SFB 1134:  Functional ensembles: cellular components, patterned activity and plasticity of co-active neurons in local networks

• Subject Area: Medicine
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 243553651

Representation is a fundamental principle of neuroscience, if not its overarching leitmotif: We all believe that perceptions, memories, thoughts, choices, actions and feelings have a physical correlate in the nervous system. Converging evidence indicates that neuronal representations are formed by reproducible multi-neuronal activity patterns. Thus, elementary cognitive or behavioral states are causally linked to groups of co-active neurons, called neuronal ensembles.We use a large variety of modern approaches to monitor, analyse and manipulate neuronal ensembles in defined functional systems and networks. Our technical approaches comprise electrophysiology at the single- and multiple cell level, life imaging of neuronal activity, virus-mediated modification of defined cell populations, optogenetic manipulations, anatomical tracing techniques, ultrastructural analyses and advanced data analysis. We study mnemonic, sensory, emotional and executive control systems in behaving rodents or brain slice preparations. With this interdisciplinary approach and the unifying idea of functional ensembles as elementary representations we will clarify three important questions: i) How are selected neurons entrained into an ensemble, and how are others excluded? ii) What are the characteristic features of spatio-temporal activity patterns in different networks?iii) How do ensembles adapt to novel experience and to changing inner or outer conditions?Together, we hope to contribute to understanding the cell- and network-level mechanisms allowing our nervous system to form representations in a functionally adaptive manner.

• DFG Programme: Collaborative Research Centres

Completed projects

• A01 - Downstream signalling of hippocampal ensembles in the entorhinal cortex (Project Head Draguhn, Andreas )
• A02 - The effect of synaptic short-term plasticity on granule cell activity in the dentate gyrus microcircuit (Project Head von Engelhardt, Jakob )
• A03 - Structural and functional diversity of the axon initial segment of principal neurons in hippocampal ensembles. (Project Heads Both, Martin ;  Schultz, Christian )
• A04 - Neuronal ensembles of thalamocortical networks mediating sensorimotor integration (Project Heads Kuner, Thomas ;  Körber, Christoph )
• A05 - Identified neuronal ensembles subserving spatial coding in the medial entorhinal cortex (Project Head Monyer, Hannah )
• B01 - Local and expanding glial activity patterns in memory-related networks of mice (Project Head Sprengel, Rolf )
• B02 - Neuronal ensembles and metabolic homeostasis during gamma oscillations in the hippocampal CA3 network (Project Head Kann, Oliver )
• B03 - Neuronal ensembles encoding distinct sensory modalities in the mouse somatosensory cortex (Project Head Kuner, Rohini )
• B04 - Monitoring behaviorally relevant spatio-temporal activity patterns in prefrontal networks using in vivo wide field-microendoscopy (Project Heads Kuner, Thomas ;  Sommer, Wolfgang Heinrich )
• B05 - Characterization and modulation of neuronal ensembles involved in reward learning (Project Heads Hansson, Anita ;  Köhr, Georg ;  Spanagel, Rainer )
• C01 - Role of Dnmt3a2 in the establishment and stability of experience-dependent cell ensembles (Project Heads Allen, Kevin ;  Oliveira, Ana M. M. )
• C03 - The role of calcium-induced genomic responses in co-active neurons of the ventral tegmental area (VTA) in nicotine reinforcement and sensitized locomotor activity. (Project Heads Bading, Hilmar ;  Spanagel, Rainer )
• C04 - Modulation of odour-entrained ensembles by phasic dopamine in the olfactory striatum (Project Head Kelsch, Wolfgang )
• C05 - Oxytocin in the prefrontal cortex: from neuromodulation of the local circuit to fear extinction (Project Head Grinevich, Valery )
• D01 - Statistical characterization of cell ensembles in neuronal recordings (Project Heads Durstewitz, Daniel ;  Hamprecht, Fred A. )
• V01 - Centrel Task (Project Head Draguhn, Andreas )

• Applicant Institution: Ruprecht-Karls-Universität Heidelberg
• Participating Institution: Deutsches Krebsforschungszentrum (DKFZ); Max-Planck-Institut für medizinische Forschung; Zentralinstitut für Seelische Gesundheit (ZI)
• Spokesperson: Professor Dr. Andreas Draguhn