Neurocentre Magendie

Team publications

IF du Neurocentre

114 publications

* equal contribution
The indicated IF have been collected by the Web of Sciences in July 2017

04/2018 | Cereb Cortex   IF 6.6
Dysfunctional Autism Risk Genes Cause Circuit-Specific Connectivity Deficits With Distinct Developmental Trajectories
Zerbi Valerio, Giovanna D. Ielacqua, Marija Markicevic, Matthias Georg Haberl, Mark H. Ellisman, A-Bhaskaran A, Frick A, Markus Rudin, Nicole Wenderoth

Autism spectrum disorders (ASD) are a set of complex neurodevelopmental disorders for which there is currently no targeted therapeutic approach. It is thought that alterations of genes regulating migration and synapse formation during development affect neural circuit formation and result in aberrant connectivity within distinct circuits that underlie abnormal behaviors. However, it is unknown whether deviant developmental trajectories are circuit-speciï¬c for a given autism risk-gene. We used MRI to probe changes in functional and structural connectivity from childhood to adulthood in Fragile-X (Fmr1â/y) and contactin-associated (CNTNAP2â/â) knockout mice. Young Fmr1â/y mice (30 days postnatal) presented with a robust hypoconnectivity phenotype in corticocortico and corticostriatal circuits in areas associated with sensory information processing, which was maintained until adulthood. Conversely, only small differences in hippocampal and striatal areas were present during early postnatal development in CNTNAP2â/â mice, while major connectivity deï¬cits in prefrontal and limbic pathways developed between adolescence and adulthood. These ï¬ndings are supported by viral tracing and electron micrograph approaches and deï¬ne 2 clearly distinct connectivity endophenotypes within the autism spectrum. We conclude that the genetic background of ASD strongly inï¬uences which circuits are most affected, the nature of the phenotype, and the developmental time course of the associated changes.

09/01/2018 | Curr Opin Neurobiol   IF 6.1
Neural circuit dysfunction in mouse models of neurodevelopmental disorders.
Del Pino I, Rico B, Marin O

Neuropsychiatric disorders arise from the alteration of normal brain developmental trajectories disrupting the function of specific neuronal circuits. Recent advances in human genetics have greatly accelerated the identification of genes whose variation increases the susceptibility for neurodevelopmental disorders, most notably for autism spectrum disorder (ASD) and schizophrenia. In parallel, experimental studies in animal models-most typically in mice-are beginning to shed light on the role of these genes in the development and function of specific brain circuits. In spite of their limitations, understanding the impact of pathological gene variation in animal models at the level of specific neuronal populations and circuits will likely contribute to orienting human clinical studies in the search for precise disease mechanisms and novel treatments.

26/12/2017 | arch environ occup health
Mental health in underground coal miners.
Joaquim AC, Lopes M, Stangherlin L, Castro K, Ceretta LB, Longen WC, Ferraz F, Perry IDS

As mental health goes beyond the simple absence of mental disorders, this paper characterized mental health components in 89 underground coal miners in southern Brazil. This is a cross-sectional study, that detected a low prevalence of depression; light or moderate anxiety in 13% of the workers; self-perception of good health; life quality and good psychological capacity in most of the participants; poor sleep quality in half of them; reverse correlations between anxiety and life quality, and anxiety and psychological capital; positive correlations between psychological capital and life quality; associations between self-perception of health, time, and sleep quality; associations between anxiety and sleep duration and quality; and between alcohol consumption and location at work (front, rear, or variable). The results suggest vulnerabilities regarding anxiety and sleep quality. However, there is a potential coping of determinants that impact on mental health.

12/2017 | minerva pediatr
Bioelectrical impedance analysis: body composition in children and adolescents with Down syndrome.
Goncalves Machado A, Lummertz Magenis M, Bongiolo AM, Castro K, da Silva MA, Schweigert Perry ID

22/11/2017 | J Neurophysiol   IF 2.4
Ghosh S, Reuveni I, Zidan S, Lamprecht R, Barkai E

Endocannabinoids are key modulators that regulate central brain functions and behaviours, including learning and memory. At the cellular and molecular levels, endocannabinoids are potent modulators of excitatory and inhibitory synaptic function. Most effects of cannabinoids are thought to be mediated via G protein-coupled cannabinoids receptors. In particular, cannabinoids released from post-synaptic neurons are suggested to act as retrograde messengers, activating presynaptic Type-1 Cannabinoid receptors (CB1R), thereby inducing suppression of synaptic release. Another central mechanism of cannabinoids-induced action requires activation of astroglial CB1R. CB1R are also implicated in self-modulation of cortical neurons. Rats that are trained in a particularly difficult olfactory-discrimination task show a dramatic increased ability to acquire memories of new odors. The memory of the acquired high skill acquisition, termed 'rule learning' or 'learning set' lasts for many months. Using this behavioural paradigm, we show a novel function of action for CB1R; supporting long-term memory by maintaining persistent enhancement of inhibitory synaptic transmission. Long-lasting enhancement of inhibitory synaptic transmission is blocked by a CB1R inverse agonist. This effect is mediated by a novel purely post-synaptic mechanism, obtained by enhancing the single GABAA channel conductance that is PKA-dependent. The significant role that CB1R has in maintaining learning-induced long-term strengthening of synaptic inhibition suggests that endocannabinoids have a key role in maintaining long-term memory by enhancing synaptic inhibition.

24/10/2017 | Nat Commun   IF 12.1
Altered surface mGluR5 dynamics provoke synaptic NMDAR dysfunction and cognitive defects in Fmr1 knockout mice.
Aloisi E, Le Corf K, Dupuis J, Zhang P, Ginger M, Labrousse V, Spatuzza M, Georg Haberl M, Costa L, Shigemoto R, Tappe-Theodor A, Drago F, Vincenzo Piazza P, Mulle C, Groc L, Ciranna L, Catania MV, Frick A

Metabotropic glutamate receptor subtype 5 (mGluR5) is crucially implicated in the pathophysiology of Fragile X Syndrome (FXS); however, its dysfunction at the sub-cellular level, and related synaptic and cognitive phenotypes are unexplored. Here, we probed the consequences of mGluR5/Homer scaffold disruption for mGluR5 cell-surface mobility, synaptic N-methyl-D-aspartate receptor (NMDAR) function, and behavioral phenotypes in the second-generation Fmr1 knockout (KO) mouse. Using single-molecule tracking, we found that mGluR5 was significantly more mobile at synapses in hippocampal Fmr1 KO neurons, causing an increased synaptic surface co-clustering of mGluR5 and NMDAR. This correlated with a reduced amplitude of synaptic NMDAR currents, a lack of their mGluR5-activated long-term depression, and NMDAR/hippocampus dependent cognitive deficits. These synaptic and behavioral phenomena were reversed by knocking down Homer1a in Fmr1 KO mice. Our study provides a mechanistic link between changes of mGluR5 dynamics and pathological phenotypes of FXS, unveiling novel targets for mGluR5-based therapeutics.

10/2017 | Clin Chim Acta   IF 2.9
Leptin concentrations and SCD-1 indices in classical homocystinuria: Evidence for the role of sulfur amino acids in the regulation of lipid metabolism.
Poloni S, Spritzer PM, Mendes RH, D'Almeida V, Castro K, Sperb-Ludwig F, Kugele J, Tucci S, Blom HJ, Schwartz IVD

BACKGROUND: We describe body composition, lipid metabolism and Stearoyl-CoA desaturase-1 (SCD-1) indices in patients with classical homocystinuria (HCU). METHODS: Eleven treated HCU patients and 16 healthy controls were included. Body composition and bone mineral density were assessed by dual X-ray absorptiometry. Sulfur amino acids (SAA) and their derivatives (total homocysteine, cysteine, methionine, S-adenosylmethionine, S-adenosylhomocysteine, and glutathione), lipids (free fatty acids, acylcarnitines, triglycerides and lipoproteins), glucose, insulin, leptin, adiponectin, and isoprostanes were measured in plasma. Insulin resistance was evaluated by HOMA-IR. To estimate liver SCD-1 activity, SCD-16 [16:1(n-7)/16:0] and SCD-18 [18:1(n-9)/18:0] desaturation indices were determined. RESULTS: In HCU patients, SCD-16 index was significantly reduced (p=0.03). A trend of an association of SCD-16 index with cysteine was observed (r=0.624, p=0.054). HCU patients displayed lower lean mass (p<0.05), with no differences in fat mass percentage. Leptin and low-density lipoprotein concentrations were lower in HCU patients (p<0.05). Femur bone mineral density Z-scores were correlated with plasma cysteine (r=0.829; p=0.04) and total homocysteine (r=-0.829; p=0.04) in HCU patients. CONCLUSIONS: We report alterations in leptin and SCD-1 in HCU patients. These results agree with previous findings from epidemiologic and animal studies, and support a role for SAA on lipid homeostasis.

19/07/2017 | Neuropsychopharmacology   IF 6.4
Potential Involvement of Impaired BKCa Channel Function in Sensory Defensiveness and Some Behavioral Disturbances Induced by Unfamiliar Environment in a Mouse Model of Fragile X Syndrome.
Carreno-Munoz MI, Martins F, Medrano MC, Aloisi E, Pietropaolo S, Dechaud C, Subashi E, Bony G, Ginger M, Moujahid A, Frick A, Leinekugel X

In fragile X syndrome (FXS), sensory hypersensitivity and impaired habituation is thought to result in attention overload and various behavioral abnormalities in reaction to the excessive and remanent salience of environment features that would normally be ignored. This phenomenon, termed sensory defensiveness, has been proposed as the potential cause of hyperactivity, hyperarousal, and negative reactions to changes in routine that are often deleterious for FXS patients. However, the lack of tools for manipulating sensory hypersensitivity has not allowed the experimental testing required to evaluate the relevance of this hypothesis. Recent work has shown that BMS-204352, a BKCa channel agonist, was efficient to reverse cortical hyperexcitability and related sensory hypersensitivity in the Fmr1-KO mouse model of FXS. In the present study, we report that exposing Fmr1-KO mice to novel or unfamiliar environments resulted in multiple behavioral perturbations, such as hyperactivity, impaired nest building and excessive grooming of the back. Reversing sensory hypersensitivity with the BKCa channel agonist BMS-204352 prevented these behavioral abnormalities in Fmr1-KO mice. These results are in support of the sensory defensiveness hypothesis, and confirm BKCa as a potentially relevant molecular target for the development of drug medication against FXS/ASD.Neuropsychopharmacology advance online publication, 16 August 2017; doi:10.1038/npp.2017.149.

07/2017 | nutr neurosci
The effect of ketogenic diet in an animal model of autism induced by prenatal exposure to valproic acid.
Castro K, Baronio D, Perry IS, Riesgo RDS, Gottfried C

OBJECTIVES: Autism spectrum disorder (ASD) is characterized by impairments in social interaction and communication, and by restricted repetitive behaviors and interests. Its etiology is still unknown, but different environmental factors during pregnancy, such as exposure to valproic acid (VPA), are associated with high incidence of ASD in children. In this context, prenatal exposure to VPA in rodents has been used as a reliable model of ASD. Ketogenic diet (KD) is an alternative therapeutic option for refractory epilepsy; however, the effects of this approach in ASD-like behavior need to be evaluated. We conducted a behavioral assessment of the effects of KD in the VPA model of autism. METHODS: Pregnant animals received a single-intraperitoneal injection of 600 mg/kg VPA, and their offspring were separated into four groups: (1) control group with standard diet (C-SD), (2) control group with ketogenic diet (C-KD), (3) VPA group with standard diet (VPA-SD), and (4) VPA group with ketogenic diet (VPA-KD). RESULTS: When compared with the control group, VPA animals presented increased social impairment, repetitive behavior and higher nociceptive threshold. Interestingly, the VPA group fed with KD presented improvements in social behavior. These mice displayed higher scores in sociability index and social novelty index when compared with the SD-fed VPA mice. DISCUSSION: VPA mice chronically exposed to a KD presented behavioral improvements; however, the mechanism by which KD improves ASD-like features needs to be further investigated. In conclusion, the present study reinforces the potential use of KD as a treatment for the core deficits of ASD.

07/06/2017 | autism res   IF 3.8
Behavioral abnormalities in the Fmr1-KO2 mouse model of fragile X syndrome: The relevance of early life phases.
Gaudissard J*, Ginger M*, Premoli M, Memo M, Frick A*, Pietropaolo S*

Fragile X syndrome (FXS) is a developmental disorder caused by a mutation in the X-linked FMR1 gene, coding for the FMRP protein which is largely involved in synaptic function. FXS patients present several behavioral abnormalities, including hyperactivity, anxiety, sensory hyper-responsiveness, and cognitive deficits. Autistic symptoms, e.g., altered social interaction and communication, are also often observed: FXS is indeed the most common monogenic cause of autism. Mouse models of FXS are therefore of great interest for research on both FXS and autistic pathologies. The Fmr1-KO2 mouse line is the most recent FXS model, widely used for brain studies; surprisingly, little is known about the face validity of this model, i.e., its FXS-like behavioral phenotype. Furthermore, no data are available for the age-related expression of the pathological phenotypes in this mouse line, a critical issue for modelling neurodevelopmental disorders. Here we performed an extensive behavioral characterization of the KO2 model at infancy, adolescent and adult ages. Hyperactivity, altered emotionality, sensory hyper-responsiveness and memory deficits were already present in KO mice at adolescence and remained evident at adulthood. Alterations in social behaviors were instead observed only in young KO animals: during the first 2 weeks of life, KOs emitted longer ultrasonic vocalizations compared to their WT littermates and as adolescents they displayed more aggressive behaviors towards a conspecific. These results strongly support the face validity of the KO2 mouse as a model for FXS, at the same time demonstrating that its ability to recapitulate social autistic-relevant phenotypes depends on early testing ages. Autism Res 2017. (c) 2017 International Society for Autism Research, Wiley Periodicals, Inc.