253 research outputs found

    Sensorimotor coding of vermal granule neurons in the developing mammalian cerebellum

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    The vermal cerebellum is a hub of sensorimotor integration critical for postural control and locomotion, but the nature and developmental organization of afferent information to this region have remained poorly understoo

    Low- vs high-dose ARNI effects on clinical status, exercise performance and cardiac function in real-life HFrEF patients

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    Purpose: Only a few studies are available on dose-related effects of sacubitril/valsartan (angiotensin receptor neprilysin inhibition (ARNI)) in real-life patients with heart failure and reduced ejection fraction (HFrEF). We sought to investigate clinical and functional effects in real-life HFrEF patients receiving ARNI at a different cumulative dose. Methods: This was an observational study in consecutive outpatients admitted for HFrEF from October 2017 to June 2019. The PARADIGM criteria were needed for enrolment. ARNI was uptitrated according to blood pressure, drug tolerability, renal function and kaliemia. At least 10-month follow-up was required in each patient. Clinical assessment, Kansas City Cardiomyopathy Questionnaire (KCCQ) score, 6-min walk test and strain echocardiography were performed in each patient on a regular basis during the observational period. At the end of the study, patients were divided into two groups based on the median yearly dose of the ARNI medication. Results: A total of 90 patients, 64 \ub1 11 years, 82% males, were enrolled. The cut-off dose was established in 75 mg BID, and the study population was divided into group A ( 64 75 mg), 52 patients (58%), and group B (> 75 mg), 38 patients (42%). The follow-up duration was 12 months (range 11\u201313). NYHA class, KCCQ score and 6MWT performance ameliorated in both groups, with a quicker time to benefit in group B. The proportion of patients walking > 350 m increased from 21 to 58% in group A (p < 0.001), and from 29 to 82% in group B (p < 0.001). A positive effect was also disclosed in the left ventricular remodelling, strain deformation and diastolic function. Conclusion: One-year ARNI treatment was effective in our real-life HFrEF patient population, leading to clinical and functional improvement in both study groups, slightly greater and with a shorter time to benefit in group B

    Altered neuronal physiology, development, and function associated with a common chromosome 15 duplication involving CHRNA7

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    BACKGROUND: Copy number variants (CNVs) linked to genes involved in nervous system development or function are often associated with neuropsychiatric disease. While CNVs involving deletions generally cause severe and highly penetrant patient phenotypes, CNVs leading to duplications tend instead to exhibit widely variable and less penetrant phenotypic expressivity among affected individuals. CNVs located on chromosome 15q13.3 affecting the alpha-7 nicotinic acetylcholine receptor subunit (CHRNA7) gene contribute to multiple neuropsychiatric disorders with highly variable penetrance. However, the basis of such differential penetrance remains uncharacterized. Here, we generated induced pluripotent stem cell (iPSC) models from first-degree relatives with a 15q13.3 duplication and analyzed their cellular phenotypes to uncover a basis for the dissimilar phenotypic expressivity. RESULTS: The first-degree relatives studied included a boy with autism and emotional dysregulation (the affected proband-AP) and his clinically unaffected mother (UM), with comparison to unrelated control models lacking this duplication. Potential contributors to neuropsychiatric impairment were modeled in iPSC-derived cortical excitatory and inhibitory neurons. The AP-derived model uniquely exhibited disruptions of cellular physiology and neurodevelopment not observed in either the UM or unrelated controls. These included enhanced neural progenitor proliferation but impaired neuronal differentiation, maturation, and migration, and increased endoplasmic reticulum (ER) stress. Both the neuronal migration deficit and elevated ER stress could be selectively rescued by different pharmacologic agents. Neuronal gene expression was also dysregulated in the AP, including reduced expression of genes related to behavior, psychological disorders, neuritogenesis, neuronal migration, and Wnt, axonal guidance, and GABA receptor signaling. The UM model instead exhibited upregulated expression of genes in many of these same pathways, suggesting that molecular compensation could have contributed to the lack of neurodevelopmental phenotypes in this model. However, both AP- and UM-derived neurons exhibited shared alterations of neuronal function, including increased action potential firing and elevated cholinergic activity, consistent with increased homomeric CHRNA7 channel activity. CONCLUSIONS: These data define both diagnosis-associated cellular phenotypes and shared functional anomalies related to CHRNA7 duplication that may contribute to variable phenotypic penetrance in individuals with 15q13.3 duplication. The capacity for pharmacological agents to rescue some neurodevelopmental anomalies associated with diagnosis suggests avenues for intervention for carriers of this duplication and other CNVs that cause related disorders

    Regional Precuneus Cortical Hyperexcitability in Alzheimer's Disease Patients

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    Objective: Neuronal excitation/inhibition (E/I) imbalance is a potential cause of neuronal network malfunctioning in Alzheimer's disease (AD), contributing to cognitive dysfunction. Here, we used a novel approach combining transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to probe cortical excitability in different brain areas known to be directly involved in AD pathology. Methods: We performed TMS-EEG recordings targeting the left dorsolateral prefrontal cortex (l-DLPFC), the left posterior parietal cortex (l-PPC), and the precuneus (PC) in a large sample of patients with mild-to-moderate AD (n = 65) that were compared with a group of age-matched healthy controls (n = 21). Results: We found that patients with AD are characterized by a regional cortical hyperexcitability in the PC and, to some extent, in the frontal lobe, as measured by TMS-evoked potentials. Notably, cortical excitability assessed over the l-PPC was comparable between the 2 groups. Furthermore, we found that the individual level of PC excitability was associated with the level of cognitive impairment, as measured with Mini-Mental State Examination, and with corticospinal fluid levels of Aβ42 . Interpretation: Our data provide novel evidence that precuneus cortical hyperexcitability is a key feature of synaptic dysfunction in patients with AD. The current results point to the combined approach of TMS and EEG as a novel promising technique to measure hyperexcitability in patients with AD. This index could represent a useful biomarker to stage disease severity and evaluate response to novel therapies. ANN NEUROL 2022

    Chromatin environment and cellular context specify compensatory activity of paralogous MEF2 transcription factors

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    Compensation among paralogous transcription factors (TFs) confers genetic robustness of cellular processes, but how TFs dynamically respond to paralog depletion on a genome-wide scale in vivo remains incompletely understood. Using single and double conditional knockout of myocyte enhancer factor 2 (MEF2) family TFs in granule neurons of the mouse cerebellum, we find that MEF2A and MEF2D play functionally redundant roles in cerebellar-dependent motor learning. Although both TFs are highly expressed in granule neurons, transcriptomic analyses show MEF2D is the predominant genomic regulator of gene expression in vivo. Strikingly, genome-wide occupancy analyses reveal upon depletion of MEF2D, MEF2A occupancy robustly increases at a subset of sites normally bound to MEF2D. Importantly, sites experiencing compensatory MEF2A occupancy are concentrated within open chromatin and undergo functional compensation for genomic activation and gene expression. Finally, motor activity induces a switch from non-compensatory to compensatory MEF2-dependent gene regulation. These studies uncover genome-wide functional interdependency between paralogous TFs in the brain

    A Simulation Training to Prepare Camp Counselors for Working With Children at Camp HOPE America

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    Camp has proven to be an effective positive youth development strategy for children and youth who experience trauma and adversity. However, training camp counselors who are prepared to meet the needs of trauma-exposed youth in these settings are less understood. This pilot evaluation study provides the results of a social simulation-based training for counselors who will work with children who have witnessed family violence through Camp HOPE America. Survey data (N = 76) and content analysis from video recorded training sessions in simulation that used standardized actors and scenarios from the 1st year (n = 37) were conducted. Repeated measures ANOVA results indicated statistically significant improvements from pre- to post-instruction simulation in counselors’ hope scores (p < .001); their knowledge and confidence in recognizing and reporting physical/sexual abuse, and self-harming behaviors (p < .001); as well as significant increases in their knowledge and confidence in de-escalation, preventing difficult situations, and building campers’ hope (pl < .001). Further, analysis of simulation videos suggests that camp counselors used new skils from the training during the simulation experience. Participants showed gains in knowledge, confidence, use of skills, and an overall increase in hope after completing the simulation training

    Cortico-cortical stimulation and robot-assisted therapy (CCS and RAT) for upper limb recovery after stroke: study protocol for a randomised controlled trial

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    Background: Since birth, during the exploration of the environment to interact with objects, we exploit both the motor and sensory components of the upper limb (UL). This ability to integrate sensory and motor information is often compromised following a stroke. However, to date, rehabilitation protocols are focused primarily on recovery of motor function through physical therapies. Therefore, we have planned a clinical trial to investigate the effect on functionality of UL after a sensorimotor transcranial stimulation (real vs sham) in add-on to robot-assisted therapy in the stroke population. Methods: A randomised double-blind controlled trial design involving 32 patients with a single chronic stroke (onset &gt; 180&nbsp;days) was planned. Each patient will undergo 15 consecutive sessions (5&nbsp;days for 3&nbsp;weeks) of paired associative stimulation (PAS) coupled with UL robot-assisted therapy. PAS stimulation will be administered using a bifocal transcranial magnetic stimulator (TMS) on the posterior-parietal cortex and the primary motor area (real or sham) of the lesioned hemisphere. Clinical, kinematics and neurophysiological changes will be evaluated at the end of protocol and at 1-month follow-up and compared with baseline. The Fugl-Meyer assessment scale will be the primary outcome. Secondly, kinematic variables will be recorded during the box-and-block test and reaching tasks using video analysis and inertial sensors. Single pulse TMS and electroencephalography will be used to investigate the changes in local cortical reactivity and in the interconnected areas. Discussion: The presented trial shall evaluate with a multimodal approach the effects of sensorimotor network stimulation applied before a robot-assisted therapy training on functional recovery of the upper extremity after stroke. The combination of neuromodulation and robot-assisted therapy can promote an increase of cortical plasticity of sensorimotor areas followed by a clinical benefit in the motor function of the upper limb. Trial registration: ClinicalTrials.gov NCT05478434. Registered on 28 Jul 2022

    Evidence for interhemispheric imbalance in stroke patients as revealed by combining transcranial magnetic stimulation and electroencephalography

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    Interhemispheric interactions in stroke patients are frequently characterized by abnormalities, in terms of balance and inhibition. Previous results showed an impressive variability, mostly given to the instability of motor-evoked potentials when evoked from the affected hemisphere. We aim to find reliable interhemispheric measures in stroke patients with a not-evocable motor-evoked potential from the affected hemisphere, by combining transcranial magnetic stimulation (TMS) and electroencephalography. Ninteen stroke patients (seven females; 61.26 ± 9.8 years) were studied for 6 months after a first-ever stroke in the middle cerebral artery territory. Patients underwent four evaluations: clinical, cortical, corticospinal, and structural. To test the reliability of our measures, the evaluations were repeated after 3 weeks. To test the sensitivity, 14 age-matched healthy controls were compared to stroke patients. In stroke patients, stimulation of the affected hemisphere did not result in any inhibition onto the unaffected. The stimulation of the unaffected hemisphere revealed a preservation of the inhibition mechanism onto the affected. This resulted in a remarkable interhemispheric imbalance, whereas this mechanism was steadily symmetric in healthy controls. This result was stable when cortical evaluation was repeated after 3 weeks. Importantly, patients with a better recovery of the affected hand strength were the ones with a more stable interhemispheric balance. Finally, we found an association between microstructural integrity of callosal fibers, suppression of interhemispheric TMS-evoked activity and interhemispheric connectivity. We provide direct and sensitive cortical measures of interhemispheric imbalance in stroke patients. These measures offer a reliable means of distinguishing healthy and pathological interhemispheric dynamics

    Entomologie.

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    Les principaux rabageurs de la culture cotonnière du C-4; Suivi des ravageurs dans l'écosystème et prise de décision; Méthodes de lutte intégrée; Lutte variétale; Contrôle chimique et techniques d'application; Techiques d'appliction des produits.bitstream/item/142479/1/Entomologie.pdfCOTON-4. Idioma: Francês e Português

    BAD: a good therapeutic target?

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    The major goal in cancer treatment is the eradication of tumor cells. Under stress conditions, normal cells undergo apoptosis; this property is fortunately conserved in some tumor cells, leading to their death as a result of chemotherapeutic and/or radiation-induced stress. Many malignant cells, however, have developed ways to subvert apoptosis, a characteristic that constitutes a major clinical problem. Gilmore et al. recently described the ability of ZD1839, a small-molecule inhibitor of the epidermal growth factor receptor (EGFR), to induce apoptosis of mammary cells that are dependent upon growth factors for survival. Furthermore, they showed that the major effector of the EGFR-targeted therapy is BAD, a widely expressed BCL-2 family member. These results are promising in light of the role of the EGFR in breast cancer development
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