Effects of ovariectomy on the inputs from the medial nucleus of the amygdala to the ventromedial nucleus of the hypothalamus in young adult rats.

During puberty, sexual hormones induce crucial changes in neural circuit organization, leading to significant sexual dimorphism in adult behaviours. The ventrolateral division of the ventromedial nucleus of the hypothalamus (VMHvl) is the major neural site controlling the receptive component of female sexual behaviour, which is dependent on ovarian hormones. The inputs to the VMHvl, originating from the medial nucleus of the amygdala (MeA), transmit essential information to trigger such behaviour. In this study, we investigated the projection pattern of the MeA to the VMHvl in ovariectomized rats at early puberty. Six-week-old Sprague-Dawley rats were ovariectomized (OVX) and, upon reaching 90 days of age, were subjected to iontophoretic injections of the neuronal anterograde tracer Phaseolus vulgaris leucoagglutinin into the MeA. Projections from the MeA to the VMHvl and to other structures included in the neural circuit responsible for female sexual behaviour were analysed in the Control and OVX groups. The results of the semi-quantitative analysis showed that peripubertal ovariectomy reduced the density of intra-amygdalar fibres. The stereological estimates, however, failed to find changes in the organization of the terminal fields of nerve fibres from the MeA to the VMHvl in the adult. The present data show that ovariectomized rats during the peripubertal phase did not undergo significant changes in MeA fibres reaching the VMHvl; however, they suggest a possible effect of ovariectomy on MeA connectivity under amygdalar subnuclei.

Cambios metabólicos corticales y resultado clínico en la hidrocefalia normotensiva después de la derivación ventrículo-peritoneal: nuestros resultados preliminares / Cortical metabolic changes and clinical outcome in normal pressure hydrocephalus after ventriculoperitoneal shunt: our preliminary results

INTRODUCCIÓN: Nuestro objetivo fue evaluar los cambios metabólicos corticales y el resultado clínico en los pacientes afectados por la hidrocefalia idiopática de presión normal (iNPH) después de la colocación de una derivación ventriculoperitoneal (VP). MATERIALES Y MÉTODOS: Diez pacientes afectados por la sospecha de iNPH se sometieron a una evaluación de la hidrodinámica del LCR basada en una prueba de infusión lumbar. El principal criterio de selección para la cirugía se basó en la elasticidad intracraneal (EI)>0,30. Todos los sujetos con una EI> 0,30 se sometieron a una exploración PET con 18 fluorodesoxiglucosa (18F-FDG) en la línea de base (PET1) y un mes después de la cirugía (PET2). Además, los mismos pacientes fueron sometidos a una evaluación clínica antes y un mes después de la cirugía mediante pruebas neuropsicológicas y análisis de la marcha. RESULTADOS: Se realizó un número total de 20 exploraciones de PET 18F-FDG en todos los pacientes reclutados. En comparación con la PET1, la PET2 mostró un aumento en el consumo de glucosa en el lóbulo frontal izquierdo y el lóbulo parietal izquierdo en la PET2 en comparación con la PET1 (p < 0,001). Todos los pacientes reclutados presentaron un aumento significativo en las puntuaciones neuropsicológicas (i.e. Batería de evaluación frontal y Evaluación cognitiva de Montreal) y han mejorado clínicamente en el análisis de la marcha. Se encontró una correlación significativa entre el aumento del consumo de glucosa cortical en el área parietal izquierda y la mejoría cognitiva detectable por la evaluación neuropsicológica. CONCLUSIONES: La mejora en 18F-FDG PET del metabolismo de la glucosa podría considerarse un marcador de imagen útil para la evaluación de la respuesta de la iNPH a la derivación ventriculoperitoneal

INTRODUCTION: Our objective was to evaluate the cortical metabolic changes and clinical outcome in patients affected by idiopathic normal pressure hydrocephalus (iNPH) after a placement of ventriculoperitoneal (VP) shunt. MATERIALS AND METHODS: 10 patients affected by suspected iNPH underwent a CSF hydrodynamics evaluation based on a lumbar infusion test (LIT). The main selection criterion for surgery was based on intracranial elasticity (IE)>0.30. All subjects with an IE>0.30 underwent a PET scan with 18 fluorodeoxiglucose (18F-FDG) at baseline (PET1) and 1 month after surgery (PET2). Furthermore, the same patients were submitted to clinical evaluation before and 1 month after surgery through neuropsychological tests and gait analysis. RESULTS: An overall number of 20 18F-FDG PET scans were performed in all the enrolled patients. As compared to PET1, PET2 showed an increase in glucose consumption in the left frontal and left parietal lobe in PET2 as compared to PET1 (P<.001). All the enrolled patients presented a significant increase in neuropsychological scores (i.e Frontal Assessment Battery and Montreal Cognitive Assessment) and have clinically improved at gait analysis. A significant correlation was found between the increase of cortical glucose consumption in the left parietal area and the cognitive improvement as detectable by neuropsychological assessment. CONCLUSIONS: Improvement in 18F FDG PET glucose metabolism could be considered a useful imaging marker for the assessment of iNPH response to VP shunting