Calcium Waves in Retinal Glial Cells

	Calcium Waves

	The following movies show intercellular Ca²⁺ waves as they propagate through networks of astrocytes and Müller cells at the vitreal surface of the rat retina. Glial cells were labeled with a Ca²⁺ indicator dye (Fluo-4 AM or Calcium Green-1 AM) and were imaged with a video-rate confocal microscope. Waves were initiated with a mechanical stimulus, a 10 msec, 15 to 25 mm pulse. Download QuickTime Player if you don't have it already installed.
		Low magnification view of Ca²⁺ wave propagation. Stimulation of an astrocyte soma initiates a Ca²⁺ wave which propagates outwards symmetrically from the point of stimulation. The wave propagates through both astrocytes (large polymorphic cells) and Müller cell endfeet (smaller, round profiles). The video is shown at 0.75 times normal speed. Width of image, 335 mm. (QuickTime clip, 2.3 MB.)

		Propagation of the leading edge of a Ca²⁺ wave. A fluorescence image of dye-labeled astrocytes and Müller cells is shown in black and white. The superimposed yellow regions mark the leading edge of the Ca²⁺ wave (where change in fluorescence between successive images exceeded a threshold value). Video shown at normal speed. Width of image, 240 mm. From Newman and Zahs, Science, 275:844-847, 1997. (QuickTime clip, 649 KB.)

		High magnification view of Ca²⁺ wave propagation. Stimulation of an astrocyte soma initiates a Ca²⁺ wave which begins in the stimulated soma and propagates smoothly through the processes of the astrocyte and into adjacent astrocytes. After a delay of ~1 sec, the wave also propagates into neighboring Müller cell endfeet (dimmer round profiles). Video shown at 0.75 times normal speed. Width of image, 150 mm. From Newman, J Neurosci. 21:2215-23, 2001. (QuickTime clip, 2.5 MB.)