Cell communication in neuronal networks
Hippocampal microcircuits, synaptic transmission, synaptic plasticity, Ca2+-dependent exocytosis, GABAergic interneurons, basket cells
The main research interest of Peter Jonas and his team is to understand how the biophysical properties of synapses contribute to higher brain functions. To address this fundamental question, he focuses on the hippocampus, a key circuit responsible for learning and memory. First, he wants to understand the function of fast-spiking, parvalbumin-expressing GABAergic interneurons. These cells play a key role in the control of excitation in brain circuits. In particular, he wants to unravel the molecular, subcellular, and cellular mechanisms underlying fast signaling in this important type of GABAergic neuron. Second, he plans to fully characterize the function of the hippocampal mossy fiber synapses, a key excitatory synapse in the trisynaptic circuit of the hippocampus. This synapse plays a major role in hippocampal information processing, because it is placed in the center of this brain region and therefore gates information flow between a pattern separation and a pattern completion circuit. Finally, he wants to elucidate how specific synaptic properties impact on higher network functions. To address this question, he incorporates synaptic properties into real-size models of the hippocampal CA3 region, and tries to reproduce experimental observations. In parallel, he performs in vivo recordings from neurons in rats or mice placed in a virtual environment. This allows testing of the hypotheses generated from the models. In his research, Peter Jonas uses several cutting-edge techniques, such as subcellular patch-clamp recording from dendrites, axons, and presynaptic terminals, paired recording from synaptically connected neurons, confocal and two-photon Ca2+ imaging, two-photon transmitter uncaging, in vivo patch-clamp recording, and modeling. In particular, he has pioneered the technique of direct recording from cortical presynaptic terminals and is one of the founders of the field of analysis of GABAergic interneuron function. The results emerging from his research may ultimately allow him to understand how higher brain functions are implemented in brain circuits and how these functions are perturbed in neurological and psychiatric diseases.
Collaborating research groups where PhD Students can perform their research stay
Michael Frotscher, ZMNH Hamburg, Falkenried 94, D-20251 Hamburg, Germany
Gary Westbrook, Vollum Institute, L474, 3181 SW Sam Jackson Park Road, Portland OR
Know-how and infrastructure of the research group
Paired recordings/multi-cell recordings in brain slices; subcellular patch-clamp recording; wo-photon imaging; two-photon transmitter uncaging; whole-cell recording in vivo; modeling.
Setups for paired and subcellular patch-clamp recording in slices, imaging, one confocal microscope (Leica SP5), one two-photon microscope for imaging and transmitter uncaging (Bruker Ultima), cell culture facilities, immunocytochemistry unit, computational platform (workstations, high-performance computer cluster).