Select languageSelect language
Institute of Physiology and Pathophysiology

Calcium Imaging

The dynamics of the intracellular calcium concentration regulates a broad spectrum of cellular processes like cell motility and intracellular transduction neuronal and hormonal signals. A misregulation of calcium dynamics is involved in the genesis and pathophysiology of numerous deseases, e.g. calcium induced apoptosis.

 

In particular the dynamics of intracellular calcium ion channels (inositoltrisphosphate, IP3R and ryanodine receptor, RyR) can only be analysed with optical methods. These are based on calcium sensitive dyes (Fluo-4, Fura-2), which only fluoresce with calcium ions bound.

 

Elementary Calcium Release Events

The smallest events of intracellular calcium signaling are openings of single or small groups of calcium channels. These elementary calcium release events (ECRE or "sparks") have a spatial extension of less than 1-2 µm, which means they are only detectable with confocal laser scanning microscopes. The temporal extension is in the range of 10-200 ms so that time-resolved measurements are only possible by scanning a single line or very small frames.

 

Figure 1: Confocal linescan image of ECREs through RyR type 2 in cardiac muscle cells

 

This technique is applied to study the effects of physiological modulations and diverse anesthetics on the ryanodine receptor. The detection of ECREs was automated using specifically adapted image processing techniques.

 

Figure 2: Analysis of intracellular calcium dynamics in coupled HepG2 cell clusters

Calcium Oszillation

Oscillations of the intracellular calcium concentration are known as a way of signal transduction between cells. Changes in amplitude and frequency of these oscillations can induce cell proliferation or the growth of synapses in neuronal networks.

 

We study purine receptor-mediated calcium oscillations in cultured HepG2 carcinoma cells and the effects of anesthetics on the dynamics of calcium oscillations in cultured neurons.

 


Recent Publications

*

Genetic ablation of NFAT5/TonEBP in smooth muscle cells impairs flow- and pressure-induced arterial remodeling in mice. FASEB J. 2018 Nov 1:fj201801594R. doi: 10.1096/fj.201801594R. [Epub ahead of print]

*

Synaptic entrainment of ectopic action potential generation in hippocampal pyramidal neurons.  J Physiol. 2018 Nov;596(21):5237-5249. doi: 10.1113/JP276720. Epub 2018 Sep 19.

*

The Long Noncoding RNA Cancer Susceptibility 9 and RNA Binding Protein Heterogeneous Nuclear Ribonucleoprotein L Form a Complex and Coregulate Genes Linked to AKT Signaling. Hepatology. 2018 Nov;68(5):1817-1832. doi: 10.1002/hep.30102. Epub 2018 Oct 12.

*

Reduction of Transplant Vasculopathy by Intraoperative Nucleic Acid-based Therapy in a Mouse Aortic Allograft Model. Thorac Cardiovasc Surg. 2018 Oct 23. doi: 10.1055/s-0038-1673633. [Epub ahead of print]

*

Early appearance and spread of fast ripples in the hippocampus in a model of cortical traumatic brain injury. J Neurosci. 2018 Oct 17;38(42):9034-9046. doi: 10.1523/JNEUROSCI.3507-17.2018. Epub 2018 Sep 6.

*

High-fat diet suppresses the positive effect of creatine supplementation on skeletal muscle function by reducing protein expression of IGF-PI3K-AKT-mTOR pathway. PLoS One. 2018 Oct 4;13(10):e0199728. doi: 10.1371/journal.pone.0199728. eCollection 2018.

*

Alcohol reduces muscle fatigue through atomistic interactions with nicotinic receptors. Commun Biol. 2018 Oct 3;1:159. doi: 10.1038/s42003-018-0157-9. eCollection 2018.

*

Possible neurotoxicity of the anesthetic propofol: evidence for the inhibition of complex II of the respiratory chain in area CA3 of rat hippocampal slices. Arch Toxicol. 2018 Oct;92(10):3191-3205. doi: 10.1007/s00204-018-2295-8. Epub 2018 Aug 24.

*

Endothelial progenitor cells accelerate endothelial regeneration in an in vitro model of Shigatoxin-2a-induced injury via soluble growth factors. Am J Physiol Renal Physiol. 2018 Oct 1;315(4):F861-F869. doi: 10.1152/ajprenal.00633.2017. Epub 2018 Mar 7.

*

Strategy for marker-based differentiation of pro- and anti-inflammatory macrophages using matrix-assisted laser desorption/ionization mass spectrometry imaging. Analyst. 2018 Sep 10;143(18):4273-4282. doi: 10.1039/c8an00659h. Epub 2018 Jul 20.

*

Recent advances in hippocampal structure and function. Cell Tissue Res. 2018 Sep;373(3):521-523. doi: 10.1007/s00441-018-2913-z. Epub 2018 Aug 20. doi: 10.1007/s00441-018-2913-z. Editorial. No abstract available.

*

Electrical coupling between hippocampal neurons: contrasting roles of principal cell gap junctions and interneuron gap junctions. Cell Tissue Res. 2018 Sep;373(3):671-691. doi: 10.1007/s00441-018-2881-3. Epub 2018 Aug 15. Review.

*

Metabolic modulation of neuronal gamma-band oscillations. Pflugers Arch2018 Sep;470(9):1377-1389. doi: 10.1007/s00424-018-2156-6. Epub 2018 May 28.

*

NFAT5 Isoform C Controls Biomechanical Stress Responses of Vascular Smooth Muscle Cells. Front Physiol. 2018 Aug 23;9:1190. doi: 10.3389/fphys.2018.01190. eCollection 2018.

*

Selective vulnerability of αOFF retinal ganglion cells during onset of autoimmune optic neuritis. Neuroscience. 2018 Jul 31. pii: S0306-4522(18)30515-3. doi: 10.1016/j.neuroscience.2018.07.040. [Epub ahead of print]

*

The VAMP-associated protein VAPB is required for cardiac and neuronal pacemaker channel function. FASEB J. 2018 Jun 7:fj201800246R. doi: 10.1096/fj.201800246R. [Epub ahead of print]


Institute of
Physiology and Pathophysiology

Heidelberg University

Im Neuenheimer Feld 326

69120 Heidelberg

Germany

Phone:+49 6221 54-4035
Fax:+49 6221 54-4038
E-mail:sekretariat.hecker@
physiologie.uni-heidelberg.de