Orexinergic Input to Dopaminergic Neurons of the Human Ventral Tegmental Area

The mesolimbic reward pathway arising from dopaminergic (DA) neurons of the ventral tegmental area (VTA) has been strongly implicated in reward processing and drug abuse. In rodents, behaviors associated with this projection are profoundly influenced by an orexinergic input from the lateral hypothalamus to the VTA. Because the existence and significance of an analogous orexigenic regulatory mechanism acting in the human VTA have been elusive, here we addressed the possibility that orexinergic neurons provide direct input to DA neurons of the human VTA. Dual-label immunohistochemistry was used and orexinergic projections to the VTA and to DA neurons of the neighboring substantia nigra (SN) were analyzed comparatively in adult male humans and rats. Orexin B-immunoreactive (IR) axons apposed to tyrosine hydroxylase (TH)-IR DA and to non-DA neurons were scarce in the VTA and SN of both species. In the VTA, 15.062.8% of TH-IR perikarya in humans and 3.260.3% in rats received orexin B-IR afferent contacts. On average, 0.2460.05 and 0.0560.005 orexinergic appositions per TH-IR perikaryon were detected in humans and rats, respectively. The majority(86–88%) of randomly encountered orexinergic contacts targeted the dendritic compartment of DA neurons. Finally, DA neurons of the SN also received orexinergic innervation in both species. Based on the observation of five times heavierorexinergic input to TH-IR neurons of the human, compared with the rat, VTA, we propose that orexinergic mechanism acting in the VTA may play just as important roles in reward processing and drug abuse in humans, as already established well in rodents

Hypocretin/orexin deficiency decreases cocaine abuse liability.

Compelling evidence indicates that hypocretin/orexin signaling regulates arousal, stress and reward-seeking behaviors. However, most studies on drug reward-related processes have so far described the effects of pharmacological blockers disrupting hypocretin/orexin transmission. We report here an extensive study on cocaine-related behaviors in hypocretin/orexin-deficient mice (KO) and their heterozygous (HET) and wildtype (WT) littermates. We evaluated behavioral sensitization following repeated administrations and preference for an environment repeatedly paired with cocaine injections (15 mg/kg). Mice were also trained to self-administer cocaine (0.5-1.5 mg/kg/infusion). Our observations show that whereas all mice exhibited quite similar responses to acute administration of cocaine, only Hcrt KO mice exhibited reduced cocaine-seeking behaviors following a period of abstinence or extinction, and reduced cocaine incubation craving. Further, if the present findings confirm that Hcrt deficient mice may display a hypoactive phenotype, possibly linked to a reduced alertness concomitant to a decreased exploration of their environment, hypocretin/orexin defiency did not cause any attentional deficit. We thus report that innate disruption of hypocretin/orexin signaling moderately alters cocaine reward but significantly reduces long-term affective dependence that may explain the lack of relapse for cocaine seeking seen in Hcrt KO mice. Overall, with blunted cocaine intake at the highest concentration and reduced responsiveness to cocaine cues after prolonged abstinence, our findings suggest that hypocretin deficient mice may display signs of resilience to cocaine addiction

Development and Notch Signaling Requirements of the Zebrafish Choroid Plexus

The choroid plexus (CP) is an epithelial and vascular structure in the ventricular system of the brain that is a critical part of the blood-brain barrier. The CP has two primary functions, 1) to produce and regulate components of the cerebral spinal fluid, and 2) to inhibit entry into the brain of exogenous substances. Despite its importance in neurobiology, little is known about how this structure forms.Here we show that the transposon-mediated enhancer trap zebrafish line Et(Mn16) expresses green fluorescent protein within a population of cells that migrate toward the midline and coalesce to form the definitive CP. We further demonstrate the development of the integral vascular network of the definitive CP. Utilizing pharmacologic pan-notch inhibition and specific morpholino-mediated knockdown, we demonstrate a requirement for Notch signaling in choroid plexus development. We identify three Notch signaling pathway members as mediating this effect, notch1b, deltaA, and deltaD.This work is the first to identify the zebrafish choroid plexus and to characterize its epithelial and vasculature integration. This study, in the context of other comparative anatomical studies, strongly indicates a conserved mechanism for development of the CP. Finally, we characterize a requirement for Notch signaling in the developing CP. This establishes the zebrafish CP as an important new system for the determination of key signaling pathways in the formation of this essential component of the vertebrate brain

Desarrollo gradual de las competencias transversales en el grado de farmacia. Metodologías y herramientas de evaluación para el “profesional en formación”

Aim: To set different levels of acquisition of some cross-curricular competencies in the Pharmacy Degree and to design and implement methodologies and tools to allow their development and evaluation along the whole curriculum.Matherial and Method: Different active methodologies have been used, and tasks and evaluation rubrics have been prepared to be applied in the different levels defined for the cross-curricular competencies selected: written communication skills, information seeking, and teamwork. Similarly, a student satisfaction survey has been designed in order to evaluate the implementation of the experience.Results: The results obtained in the core subjects of the 1st and 2nd year of the Pharmacy Degree (Physical Chemistry, Immunology and General Microbiology and Parasitology) for the competences of written communication skills, teamwork and information seeking, in levels 1 and 2, have been very successful in terms of the acquisition of competences and in the suitability of the different tasks and evaluation tools proposed.Conclusions: The tools designed to evaluate these cross-curricular competencies can be adapted to any subject and knowledge field, in addition, they allow the student to be aware of the criteria used for his evaluation. The present work has strengthened the formation and development of teaching groups and has eased the coordination among the different subjects of the Pharmacy Degree.Objetivo: Establecer niveles de dominio de algunas competencias transversales del Grado de Farmacia y diseñar e implementar metodologías y herramientas que permitan su desarrollo y evaluación a lo largo de la Titulación.Material y Método: Se han utilizado metodologías activas, diseñado actividades y elaborado rúbricas de evaluación para utilizar en los distintos niveles definidos para las competencias transversales elegidas: comunicación escrita, búsqueda de información y trabajo en equipo. Se ha elaborado una encuesta de satisfacción, que ha permitido valorar la experiencia realizada.Resultados: Los resultados obtenidos en tres asignaturas de primer y segundo curso de Farmacia (Fisicoquímica, Inmunología y Microbiología y Parasitología General) para las competencias de la comunicación escrita, trabajo en equipo y búsqueda de información, en los niveles de dominio 1 y 2, han sido muy positivos en la adquisición de las competencias y en la adecuación de actividades y herramientas de evaluación.Conclusiones: Las herramientas diseñadas, se pueden adaptar a cualquier materia y área de conocimiento para valorar estas competencias transversales, además, permiten al alumno conocer los criterios con los que va a ser evaluado. El presente trabajo ha potenciado la creación y desarrollo de grupos docentes y favorecido la coordinación entre asignaturas de la titulación

Narcolepsy patients have antibodies that stain distinct cell populations in rat brain and influence sleep patterns.

Narcolepsy is a chronic sleep disorder, likely with an autoimmune component. During 2009 and 2010, a link between A(H1N1)pdm09 Pandemrix vaccination and onset of narcolepsy was suggested in Scandinavia. In this study, we searched for autoantibodies related to narcolepsy using a neuroanatomical array: rat brain sections were processed for immunohistochemistry/double labeling using patient sera/cerebrospinal fluid as primary antibodies. Sera from 89 narcoleptic patients, 52 patients with other sleep-related disorders (OSRDs), and 137 healthy controls were examined. Three distinct patterns of immunoreactivity were of particular interest: pattern A, hypothalamic melanin-concentrating hormone and proopiomelanocortin but not hypocretin/orexin neurons; pattern B, GABAergic cortical interneurons; and pattern C, mainly globus pallidus neurons. Altogether, 24 of 89 (27%) narcoleptics exhibited pattern A or B or C. None of the patterns were exclusive for narcolepsy but were also detected in the OSRD group at significantly lower numbers. Also, some healthy controls exhibited these patterns. The antigen of pattern A autoantibodies was identified as the common C-terminal epitope of neuropeptide glutamic acid-isoleucine/alpha-melanocyte-stimulating hormone (NEI/alphaMSH) peptides. Passive transfer experiments on rat showed significant effects of pattern A human IgGs on rapid eye movement and slow-wave sleep time parameters in the inactive phase and EEG theta-power in the active phase. We suggest that NEI/alphaMSH autoantibodies may interfere with the fine regulation of sleep, contributing to the complex pathogenesis of narcolepsy and OSRDs. Also, patterns B and C are potentially interesting, because recent data suggest a relevance of those brain regions/neuron populations in the regulation of sleep/arousal

Desarrollo gradual de las competencias transversales en el Grado en Farmacia. Metodologías y herramientas de evaluación para el “profesional en formación”

Objetivo: Establecer niveles de dominio de algunas competencias transversales del Grado en Farmacia y diseñar e implementar metodologías y herramientas que permitan su desarrollo y evaluación a lo largo de la Titulación. Material y Método: Se han utilizado metodologías activas, diseñado actividades y elaborado rúbricas de evaluación para utilizar en los distintos niveles definidos para las competencias transversales elegidas: comunicación escrita, búsqueda de información y trabajo en equipo. Se ha elaborado una encuesta de satisfacción, que ha permitido valorar la experiencia realizada. Resultados: Los resultados obtenidos en tres asignaturas de primer y segundo curso de Farmacia (Fisicoquímica, Inmunología y Microbiología y Parasitología General) para las competencias de la comunicación escrita, trabajo en equipo y búsqueda de información, en los niveles de dominio 1 y 2, han sido muy positivos en la adquisición de las competencias y en la adecuación de actividades y herramientas de evaluación. Conclusiones: Las herramientas diseñadas, se pueden adaptar a cualquier materia y área de conocimiento para valorar estas competencias transversales, además, permiten al alumno conocer los criterios con los que va a ser evaluado. El presente trabajo ha potenciado la creación y desarrollo de grupos docentes y favorecido la coordinación entre asignaturas de la titulación.Aim: To set different levels of acquisition of some cross-curricular competencies in the Pharmacy Degree and to design and implement methodologies and tools to allow their development and evaluation along the whole curriculum. Material and Method: Different active methodologies have been used, and tasks and evaluation rubrics have been prepared to be applied in the different levels defined for the cross-curricular competencies selected: written communication skills, information seeking, and teamwork. Similarly, a student satisfaction survey has been designed in order to evaluate the implementation of the experience. Results: The results obtained in the core subjects of the 1st and 2nd year of the Pharmacy Degree (Physical Chemistry, Immunology and General Microbiology and Parasitology) for the competences of written communication skills, teamwork and information seeking, in levels 1 and 2, have been very successful in terms of the acquisition of competences and in the suitability of the different tasks and evaluation tools proposed. Conclusions: The tools designed to evaluate these cross-curricular competencies can be adapted to any subject and knowledge field, in addition, they allow the student to be aware of the criteria used for his evaluation. The present work has strengthened the formation and development of teaching groups and has eased the coordination among the different subjects of the Pharmacy Degree.El trabajo forma parte de un programa piloto que se está desarrollando en el Grado de Farmacia de la UPV/EHU (PIE 12-14 6536, financiado por el Vicerrectorado de Estudios de Grado e Innovación, Servicio de Asesoramiento Educativo)

Increased Immune Complexes of Hypocretin Autoantibodies in Narcolepsy

International audienceBACKGROUND: Hypocretin peptides participate in the regulation of sleep-wake cycle while deficiency in hypocretin signaling and loss of hypocretin neurons are causative for narcolepsy-cataplexy. However, the mechanism responsible for alteration of the hypocretin system in narcolepsy-cataplexy and its relevance to other central hypersomnias remain unknown. Here we studied whether central hypersomnias can be associated with autoantibodies reacting with hypocretin-1 peptide present as immune complexes. METHODOLOGY: Serum levels of free and dissociated (total) autoantibodies reacting with hypocretin-1 peptide were measured by enzyme-linked immunosorbent assay and analyzed with regard to clinical parameters in 82 subjects with narcolepsy-cataplexy, narcolepsy without cataplexy or idiopathic hypersomnia and were compared to 25 healthy controls. PRINCIPAL FINDINGS: Serum levels of total but not free IgG autoantibodies against hypocretin-1 were increased in narcolepsy-cataplexy. Increased levels of complexed IgG autoantibodies against hypocretin-1 were found in all patients groups with a further increase in narcolepsy-cataplexy. Levels of total IgM hypocretin-1 autoantibodies were also elevated in all groups of patients. Increased levels of anti-idiotypic IgM autoantibodies reacting with hypocretin-1 IgG autoantibodies affinity purified from sera of subjects with narcolepsy-cataplexy were found in all three groups of patients. Disease duration correlated negatively with serum levels of hypocretin-1 IgG and IgM autoantibodies and with anti-idiotypic IgM autoantibodies. CONCLUSION: Central hypersomnias and particularly narcolepsy-cataplexy are characterized by higher serum levels of autoantibodies directed against hypocretin-1 which are present as immune complexes most likely with anti-idiotypic autoantibodies suggesting their relevance to the mechanism of sleep-wake cycle regulation

Evidence for an association between migraine and the hypocretin receptor 1 gene

The aim of our study was to investigate whether genetic variants in the hypocretin receptor 1 (HCRTR1) gene could modify the occurrence and the clinical features of migraine. Using a case–control strategy we genotyped 384 migraine patients and 259 controls for three SNPs in the HCRTR1 gene. Genotypic and allelic frequencies of the rs2271933 non-synonymous polymorphism resulted different (χ2 = 9.872, p = 0.007; χ2 = 8.108, p = 0.004) between migraineurs and controls. The carriage of the A allele was associated with an increased migraine risk (OR 1.42, 95% CI 1.11–1.81). When we divided the migraine patients into different subgroups, the difference reached the level of statistical significance only in migraine without aura. The different genotypes had no significant effect on the examined clinical characteristics of the disease. In conclusion, our data supports the hypothesis that the HCRTR1 gene could represent a genetic susceptibility factor for migraine without aura and suggests that the hypocretin system may have a role in the pathophysiology of migraine

Networks of Neuronal Genes Affected by Common and Rare Variants in Autism Spectrum Disorders

Autism spectrum disorders (ASD) are neurodevelopmental disorders with phenotypic and genetic heterogeneity. Recent studies have reported rare and de novo mutations in ASD, but the allelic architecture of ASD remains unclear. To assess the role of common and rare variations in ASD, we constructed a gene co-expression network based on a widespread survey of gene expression in the human brain. We identified modules associated with specific cell types and processes. By integrating known rare mutations and the results of an ASD genome-wide association study (GWAS), we identified two neuronal modules that are perturbed by both rare and common variations. These modules contain highly connected genes that are involved in synaptic and neuronal plasticity and that are expressed in areas associated with learning and memory and sensory perception. The enrichment of common risk variants was replicated in two additional samples which include both simplex and multiplex families. An analysis of the combined contribution of common variants in the neuronal modules revealed a polygenic component to the risk of ASD. The results of this study point toward contribution of minor and major perturbations in the two sub-networks of neuronal genes to ASD risk