Evaluación temporal del efecto del status epilepticus inducido en la rata en desarrollo en la concentración cerebelar de ácido gama-aminobutírico y glutamato / Time course of the effect of status epilepticus induced in the developing rat on gama-amino butyric acid and glutamate cerebellar concentration

INTRODUCCIÓN: El status epilepticus (SE) es un tipo de actividad epiléptica que causa atrofia cerebelar y pérdida de células de Purkinje en humanos y en animales de experimentación. El cerebelo es una región con alto contenido de ácido gama-aminobutírico (GABA) y glutamato, y algunos estudios refieren cambios en su concentración después de las convulsiones. Sin embargo, hasta la fecha no existen estudios que hayan analizado su efecto en diferentes regiones cerebelares en ratas en desarrollo. El objetivo del presente estudio fue realizar un curso temporal del efecto del SE inducido en ratas Wistar de 14 días de edad (P14) sobre el contenido tisular de GABA y glutamato en el vermis y los hemisferios cerebelares. MÉTODOS: El SE se indujo con el modelo de litio-pilocarpina; las ratas control se inyectaron con salina. Seis h, 24 h o 30 días después del inicio del SE o de la aplicación de solución salina, las ratas se anestesiaron y decapitaron, se extrajo su cerebelo y se separaron el vermis y los hemisferios. Las ratas de ambos grupos se anestesiaron y decapitaron, se extrajo su cerebelo y se separaron el vermis y los hemisferios. Ambas regiones se homogeneizaron (ácido perclórico 0,1 M conteniendo metabisulfito de sodio 4 mM) y centrifugaron, y el sobrenadante se empleó para cuantificar la concentración tisular de GABA y glutamato por cromatografía de líquidos de alta resolución acoplada a un detector fluorométrico. RESULTADOS: El SE no modificó la concentración de GABA y glutamato a los diferentes tiempos de análisis ni en el vermis ni en los hemisferios cerebelares. CONCLUSIONES: El cerebelo en desarrollo es resistente a los cambios neuroquímicos a corto y largo plazo producidos por el SE

INTRODUCTION: Status epilepticus (SE) is an epileptic condition that can cause cerebellar atrophy and loss of Purkinje cells in both humans and research animals. Cerebellum is a region rich in γ-aminobutyric acid (GABA) and glutamate, and some studies have shown that their concentrations may be altered after convulsions. However, there are no studies showing the effect of seizures on different cerebellar regions in developing rats. Time course of the effect of status epilepticus induced in the developing rat on γ-amino butyric acid and glutamate cerebellar concentration. METHODS: SE was induced using the lithium-pilocarpine model; control rats were injected with saline solution. At 6h, 24h, and 1 month after SE o saline injection, rats were anaesthetised with pentobarbital and decapitated, and cerebella were extracted. The vermis and hemispheres were dissected and homogenised in 0.1M perchloric acid containing 4mM sodium bisulfite. Homogenates were centrifuged and supernatant was used to quantify GABA, and glutamate tissue concentrations by HPLC coupled with fluorometric detection. RESULTS: SE did not alter GABA and glutamate tissue concentration in the cerebellar vermis and hemispheres. CONCLUSION: The developing rat cerebellum is resistant to both short- and long-term neurochemical changes induced by SE

Time course of the effect of status epilepticus induced in the developing rat on γ-amino butyric acid and glutamate cerebellar concentration. / Evaluación temporal del efecto del status epilepticus inducido en la rata en desarrollo en la concentración cerebelar de ácido γ-aminobutírico y glutamato.

INTRODUCTION: Status epilepticus (SE) is an epileptic condition that can cause cerebellar atrophy and loss of Purkinje cells in both humans and research animals. Cerebellum is a region rich in γ-aminobutyric acid (GABA) and glutamate, and some studies have shown that their concentrations may be altered after convulsions. However, there are no studies showing the effect of seizures on different cerebellar regions in developing rats. Time course of the effect of status epilepticus induced in the developing rat on γ-amino butyric acid and glutamate cerebellar concentration. METHODS: SE was induced using the lithium-pilocarpine model; control rats were injected with saline solution. At 6h, 24h, and 1 month after SE o saline injection, rats were anaesthetised with pentobarbital and decapitated, and cerebella were extracted. The vermis and hemispheres were dissected and homogenised in 0.1M perchloric acid containing 4mM sodium bisulfite. Homogenates were centrifuged and supernatant was used to quantify GABA, and glutamate tissue concentrations by HPLC coupled with fluorometric detection. RESULTS: SE did not alter GABA and glutamate tissue concentration in the cerebellar vermis and hemispheres. CONCLUSION: The developing rat cerebellum is resistant to both short- and long-term neurochemical changes induced by SE.

La interleucina-1Beta aumenta la muerte neuronal en el giro dentado del hipocampo asociada al estado epiléptico en la rata en desarrollo / Interleukin-1Beta increases neuronal death in the hippocampal dentate gyrus associated with status epilepticus in the developing rat

Introducción: La interleucina 1β (IL-1Beta) aumenta la muerte neuronal necrótica debido al estado epiléptico (EE) en el área CA1 del hipocampo de ratas en desarrollo; sin embargo, se desconoce si ejerce un efecto similar en el giro dentado (GD) hipocampal. El objetivo de esta investigación fue analizar el efecto de IL-1Beta en la muerte neuronal inducida por el EE en el GD de ratas Wistar de 14 días de edad. Métodos: El EE se indujo con el modelo de litio-pilocarpina. Seis horas después del inicio del EE, la IL-1Beta se inyectó intracerebroventricularmente (0, 0,3, 3, 30 o 300 ng/μl); grupos adicionales se inyectaron con el antagonista natural del receptor tipoi (IL-1RI) de IL-1Beta (IL-1Ra, 30 ng/μl) en ausencia o presencia de IL-1Beta (3 ng/μl). La muerte neuronal se evaluó en la capa granular del GD 24 h después del EE mediante la tinción de hematoxilina-eosina. Las células muertas se caracterizaron por presentar citosol eosinofílico y núcleos condensados y fragmentados. Resultados: Se observó un incremento en el número de células eosinofílicas en el GD ipsilateral a la inyección de 3 y 300 ng/μl de IL-1Beta en comparación con el grupo vehículo; en el GD contralateral se observó un efecto similar únicamente con 3 ng/μl de IL-1Beta. La coadministración de IL-1Beta con el IL-1Ra no evitó el aumento en el número de células eosinofílicas. Conclusión: La IL-1Beta aumenta la muerte neuronal con morfología apoptótica provocada por el EE en el GD del hipocampo, mecanismo independiente de la activación del receptor IL-1RI (AU)

Background: Interleukin-1Beta (IL-1Beta) increases necrotic neuronal cell death in the CA1 area after induced status epilepticus (SE) in developing rats. However, it remains uncertain whether IL-1Beta has a similar effect on the hippocampal dentate gyrus (DG). In this study, we analysed the effects of IL-1Beta on 14-day-old Wistar rats experiencing DG neuronal death induced by SE. Methods: SE was induced with lithium-pilocarpine. Six hours after SE onset, a group of pups was injected with IL-1β (at 0, 0.3, 3, 30, or 300 ng/μL) in the right ventricle; another group was injected with IL-1Beta receptor (IL-1R1) antagonist (IL-1Ra, at 30 ng/μL) of IL-1RI antagonist (IL-1Ra) alone, and additional group with 30 ng/μL of IL-1Ra plus 3 ng/μL of IL-1Beta. Twenty-four hours after SE onset, neuronal cell death in the dentate gyrus of the dorsal hippocampus was assessed using haematoxylin-eosin staining. Dead cells showed eosinophilic cytoplasm and condensed and fragmented nuclei. Results: We observed an increased number of eosinophilic cells in the hippocampal DG ipsilateral to the site of injection of 3ng/μL and 300 ng/μL of IL-1Beta in comparison with the vehicle group. A similar effect was observed in the hippocampal DG contralateral to the site of injection of 3 ng/μL of IL-1Beta. Administration of both of IL-1Beta and IL-1Ra failed to prevent an increase in the number of eosinophilic cells. Conclusion: Our data suggest that IL-1Betaincreases apoptotic neuronal cell death caused by SE in the hippocampal GD, which is a mechanism independent of IL-1RI activation (AU)

Interleukin-1ß increases neuronal death in the hippocampal dentate gyrus associated with status epilepticus in the developing rat. / La interleucina-1ß aumenta la muerte neuronal en el giro dentado del hipocampo asociada al estado epiléptico en la rata en desarrollo.

BACKGROUND: Interleukin-1ß (IL-1ß) increases necrotic neuronal cell death in the CA1 area after induced status epilepticus (SE) in developing rats. However, it remains uncertain whether IL-1ß has a similar effect on the hippocampal dentate gyrus (DG). In this study, we analysed the effects of IL-1ß on 14-day-old Wistar rats experiencing DG neuronal death induced by SE. METHODS: SE was induced with lithium-pilocarpine. Six hours after SE onset, a group of pups was injected with IL-1ß (at 0, 0.3, 3, 30, or 300ng/µL) in the right ventricle; another group was injected with IL-1ß receptor (IL-1R1) antagonist (IL-1Ra, at 30ng/µL) of IL-1RI antagonist (IL-1Ra) alone, and additional group with 30ng/µL of IL-1Ra plus 3ng/µL of IL-1ß. Twenty-four hours after SE onset, neuronal cell death in the dentate gyrus of the dorsal hippocampus was assessed using haematoxylin-eosin staining. Dead cells showed eosinophilic cytoplasm and condensed and fragmented nuclei. RESULTS: We observed an increased number of eosinophilic cells in the hippocampal DG ipsilateral to the site of injection of 3ng/µL and 300ng/µL of IL-1ß in comparison with the vehicle group. A similar effect was observed in the hippocampal DG contralateral to the site of injection of 3ng/µL of IL-1ß. Administration of both of IL-1ß and IL-1Ra failed to prevent an increase in the number of eosinophilic cells. CONCLUSION: Our data suggest that IL-1ß increases apoptotic neuronal cell death caused by SE in the hippocampal GD, which is a mechanism independent of IL-1RI activation.