Calcium firework in slow motion

First time history of biological "calcium sparks" observed in muscle cells

Fast measurements of calcium sparks in the muscle allow one to observe the course and extent in one plane. The numbers show the time interval of the pictures in milliseconds. © University Hospital Heidelberg
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It happens in a few milliseconds and has not been recorded in the picture so far: Cells release the messenger calcium from stores inside the cell and thus transmit vital signals to proteins within the cell - for example, movement in the muscle. By combining state-of-the-art laser microscopy with a high-speed camera, scientists have for the first time made the extremely short-lived release of calcium, a so-called "calcium spark", visible in its time course and spatial extent.

Thanks to new technology, the researchers at the Institute of Physiology and Pathophysiology at the University of Heidelberg were now able to measure the calcium release from the cells 60 times faster than with conventional methods. The new findings from basic research shed light on an elementary process of life, namely how the passage of time and the spatial extent of communication of molecular levels within the cell look like, according to the scientists in the journal "IEEE - Transaction of Medical Imaging".

Vital calcium

Calcium is involved in the regulation of almost all important cell functions: It activates muscle cells, regulates cell division, the formation and function of proteins. It is stored separately within the cell and can be released very quickly via channels. Subsequently, pumps transport the calcium back into the cell storage. The bursting release was first described in 2001 in the mammalian muscle at the Heidelberg Institute of Physiology and Pathophysiology. Previously, it was thought that these mammalian events did not exist.

"The calcium release from the cells resembles a" calcium spark "in the range of a thousandth of a millimeter and can be visualized using modern laser microscopy, " explains Heidelberg researcher Dr. med. Oliver Friedrich. For this form of microscopy, cells are added with a calcium dye. Under the microscope, a laser beam illuminates the marked calcium (confocal microscopy) - but only in the tiny detail that the laser beam is currently scanning.

Conventional laser microscopes are too slow

"Conventional confocal microscopy is simply too slow for the fast calcium sparks, " says Friedrich. To be able to follow these events in their spatial extent completely, he and his Heidelberg colleague Dr. Frederic Wegner a new technique of the company LaVision Biotec in Göttingen on isolated muscle cells. display

The two Heidelberg physiologists used a new form of laser microscopy in combination with a high-speed camera: In the method, a single laser beam does not scan the sample as before, but is split into 64 sub-beams, which simultaneously cover a larger area high speed can be read (multifocal microscopy).

(idw - University Hospital Heidelberg, 21.11.2007 - DLO)