Figure 2.

Spermine-NONOate, an NO donor, produces a significant enhancement in [Zn²⁺]_i. A, Images indicate that NO released from spermine-NONOate caused an increase in [Zn²⁺]_i detected with NG in the CA1 region of a hippocampal slice. The left image (1) is the control. The middle (2) and right (3) images were taken 10 and 20 min, respectively, after the start of perfusion with spermine-NONOate. P, Pyramidal cell layer. Scale bars, 100 μm. B, Images of the control experiment with spermine showing no change in NG fluorescence in the absence of spermine (1) or in the presence of 500 μm spermine (2). KCl (60 mm), which increased the fluorescence (3), was applied at the end of the experiment to verify the viability of the hippocampal slice. Scale bars, 100 μm. C, An individual graph shows that NO increased in [Zn²⁺]_i detected with NG. D, A graph shows that spermine does not increase NG fluorescence in control hippocampal slices.