Prof. Dr. Fritjof Helmchen

 

Main Goals, Keywords

Principles of single-cell and neural network computation in the mammalian neocortex. In vivo analysis of spontaneous, sensory-evoked, and behavior-related neural activity. Neuron-glia relationships. (Synaptic integration, dendrites, excitability, synaptic plasticity, action potentials, population activity, cortical column, microcircuits)

Group Members

1 professor, 1 scientific coordinator, 5 postdocs, 6 PhD students, 4 technicians

Previous and Current Research

The outside-world is represented in the brain by the concerted activity of neuronal ensembles. We are interested how information is encoded and processed in neuronal assemblies within the local microcircuits of the intact neocortex. We are characterizing the properties of individual neurons in vivo and investigate how synaptic inputs are integrated in their dendrites to eventually cause action potentials that are transmitted to target neurons. Using in vivo electrophysiology and 2-photon imaging we perform both intracellular recordings from individual neurons as well as optical measurements of population activity. Development of 2-photon microscopy techniques for high-resolution imaging in living and behaving rodents.

Future Projects

Characterization of single-cell and network activity patterns in rat neocortex upon sensory stimulation (tactile, visual, or auditory) and during motor behaviour. Studies of the functional role of different classes of inhibitory interneurons. Development of tools for analyzing neuronal population dynamics. In vivo studies of dendritic integration in neocortical pyramidal neurons

Techniques and Equipment

2-photon laser-scanning microscopy, electrophysiology, in vivo patch-clamp recordings, in vivo long-term imaging, fiber-optic miniaturized microscopy, histological neuron reconstruction, single-cell and network simulations.

Selected Publications

• Lütcke H, Margolis DJ, Helmchen F. Steady or changing? Long-term monitoring of neuronal population activity. Trends Neurosci. 2013 Apr 19. doi:pii: S0166-2236(13)00055-6. 10.1016/j.tins.2013.03.008. [Epub ahead of print]
• Langer D, van 't Hoff M, Keller AJ, Nagaraja C, Pfäffli OA, Göldi M, Kasper H, Helmchen F. HelioScan: A software framework for controlling in vivo microscopy setups with high hardware flexibility, functional diversity and extendibility. J Neurosci Methods. 2013 Apr 30;215(1):38-52. doi: 10.1016/j.jneumeth.2013.02.006. Epub 2013 Feb 14.
• Margolis DJ, Lütcke H, Schulz K, Haiss F, Weber B, Kügler S, Hasan MT, Helmchen F. Reorganization of cortical population activity imaged throughout long-term sensory deprivation. Nat Neurosci. 2012 Nov;15(11):1539-46. doi: 10.1038/nn.3240. Epub 2012 Oct 21.
• Roth MM, Helmchen F, Kampa BM. Distinct functional properties of primary and posteromedial visual area of mouse neocortex. J Neurosci. 2012 Jul 11;32(28):9716-26. doi: 10.1523/JNEUROSCI.0110-12.2012.

Funding

Swiss National Science Foundation, SystemsX.ch, EU-FP7 projects “Brain-i-Nets”, “PLASTICISE”, “Spacebrain”, “BrainScaleS”; German-Swiss Research Group "BaCoFun"

URL

http://www.hifo.uzh.ch/research/helmchen.html