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X-WR-CALNAME:Bordeaux Neurocampus
X-ORIGINAL-URL:https://www.bordeaux-neurocampus.fr
X-WR-CALDESC:Évènements pour Bordeaux Neurocampus
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DTSTART:20260329T010000
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DTSTART;TZID=Europe/Paris:20260403T113000
DTEND;TZID=Europe/Paris:20260403T113000
DTSTAMP:20260406T034111
CREATED:20250624T075248Z
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UID:185239-1775215800-1775215800@www.bordeaux-neurocampus.fr
SUMMARY:PhD Seminar - Joechen Roeper
DESCRIPTION:Venue: Centre Broca \n\nPr. Joechen Roeper\nInstitute of Neurophysiology\nGoethe University\, Frankfurt\nGermany \nInvited by Jakob Scharnholz (IMN) \n\n\n\n\n\n\n\n\n\n\n\nScientific Focus\nDiversity of Dopamine Neurons and the 22q11 model of Schizophrenia\nAbstract\nSchizophrenia (SCZ) is associated with presynaptic dopaminergic (DA) hyperactivity\, particularly in the associative striatum. However\, direct mechanistic insights from preclinical models have remain limited. Here\, we present the first direct evidence of elevated baseline nigrostriatal dopaminergic activity in a mouse model of the highest known genetic risk factor for SCZ\, the 22q11.2 microdeletion. The Df(16)A+/- mouse model\, which harbors a hemizygous chromosomal deletion on chromosome 16 syntenic to the human 22q11.2 locus\, showed selective hyperactivity in the medial substantia nigra (mSN) DA neurons of both sexes during chronic in vivo single-unit recordings in freely moving animals\, in the absence of pharmacological manipulations. Chemogenetic tagging refined the specific hyperactive DA subpopulation within the mSN revealing that this hyperactivity was confined to DA neurons projecting to the dorsomedial striatum (DMS). DA release dynamics with dLight fiber photometry confirmed elevated DA release specifically in the DMS. Projection-resolved single-nucleus RNA sequencing uncovered the upregulation of the NMDA subunit Grin2c and downregulation of the voltage-gated sodium channel modulator Fgf12 in DMS-projecting DA neurons in Df(16)A+/- mice. In vitro patch-clamp recordings further confirmed functional impact on excitability. Our findings reveal the specific locus of a baseline hyperdopaminergic state within DMS-projecting mSN neurons of Df(16)A+/- mice and provide molecular mechanistic insights linking SCZ genetic risk to dopaminergic dysfunction in defined nigrostriatal subcircuits.\nRecent publications\n\n\nRebound Bursting Selectively Enables Fast Dynamics in Dopamine Midbrain Neurons Projecting to the Dorsolateral Striatum.\nStojanovic S\, Knowlton CJ\, Egger-Mackrodt R\, Mankel J\, Shin J\, Lammel S\, Canavier CC\, Roeper J.\nJ Neurosci. 2025 Oct 29;45(44):e0361252025. doi: 10.1523/JNEUROSCI.0361-25.2025.\n\n\n\nRecovery of the full in vivo firing range in post-lesion surviving DA SN neurons associated with Kv4.3-mediated pacemaker plasticity.\nKovacheva L\, Shin J\, Zaldivar-Diez J\, Mankel J\, Farassat N\, Costa KM\, Thakur P\, Obeso JA\, Roeper J.\nElife. 2025 Sep 18;14:e104037. doi: 10.7554/eLife.104037\n\n\n\nOptogenetic action potentials and intrinsic pacemaker interplay in retrogradely identified midbrain dopamine neurons.\nHammer N\, Vogel P\, Lee S\, Roeper J.\nEur J Neurosci. 2024 Mar;59(6):1311-1331. doi: 10.1111/ejn.16208\n\n\n\nCav1.3 calcium channels are full-range linear amplifiers of firing frequencies in lateral DA SN neurons.\nShin J\, Kovacheva L\, Thomas D\, Stojanovic S\, Knowlton CJ\, Mankel J\, Boehm J\, Farassat N\, Paladini C\, Striessnig J\, Canavier CC\, Geisslinger G\, Roeper J.\nSci Adv. 2022 Jun 10;8(23):eabm4560. doi: 10.1126/sciadv.abm4560.\n\n\n\n\n\n\n\n\n\n\n\n\n\nMeet the speaker!\nYou are a research staff ? Write to Julia Goncalves and Jakob Scharnholz who will organize the schedule. \nYou are a PhD student? You can register to share some pizza after the talk. Registration opens 3 weeks before. \n\nPhD seminars are organized by the NBA\, Bordeaux Neurocampus\, and the Bordeaux Neurocampus Graduate Program.  \n \n
URL:https://www.bordeaux-neurocampus.fr/event/phd-seminar-joechen-roeper/
CATEGORIES:A la une,Conférences mensuelles,IMN,Pour les scientifiques
ATTACH;FMTTYPE=image/jpeg:https://www.bordeaux-neurocampus.fr/wp-content/uploads/2025/06/roeper-vign.jpg
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