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ZusammenfassungDer kardiogene Schock (CS) stellt den schwersten Verlauf einer akuten Herzinsuffizienz (AHF) mit exzessiven Letalitätsraten von bis zu 50% dar. Bei refraktärem Verlauf bieten temporäre mechanische Kreislaufunterstützungssysteme eine wertvolle Therapieoption. Insbesondere die ECLS-Therapie (extracorporeal life support) wird dem klinischen Bedarf entsprechend, trotz bislang fehlender Evidenz aus randomisiert-kontrollierten Studien, zunehmend häufiger bei CS eingesetzt. Vor diesem Hintergrund muss die ECLS-Indikation weiterhin unter kritischer Nutzen-Risiko-Abwägung und unter Berücksichtigung objektiver hämodynamischer sowie patientenbezogener klinischer Parameter gestellt werden. Aktuelle Leitlinien empfehlen ferner die Etablierung von CS-Zentren mit strukturierten Therapiekonzepten und eingespielten Teams. In diesem Artikel werden grundlegende pathophysiologische Konzepte und Therapieansätze der AHF und des CS beleuchtet und der Stellenwert der ECLS in diesem Setting eingeordnet.

How the body interacts with the brain to perform vital life functions such as feeding is one of the fundamental questions in physiology and neuroscience. Here, we use a whole-animal scanning transmission electron microscopy dataset of Drosophila to map out the neuronal circuits that connect the entire enteric nervous system to the brain via the insect vagus nerve at synaptic resolution. This revealed a periphery-brain feedback loop in which Piezo-expressing mechanosensory neurons sense food intake and convey that information onto serotonergic neurons within the brain. These serotonergic neurons integrate the interoceptive information with external and central inputs, and in turn stabilize rhythmic activity of serotonin receptor 7 expressing peripheral motor neurons that drive swallowing. Strikingly, the very same motor neurons also share an efference copy of their activity with the aforementioned mechanosensory neurons, thereby closing the motor-sensory-modulatory loop. Our analysis elucidates an elemental, albeit surprisingly complex reinforcement circuit in which rhythmic motor patterns are stabilized through afferent signaling to central serotonergic neurons upon completion of a rewarding action. The circuit motif is constructed to allow the distinction between self-generated action and those in response to the environment.

The forthcoming assembly of the adultDrosophila melanogastercentral 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 entireDrosophilabrain, 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 theDrosophilabrain 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.

SummarySex pheromones are key social signals in most animals. In Drosophila a dedicated olfactory channel senses a male pheromone, cis-vaccenyl acetate (cVA) that promotes female courtship while repelling males. Here we show that flies use separate cVA processing streams to extract qualitative and positional information. cVA olfactory neurons are sensitive to concentration differences in a 5 mm range around a male. Second-order projection neurons detect inter-antennal differences in cVA concentration, encoding the angular position of a male. We identify a circuit mechanism increasing left-right contrast through an interneuron which provides contralateral inhibition. At the third layer of the circuit we identify neurons with distinct response properties and sensory integration motifs. One population is selectively tuned to an approaching male with speed-dependent responses. A second population responds tonically to a male’s presence and controls female mating decisions. A third population integrates a male taste cue with cVA; only a simultaneous presentation of both signals promotes female mating via this pathway. Thus the olfactory system generates a range of complex percepts in discrete populations of central neurons that allow the expression of appropriate behaviors depending on context. Such separation of olfactory features resembles the mammalian what and where visual streams.HighlightscVA male pheromone has a 5 mm signaling range, activating two parallel central pathwaysPheromone-sensing neurons have spatial receptive fields sharpened by contralateral inhibitionPosition (where) and identity (what) are separated at the 3rd layer of cVA processingIntegrating taste and cVA in sexually dimorphic aSP-g controls female receptivity

SummaryToxicity by recombinant adeno-associated viruses (rAAV) in clinical gene therapy trials (e.g., by rAAV9-mediated fatal liver failure) significantly impairs translation of preclinical rAAV-based cardiac gene therapies employing these vectors. For rAAV5 - a capsid that has shown long-term safety in clinical trials - our translational study demonstrates effective transduction of the left ventricle (LV) of healthy pigs via catheter-based retrograde intravenous delivery (CRID) by means of luciferase reporter gene biodistribution analyses. Combination of rAAV5 with the cardioprotective human geneS100A1(hS100A1) prevents LV myocardial infarct (MI) enlargement and improves LV systolic contractile performance in a porcine model of post-MI chronic cardiac dysfunction. Use of a cardiac-biased promoter ensured the cardiac-directed expression of the therapeutic human transgene without signs of clinical toxicity. The beneficial effects of rAAV5-hS100A1were linked to an attenuated activity of post-MI inflammatory gene networks and this was further validated in a murine model. These novel data together with proven scalable producibility and low pre-existing immunity against rAAV5 in humans may collectively advance clinical translation of rAAV5-hS100A1as a gene therapy medicinal product (GTMP) for a common cardiovascular disease, such as chronic heart failure (CHF).HighlightsRecent fatal adverse events in recombinant adeno-associated virus (AAV)-based clinical gene therapy trials advise the use of rAAV serotypes with proven long-term clinical safety, such as rAAV5, for the pre-clinical development and clinical translation of rAAV-based cardiac gene therapy medicinal products.In a biodistribution and therapeutic proof-of-concept study in farm pigs, rAAV5 was identified as an effective viral vector for cardiac gene transfer and gene therapy for post-ischemic cardiac dysfunction when applied by a standardized cardiac-targeted catheter-based route of administration with the luciferase reporter and cardioprotective human gene S100A1 (hS100A1), respectively.A systems biology analysis linked the novel finding of mitigated inflammatory and activated cardioprotective gene network activities in rAAV5-hS100A1treated postischemic myocardium with improved study left ventricular ejection fraction and prevention of myocardial infarct extension, respectively, which warrants further mechanistic molecular studies.Since rAAV5 has been recently approved for clinical use in a non-cardiac indication and cardiac-targeted S100A1 gene therapy has been effective in numerous pre-clinical animal models of acute and chronic cardiac dysfunction, our translational data support an expedited developmental path for rAAV5-hS100A1throughout investigational new drug-enabling studies towards a first-in-human clinical trial for post-myocardial infarction heart failure.

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.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.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.

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.

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.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.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.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.

Introduction: For S100A1-based heart failure gene therapies, AAV9 and 6 have shown efficacy in pre-clinical large animal studies. As AAV9 has shown concerning signs of toxicity in clinical studies and AAV6 displays poor production yields, there is need for a novel safe and cardiac-specific AAV serotype. Hypothesis: We hypothesized that in a pig model the safety proven and scalably manufacturable AAV5 may be a suitable vector for S100A1-based gene therapy of post-ischemic cardiac dysfunction. Methods: AAV production, 2h balloon-occlusion of the LCX, retrograde cardiac gene delivery, cardiac MRI, late gadolinium enhancement (LGE), global T1 relaxation, qPCR, RNA-Seq, WGCNA, KEGG, Reactome, LAD-ligation mouse model Results: In a comparative study of AAV5-, 6- and 9-luciferase (luc) in healthy farm pigs (n=5 each; 1x10 13 vgc/pig), AAV5 achieved a more homogeneous cardiac apical-basal transduction pattern than AAV6 with a higher luc activity than AAV9. In a clinically relevant endpoint driven study, we demonstrated a significant improvement in EF (+19 ± 5 %) 12 weeks after retrograde AAV5- S100A1 gene delivery compared to AAV5-luc in infarcted pigs (n=4 each; 1x10 13 vgc/pig). Moreover, S100A1 -treated pigs showed significantly less infarct extension (-0.5 ± 0.3 g vs. 5 ± 1.3 g (luc)) measured by cardiac MRI. There were no unfavorable alterations in blood chemistry or ECG. S100A1 expression was predominantly contained to the heart. The WGCNA unveiled a significant correlation between the improved EF and a suppression of inflammatory and immunological pathways (r=-0.96, p < 0.01) and between the absent infarct extension and enhanced activity of cardioprotective signaling (r=-0.82, p < 0.05). With injections of 2х10 11 vgc of AAV5- S100A1 or AAV5-gfp (n=4 each) into the remote myocardium in the mouse model, we confirmed a significant improvement in FS (+43.8 ± 8.8 %, vs. gfp) and suppression of inflammatory gene expression including i.e., IL1b or TNFa by S100A1. Conclusion: We conclude that AAV5 is suitable for S100A1-based gene therapy of post-ischemic cardiac dysfunction and that this vector/target combination can help accelerating the way towards a clinical trial. We also found novel signaling pathways that may be involved in S100A1’s therapeutic actions.

Introduction: A high transduction efficacy and potency of AAV-based cardiac gene therapies is key for the clinical translation in which hereditary and acquired cardiac disorders will be targeted. As such, ultrapure vectors with superior biological and therapeutic capabilities are a must for these therapies. Hypothesis: We hypothesized that our developed affinity chromatography (AC) based purification system will increase AAV recovery and - potency. Methods: AAV vector production, AC based - or iodixanol density gradient (DG) based purification, Q-PCR, WB, EM, LC-MS/MS, P-loop Results: Using the same vector input quantity, the AC-based purification enabled an approximately 13-fold greater vector genome copy (vgc) recovery than the DG-based purification. Mass spectrometry analysis demonstrated ultrapure AAV9 vectors as a result of an AC purification (AAV9 93.24% vs. 6,76% contaminants) whereas corresponding DG preparations resulted in highly contaminated vectors (AAV9 5.49% vs. 94,51% contaminants). Biological potency of AC- and DG-purified AAV9 vectors towards cardiac transduction were determined by systemic injections of 1·10 10 , 1·10 11 or 1·10 12 vgc of AAV9-EGFP in C57BL/6 mice (n=8 each group). AC-purified AAVs achieved a significantly higher cardiac transduction efficacy for every dosage assessed by comparative bulk myocardial DNA, RNA and protein level analysis after 2 weeks. Therapeutic potency was examined for a recently published novel target for chronic heart failure namely the RFXP1-RLN system. To this end, a dosage of 5·10 11 vgcs of either AC- or DG purified AAV9-RXFP1 vectors were systemically injected and the cardiac contractile performance increase was captured after 2 weeks in mice of both groups. Of note, 10 minutes after RLN administration, the rise in LV +dp/dt max. was already significantly greater in the AC- than the DG-vector treated group (AC: 13594+/-1972 vs. DC: 9822+/-801 mmHg/s; n=8 per group, p Conclusion: The data clearly promote AC-based AAV purification as a novel standard for cardiovascular basic and translational research. Higher consistency in results, higher therapeutic effects and superior biological potency can be expected from higher production yields of ultrapure AAVs even at lower vector dosages.

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. A deep-learning-based approach enables automatic identification of synaptically connected neurons in electron microscopy datasets of the fly brain.

The trend towards electrification in the energy and transportation sector requires the build-up of new production capacities for the next generation of high-end battery cells and packs. Consistent high quality products, minimum manufacturing costs and modularity of the production system are considered central planning targets. Here we present a multi-level-simulation approach that is able to complement conventional planning targets while assessing the usage of energy within battery cell manufacturing considering machine availability and site locations. The energy assessment combines simulation models at machine and process level with a model that specifies technical building systems and the building shell. The simulation model was parameterized based on insights from scientific literature, equipment manufacturer data sheets and was checked for plausability through expert interviews. Our results show that improving the energy efficiency of the coating / drying process can reduce total energy consumption of the battery manufacturing system by 13 to 30 % depending on machine availability. Considering the location of the reference factory, Germany performed best in terms of primary energy demand, Sweden best in terms of energy related CO2 emissions and China achieved superior results in terms of energy related costs.

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.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).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.

Summary 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.

Funder: Howard Hughes Medical Institute; FundRef: http://dx.doi.org/10.13039/100000011, 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.

The hemibrain connectome (Scheffer et al., 2020) provides large scale connectivity and morphology information for the majority of the central brain of Drosophila melanogaster. Using this data set, we provide a complete description of the most complex olfactory system studied at synaptic resolution to date, covering all first, second and third-order neurons of the olfactory system associated with the antennal lobe and lateral horn (mushroom body neurons are described in a parallel paper, Li et al., 2020). We develop a generally applicable strategy to extract information flow and layered organisation from synaptic resolution connectome graphs, mapping olfactory input to descending interneurons. This identifies a range of motifs including highly lateralised circuits in the antennal lobe and patterns of convergence downstream of the mushroom body and lateral horn. We also leverage a second data set (FAFB, Zheng et al., 2018) to provide a first quantitative assessment of inter- versus intra-individual stereotypy. Complete reconstruction of select developmental lineages in two brains (three brain hemispheres) reveals striking similarity in neuronal morphology across brains for >170 cell types. Within and across brains, connectivity correlates with morphology. Notably, neurons of the same morphological type show similar connection variability within one brain as across brains; this property should enable a rigorous quantitative approach to cell typing.

ZusammenfassungDie koronare Herzerkrankung (KHK) stellt mit circa 70% die häufigste Ursache für die Entwicklung einer chronischen Herzinsuffizienz dar. Als einziger kausaler Ansatz ist die Revaskularisation die wichtigste Therapie, um eine Verbesserung der kardialen Funktion und Gesamtprognose zu erreichen. Bislang liegen nur für die chirurgische Revaskularisation positive Daten aus randomisierten, kontrollierten Studien vor. Die Entscheidung hinsichtlich Bypassoperation oder perkutaner Koronarintervention ist eine klassische Fragestellung für das Heartteam, wobei neben dem klinischen Zustand und operativen Risiko des Patienten die Erreichbarkeit einer vollen Revaskularisation, die Koronaranatomie, Herzklappenerkrankungen und weitere Komorbiditäten mit einkalkuliert werden müssen. Bei Mehrgefäß-KHK kommt eine perkutane Koronarintervention infrage, wenn dadurch eine vollständige Revaskularisation erreicht werden kann und/oder das OP-Risiko als deutlich erhöht einzuschätzen ist. Weiterführende Therapieansätze bis hin zu kardialen Unterstützungssystemen und die Listung zur Herztransplantation sollten erst nach Revaskularisation erwogen werden.

Large animal ischemic cardiomyopathy models are widely used for preclinical testing of promising novel therapeutic approaches. Pressure volume (PV) loop analysis and cardiac magnetic resonance imaging (CMRI) allow functional and morphological phenotyping. In this study we performed a comparative analysis of both methods highlighting the strength of each and their synergistic potential. Myocardial infarction (MI) was created in German farm pigs (German Landrace) by 2 h LCX occlusion (n = 11) and subsequent reperfusion. Cardiac function was assessed by PV-loops and CMRI 56 and 112 days post-MI. Two hours occlusion of the LCX led to mid-size left ventricular (LV) MI represented by high-sensitive troponin T (hsTnT) 3 days post-MI, correlating well with cardiac CMRI late enhancement. CMRI determined end-diastolic and end-systolic volumes significantly increased post-MI, while ejection fraction was reduced in infarcted animals compared to the sham group (n = 6). PV-loop derived preload-insensitive parameters of systolic and diastolic function were diminished post-MI compared to sham animals while preload-dependent parameters only deteriorated in advanced HF. PV-loop analysis significantly correlates with CMRI analysis of cardiac function in pig post-MI ischemic cardiomyopathy. PV-Loop analysis accurately quantifies LV volumetry and function in post-MI HF, and thus eccentric LV morphology. PV-loop analysis correlates well to cardiac MRI. Preload-insensitive parameters show high sensitivity to quantify HF while preload-sensitive parameters are not able to quantify early-stages of LV HF.

Making inferences about the computations performed by neuronal circuits from synapse-level connectivity maps is an emerging opportunity in neuroscience. The mushroom body (MB) is well positioned for developing and testing such an approach due to its conserved neuronal architecture, recently completed dense connectome, and extensive prior experimental studies of its roles in learning, memory, and activity regulation. Here, we identify new components of the MB circuit inDrosophila, including extensive visual input and MB output neurons (MBONs) with direct connections to descending neurons. We find unexpected structure in sensory inputs, in the transfer of information about different sensory modalities to MBONs, and in the modulation of that transfer by dopaminergic neurons (DANs). We provide insights into the circuitry used to integrate MB outputs, connectivity between the MB and the central complex and inputs to DANs, including feedback from MBONs. Our results provide a foundation for further theoretical and experimental work.

Recurrent episodes of decompensated heart failure (HF) represent an emerging cause of hospitalizations in developed countries with an urgent need for effective therapies. Recently, the pregnancy-related hormone relaxin (RLN) was found to mediate cardio-protective effects and act as a positive inotrope in the cardiovascular system. RLN binds to the RLN family peptide receptor 1 (RXFP1), which is predominantly expressed in atrial cardiomyocytes. We therefore hypothesized that ventricular RXFP1 expression might exert potential therapeutic effects in an in vivo model of cardiac dysfunction. Thus, mice were exposed to pressure overload by transverse aortic constriction and treated with AAV9 to ectopically express RXFP1. To activate RXFP1 signaling, RLN was supplemented subcutaneously. Ventricular RXFP1 expression was well tolerated. Additional RLN administration not only abrogated HF progression but restored left ventricular systolic function. In accordance, upregulation of fetal genes and pathological remodeling markers were significantly reduced. In vitro, RLN stimulation of RXFP1-expressing cardiomyocytes induced downstream signaling, resulting in protein kinase A (PKA)-specific phosphorylation of phospholamban (PLB), which was distinguishable from β-adrenergic activation. PLB phosphorylation corresponded to increased calcium amplitude and contractility. In conclusion, our results demonstrate that ligand-activated cardiac RXFP1 gene therapy represents a therapeutic approach to attenuate HF with the potential to adjust therapy by exogenous RLN supplementation.

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 Drosophila (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. These results suggest co-expression of chemosensory receptors is common in 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.