Fig. 2.

Propagation of Ca²⁺ waves from astrocytes to Müller cells. A and Cshow fluorescence intensity (arbitrary units) from selected regions of astrocytes (1, 3) and Müller cells (2, 4). The location of each region is indicated in the fluorescence images in B andD. A, B, Control. Stimulation of an astrocyte soma evokes a wave that propagates rapidly into adjacent Müller cells. Near the stimulated soma (*) the wave propagates from the astrocyte process (1) into an adjacent Müller cell (2) with a delay of 1.1 sec. Farther from the soma the delay in propagation from the astrocyte process (3) to a Müller cell (4) is 1.3 sec. C,D, PPADS, 50 μm. PPADS impairs astrocyte-to-Müller cell propagation. Near the stimulated soma (*) the wave propagates from the astrocyte process (1) to an adjacent Müller cell (2) with a delay of 2.3 sec. (The secondary rise in Ca²⁺ in region 1 represents the arrival of the Ca²⁺ wave in the Müller cells underneath the astrocyte process.) The wave propagates into the soma of a nearby astrocyte (3) but fails to invade an adjacent Müller cell (4). Recordings are from eyecups. In A and C the small dots mark the onset of Ca²⁺ increases, andvertical arrows indicate the time of mechanical stimulation. Scale bar in D, 50 μm.