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Nieto E.,University of Alcala | Alajarin R.,University of Alcala | Alvarez-Builla J.,University of Alcala | Larranaga I.,Instituto Tecnologico PET | And 2 more authors.
Synthesis | Year: 2010

A new synthetic approach to the precursor of the hypoxia marker [ 18F]-FMISO has been developed. Three different tosylation methods were studied for the preparation of the key intermediate. The overall yield is markedly higher than the yields reported for previous syntheses. The precursor was used to prepare [18F]-FMISO and the results were comparable to those obtained when a commercial precursor was used. © 2010 Georg Thieme Verlag Stuttgart New York. Source

Garcia-Garcia L.,Complutense University of Madrid | Shiha A.A.,Complutense University of Madrid | Bascunana P.,Complutense University of Madrid | de Cristobal J.,Complutense University of Madrid | And 4 more authors.
Cellular and Molecular Neurobiology | Year: 2015

It has been reported that fluoxetine, a selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitor, has neuroprotective properties in the lithium–pilocarpine model of status epilepticus (SE) in rats. The aim of the present study was to investigate the effect of 5-HT depletion by short-term administration of p-chlorophenylalanine (PCPA), a specific tryptophan hydroxylase inhibitor, on the brain hypometabolism and neurodegeneration induced in the acute phase of this SE model. Our results show that 5-HT depletion did modify neither the brain basal metabolic activity nor the lithium–pilocarpine-induced hypometabolism when evaluated 3 days after the insult. In addition, hippocampal neurodegeneration and astrogliosis triggered by lithium–pilocarpine were not exacerbated by PCPA treatment. These findings point out that in the early latent phase of epileptogenesis, non-5-HT-mediated actions may contribute, at least in some extent, to the neuroprotective effects of fluoxetine in this model of SE. © 2015 Springer Science+Business Media New York Source

Garcia-Garcia L.,Complutense University of Madrid | Delgado M.,Complutense University of Madrid | Al-Sayed A.A.,Complutense University of Madrid | Bascunana P.,Complutense University of Madrid | And 5 more authors.
Molecular Imaging and Biology | Year: 2015

Purpose: p-Chloroamphetamine (PCA) is a neurotoxin that selectively degenerates the serotonin (5-HT) axon terminals. In order to study the brain metabolic consequences induced by serotonergic denervation, a single dose of PCA (2.5 or 10 mg/kg i.p.) was administered to male adult rats.Procedures: In vivo regional brain metabolism was evaluated 3 and 21 days after PCA (2.5 or 10 mg/kg; i.p.) injection by 2-deoxy-2-[18F] fluoro-d-glucose ([18F] FDG) positron emission tomography (PET). At day 22, the following markers of neurotoxicity were determined: (a) 5-HT axon terminal lesion by 5-HT transporter (SERT) autoradiography, (b) reactive gliosis by glial fibrillary acidic protein immunohistochemistry, and (c) eventual neurodegeneration by DAPI/Fluoro-Jade C labeling.Results: An average of 20 % reduction of [18F] FDG uptake in most brain areas was observed at day 21 under 10 mg/kg PCA treatment. Instead, 2.5 mg/kg PCA only reduced metabolic activity in neocortex. Likewise, the high dose of PCA exerted a strong decrease (>30 %) in SERT density in several 5-HT innervated regions, but no effect was found in midbrain raphe nuclei, the main source of serotonergic neurons. Although PCA induced astroglial activation both in hippocampus and cortex in response to axotomy, no signs of neuronal death in these areas were detected.Conclusions: Overall, [18F] FDG PET revealed that the reduction of the brain metabolic activity induced by PCA is related to 5-HT axon terminal lesion, with no apparent affectation of neuronal viability. © 2014, World Molecular Imaging Society. Source

de Cristobal J.,Noscira S.A. | de Cristobal J.,Complutense University of Madrid | Garcia-Garcia L.,Complutense University of Madrid | Delgado M.,Complutense University of Madrid | And 4 more authors.
Current Alzheimer Research | Year: 2014

Increased Glycogen synthase kinase-3 (GSK-3) activity is believed to contribute to the etiology of chronic disorders such as Alzheimer's disease, one of the earliest diseases linked to GSK-3 dysfunction. Numerous mouse models with modified GSK-3 have been generated in order to study the physiology of GSK-3, its implication in diverse pathologies and the potential effect of GSK-3 inhibitors. In this study we have characterised and evaluated the brain metabolic changes induced by GSK-3β overexpression in transgenic mice throughout their lifespan. The conditional Tet/GSK-3β transgenic line used in this study has been previously extensively characterized at the pathological, biochemical and cognitive levels. Now we have investigated the effect GSK-3β overexpression on the 18F-fluoro-deoxyglucose (FDG) uptake by positron emission tomography (PET), taking advantage from this non-invasive technique which has allowed us to track individually the same animals throughout their lives. The results obtained during the longitudinal analysis showed a reduction of metabolic activity in several brain regions, such as cortex, striatum and hippocampus, consistent with the areas where the transgene is being expressed. The reduction of the metabolic activity in these mice is observed from the first time point, performed at the age of 3 months, and maintained throughout the whole study, until the oldest age tested (19 months). This effect seems to be reverted in a satellite group of 3-month transgenic animals treated with the classical GSK-3 inhibitor lithium, as they show higher FDG uptake values compared with untreated age-matched transgenic animals. © 2014 Bentham Science Publishers. Source

De Cristobal J.,Complutense University of Madrid | De Cristobal J.,Noscira S.A. | Garcia-Garcia L.,Complutense University of Madrid | Delgado M.,Complutense University of Madrid | And 4 more authors.
Journal of Alzheimer's Disease | Year: 2014

Abnormal levels and hyperphosphorylation of tau protein have been proposed as the underlying cause of a group of neurodegenerative disorders collectively known as 'tauopathies'. The detrimental consequence is the loss of affinity between this protein and the microtubules, increased production of fibrillary aggregates, and the accumulation of insoluble intracellular neurofibrillary tangles. A similar phenotype can be observed in various preclinical models, which have been generated to study the role of tau protein in neurodegenerative disorders. In this study, we have analyzed the brain metabolic activity in an animal model of tauopathy (tauVLW transgenic mice), which has been previously reported to mimic some of the phenotypic features of these disorders. By using a non-invasive technique, positron emission tomography (PET), a longitudinal non-clinical follow up study was carried out during most of the lifespan of these transgenic mice, from the youth to the senescence stages. The results obtained point out to an aging-dependent decrease in 18F-fluoro- deoxyglucose (FDG) uptake in the cerebral areas analyzed, which was already significant at the adult age, i.e., 11 months, and became much more prominent in the oldest animals (19 months old). This observation correlates well with the histopathological observation of neurodegeneration in brain areas where there is overexpression of tau protein. © 2014 - IOS Press and the authors. Source

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