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PD Dr. Georg Köhr

DFG - Deutsche Forschungsgemeinschaft SFB 1134: B05: Charakterisierung und Molulation neuronaler Ensembles des Belohnungslernens. 01/2015-12/2018.

BMBF - Bundesministerium für Bildung und Forschung 01ZX1611A: e:Med II SPs 11 - Functional Validation III: Functional local network activity and neurotransmitter release. 01/2017-12/2018.

The research goals of SP11 are to study the electrophysiological properties of m/hiPSCs deriving from SP3, to compare local field potentials (LFPs) and multiple single-units in alcohol addicted rats from SP5 (same limitations as in SP7 therefore animals from the “post-dependent model”7, and to validate the neurochemical prediction from SP8 via in vivo microdialysis. Major progress has been made in in vivo tetrode recordings and we have examined the effect of acute alcohol treatment in the medial prefrontal cortex. Most importantly, we have validated by in vivo microdialysis the in silcio prediction made in SP8 by demonstrating a hyper-dopaminergic state in protracted abstinence (Hirth et al., 2015).

Köhr G. DFG - Deutsche Forschungsgemeinschaft SFB 636: Addiction and the nucleus accumbens. 06/2012-12/2015.

We are planning to monitor changes in synaptic strength in the nucleus accumbens in vivo via chronically implanted electrodes in rats during long-term cocaine exposure, and examine the mechanism of underlying synaptic changes in brain slices of addicted versus non-addicted rats in distinct disease states.

Köhr G. DFG - Deutsche Forschungsgemeinschaft KO 1064/7: Pathway-dependent plasticity. 01/2010-12/2014.

Hippocampal CA1 pyramidal neurons receive direct sensory information from the entorhinal cortex and indirect information from CA3 pyramidal neurons which project via the Schaffer collateral/commissural fibers to apical and basal CA1 dendrites. We compare the latter two pathways in acute brain slices, because we observe differences when applying spike-timing-dependent plasticity paradigms. Such differences could be relevant to the timing of interactions between these two major pathways during hippocampal network activity.

Köhr G. BMBF - Bundesministerium für Bildung und Forschung 01DN12062: Noradrenaline and the cortex. 06/2011-12/2013.

Recent evidence has revealed that noradrenaline modulates the state of cortical inhibition in addition to its control of excitatory glutamatergic transmission. Using behaviorally-relevant electrical stimulations in cortical slices, we could induce long-term depression (LTD) of inhibitory postsynaptic currents in layer II/III pyramidal cells. In the presence of beta-adrenergic agonists, however, we were able to induce long-term potentiation (LTP) instead of LTD, and are therefore currently examining the underlying mechanisms.

Köhr G, Li SB. : CSC China Scholarship Council: Dopamine and the hippocampus. 09/2010-08/2013.

We activate the dopaminergic system pharmacologically, electrically, or optogenetically following virus-mediated transfer of channelrhodopsin, to investigate the role of endogenous dopamine in hippocampal synaptic plasticity and network activity in brain slices and in awake mice during learning and memory formation.

Zentralinstitut für Seelische Gesundheit (ZI) - https://www.zi-mannheim.de