An ex-vivo and in-vitro dynamic simulator for surgical and transcatheter mitral valve interventions.

PURPOSE: Minimally invasive mitral valve surgery (MIMVS) and transcatheter edge-to-edge repair (TEER) are complex procedures used to treat mitral valve (MV) pathologies, but with limited training opportunities available. To enable training, a realistic hemodynamic environment is needed. In this work we aimed to develop and validate a simulator that enables investigation of MV pathologies and their repair by MIMVS and TEER in a hemodynamic setting. METHODS: Different MVs were installed in the simulator, and pressure, flow, and transesophageal echocardiographic measurements were obtained. To confirm the simulator's physiological range, we first installed a biological prosthetic, a mechanical prosthetic, and a competent excised porcine MV. Subsequently, we inserted two porcine MVs-one with induced chordae tendineae rupture and the other with a dilated annulus, along with a patient-specific silicone valve extracted from echocardiography with bi-leaflet prolapse. Finally, TEER and MIMVS procedures were conducted by experts to repair the MVs. RESULTS: Systolic pressures, cardiac outputs, and regurgitations volumes (RVol) with competent MVs were 119 ± 1 mmHg, 4.78 ± 0.16 l min-1, and 5 ± 3 ml respectively, and thus within the physiological range. In contrast, the pathological MVs displayed increased RVols. MIMVS and TEER resulted in a decrease in RVols and mitigated the severity of mitral regurgitation. CONCLUSION: Ex-vivo modelling of MV pathologies and repair procedures using the described simulator realistically replicated physiological in-vivo conditions. Furthermore, we showed the feasibility of performing MIMVS and TEER at the simulator, also at patient-specific level, thus providing new clinical perspectives in terms of training modalities and personalized planning.

From connectome to effectome: learning the causal interaction map of the fly brain.

A long-standing goal of neuroscience is to obtain a causal model of the nervous system. This would allow neuroscientists to explain animal behavior in terms of the dynamic interactions between neurons. The recently reported whole-brain fly connectome [1-7] specifies the synaptic paths by which neurons can affect each other but not whether, or how, they do affect each other in vivo. To overcome this limitation, we introduce a novel combined experimental and statistical strategy for efficiently learning a causal model of the fly brain, which we refer to as the "effectome". Specifically, we propose an estimator for a dynamical systems model of the fly brain that uses stochastic optogenetic perturbation data to accurately estimate causal effects and the connectome as a prior to drastically improve estimation efficiency. We then analyze the connectome to propose circuits that have the greatest total effect on the dynamics of the fly nervous system. We discover that, fortunately, the dominant circuits significantly involve only relatively small populations of neurons-thus imaging, stimulation, and neuronal identification are feasible. Intriguingly, we find that this approach also re-discovers known circuits and generates testable hypotheses about their dynamics. Overall, our analyses of the connectome provide evidence that global dynamics of the fly brain are generated by a large collection of small and often anatomically localized circuits operating, largely, independently of each other. This in turn implies that a causal model of a brain, a principal goal of systems neuroscience, can be feasibly obtained in the fly.

Network Statistics of the Whole-Brain Connectome of Drosophila.

Brains comprise complex networks of neurons and connections. Network analysis applied to the wiring diagrams of brains can offer insights into how brains support computations and regulate information flow. The completion of the first whole-brain connectome of an adult Drosophila , the largest connectome to date, containing 130,000 neurons and millions of connections, offers an unprecedented opportunity to analyze its network properties and topological features. To gain insights into local connectivity, we computed the prevalence of two- and three-node network motifs, examined their strengths and neurotransmitter compositions, and compared these topological metrics with wiring diagrams of other animals. We discovered that the network of the fly brain displays rich club organization, with a large population (30% percent of the connectome) of highly connected neurons. We identified subsets of rich club neurons that may serve as integrators or broadcasters of signals. Finally, we examined subnetworks based on 78 anatomically defined brain regions or neuropils. These data products are shared within the FlyWire Codex and will serve as a foundation for models and experiments exploring the relationship between neural activity and anatomical structure.

Neuronal wiring diagram of an adult brain.

Connections between neurons can be mapped by acquiring and analyzing electron microscopic (EM) brain images. In recent years, this approach has been applied to chunks of brains to reconstruct local connectivity maps that are highly informative, yet inadequate for understanding brain function more globally. Here, we present the first neuronal wiring diagram of a whole adult brain, containing 5×107 chemical synapses between ~130,000 neurons reconstructed from a female Drosophila melanogaster. The resource also incorporates annotations of cell classes and types, nerves, hemilineages, and predictions of neurotransmitter identities. Data products are available by download, programmatic access, and interactive browsing and made interoperable with other fly data resources. We show how to derive a projectome, a map of projections between regions, from the connectome. We demonstrate the tracing of synaptic pathways and the analysis of information flow from inputs (sensory and ascending neurons) to outputs (motor, endocrine, and descending neurons), across both hemispheres, and between the central brain and the optic lobes. Tracing from a subset of photoreceptors all the way to descending motor pathways illustrates how structure can uncover putative circuit mechanisms underlying sensorimotor behaviors. The technologies and open ecosystem of the FlyWire Consortium set the stage for future large-scale connectome projects in other species.

Whole-brain annotation and multi-connectome cell typing quantifies circuit stereotypy in Drosophila.

The fruit fly Drosophila melanogaster combines surprisingly sophisticated behaviour with a highly tractable nervous system. A large part of the fly's success as a model organism in modern neuroscience stems from the concentration of collaboratively generated molecular genetic and digital resources. As presented in our FlyWire companion paper 1 , this now includes the first full brain connectome of an adult animal. Here we report the systematic and hierarchical annotation of this ~130,000-neuron connectome including neuronal classes, cell types and developmental units (hemilineages). This enables any researcher to navigate this huge dataset and find systems and neurons of interest, linked to the literature through the Virtual Fly Brain database 2 . Crucially, this resource includes 4,552 cell types. 3,094 are rigorous consensus validations of cell types previously proposed in the hemibrain connectome 3 . In addition, we propose 1,458 new cell types, arising mostly from the fact that the FlyWire connectome spans the whole brain, whereas the hemibrain derives from a subvolume. Comparison of FlyWire and the hemibrain showed that cell type counts and strong connections were largely stable, but connection weights were surprisingly variable within and across animals. Further analysis defined simple heuristics for connectome interpretation: connections stronger than 10 unitary synapses or providing >1% of the input to a target cell are highly conserved. Some cell types showed increased variability across connectomes: the most common cell type in the mushroom body, required for learning and memory, is almost twice as numerous in FlyWire as the hemibrain. We find evidence for functional homeostasis through adjustments of the absolute amount of excitatory input while maintaining the excitation-inhibition ratio. Finally, and surprisingly, about one third of the cell types proposed in the hemibrain connectome could not yet be reliably identified in the FlyWire connectome. We therefore suggest that cell types should be defined to be robust to inter-individual variation, namely as groups of cells that are quantitatively more similar to cells in a different brain than to any other cell in the same brain. Joint analysis of the FlyWire and hemibrain connectomes demonstrates the viability and utility of this new definition. Our work defines a consensus cell type atlas for the fly brain and provides both an intellectual framework and open source toolchain for brain-scale comparative connectomics.

Long-Term Trajectories of Biomarkers, Functional, and Echocardiographic Parameters in Patients with Chronic Heart Failure from Dilated or Ischaemic Cardiomyopathy.

INTRODUCTION: The long-term evolution of clinical, echocardiographic, and laboratory parameters of cardiac function in patients with chronic heart failure (HF) with either reduced (HFrEF) or mildly reduced (HFmrEF) left ventricular ejection fraction (LVEF) is incompletely characterised. METHODS: We identified patients with chronic stable HF who presented at least twice to a university HF outpatient clinic between 1995 and 2021. Trajectories of NYHA functional class, LVEF, left ventricular internal end-diastolic diameter (LVIDD), NT-proBNP concentrations, and HF treatment over 10 years of follow-up were analysed using fractional polynomials. Analyses were repeated after stratifying patients according to aetiology (ischaemic vs. dilated) or HF category (HFrEF vs. HFmrEF). RESULTS: A total of 2,132 patients were included, of whom 51% had ischaemic and 49% had dilated HF. Eighty six percent and 14% were classified as HFrEF and HFmrEF, respectively. Mean LVEF was 28 ± 10%, and median NT-proBNP and estimated glomerular filtration rate values were 1,170 (385-3,176) pmol/L and 81 (62-100) mL/min/1.73 m2, respectively. Median follow-up was 5.2 (2.6-9.2) years. Overall, NYHA functional class and LVIDD trajectories were U-shaped, whereas LVEF and NT-proBNP concentrations markedly improved during the first year and remained stable thereafter. However, the evolution of HF parameters significantly differed with respect to HF category and aetiology, with greater improvements seen in patients with HFrEF of non-ischaemic origin. Improvements in HF variables were associated with optimization of HF therapy, notably with initiation and up-titration of renin-angiotensin-system blockers. CONCLUSION: This study provides insights into the natural history of HF in a large cohort of well-treated chronic HF outpatients with respect to subgroups of HF and different aetiologists.

A leaky integrate-and-fire computational model based on the connectome of the entire adult Drosophila brain reveals insights into sensorimotor processing.

The forthcoming assembly of the adult Drosophila melanogaster central brain connectome, containing over 125,000 neurons and 50 million synaptic connections, provides a template for examining sensory processing throughout the brain. Here, we create a leaky integrate-and-fire computational model of the entire Drosophila brain, based on neural connectivity and neurotransmitter identity, to study circuit properties of feeding and grooming behaviors. We show that activation of sugar-sensing or water-sensing gustatory neurons in the computational model accurately predicts neurons that respond to tastes and are required for feeding initiation. Computational activation of neurons in the feeding region of the Drosophila brain predicts those that elicit motor neuron firing, a testable hypothesis that we validate by optogenetic activation and behavioral studies. Moreover, computational activation of different classes of gustatory neurons makes accurate predictions of how multiple taste modalities interact, providing circuit-level insight into aversive and appetitive taste processing. Our computational model predicts that the sugar and water pathways form a partially shared appetitive feeding initiation pathway, which our calcium imaging and behavioral experiments confirm. Additionally, we applied this model to mechanosensory circuits and found that computational activation of mechanosensory neurons predicts activation of a small set of neurons comprising the antennal grooming circuit that do not overlap with gustatory circuits, and accurately describes the circuit response upon activation of different mechanosensory subtypes. Our results demonstrate that modeling brain circuits purely from connectivity and predicted neurotransmitter identity generates experimentally testable hypotheses and can accurately describe complete sensorimotor transformations.

Generating parallel representations of position and identity in the olfactory system.

In Drosophila, a dedicated olfactory channel senses a male pheromone, cis-vaccenyl acetate (cVA), promoting female courtship while repelling males. Here, we show that separate cVA-processing streams extract qualitative and positional information. cVA sensory neurons respond to concentration differences in a 5-mm range around a male. Second-order projection neurons encode the angular position of a male by detecting inter-antennal differences in cVA concentration, which are amplified through contralateral inhibition. At the third circuit layer, we identify 47 cell types with diverse input-output connectivity. One population responds tonically to male flies, a second is tuned to olfactory looming, while a third integrates cVA and taste to coincidentally promote female mating. The separation of olfactory features resembles the mammalian what and where visual streams; together with multisensory integration, this enables behavioral responses appropriate to specific ethological contexts.

Influence of Tricuspid Regurgitation After Heart Transplantation: A Single-center Experience.

Tricuspid valve regurgitation (TVR) is often observed after orthotopic heart transplantation. However, there is a scarcity of data regarding long-term outcomes of patients with TVR. Methods: Between January 2008 and December 2015, 169 patients underwent orthotopic heart transplantation at our center and were included in this study. TVR trends and associated clinical parameters were retrospectively analyzed. TVR was assessed after 30 d, 1 y, 3 y, and 5 y, and groups were defined according to changes in TVR grade: constant (group 1; n = 100), improvement (group 2; n = 26), and deterioration (group 3; n = 43). Survival, outcome with regard to operative technique, and long-term kidney and liver function during follow-up were assessed. Results: Mean follow-up time was 7.67 ± 4.17 y (median 8.62, Q1 5.06, Q3 11.16). Overall mortality was 42.0%, with differences between the groups (P < 0.01). Cox regression analysis revealed improvement of TVR as a significant predictor for survival (hazard ratio 0.23; 95% confidence interval, 0.08-0.63, P < 0.01). After 1 y 2.7%, after 3 y 3.7%, and after 5 y 3.9% of the patients showed persistent severe TVR. Creatinine levels after 30 d and 1, 3, and 5 y showed significant differences between the groups (P = 0.02, P < 0.01, P < 0.01, and P = 0.01), deterioration of TVR being associated with higher creatinine levels during follow-up. Conclusions: Deterioration of TVR is associated with higher mortality and renal dysfunction. Improvement of TVR may function as a positive predictor for long-term survival after heart transplantation. Improvement of TVR should be a therapeutic goal offering a prognostic value for long-term survival.

Initial experience with transcatheter tricuspid valve repair in patients with cardiac amyloidosis.

AIMS: Wildtype transthyretin amyloid cardiomyopathy is an under-recognized cause of heart failure in elderly patients. Transcatheter tricuspid valve repair is a newly emerging therapeutic option for severe tricuspid regurgitation (TR). We present first insights into safety and possible benefits of this procedure in patients with cardiac amyloidosis. METHODS AND RESULTS: Eight patients with cardiac non-hereditary (wildtype) transthyretin (ATTRwt) amyloidosis and severe to torrential TR, undergoing successful transcatheter tricuspid valve repair, were included in the analysis and compared to a control group of 21 patients without cardiac amyloidosis. All patients presented with an advanced stage of amyloid cardiomyopathy. Primary endpoint was reduction in TR at 3 months follow-up. Secondary endpoints were feasibility, safety, hospitalization or death, clinical improvement, cardiac biomarkers, and structural and functional right heart parameter obtained by echocardiography. Transcatheter tricuspid valve repair resulted in a significant reduction of TR (IV to II, P = 0.008) in all eight patients with cardiac amyloidosis (100%). Device success (amyloidosis 75% vs. control group 86%, P = 0.597) and overall probability of hospitalization or death (amyloidosis 13% vs. control group 25%, P = 0.646) were similar compared with those in the control group at 3 months follow-up. Transcatheter tricuspid valve repair led to an improvement of New York Heart Association functional class (P = 0.031) and 6 min walking distance (from 313 ± 118 to 337 ± 106, P = 0.012). TR reduction in amyloidosis patients was less extensive compared with that in control group (TR-reduction 1.6 ± 0.3, P = 0.008 vs. control group 2.3 ± 0.3, P < 0.0001). Furthermore, these patients showed no significant improvement of structural right heart parameters. CONCLUSIONS: Transcatheter tricuspid valve repair is a safe and feasible new treatment option in patients with amyloid cardiomyopathy and has the potential to improve TR-grade and clinical status. However, the benefit appears to be less pronounced compared with patients without cardiac amyloidosis.

Wound Infections in Adult Patients after Berlin Heart® EXCOR Biventricular Assist Device Implantation.

The Berlin Heart® EXCOR is a paracorporeal, pulsatile ventricular assist device used in patients of all age groups. However, adolescent and adult patients on EXCOR support are scarcely explored. Herein, we present a detailed description of infectious complications in this patient cohort. From 2006 to 2020, 58 patients received a biventricular assist device (BiVAD) at our institution and were included in this study. Postoperative infections were assessed after BiVAD implantation and subsequent heart transplantation (HTx). A Berlin Heart® EXCOR BiVAD was implanted as a bridge to transplantation in 58 patients (12-64 years). Most patients were INTERMACS I, and their median age was 49 years. Wound infections (WI) specific to the ventricular assist device (VAD) occurred in 31 (53.4%) patients with a mean time of 113 ± 155 days after BiVAD implantation. HTx was performed in 30 (51.7%) patients and thereof 10 (33.3%) patients developed at least one WI post-HTx. The mean time of WI after HTx was 17 ± 14 days. In four cases, WIs were caused by the same pathogen as before HTx. According to our institutional BiVAD wound classification, the mean wound score was 3. The VAD-specific wound infections were manageable and did not increase mortality nor precluded HTx in Berlin Heart® EXCOR patients. No specific risk factors for VAD-specific wound infections could be identified.

Haemodynamic Effects of Sacubitril/Valsartan Initiation in Outpatients with Chronic Heart Failure.

BACKGROUND: Sacubitril/valsartan (S/V) improves outcomes in patients with heart failure with reduced ejection fraction (HFrEF). Data about the immediate, short-, and intermediate-term hemodynamic effects of S/V are limited. METHODS: In this prospective observational study, 37 outpatients with chronic HFrEF were treated with S/V according to current guideline recommendations. Next to clinical, laboratory and echocardiographic parameters, haemodynamic variables were assessed non-invasively by use of inert gas rebreathing and bioimpedance cardiography at baseline and at 2-week, 3-month and 6-month follow-up. The course of variables throughout the study and the relationship between variables were analysed using fractional polynomials. RESULTS: S/V treatment resulted in short- and intermediate-term improvements in NYHA functional class (2.3 ± 0.6 at baseline vs. 1.9 ± 0.5 at 6-month follow-up, p = 0.14), 6-min walk test (453 ± 110 vs. 528 ± 98 m, p = 0.02), ejection fraction (31 ± 9 vs. 36 ± 12%, p = 0.13), pulmonary artery pressure (39 ± 10 vs. 31 ± 10 mmHg, p = 0.02), and NT-proBNP values (1702 (782-2897 vs. 1004 (599-1627) ng/L, p = 0.03). In addition, S/V caused immediate decreases in systemic vascular resistance index (SVRI) and systolic blood pressure (SBP), which were associated with a simultaneous drop in stroke volume (SV) and cardiac index (CI). However, while SVRI and SBP remained at low levels during further treatment, SV and CI restored rapidly and increased to slightly higher levels thereafter. CONCLUSION: The vasodilative effects of S/V result in immediate reductions in SVRI, SBP, SV and CI. However, S/V induces reverse cardiac remodelling, which is apparent shortly after treatment initiation and leads to improvements of clinical, functional, echocardiographic, laboratory and haemodynamic variables.

Cardiac Gene Delivery in Large Animal Models: Selective Retrograde Venous Injection.

Delivery of viral vectors to the heart represents a challenging endeavor. Besides vector design, the route of substrate administration is significantly influencing gene delivery success. The selective retrograde venous injection (SRVI) represents one of the most efficient percutaneous delivery strategies for transduction of the anterior left ventricular myocardium. In this chapter, we discuss the advantages and limitations of this vector delivery approach and provide a protocol for selective retrograde venous injection in a preclinical large animal model. As limited transgene expression frequently hampers generation of reliable proof-of-principle data and thus translation, this technique provides a valuable tool to ensure high myocardial transduction in preclinical research.

Chemoreceptor co-expression in Drosophila melanogaster olfactory neurons.

Drosophila melanogaster olfactory neurons have long been thought to express only one chemosensory receptor gene family. There are two main olfactory receptor gene families in Drosophila, the odorant receptors (ORs) and the ionotropic receptors (IRs). The dozens of odorant-binding receptors in each family require at least one co-receptor gene in order to function: Orco for ORs, and Ir25a, Ir8a, and Ir76b for IRs. Using a new genetic knock-in strategy, we targeted the four co-receptors representing the main chemosensory families in D. melanogaster (Orco, Ir8a, Ir76b, Ir25a). Co-receptor knock-in expression patterns were verified as accurate representations of endogenous expression. We find extensive overlap in expression among the different co-receptors. As defined by innervation into antennal lobe glomeruli, Ir25a is broadly expressed in 88% of all olfactory sensory neuron classes and is co-expressed in 82% of Orco+ neuron classes, including all neuron classes in the maxillary palp. Orco, Ir8a, and Ir76b expression patterns are also more expansive than previously assumed. Single sensillum recordings from Orco-expressing Ir25a mutant antennal and palpal neurons identify changes in olfactory responses. We also find co-expression of Orco and Ir25a in Drosophila sechellia and Anopheles coluzzii olfactory neurons. These results suggest that co-expression of chemosensory receptors is common in insect olfactory neurons. Together, our data present the first comprehensive map of chemosensory co-receptor expression and reveal their unexpected widespread co-expression in the fly olfactory system.

Impact of Percutaneous Mitral Valve Repair Using the MitraClipTM System on Ventricular Arrhythmias and ICD Therapies.

Transcatheter edge-to-edge repair (TEER) using the MitraClip™ device has been established as a suitable alternative to mitral valve surgery in patients with severe mitral regurgitation (MR) and high or prohibitive surgical risk. Only limited information regarding the impact of TEER on ventricular arrhythmias (VA) has been reported. The aim of the present study was to assess the impact of TEER using the MitraClipTM device on the burden of VA and ICD (Implantable Cardioverter Defibrillator) therapies. Among 600 MitraClipTM implantations performed in our clinic between September 2009 and October 2018, we identified 86 patients with successful TEER and an active implantable cardiac device (pacemaker, ICD, CRT-P/D (Cardiac Resynchronization Therapy-Pacemaker/Defibrillator)) eligible for retrospective VA analyses. These patients presented with mainly functional MR (81.4%) and severely reduced left ventricular ejection fraction (mean LVEF 22.1% ± 10.3%). The observation period comprised 456 ± 313 days before and 424 ± 287 days after TEER. The burden of ventricular arrhythmias (sustained ventricular tachycardia (sVT) and ventricular fibrillation (VF)) was significantly reduced after TEER (0.85 ± 3.47 vs. 0.43 ± 2.03 events per patient per month, p = 0.01). Furthermore, the rate of ICD therapies (anti-tachycardia pacing (ATP) and ICD shock) decreased significantly after MitraClipTM implantation (1.0 ± 3.87 vs. 0.32 ± 1.41, p = 0.014). However, reduction of VA burden did not result in improved two-year survival in this patient cohort with severely reduced LVEF. Mitral valve TEER using the MitraClip™ device was associated with a significant reduction of ventricular arrhythmias and ICD therapies.

One-year results following PASCAL-based or MitraClip-based mitral valve transcatheter edge-to-edge repair.

AIMS: Mitral valve transcatheter edge-to-edge repair (TEER) has been established as a suitable alternative to mitral valve surgery in patients with severe mitral regurgitation (MR) and high surgical risk. The PASCAL system represents a novel device, potentially augmenting the toolkit for TEER. The aim of this study was to assess and compare short and 1 year safety and efficacy of the PASCAL and MitraClip systems for TEER. METHODS AND RESULTS: Procedural, short, and 1 year outcomes of a 1:2 propensity-matched cohort including 41 PASCAL and 82 MitraClip cases were investigated. Matching was based on clinical, laboratory, echocardiographic, and functional characteristics. The primary endpoints assessed were procedural success [as defined by the Mitral Valve Academy Research Consortium (MVARC)], residual MR, functional class, and a composite endpoint comprising death, heart failure hospitalization, and mitral valve re-intervention. We found for the PASCAL and the matched MitraClip cohort no significant differences in MVARC defined technical (90.2% vs. 95.1%, P = 0.44), device (90.2% vs. 89.0%, P = 1.0), or procedural (87.8% vs. 80.5%, P = 0.45) success rates. Accordingly, the overall MR reduction and improvement in New York Heart Association (NYHA) class were comparable (1 year follow-up: MR ≤ 2 95% vs. 93.6%, P = 1.0; NYHA ≤ 2 57.1% vs. 66.7%, P = 0.59). The composite outcome revealed no statistically significant difference between both devices (1 year follow-up: 31.7% vs. 37.8%, P = 0.55). Interestingly, we found at both short and 1 year follow-up a significantly higher rate of patients with none or trace MR in the PASCAL-treated cohort (short follow-up: 17.9% vs. 0%, P = 0.0081; 1 year follow-up: 25% vs. 0%, P = 0.0016). Conversely, the rate of aborted device implantations due to an elevated transmitral gradient was higher in PASCAL interventions (9.8% vs. 1.2%, P = 0.04). CONCLUSIONS: Transcatheter edge-to-edge repair using the PASCAL or MitraClip device results in favourable and comparable outcomes regarding safety, efficacy, and clinical improvement after 1 year.

A neuropeptidergic circuit gates selective escape behavior of Drosophila larvae.

Animals display selective escape behaviors when faced with environmental threats. Selection of the appropriate response by the underlying neuronal network is key to maximizing chances of survival, yet the underlying network mechanisms are so far not fully understood. Using synapse-level reconstruction of the Drosophila larval network paired with physiological and behavioral readouts, we uncovered a circuit that gates selective escape behavior for noxious light through acute and input-specific neuropeptide action. Sensory neurons required for avoidance of noxious light and escape in response to harsh touch, each converge on discrete domains of neuromodulatory hub neurons. We show that acute release of hub neuron-derived insulin-like peptide 7 (Ilp7) and cognate relaxin family receptor (Lgr4) signaling in downstream neurons are required for noxious light avoidance, but not harsh touch responses. Our work highlights a role for compartmentalized circuit organization and neuropeptide release from regulatory hubs, acting as central circuit elements gating escape responses.

PASCAL-based mitral valve repair in an all-comer population: acute and mid-term clinical results.

AIMS: We investigated short and mid-term safety and efficacy of the PASCAL system for percutaneous mitral valve repair (PMVr) in severe mitral regurgitation (MR) in an all-comer population. METHODS AND RESULTS: In the first consecutive 41 patients undergoing PMVr using the PASCAL system in our centre, procedural success and safety were assessed. Efficacy in improving MR and functional class were evaluated. Median patient age was 74 years, 58.5% were male patients, and median European System for Cardiac Operative Risk Evaluation Score II was 5.1%. All patients suffered from severe MR with 59% functional MR, 29% degenerative MR, and 12% of mixed aetiology MR. The technical success rate was 90%, limited by four cases where PASCAL implantation was aborted due to a prohibitive mitral gradient. On average, 1.16 PASCAL devices per patient were implanted. All patients successfully implanted with a PASCAL device were discharged with MR grade ≤ 2 and 79% with MR grade ≤ 1. Mean follow-up was 8.7 ± 4.9 months. Ninety-seven per cent of patients remained at MR ≤ 2 at follow-up, which translated into a significantly improved New York Heart Association functional class as well as a significant reduction of systolic pulmonary artery pressure and brain natriuretic peptide levels. The procedure-related rate for major adverse events was 3%. Neither early nor late single-leaflet detachment was found. In one patient, air embolism occurred, resulting in modification of the PASCAL instructions for use. CONCLUSIONS: Percutaneous mitral valve repair using PASCAL in a real-world, all-comer population was feasible and safe, resulting in a significant mid-term reduction of MR with persistent clinical improvement.

Unveiling the sensory and interneuronal pathways of the neuroendocrine connectome in Drosophila.

Neuroendocrine systems in animals maintain organismal homeostasis and regulate stress response. Although a great deal of work has been done on the neuropeptides and hormones that are released and act on target organs in the periphery, the synaptic inputs onto these neuroendocrine outputs in the brain are less well understood. Here, we use the transmission electron microscopy reconstruction of a whole central nervous system in the Drosophila larva to elucidate the sensory pathways and the interneurons that provide synaptic input to the neurosecretory cells projecting to the endocrine organs. Predicted by network modeling, we also identify a new carbon dioxide-responsive network that acts on a specific set of neurosecretory cells and that includes those expressing corazonin (Crz) and diuretic hormone 44 (Dh44) neuropeptides. Our analysis reveals a neuronal network architecture for combinatorial action based on sensory and interneuronal pathways that converge onto distinct combinations of neuroendocrine outputs.

Automatic detection of synaptic partners in a whole-brain Drosophila electron microscopy data set.

We develop an automatic method for synaptic partner identification in insect brains and use it to predict synaptic partners in a whole-brain electron microscopy dataset of the fruit fly. The predictions can be used to infer a connectivity graph with high accuracy, thus allowing fast identification of neural pathways. To facilitate circuit reconstruction using our results, we develop CIRCUITMAP, a user interface add-on for the circuit annotation tool CATMAID.