Fig. 4.

Effects of excitation light intensity on Dye 1 fluorescence. (a) Responses recorded from the same slice at two different excitation light intensities. (b) Relationship between excitation light intensity and fluorescence emission in slices stained with Dye 1 (n = 13). Open symbols show autofluorescence measured from slices not stained with dye (n = 3). (c) Varying excitation light intensity had little effect on the relative change in dye fluorescence produced in response to neural activity, as measured by the normalized change in fluorescence (ΔF/F; n = 13). (d) Relationship between excitation light intensity and S/N′ of responses (n = 13)