2-Photon calcium imaging

We are using 2-photon fluorescence microscopy in vivo to record neuronal network activity following sensory stimulation. During the experiment, the cell-specific expression of fluorescent proteins allows to identify different cell types, e.g. inhibitory and excitatory neurons (see figure). Individual cells often respond specifically to certain stimulus properties, e.g. the orientation of the gratings presented.

Figure: Left: Schematic drawing of experimental setup. During sensory stimulation with moving gratings neuronal network activity is recorded using 2-photon microscopy and fluorescent indicator dyes. Right: Response pattern of an excitatory neuron (red 1) and of an inhibitory neuron (blue 2) is displayed (A). The excitatory neuron responded specifically to the orientation of the grating, whereas the inhibitory neuron responded unspecifically (B).

Graf J, Samiree A, Flossmann T, Holthoff K, Kirmse K (2024) Chemogenetic silencing reveals presynaptic Gi/o protein mediated inhibition of synchronized activity in the developing hippocampus in vivo. iScience. DOI: 10.1016/j.isci.2024.110997
Weiler S, Teichert M, Margrie TW (2024) Layer 6 corticocortical cells dominate the anatomical organization of intra and interhemispheric feedback. bioRxiv doi: https://doi.org/10.1101/2024.05.01.590702oRxiv
Weiler S, Rahmati V, Isstas M, Wutke J, Stark AW, Franke C, Graf J, Geis C, Witte OW, Hübener M, Bolz J, Margrie TW, Holthoff K, Teichert M (2024) A primary sensory cortical interareal feedforward inhibitory circuit for tacto-visual integration. Nat Commun 15, 3081. https://doi.org/10.1038/s41467-024-47459-2
Graf J, Samiree A, Flossmann T, Holthoff K, Kirmse K (2024) Chemogenetic silencing reveals presynaptic Gi/o protein mediated inhibition of synchronized activity in the developing hippocampus in vivo. bioRxiv doi: https://doi.org/10.1101/2024.02.02.578550
Graf J, Rahmati V, Majoros M, Witte OW, Geis C, Kiebel SJ, Holthoff K, Kirmse K (2022) Network instability dynamics drive a transient bursting period in the developing hippocampus in vivo. eLife 11:e82756. DOI: https://doi.org/10.7554/eLife.82756
Weiler S, Rahmati V, Isstas M, Wutke J, Stark AW, Franke C, Geis C, Witte OW, Huebener M, Bolz J, Margrie TW, Holthoff K, Teichert M (2022) A primary sensory cortical interareal feedforward inhibitory circuit for tacto-visual integration. bioRxiv 2022.11.04.515161; doi: https://doi.org/10.1101/2022.11.04.515161
Graf J, Rahmati V, Majoros M, Witte OW, Geis C, Kiebel SJ, Holthoff K, Kirmse K (2022) Network instability dynamics drive a transient bursting period in the developing hippocampus in vivo. bioRxiv doi: https://doi.org/10.1101/2021.05.28.446133
Graf J, Zhang C, Marguet SL, Herrmann T, Flossmann T, Hinsch R, Rahmati V, Guenther M, Frahm C, Urbach A, Neves RM, Witte OW, Kiebel SJ, Isbrandt D, Hübner CA, Holthoff K, Kirmse K (2021) A limited role of NKCC1 in telencephalic glutamatergic neurons for developing hippocampal network dynamics and behavior. Proc Natl Acad Sci U S A. 2021 Apr 6;118(14):e2014784118. doi: 10.1073/pnas.2014784118
Graf J, Zhang C, Marguet SL, Herrmann T, Flossmann T, Hinsch R, Rahmati V, Guenther M, Frahm C, Urbach A, Neves RM, Witte OW, Kiebel SJ, Isbrandt D, Hübner CA, Holthoff K, Kirmse K (2020) Intraneuronal chloride accumulation via NKCC1 is not essential for hippocampal network development in vivo. doi: https://doi.org/10.1101/2020.07.13.200014
Kirmse K, Holthoff K (2020) Chloride transporter activities shape early brain circuit development, Book chapter in ´Neuronal Chloride Transporters in Health and Disease´, Academic Press, ISBN: 9780128153185
Holthoff K (2020) The Janus-face of GABAergic synaptic transmission during brain development. J Physiol. doi: 10.1113/JP279623
Zhang C, Yang S, Flossmann T, Gao S, Witte OW, Nagel G, Holthoff K, Kirmse K (2019) Optimized photo-stimulation of halorhodopsin for long-term neuronal inhibition. BMC Biology 17:95
Kirmse K (2019) Editorial: GABAergic networks in the developing and mature brain. Brain Res. 1718:10-11. doi: 10.1016/j.brainres.2019.04.029
Flossmann T, Kaas T, Rahmati V, Kiebel SJ, Witte OW, Holthoff K, Kirmse K (2019) Somatostatin Interneurons Promote Neuronal Synchrony in the Neonatal Hippocampus, Cell Rep 26(12):3173-3182.e5, https://doi.org/10.1016/j.celrep.2019.02.061
Rahmati V, Kirmse K, Holthoff K, Kiebel SJ (2018) Ultra-Fast Accurate Reconstruction of Spiking Activity from Calcium Imaging Data. J Neurophysiol doi: 10.1152/jn.00934.2017.
Kirmse K, Hübner CA, Isbrandt D, Witte OW, Holthoff K (2017) GABAergic Transmission during Brain Development: Multiple Effects at Multiple Stages. The Neuroscientist. DOI: 10.1177/1073858417701382
Kirmse K and Holthoff K (2017) Functions of GABAergic transmission in the immature brain. Neuroforum 23(1):A27–A33.
Kummer M, Kirmse K, Zhang C, Haueisen J, Witte OW, Holthoff K (2016) Column-like Ca2+ clusters in the mouse neonatal neocortex revealed by three-dimensional two-photon Ca2+ imaging in vivo. Neuroimage 138, 64-75. doi:10.1016/j.neuroimage.2016.05.050.
Rahmati V, Kirmse K, Markovic D, Holthoff K, Kiebel SJ (2016) Inferring neuronal dynamics from calcium imaging data using biophysical models and Bayesian inference. PLoS Comput Biol 12(2): e1004736. doi:10.1371/journal.pcbi.1004736
Kummer M, Kirmse K, Witte OW, Haueisen J, Holthoff K (2015) A method to quantify accuracy of position feedback signals of a three-dimensional two-photon laser-scanning microscope. Biomed Opt Express 6(10):3678-3693.
Kirmse K, Kummer M, Kovalchuk Y, Witte OW, Garaschuk O, Holthoff K (2015) GABA depolarizes immature neurons and inhibits network activity in the neonatal neocortex in vivo. Nat Commun 6:7750, doi:10.1038/ncomms8750
Hübner CA and Holthoff K (2013). Anion transport and GABA signaling. Front Cell Neurosci 7:177. doi: 10.3389/fncel.2013.00177
Kummer M, Kirmse K, Witte OW, Holthoff K (2012) Reliable in vivo identification of both GABAergic and glutamatergic neurons using Emx1-Cre driven fluorescent reporter expression, Cell Calcium 52: 182-189.