BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250804T233041EDT-8311sJkuEm@132.216.98.100 DTSTAMP:20250805T033041Z DESCRIPTION: \n\n \n\nNeuromodulation shapes motor output at all levels of neural processing\n\n \n\nDirk Bucher\, PhD\n\nAssociate Professor\n\nFede rated Department of Biological Sciences\n New Jersey Institute of Technolog y and Rutgers University-Newark\n\n \n\n A detailed and realistic quantita tive understanding of neural circuit function is difficult for two reasons . First\, despite similar activity patterns\, underlying circuit component properties (like the expression levels of specific ion channels in specif ic cell types or the strength of synapses) can vary substantially across i ndividuals. Second\, circuit activity is critically dependent on the prese nce of neuromodulators. A multitude of substances like biogenic amines and neuropeptides sculpt circuit activity by tuning the properties of ion cha nnels and synapses\, most often through G protein-coupled receptors and se cond messenger signaling. Although the influence of neuromodulators on ion -channel and synaptic currents has been extensively studied and there is a lso broad understanding of how neuromodulators change the output of neural circuits\, systems and even behavior\, the mechanisms through which modul ation of the components results in particular system outputs is much less understood. Moreover\, few studies have examined how neuromodulators\, eve n those with overlapping or convergent actions\, interact at the component or circuit level. Such an exploration requires a neural circuit whose ana tomical connectivity is known and which can produce distinct and readily q uantifiable output in the presence of different neuromodulators.\n\nThe py loric circuit in the crustacean stomatogastric nervous system is one of th e few systems that satisfies these requirements\, and the rhythmic motor a ctivity of this central pattern generating circuit has served for decades as a testbed for understanding the organizing principles of circuit activa tion. In our efforts towards a quantitative understanding of circuit activ ation\, our recent work shows modulation at all levels of processing\, inc luding intrinsic excitability\, synapse function\, axonal action potential conduction\, and muscle activation. Importantly\, the complex patterns of convergence and divergence of co-modulator effects are modulator- and cel l type-specific. Convergent co-modulation can be either mostly linearly ad ditive or exhibit substantial nonlinearities. In the first case\, converge nt modulation can actually serve to reduce variability\, i.e. ensure consi stent circuit responses across individuals in the face of variability of b aseline excitability and synaptic strengths. Finally\, we also have starte d to show that neuromodulator signaling itself is subject to ligand- and a ctivity-dependent long-term regulation to ensure stable responses.\n DTSTART:20171012T160000Z DTEND:20171012T170000Z LOCATION:908\, McIntyre Medical Building\, CA\, QC\, Montreal\, H3G 1Y6\, 3 655 promenade Sir William Osler SUMMARY:QLS Featured Seminar Series - Dr. Dirk Bucher URL:/qls/channels/event/qls-featured-seminar-series-dr -dirk-bucher-282977 END:VEVENT END:VCALENDAR