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X-WR-CALNAME:Bordeaux Neurocampus
X-ORIGINAL-URL:https://www.bordeaux-neurocampus.fr/en/
X-WR-CALDESC:Events for Bordeaux Neurocampus
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TZID:Europe/Paris
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DTSTART:20230326T010000
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DTSTART:20231029T010000
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DTSTART;TZID=Europe/Paris:20230908T113000
DTEND;TZID=Europe/Paris:20230908T113000
DTSTAMP:20260527T130128
CREATED:20230222T083117Z
LAST-MODIFIED:20230825T065652Z
UID:156162-1694172600-1694172600@www.bordeaux-neurocampus.fr
SUMMARY:Seminar - Nako Nakatsuka
DESCRIPTION:Venue: Centre Broca Nouvelle-Aquitaine \n\nNako Nakatsuka\nLaboratory of Biosensors and Bioelectronics (LBB)\nETH Zürich\nhttps://lbb.ethz.ch/the-group/principal-investigator/nakatsuka-nako.html \nInvited by Clémentine Bosch Bouju (NutriNeuro) \nTitle\nAptamer-based biosensors for ex vivo neurotransmitter monitoring  \nAbstract\nAdvancing our understanding of brain (dys)function necessitates novel nanotools that can monitor chemical signaling with high spatial resolutions. While advanced methods to record electrical signaling from neurons are prevalent (e.g.\, microelectrode arrays\, MEAs)\, tools to monitor chemical signaling have been limited. We have tackled this challenge by coupling the inherent selectivity of DNA-based recognition elements termed aptamers\, with nanoscale pipettes with openings of ca. 10 nm. Aptamers are systematically designed oligonucleotide receptors that exhibit highly specific and selective recognition of targets. Aptamers that recognize small-molecule neurotransmitters\, including serotonin and dopamine\, have recently been isolated. Upon reversible target binding\, aptamers undergo a rearrangement of the negatively charged backbone\, and these dynamic structural changes can be transduced as measurable changes in current through the nanoscale orifice of the sensors. Nanoscale confinement of the sensor surface results in single-molecule sensitivity while simultaneously reducing biofouling for long-term recordings in complex environments\, overcoming a critical bottleneck for clinical biosensors. We have demonstrated the capacity to detect physiologically relevant differences in neurotransmitter amounts released by live neurons in complex media with unprecedented sensitivity. Further\, through seamless integration into patch clamp setups\, our sensors have been deployed to track endogenous dopamine release in acute brain slices. Through collaboration\, we are currently tracking serotonin while simultaneously recording electrical responses in acute mouse embryonic hindbrain–spinal cord preparations isolated on MEAs. Thus\, we demonstrate the translatability of these sensors to other neuroscience groups and the possibility to conduct continuous recordings in localized regions with nanoscale resolution. \nKey publications\nWeaver S\, Mohammadi MH\, Nakatsuka N. Aptamer-functionalized capacitive biosensors. Biosens Bioelectron. 2023 Mar 15;224:115014. doi: 10.1016/j.bios.2022.115014. Epub 2022 Dec 23. PMID: 36628826. \nZhao C\, Cheung KM\, Huang IW\, Yang H\, Nakatsuka N\, Liu W\, Cao Y\, Man T\, Weiss PS\, Monbouquette HG\, Andrews AM. Implantable aptamer-field-effect transistor neuroprobes for in vivo neurotransmitter monitoring. Sci Adv. 2021 Nov 26;7(48):eabj7422. doi: 10.1126/sciadv.abj7422. Epub 2021 Nov 24. PMID: 34818033; PMCID: PMC8612678. \nNako Nakatsuka\, Alix Faillétaz\, Dominic Eggemann\, Csaba Forró\, János Vörös\, and Dmitry Momotenko. Aptamer Conformational Change Enables Serotonin Biosensing with Nanopipettes. Anal. Chem. 2021\, 93\, 8\, 4033–4041. doi  10.1021/acs.analchem.0c05038 \nMoraldo C\, Vuille-Dit-Bille E\, Shkodra B\, Kloter T\, Nakatsuka N. Aptamer-modified biosensors to visualize neurotransmitter flux. J Neurosci Methods. 2022 Jan 1;365:109386. doi: 10.1016/j.jneumeth.2021.109386. Epub 2021 Oct 13. PMID: 34653500. \nNakatsuka N\, Heard KJ\, Faillétaz A\, Momotenko D\, Vörös J\, Gage FH\, Vadodaria Sensing serotonin secreted from human serotonergic neurons using aptamer-modified nanopipettes. Mol Psychiatry. 2021 Jul;26(7):2753-2763. doi: 10.1038/s41380-021-01066-5. Epub 2021 Mar 25. PMID: 33767349. \nNakatsuka N\, Yang KA\, Abendroth JM\, Cheung KM\, Xu X\, Yang H\, Zhao C\, Zhu B\, Rim YS\, Yang Y\, Weiss PS\, Stojanović MN\, Andrews AM. Aptamer-field-effect transistors overcome Debye length limitations for small-molecule sensing. Science. 2018 Oct 19;362(6412):319-324. doi: 10.1126/science.aao6750. Epub 2018 Sep 6. PMID: 30190311; PMCID: PMC6663484. \n
URL:https://www.bordeaux-neurocampus.fr/en/event/seminar-nako-nakatsuka/
CATEGORIES:For scientists,home-event,Seminars
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DTSTART;TZID=Europe/Paris:20230908T143000
DTEND;TZID=Europe/Paris:20230908T143000
DTSTAMP:20260527T130128
CREATED:20230703T073559Z
LAST-MODIFIED:20230727T122911Z
UID:160849-1694183400-1694183400@www.bordeaux-neurocampus.fr
SUMMARY:Thesis defense - Stéphane Léon
DESCRIPTION:Venue: Centre Broca \nDefense in english \n\nStéphane Léon\nInserm\nTeam: Energy balance and obesity\nThesis supervisor: Carmelo Quarta \n\nTitle\nSingle-cell mapping of POMC neurons in obesity \nAbstract\nThe hypothalamus contains heterogeneous neurons with different functional identities\, a critical feature for brain-mediated control of body weight and energy metabolism. Alterations in the synaptic activity and neuropeptide production capacity of neurons in this brain region are implicated in the pathogenesis of obesity and its associated metabolic sequelae. However\, the specific neuronal subtypes that contribute to metabolic control or brain-mediated disease progression remain to be elucidated. Hypothalamic pro-opiomelanocortin (POMC) neurons\, which are responsible for the induction of satiety\, represent a potential therapeutic target. Although traditionally thought to be relatively homogeneous\, recent studies have revealed multiple layers of heterogeneity within hypothalamic POMC-expressing neurons. In adult mammals\, mature POMC neurons express variable levels of their main marker Pomc. However\, no study has thus far investigated the relationship between the molecular and functional heterogeneity of subsets of POMC neurons expressing different levels of their main identity marker. Diet-induced obesity (DIO) is associated with functional alterations involving POMC neurons\, but most of the studies have so far explored how dietary or metabolic cues affect the whole neuronal population\, without providing detailed information on possible cell-specific effects.  \n     This project aimed to (i) investigate the molecular and functional heterogeneity of POMC neurons at single cell level under physiological conditions and (ii) uncover the cell-specific impact of DIO on POMC neuron function. By combining genetic mouse models for lineage tracing of mature POMC neurons with multimodal single-cell profiling approaches\, we revealed a subpopulation of ‘Ghost’ neurons endowed with postnatal identity plasticity. Compared to ‘classical’ POMC neurons\, Ghost neurons exhibit negligible expression of Pomc and other cell identity markers\, impaired functional responses to nutrient and hormonal cues\, and distinct neuroanatomical properties. Intriguingly\, the number of Ghost neurons is increased in DIO mice\, independent of neurogenesis or cell death\, and this identity switch can be rescued by diet-induced weight loss. DIO did not lead to global changes but rather to cell-specific adaptations in the electrophysiological properties in one clusters of cells that resemble the identified Ghost neurons. \n     My data\, therefore\, shed new light on the high degree of molecular and functional heterogeneity of POMC neurons under both physiological conditions and obesogenic states. Such heterogeneity includes the presence of atypical clusters of POMC cells with atypical molecular and functional identity that are insensitive to acute dietary cues. Moreover\, my data suggests that specialised hypothalamic neurons can lose or possibly regain their functional identity throughout adult life in response to changes in body weight\, challenging the current dogma that neuronal fate is ‘fixed’ after development. Thus\, prolonged exposure to dietary cues in adulthood may alter mechanisms of neuronal identity maintenance\, and this novel mechanism may potentially contribute to the progression of diet-induced obesity and its associated health sequelae. \nKey words: POMC neurons\, Heterogeneity\, Hypothalamus\, Obesity \nJury\nQuarta Carmelo\, Dr\nGangarossa Guiseppe\, Pr\nMagnan Christophe\, Pr\nRovere Carole\, Dr\nMoisan Marie-Pierre\, Dr \nPublications\n1. Leon S\, Nadjar A\, Quarta C. Microglia–Neuron Crosstalk in Obesity: Melodious Interaction or Kiss of Death? (2021) International Journal of Molecular Sciences. 2021.22(10):5243. \n2. Saucisse N\, Mazier W\, Simon V\, Binder E\, Catania C\, Bellocchio L\, Romanov RA\, Leon S\, Matias I\, Zizzari P\, Quarta C\, Cannich A\, Meece K\, Gonzales D\, Clark S\, Becker JM\, Yeo GSH\, Merkle FT\, Wardlaw SL\, Harkany T\, Massa F\, Marsicano G\, Cota D (2020). POMC neurons functional heterogeneity relies on mTORC1 signaling. Cell Rep. 2021 Oct 12;37(2):109800. doi: 10.1016/j.celrep.2021.109800. \n3. Leyrolle Q\, Decoeur F\, Dejean C\, Bosch-Bouju C\, Morel L\, Leon S\, Amadieu C\, Sere A\, Schwendimann L\, Aubert A\, De Smedt-Peyrusse V\, Grégoire S\, Bretillon L\, Acar N\, Pallet V\, Joffre C\, Tremblay ME\, Gressens P\, Layé S\, Nadjar A (2021). Dietary n-3 PUFA deficiency disrupts myelination processes during brain development\, Glia. 2022 Jan;70(1):50-70. doi: 10.1002/glia.24088. Epub 2021 Sep 14. \n
URL:https://www.bordeaux-neurocampus.fr/en/event/thesis-defense-stephane-leon/
LOCATION:Amphi Centre Broca Nouvelle Aquitaine\, Université de Bordeaux\, 146 Rue Léo Saignat\, Bordeaux\, France\, France
CATEGORIES:Thesis
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