the end of the experiment when they were sacrificed and the brains removed for histology and immunohistochemistry. Solochrome cyanine staining was performed to assess the thickness of the corpus callosum. The glial fibrillary acidic protein method was used to evaluate reactive astrocytes, and the Ki67 method to assess cellular proliferation in the subventricular zone. RESULTS: The hydrocephalic animals exposed to EE showed better performance in Open Field tests (p < 0.05), while presenting lower weight gain. In addition, these animals showed better myelination as revealed by magnetization transfer (p < 0.05). Finally, the EE group showed a reduction in reactive astrocytes by means of glial fibrillary acidic protein immunostaining and preservation of the proliferation potential of progenitor cells. CONCLUSION: The results suggest that EE can protect the developing brain against damaging effects caused by hydrocephalus.

Asunto(s)

Lesiones Encefálicas/diagnóstico por imagen , Lesiones Encefálicas/prevención & control , Ambiente , Hidrocefalia/diagnóstico por imagen , Factores de Edad , Animales , Animales Recién Nacidos , Lesiones Encefálicas/patología , Conducta Exploratoria/fisiología , Hidrocefalia/patología , Masculino , Ratas , Ratas Wistar

RESUMEN

PURPOSE: We investigated the possible neuroprotective effects of the free radical scavenger edaravone in experimental hydrocephalus. METHODS: Seven-day-old Wistar rats were divided into three groups: control group (C), untreated hydrocephalic (H), and hydrocephalic treated with edaravone (EH). The H and EH groups were subjected to hydrocephalus induction by 20% kaolin intracisternal injection. The edaravone (20 mg/kg) was administered daily for 14 days from the induction of hydrocephalus. All animals were daily weighed and submitted to behavioral test and assessment by magnetic resonance imaging. After 14 days, the animals were sacrificed and the brain was removed for histological, immunohistochemical, and biochemical studies. RESULTS: The gain weight was similar between groups from the ninth post-induction day. The open field test performance of EH group was better (p < 0.05) as compared to untreated hydrocephalic animals. Hydrocephalic animals (H and EH) showed ventricular ratio values were higher (p < 0.05), whereas magnetization transfer values were lower (p < 0.05), as compared to control animals. Astrocyte activity (glial fibrillary acidic protein) and apoptotic cells (caspase-3) of EH group were decreased on the corpus callosum (p > 0.01), germinal matrix (p > 0.05), and cerebral cortex (p > 0.05), as compared to H group. CONCLUSIONS: We have demonstrated that administration of edaravone for 14 consecutive days after induction of hydrocephalus reduced astrocyte activity and that it has some beneficial effects over apoptotic cell death.

Asunto(s)

Antipirina/análogos & derivados , Apoptosis/efectos de los fármacos , Gliosis/tratamiento farmacológico , Gliosis/patología , Hidrocefalia/complicaciones , Animales , Antidiarreicos/toxicidad , Antipirina/farmacología , Antipirina/uso terapéutico , Peso Corporal/efectos de los fármacos , Caspasa 3/metabolismo , Modelos Animales de Enfermedad , Edaravona , Conducta Exploratoria/efectos de los fármacos , Depuradores de Radicales Libres/farmacología , Depuradores de Radicales Libres/uso terapéutico , Proteína Ácida Fibrilar de la Glía/metabolismo , Gliosis/etiología , Hidrocefalia/inducido químicamente , Hidrocefalia/diagnóstico por imagen , Etiquetado Corte-Fin in Situ , Caolín/toxicidad , Imagen por Resonancia Magnética , Masculino , Neuroglía/efectos de los fármacos , Neuroglía/patología , Fosfopiruvato Hidratasa/metabolismo , Ratas , Ratas Wistar

RESUMEN

The search for a completely noninvasive intracranial pressure (ICPni) monitoring technique capable of real-time digitalized monitoring is the Holy Grail of brain research. If available, it may facilitate many fundamental questions within the range of ample applications in neurosurgery, neurosciences and translational medicine, from pharmaceutical clinical trials, exercise physiology, and space applications. In this work we compare invasive measurements with noninvasive measurements obtained using the proposed new noninvasive method. Saline was infused into the spinal channel of seven rats to produce ICP changes and the simultaneous acquisition of both methods was performed. The similarity in the invasive and noninvasive methods of ICP monitoring was calculated using Pearson's correlation coefficients (r). Good agreement between measures < r > = 0.8 ± 0.2 with a range 0.28-0.96 was shown.

Asunto(s)

Hipertensión Intracraneal/fisiopatología , Presión Intracraneal/fisiología , Cráneo/fisiopatología , Animales , Diseño de Equipo , Hipertensión Intracraneal/diagnóstico , Monitoreo Fisiológico , Ratas , Cráneo/fisiología

RESUMEN

BACKGROUND: Hydrocephalus is a complex disease that affects cerebrospinal fluid (CSF) dynamics and is very common in children. To this date, CSF shunting is still the standard treatment for childhood hydrocephalus, but, nevertheless, the effects of such an operation on the developing brain are widely unknown. To help overcome this, experimental models of CSF shunts are surely very useful tools. OBJECTIVE: The objective of this study was to describe a feasible and reliable technique of an adapted ventricular-subcutaneous shunt for the treatment of kaolin-induced hydrocephalus in young rats. METHODS: We developed a ventricular-subcutaneous shunt (VSCS) technique which was used in 31 Wistar young rats with kaolin-induced hydrocephalus. Hydrocephalus was induced at 7 days of age, and shunt implantation was performed 7 days later. Our technique used a 0.7-mm gauge polypropylene catheter tunneled to a subcutaneous pocket created over the animal's back and inserted into the right lateral ventricle. All animals were sacrificed 14 days after shunt insertion. RESULTS: Twenty-four rats survived and remained well until the study was ended. No major complications were seen. Their weight gain went back to normal. They all underwent ambulatory behavioral testing prior and after VSCS, which showed improvement in their motor skills. We have also obtained magnetic resonance (MR) scans of 16 pups confirming reduction of ventricular size after shunting and indicating effective treatment. Histopathological analysis of brain samples before and after shunting showed reversion of ependymal and corpus callosum disruption, as well as fewer reactive astrocytes in shunted animals. CONCLUSIONS: An experimental CSF shunt technique was devised. Excessive CSF of hydrocephalic rats is diverted into the subcutaneous space where it can be resorbed. This technique has a low complication rate and is effective. It might be applied to various types of experimental studies involving induction and treatment of hydrocephalus.

Asunto(s)

Derivaciones del Líquido Cefalorraquídeo/métodos , Modelos Animales de Enfermedad , Hidrocefalia/cirugía , Análisis de Varianza , Animales , Antidiarreicos/toxicidad , Encéfalo/diagnóstico por imagen , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Catéteres , Proteína Ácida Fibrilar de la Glía/metabolismo , Hidrocefalia/inducido químicamente , Hidrocefalia/diagnóstico por imagen , Infusiones Subcutáneas , Caolín/toxicidad , Imagen por Resonancia Magnética , Ratas , Ratas Wistar

RESUMEN

Hydrocephalus is a common neurological condition in children characterized by an imbalance between the production and absorption of cerebrospinal fluid (CSF), causing abnormal fluid accumulation in the brain cavities. Shunt systems have been used to drain excess CSF and to prevent progressive ventricular enlargement. However, despite improvements in these systems, neurological and structural changes cannot always be reversed. Our aim was to evaluate the magnetization transfer ratio as a biomarker for the effectiveness of a CSF shunt system to treat neurological and behavioral disorders observed in experimental hydrocephalus. Seven-day-old Wistar rats were used in this study. The pups were subjected to hydrocephalus induction via 20% kaolin intracisternal injection. After confirmation of ventriculomegaly by magnetic resonance imaging (MRI), a group of animals underwent placement of a ventriculosubcutaneous shunt (VSS). The reduction in ventricular size in hydrocephalic rats operated with functional VSS was observed as a decrease in ventricular ratio values and preservation of the corpus callosum thickness. Magnetization transfer values were significantly increased and matched to the recovery process of axonal myelination observed based on more-intense blue staining by solochrome cyanin. The histopathological analysis revealed a reduction in reactive astrocytes by means of GFAP immunostaining. The hydrocephalic rats operated with functional VSS also showed significant progress in motor and exploratory activities, similar to the control animals, at the end of the experiment. In conclusion, the VSS system employed 7 days after hydrocephalus induction was able to prevent structural damage and restore the axonal myelination process in periventricular structures by stabilizing and reducing the ventricular enlargement, and the results are in accordance with the magnetization transfer ratio in MRI.

Asunto(s)

Axones/fisiología , Conducta Animal/fisiología , Ventrículos Cerebrales/patología , Derivaciones del Líquido Cefalorraquídeo/métodos , Hidrocefalia/cirugía , Vaina de Mielina/fisiología , Animales , Biomarcadores , Ventrículos Cerebrales/cirugía , Modelos Animales de Enfermedad , Imagen por Resonancia Magnética , Masculino , Ratas , Ratas Wistar

RESUMEN

PURPOSE: Hydrocephalus causes countless cerebral damages, especially on the structures around the ventricles. Hydrocephalic children present deficiencies in the nonverbal skills more than in the verbal skills, and not always revertible with an early treatment. As the corpus callosum has an important role in the nonverbal acquisition it is possible that the injuries in this structure are responsible for the cognitive dysfunctions of these children. This present study tries to establish the alterations caused by hydrocephalus on the corpus callosum of developing Wistar rats, induced by intracisternal injection of kaolin. METHODS : Seven, fourteen and twenty one days after the injection, the animals were killed, and the corpus callosum was dissected and prepared for the study of the axonal fibers. RESULTS AND CONCLUSION: The seven-day old rats in hydrocephalus development presented a delay in myelination in relation to the control rats. With the fourteen-day old rats in hydrocephalus development the corpus callosum showed a recovery of myelin, but with the twenty one-day old rats in hydrocephalus development the axonal fibers were damaged and reduced in number.

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OBJETIVO: A hidrocefalia causa inúmeros danos cerebrais, especialmente nas estruturas ao redor dos ventrículos cerebrais. As crianças com hidrocefalia apresentam déficits nas aquisições não verbais mais do que nas verbais, nem sempre revertidos com o tratamento precoce. Como o corpo caloso tem um papel essencial nas aquisições não verbais, é provável que as lesões nesta estrutura estejam envolvidas com as disfunções cognitivas dessas crianças. Este trabalho procura estabelecer as alterações causadas pela hidrocefalia, induzida pela injeção de caulim intracisternal ao corpo caloso de ratos Wistar em desenvolvimento. MÉTODOS: Sete, 14 e 21 dias após a injeção, os animais foram sacrificados, sendo o corpo caloso dissecado e processado para estudo das fibras axonais. RESULTADOS E CONCLUSÕES: Os ratos com 7 dias de evolução da hidrocefalia apresentaram um atraso na mielinização em relação aos controles. Em ratos com 14 dias de evolução da hidrocefalia, o corpo caloso mostrou recuperação da mielina, mas em ratos com hidrocefalia com 21 dias de evolução, as fibras apresentavam-se lesadas e reduzidas em número.

RESUMEN

PURPOSE: Hydrocephalus causes countless cerebral damages, especially on the structures around the ventricles. Hydrocephalic children present deficiencies in the nonverbal skills more than in the verbal skills, and not always revertible with an early treatment. As the corpus callosum has an important role in the nonverbal acquisition it is possible that the injuries in this structure are responsible for the cognitive dysfunctions of these children. This present study tries to establish the alterations caused by hydrocephalus on the corpus callosum of developing Wistar rats, induced by intracisternal injection of kaolin. METHODS : Seven, fourteen and twenty one days after the injection, the animals were killed, and the corpus callosum was dissected and prepared for the study of the axonal fibers. RESULTS AND CONCLUSION: The seven-day old rats in hydrocephalus development presented a delay in myelination in relation to the control rats. With the fourteen-day old rats in hydrocephalus development the corpus callosum showed a recovery of myelin, but with the twenty one-day old rats in hydrocephalus development the axonal fibers were damaged and reduced in number.

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OBJETIVO: A hidrocefalia causa inúmeros danos cerebrais, especialmente nas estruturas ao redor dos ventrículos cerebrais. As crianças com hidrocefalia apresentam déficits nas aquisições não verbais mais do que nas verbais, nem sempre revertidos com o tratamento precoce. Como o corpo caloso tem um papel essencial nas aquisições não verbais, é provável que as lesões nesta estrutura estejam envolvidas com as disfunções cognitivas dessas crianças. Este trabalho procura estabelecer as alterações causadas pela hidrocefalia, induzida pela injeção de caulim intracisternal ao corpo caloso de ratos Wistar em desenvolvimento. MÉTODOS: Sete, 14 e 21 dias após a injeção, os animais foram sacrificados, sendo o corpo caloso dissecado e processado para estudo das fibras axonais. RESULTADOS E CONCLUSÕES: Os ratos com 7 dias de evolução da hidrocefalia apresentaram um atraso na mielinização em relação aos controles. Em ratos com 14 dias de evolução da hidrocefalia, o corpo caloso mostrou recuperação da mielina, mas em ratos com hidrocefalia com 21 dias de evolução, as fibras apresentavam-se lesadas e reduzidas em número.