scholarly journals A closed-loop optogenetic screen for neurons controlling feeding in Drosophila

Author(s):  
Celia K S Lau ◽  
Meghan Jelen ◽  
Michael D Gordon

Abstract Feeding is an essential part of animal life that is greatly impacted by the sense of taste. Although the characterization of taste-detection at the periphery has been extensive, higher order taste and feeding circuits are still being elucidated. Here, we use an automated closed-loop optogenetic activation screen to detect novel taste and feeding neurons in Drosophila melanogaster. Out of 122 Janelia FlyLight Project GAL4 lines preselected based on expression pattern, we identify six lines that acutely promote feeding and 35 lines that inhibit it. As proof of principle, we follow up on R70C07-GAL4, which labels neurons that strongly inhibit feeding. Using split-GAL4 lines to isolate subsets of the R70C07-GAL4 population, we find both appetitive and aversive neurons. Furthermore, we show that R70C07-GAL4 labels putative second-order taste interneurons that contact both sweet and bitter sensory neurons. These results serve as a resource for further functional dissection of fly feeding circuits.

2020 ◽  
Author(s):  
Celia KS Lau ◽  
Michael D Gordon

AbstractFeeding is an essential part of animal life that is impacted greatly by the sense of taste. Although the characterization of taste-detection at the periphery is extensive, higher-order taste and feeding circuits are still being elucidated. Here, we use an automated closed-loop optogenetic activation screen for novel taste and feeding neurons in Drosophila melanogaster. Out of 122 Janelia FlyLight Project GAL4 lines preselected based on expression pattern, we identify six lines that acutely promote feeding and 35 lines that inhibit it. As proof of principle, we follow up on the R70C07-GAL4 neuron population, which strongly inhibits feeding. Using split-GAL4 lines to isolate subsets of the R70C07-GAL4 population, we find both appetitive and aversive neurons. We also show that R70C07-GAL4 labels a population of putative second-order taste interneurons that contact both sweet and bitter sensory neurons. These results serve as a resource for further functional dissection of fly feeding circuits.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Pierre-Yves Musso ◽  
Pierre Junca ◽  
Meghan Jelen ◽  
Damian Feldman-Kiss ◽  
Han Zhang ◽  
...  

Manipulating feeding circuits in freely moving animals is challenging, in part because the timing of sensory inputs is affected by the animal’s behavior. To address this challenge in Drosophila, we developed the Sip-Triggered Optogenetic Behavior Enclosure (‘STROBE’). The STROBE is a closed-looped system for real-time optogenetic activation of feeding flies, designed to evoke neural excitation coincident with food contact. We previously demonstrated the STROBE’s utility in probing the valence of fly sensory neurons (Jaeger et al., 2018). Here we provide a thorough characterization of the STROBE system, demonstrate that STROBE-driven behavior is modified by hunger and the presence of taste ligands, and find that mushroom body dopaminergic input neurons and their respective post-synaptic partners drive opposing feeding behaviors following activation. Together, these results establish the STROBE as a new tool for dissecting fly feeding circuits and suggest a role for mushroom body circuits in processing naïve taste responses.


Robotica ◽  
2020 ◽  
pp. 1-18
Author(s):  
M. Garcia ◽  
P. Castillo ◽  
E. Campos ◽  
R. Lozano

SUMMARY A novel underwater vehicle configuration with an operating principle as the Sepiida animal is presented and developed in this paper. The mathematical equations describing the movements of the vehicle are obtained using the Newton–Euler approach. An analysis of the dynamic model is done for control purposes. A prototype and its embedded system are developed for validating analytically and experimentally the proposed mathematical representation. A real-time characterization of one mass is done to relate the pitch angle with the radio of displacement of the mass. In addition, first validation of the closed-loop system is done using a linear controller.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Proff ◽  
B Merkely ◽  
R Papp ◽  
C Lenz ◽  
P.J Nordbeck ◽  
...  

Abstract Background The prevalence of chronotropic incompetence (CI) in heart failure (HF) population is high and negatively impacts prognosis. In HF patients with an implanted cardiac resynchronisation therapy (CRT) device and severe CI, the effect of rate adaptive pacing on patient outcomes is unclear. Closed loop stimulation (CLS) based on cardiac impedance measurement may be an optimal method of heart rate adaptation according to metabolic need in HF patients with severe CI. Purpose This is the first study evaluating the effect of CLS on the established prognostic parameters assessed by the cardio-pulmonary exercise (CPX) testing and on quality of life (QoL) of the patients. Methods A randomised, controlled, double-blind and crossover pilot study has been performed in CRT patients with severe CI defined as the inability to achieve 70% of the age-predicted maximum heart rate (APMHR). After baseline assessment, patients were randomised to either DDD-CLS pacing (group 1) or DDD pacing at 40 bpm (group 2) for a 1-month period, followed by crossover for another month. At baseline and at 1- and 2-month follow-ups, a CPX was performed and QoL was assessed using the EQ-5D-5L questionnaire. The main endpoints were the effect of CLS on ventilatory efficiency (VE) slope (evaluated by an independent CPX expert), the responder rate defined as an improvement (decrease) of the VE slope by at least 5%, percentage of maximal predicted heart rate reserve (HRR) achieved, and QoL. Results Of the 36 patients enrolled in the study, 20 fulfilled the criterion for severe CI and entered the study follow-up (mean age 68.9±7.4 years, 70% men, LVEF=41.8±9.3%, 40%/60% NYHA class II/III). Full baseline and follow-up datasets were obtained in 17 patients. The mean VE slope and HRR at baseline were 34.4±4.4 and 49.6±23.8%, respectively, in group 1 (n=7) and 34.5±12.2 and 54.2±16.1% in group 2 (n=10). After completing the 2-month CPX, the mean difference between DDD-CLS and DDD-40 modes was −2.4±8.3 (group 1) and −1.2±3.5 (group 2) for VE slope, and 17.1±15.5% (group 1) and 8.7±18.8% (group 2) for HRR. Altogether, VE slope improved by −1.8±2.95 (p=0.31) in DDD-CLS versus DDD-40, and HRR improved by 12.9±8.8% (p=0.01). The VE slope decreased by ≥5% in 47% of patients (“responders to CLS”). The mean difference in the QoL between DDD-CLS and DDD-40 was 0.16±0.25 in group 1 and −0.01±0.05 in group 2, resulting in an overall increase by 0.08±0.08 in the DDD-CLS mode (p=0.13). Conclusion First results of the evaluation of the effectiveness of CLS in CRT patients with severe CI revealed that CLS generated an overall positive effect on well-established surrogate parameters for prognosis. About one half of the patients showed CLS response in terms of improved VE slope. In addition, CLS improved quality of life. Further clinical research is needed to identify predictors that can increase the responder rate and to confirm improvement in clinical outcomes. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Biotronik SE & Co. KG


Author(s):  
Justine Huart ◽  
Antoine Bouquegneau ◽  
Laurence Lutteri ◽  
Pauline Erpicum ◽  
Stéphanie Grosch ◽  
...  

Abstract Background Proteinuria has been commonly reported in patients with COVID-19. However, only dipstick tests have been frequently used thus far. Here, the quantification and characterization of proteinuria were investigated and their association with mortality was assessed. Methods This retrospective, observational, single center study included 153 patients, hospitalized with COVID-19 between March 28th and April 30th, 2020, in whom total proteinuria and urinary α1-microglobulin (a marker of tubular injury) were measured. Association with mortality was evaluated, with a follow-up until May 7th, 2020. Results According to the Kidney Disease Improving Global Outcomes staging, 14% (n = 21) of the patients had category 1 proteinuria (< 150 mg/g of urine creatinine), 42% (n = 64) had category 2 (between 150 and 500 mg/g) and 44% (n = 68) had category 3 proteinuria (over 500 mg/g). Urine α1-microglobulin concentration was higher than 15 mg/g in 89% of patients. After a median follow-up of 27 [14;30] days, the mortality rate reached 18%. Total proteinuria and urinary α1-microglobulin were associated with mortality in unadjusted and adjusted models. This association was stronger in subgroups of patients with normal renal function and without a urinary catheter. Conclusions Proteinuria is frequent in patients with COVID-19. Its characterization suggests a tubular origin, with increased urinary α1-microglobulin. Tubular proteinuria was associated with mortality in COVID-19 in our restropective, observational study.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2543
Author(s):  
Ruidong Ni ◽  
Suzeeta Bhandari ◽  
Perry R. Mitchell ◽  
Gabriela Suarez ◽  
Neel B. Patel ◽  
...  

Fatty acid amides are a diverse family of underappreciated, biologically occurring lipids. Herein, the methods for the chemical synthesis and subsequent characterization of specific members of the fatty acid amide family are described. The synthetically prepared fatty acid amides and those obtained commercially are used as standards for the characterization and quantification of the fatty acid amides produced by biological systems, a fatty acid amidome. The fatty acid amidomes from mouse N18TG2 cells, sheep choroid plexus cells, Drosophila melanogaster, Bombyx mori, Apis mellifera, and Tribolium castaneum are presented.


2021 ◽  
Vol 16 (01) ◽  
pp. e46-e50
Author(s):  
Carmen Joanna González Lemus ◽  
Fernando Xavier Romero Prieto

Abstract Objective This study aimed to estimate the prevalence of brachial plexus injuries and to characterize clinically and epidemiologically patients with brachial plexus injury. Materials and Methods In this cross-sectional descriptive study, 2,923 medical records of patients aged 1 to 64 years who presented at outpatient peripheral nerve unit of the Orthopedic Surgery Department of Hospital Roosevelt, Guatemala, from January 2017 to December 2017, were prospectively analyzed to identify the prevalence and factors associated with brachial plexus injuries. Results The prevalence rate of brachial plexus injuries in patients was 5.74%. This injury is more common in men (90.5%) aged 24 to 64 years. Brachial plexus injuries occurred secondary to motorcycle accident in 72% of the cases, with the majority affecting the dominant upper extremity. In addition, 64.28% of the patients took 1 to 6 months to seek consultation, whereas only 16.07% requested medical assistance <1 month from the onset of symptoms, and this result was associated with early diagnosis and adequate recovery during follow-up. Furthermore, 66.67% presented upper brachial plexus injury with no associated fractures or vascular injury, manifesting distress while performing daily activities that required hand, arm, and elbow movements. Conclusion The risk of suffering BPIs in Guatemala increases in economically active male patients that use motorcycles as main mode of transportation. Patients should consult immediately after injury onset to optimize management results. For this reason, hospitals must develop specialized clinical guidelines to speed up the identification and treatment of BPI injuries.


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