Besides classical electrophysiological approaches we offer life cell imaging based techniques in order to monitor cell-cell interactions / analyze compound induced effects on intracellular ion homeostasis.
Monitoring the dynamic changes of the intracellular Ca2+ concentration enables the understanding of cardiac function including inotropic effects and the occurrence of proarrhythmic events.
Two technologies are available for detailed investigations of the intracellular Ca2+ concentrations:
Confocal Ca2+ imaging of cultivated, spontaneously beating cardiomyocytes using the Zeiss Cell Observer system. Top: Time series of false-color coded Ca2+ dependent fluorescence of Cal520-AM loaded cardiomyocytes. Excitation leads to an transient intracellular Ca2+ increase, visualized by a color shift from blue via green to red. Bottom: Fluorescence intensity-over time trace of above shown recording. Numbers indicate time points of the images.
Intracellular Ca2+ Imaging of spontaneously beating cardiomyocytes using the higher throuput Hamamatsu FDSS/uCell system. A: Positive inotropic effect. Application of this beta2-sympathomimetic compound results in a concentration-dependent increase of intracellular Ca2+ concentration during each beat. B: A Ca2+ channel inhibitor both reduces Ca2+ transient amplitude and duration, resulting in negative inotropicity. C: Application of a potent hERG channel inhibitor results in the detection of proarrhythmic behavior in the investigated cardiomyocytes.
Hamamatsu user Meeting June 2018 in Basel, CH:
"Bringing human neuronal biology to HTS: Functional Drug Screening with iCell GlutaNeurons and Astrocyte on the Hamamatsu FDSS/µCELL"
Click here for the presentation
The development of pharmacological compounds requires highly predictive in vitro test systems. Assays based on primary neuronal cultures obtained from animals are commonly used although correlation between animal and human data might be weak in some cases. As a solution to this problem, the drug discovery field is strongly moving towards human induced pluripotent stem-cell derived (hiPSC) neurons. Here we developed several live-cell Ca imaging screening assays on the Hamamatsu uCell instrument based on Cellular Dynamics’ iCell Glutaneurons. Intracellular Ca dynamics as indicator of neuronal network activity was recorded and modulated using different pharmacological tool compounds with known neurophysiological effects. We focussed on three classes of experiments: compounds with seizurogenic potential from the current NeuTox panel of HESI, mGluR modulators alone or after pharmacological treatment of the neuronal culture, and cultivation in the presence of amyloid-beta peptid which plays a major role in Alzheimer disease. As astrocytes are highly important for the neuronal network activity, we were also interested in a comparison between data obtained from a pure iCell GlutaNeuron culture and a coculture of iCell GlutaNeuron and iCell Astrocytes. For a subset of experiments the results were benchmarked against data obtained from rat cortex primary neuron culture. iCell GlutaNeurons were responsive to the tested compounds concentration-dependently and with, in parts, higher sensitivity compared to the primary cell system. The cocultivation with iCell Astrocytes, furthermore, had a substantial impact on the network activity after compound treatment indicating a possibly even more physiological reaction than iCell GlutaNeuron cultivation alone.