Suchergebnisse

3,4-Methylenedioxymethamphetamine (MDMA, 'ecstasy') is a recreational drug widely used by adolescents and young adults. Although its rewarding effects are well established, there is controversy on its addictive potential. We aimed to compare the consequences of active and passive MDMA administration on gene expression in the mouse brain since all previous studies were based on passive MDMA administration. We used a yoked-control operant intravenous self-administration paradigm combined with microarray technology. Transcriptomic profiles of ventral striatum, frontal cortex, dorsal raphe nucleus and hippocampus were analysed in mice divided in contingent MDMA, yoked MDMA and yoked saline groups, and several changes were validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The comparison of contingent MDMA and yoked MDMA vs. yoked saline mice allowed the identification of differential expression in several genes, most of them with immunological and inflammatory functions, but others being involved in neuroadaptation. In the comparison of contingent MDMA vs. yoked MDMA administration, hippocampus and the dorsal raphe nucleus showed statistically significant changes. The altered expression of several genes involved in neuroadaptative changes and synapse function, which may be related to learning self-administration behaviour, could be validated in these two brain structures. In conclusion, our study shows a strong effect of MDMA administration on the expression of immunological and inflammatory genes in all the four brain regions studied. In addition, experiments on MDMA self-administration suggest that the dorsal raphe nucleus and hippocampus may be involved in active MDMA-seeking behaviour, and show specific alterations on gene expression that support the addictive potential of this drug. ; This work was supported by the Spanish 'Ministerio de Ciencia e Innovación (MICINN)'(SAF2007-64062), 'Instituto de Salud Carlos III' (RD06/001/001 and PI070709), the Catalan Government (SGR2009-00131 and SGR2009-00971), the ICREA Foundation (ICREA Academia-2008), 'Plan Nacional Sobre Drogas' (PNSD#2009/022 and PNSD#2009/026), Fundació 'La Marató/nde TV3' (2007) and the DG Research of the European Commission (GENADDICT, LSHM-CT-2004-05166; and PHECOMP, LSHM-CT-2007-037669). Partial support from FEDER funds is/nalso acknowledged. MR is a recipient of a Miguel de Servet contract from 'Instituto de Salud Carlos III-MICINN' (Spain) and NF-C was supported by a fellowship from the Biomedical Network/nResearch Centre on Rare Diseases (CIBERER)

Frustration represents a particular aspect of the addictive process that is related to loss of control when the expected reward is not obtained. We aim to study the consequences of frustrated expected reward on gene expression in the mouse brain. For this purpose, we used an operant model of frustration using palatable food as reward combined with microarrays. Transcriptomic profiles of frontal cortex, ventral striatum and hippocampus were analysed in five groups of mice: (1) positive control receiving palatable food and the cue light as conditioned stimulus; (2) frustrated group only receiving the cue light; (3) extinction learning group that did not receive palatable food nor the light; (4) negative control that never received the reinforcer nor the light during the whole experiment; and (5) yoked that received palatable food passively. Gene expression changes produced by frustration were revealed in the frontal cortex and ventral striatum, but not in the hippocampus. Most of the changes, such as the modification of the dopamine-DARPP-32 signalling pathway, were common in both areas and estimated to have neuronal origin. Extinction learning induced transcriptional changes only in the ventral striatum, with most genes showing down-regulation and without alteration in the dopamine-DARPP-32 signalling pathway. Active palatable food-seeking behaviour induced changes in gene expression in ventral striatum mainly affecting cell communication. In conclusion, frustration behaviour-induced changes in frontal cortex and ventral striatum mainly related to dopamine-DARPP-32 signalling that could play an important role in the loss of behavioural control during the addictive processes. ; This work was supported by the Spanish 'Instituto de Salud Carlos III' (RTA,RD06/001/001andPI11/01629), the Spanish 'Ministerio de Ciencia e Innovación' (SAF2007-64062 and SAF2012-33484), the Spanish 'Ministerio de Sanidad y Política Social' (Plan Nacional Sobre Drogas, no. 2009/022 and 2009/026), the Catalan Government (2009-SGR-00131 and 2014-SGR-0932), the ICREA Foundation (ICREA Academia-2008). The research leading to these results has also received funding from the European Community's Seventh Framework Programme (FP7/2007–2013) under Grant Agreement No. 602805. A.B. was supported by a FI predoctoral fellowship of the Catalan Government, J.G-C. was supported by a 'Juan de la Cierva' post-doctoral fellowship from the Spanish 'Ministerio de Ciencia e Innovación', E.M-G. was supported by a 'Sara Borrell' post-doctoral fellowship from the Spanish 'Instituto de Salud Carlos III', N.F-C.was supported by a contract from the Biomedical Network Research Centre on Rare Diseases (CIBERER) and M.R. was supported by a 'Miguel i Servet' contract the Spanish 'Instituto de Salud Carlos III'. Partial support from FEDER funds is also acknowledged

Episodic ataxia is an autosomal dominant ion channel disorder characterized by episodes of imbalance and incoordination. The disease is genetically heterogeneous and is classified as episodic ataxia type 2 (EA2) when it is caused by a mutation in the CACNA1A gene, encoding the α1A subunit of the P/Q-type voltage-gated calcium channel Cav2.1. The vast majority of EA2 disease-causing variants are loss-of-function (LoF) point changes leading to decreased channel currents. CACNA1A exonic deletions have also been reported in EA2 using quantitative approaches. We performed a mutational screening of the CACNA1A gene, including the promoter and 3'UTR regions, in 49 unrelated patients diagnosed with episodic ataxia. When pathogenic variants were not found by sequencing, we performed a copy number variant (CNV) analysis to screen for duplications or deletions. Overall, sequencing screening allowed identification of six different point variants (three nonsense and three missense changes) and two coding indels, one of them found in two unrelated patients. Additionally, CNV analysis identified a deletion in a patient spanning exon 35 as a result of a recombination event between flanking intronic Alu sequences. This study allowed identification of potentially pathogenic alterations in our sample, five of them novel, which cover 20% of the patients (10/49). Our data suggest that most of these variants are disease-causing, although functional studies are required. ; The funding for this study was provided by the Spanish Ministerio de Economía y Competitividad (SAF2009-13182-C01, SAF2009-13182-C03), AGAUR (2014SGR-0932, 2009SGR-0078) and Fundació La Marató de TV3 (grant 100731). These institutions had no further role in study design, collection, analysis, interpretation of data or in the submission of this paper for publication. CS and OC were supported by Ministerio de Economía y Competitividad (BES-2007-16450 and BES-2010-033895, respectively) and NF-C by Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER, ISCIII). MV-P was supported by a predoctoral grant from VHIR, Barcelona (Spain). CT was supported by the European Union (Marie Curie, PIEF-GA-2009-254930). EC-L is the recipient of the Beatriu de Pinós programme scholarship (BP-DGR 2010).

Hemiplegic migraine (HM) is a rare and severe subtype of autosomal dominant migraine, characterized by a complex aura including some degree of motor weakness. Mutations in four genes (CACNA1A, ATP1A2, SCN1A and PRRT2) have been detected in familial and in sporadic cases. This genetically and clinically heterogeneous disorder is often accompanied by permanent ataxia, epileptic seizures, mental retardation, and chronic progressive cerebellar atrophy. Here we report a mutation screening in the CACNA1A and ATP1A2 genes in 18 patients with HM. Furthermore, intragenic copy number variant (CNV) analysis was performed in CACNA1A using quantitative approaches. We identified four previously described missense CACNA1A mutations (p.Ser218Leu, p.Thr501Met, p.Arg583Gln, and p.Thr666Met) and two missense changes in the ATP1A2 gene, the previously described p.Ala606Thr and the novel variant p.Glu825Lys. No structural variants were found. This genetic screening allowed the identification of more than 30% of the disease alleles, all present in a heterozygous state. Functional consequences of the CACNA1A-p.Thr501Met mutation, previously described only in association with episodic ataxia, and ATP1A2-p.Glu825Lys, were investigated by means of electrophysiological studies, cell viability assays or Western blot analysis. Our data suggest that both these variants are disease-causing. ; The work was funded by the Spanish Ministry of Science and Innovation, the Spanish Ministry of Economy and Competitiveness,Fondos Europeos de Desarrollo Regional (FEDER) and Plan E (Grants SAF2012 -31089, SAF2012-3814 0, BES-2010-033895, SAF2009-13182-C03-01, SAF2009-13182-C03-02, and SAF2009-13182-C03-03), Fondo de Investigación Sanitaria (Cardiovascular Disease Network RD12/0042/0014) and Generalitat de Catalunya (grants 2009SGR0971, 2009SGR0078 and 2009SGR1369). M. A. V. and N. F.-C. are the recipients of an ICREA Academia Award (Generalitat de Catalunya) and a grant from "CIBER-ER," respectively. C. T. was supported by the European Union (Marie Curie, PIEF-GA-2009-254930).