Project
Role of heterogeneous pyramidal cell populations and specific connectivity motifs in pattern completion and replay of memory sequences
Hippocampal sharp wave/ripple complexes (SWRs) are short (50–100 ms) episodes of coordinated network activity arising in the hippocampal CA3 area. They mediate the consolidation of explicit memories, and their disruption impairs memory whereas their prolongation enhances memory. However, the mechanisms governing the occurrence of these episodes remain obscure. To better understand SWR dynamics, we will focus on the role of heterogeneous pyramidal cell populations and specific connectivity motifs in pattern completion and replay of memory sequences. We will analyze the differential embedding of CA3 pyramids during SWRs, assess their specific connectivity, manipulate subsets of neurons using optogenetics in vitro and in vivo, and develop computational network models of SWRs that can be numerically simulated and analyzed mathematically. This work will considerably extend our understanding of sharp-wave models, which were established in our joint experimental-theoretical work in the previous funding period.
Image Poster excerpt showing model of interactions between (P) pyramidal cells, PV+ (B) basket cells, and (A) anti-SWR cells. Courtesy of Richard Kempter and Gaspar Cano
Team
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Prof Dr Richard Kempter
Humboldt-Universität zu Berlin
Deputy Spokesperson, Head Theoretical Neuroscience Lab
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Prof Dr Dietmar Schmitz
Charité-Universitätsmedizin Berlin
Head Schmitz Lab
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Dr Laura Moreno Velasquez
Charité – Universitätsmedizin Berlin
A01 Postdoc (AG Schmitz)
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Dr med Jörg Breustedt
Charité – Universitätsmedizin Berlin
A01 Postdoc (AG Schmitz)
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Dr Marta Orlando
Charité-Universitätsmedizin Berlin
A01/A02 Associate Postdoc
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Dr Rosanna Sammons
Charité-Universitätsmedizin Berlin
A01 Associated Postdoc
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Dr Nikolaus Maier
Charité–Universitätsmedizin Berlin
Senior Research Associate Neuroscience Research Center (NWFZ)
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Claire Cooper
Charité-Universitätsmedizin Berlin
A01 PhD (C01 alumna)
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Gaspar Cano
Humboldt-Universität zu Berlin
A01 PhD
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Stefano Masserini
A01 Associate PhD
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Alexandra Tzilivaki
Einstein Centre for Neurosciences Berlin
A01 Associate PhD
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Dr Eric Reifenstein
Humboldt-Universität zu Berlin
B01 Alumnus
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Dr Natalie Schieferstein
University of Bonn
A01 Alumna
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Dr Roberta Evangelista
BASE Foundation, Basel Switzerland
A01 Alumna
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Ana Toro
Humboldt-Universität zu Berlin
Student helper 2020-2021 - A01 Alumna
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Tizia Kaplan
(A01 Alumna) Student helper 2019
Publications
Ultraslow serotonin oscillations in the hippocampus delineate substates across NREM and waking
Claire Cooper, Daniel Parthier, Jérémie Sibille, John Tukker, Nicolas X. Tritsch, Dietmar Schmitz
bioRxiv (2024)
Sub-type specific connectivity between CA3 pyramidal neurons may underlie their sequential activation during sharp waves
Rosanna P. Sammons, Stefano Masserini, Laura Moreno-Velasquez, Verjinia D. Metodieva, Gaspar Cano, Andrea Sannio, Marta Orlando, Nikolaus Maier, Richard Kempter, Dietmar Schmitz
bioRxiv (2024)
Temperature elevations can induce switches to homoclinic action potentials that alter neural encoding and synchronization
Janina Hesse, Jan-Hendrik Schleimer, Nikolaus Maier, Dietmar Schmitz, Susanne Schreiber
Nat Commun. 13(1):3934 (2022)
Intra-ripple frequency accommodation in an inhibitory network model for hippocampal ripple oscillations
Natalie Schieferstein, Tilo Schwalger, Benjamin Lindner, Richard Kempter
PLoS Comput Biol. 20(2): e1011886 (2024)
Efficient generation of a self-organizing neuromuscular junction model from human pluripotent stem cells
Alessia Urzi, Ines Lahmann, Lan Vi N. Nguyen, Benjamin R. Rost, Angélica García-Pérez, Noemie Lelievre, Megan E. Merritt-Garza, Han C. Phan, Gary J. Bassell, Wilfried Rossoll, Sebastian Diecke, Severine Kunz, Dietmar Schmitz & Mina Gouti
Nat Commun. 14(1):8043 (2023)
Structure and function of the hippocampal CA3 module
Rosanna P. Sammons, Mourat Vezir, Laura Moreno-Velasqueza, Gaspar Cano, Marta Orlando, Meike Sievers, Eleonora Grass, Verjinia D. Metodieva, Richard Kempter, Helene Schmidt and Dietmar Schmitz
PNAS. 121 (6) e2312281120 (2024)
Synthetic surprise as the foundation of the psychedelic experience
Roberto De Filippo, Dietmar Schmitz
Neurosci Biobehav Rev. 157:105538 (2024)
Hippocampal GABAergic interneurons and memory
Alexandra Tzilivaki, John J. Tukker, Nikolaus Maier, Panayiota Poirazi, Rosanna P. Sammons, Dietmar Schmitz
Neuron. 111 (2023)
Gamma oscillation plasticity is mediated via parvalbumin interneurons
Michael D. Hadler, Alexandra Tzilivaki, Dietmar Schmitz, Henrik Alle, Jörg R. P. Geiger
Sci. Adv. 10,eadj7427(2024)
Differential ripple propagation along the hippocampal longitudinal axis
Roberto De Filippo, Dietmar Schmitz
eLife. 12:e85488 (2023)
Calcium-permeable channelrhodopsins for the photocontrol of calcium signalling
Rodrigo G. Fernandez Lahore, Niccolò P. Pampaloni, Enrico Peter, M.-Marcel Heim, Linda Tillert, Johannes Vierock, Johannes Oppermann, Jakob Walther, Dietmar Schmitz, David Owald, Andrew J. R. Plested, Benjamin R. Rost, Peter Hegemann
Nat Commun. 13:7844 (2022)
Interneuron switching on and off across memory rhythms
Alexandra Tzilivaki, Nikolaus Maier, Dietmar Schmitz
Neuron. 110(12):1884-1886 (2022)
GABAergic interneurons with nonlinear dendrites: from neuronal computations to memory engrams
Alexandra Tzilivaki, George Kastellakis, Dietmar Schmitz, Panayiota Poirazi
Neuroscience 489, 34-43 (2022)
A neural code for egocentric spatial maps in the human medial temporal lobe
Lukas Kunz, Armin Brandt, Peter C. Reinacher, Bernhard P. Staresina, Eric T. Reifenstein, Christoph T. Weidemann, Nora A. Herweg, Ansh Patel, Melina Tsitsiklis, Richard Kempter, Michael J. Kahana, Andreas Schulze-Bonhage, Joshua Jacobs
Neuron. 109(17) 2781-2796.e10 (2021)
Microcircuits for spatial coding in the medial entorhinal cortex
John J Tukker, Prateep Beed, Michael Brecht, Richard Kempter, Edvard I Moser, and Dietmar Schmitz
Physiol Rev. 102:653–688 (2022)
Recruitment of release sites underlies chemical presynaptic potentiation at hippocampal mossy fiber boutons
Marta Orlando, Anton Dvorzhak, Felicitas Bruentgens, Marta Maglione, Benjamin R. Rost, Stephan J. Sigrist, Jörg Breustedt, Dietmar Schmitz
PLoS Biol. 19(6):e3001149 (2021)
Synaptic learning rules for sequence learning
Eric T. Reifenstein, Ikhwan Bin Khalid, Richard Kempter
eLife. 10:e67171 (2021)
The sensory coding of warm perception
Ricardo Paricio-Montesinos, Frederick Schwaller, Annapoorani Udhayachandran, Florian Rau, Jan Walcher, Roberta Evangelista, Joris Vriens, Thomas Voets, James FA Poulet, Gary R. Lewin
Neuron. 106(5):830-841.e3 (2020)
Generation of sharp wave-ripple events by disinhibition
Roberta Evangelista, Gaspar Cano, Claire Cooper, Dietmar Schmitz, Nikolaus Maier and Richard Kempter
J Neurosci. 40(41):7811-7836 (2020)
Spikelets in pyramidal neurons: generating mechanisms, distinguishing properties, and functional implications
Martina Michalikova, Michiel WH Remme, Dietmar Schmitz, Susanne Schreiber and Richard Kempter
Rev Neurosci. 31(1):101-119 (2019)
Extracellular waveforms reveal an axonal origin of spikelets in pyramidal neurons
Martina Michalikova, Michiel WH Remme and Richard Kempter
J Neurophysiol. 120(4):1484-1495 (2018)
Interneuronal gap junctions increase synchrony and robustness of hippocampal ripple oscillations
André Holzbecher, Richard Kempter
Eur J Neurosci. 48(12):3446-3465 (2018)