Figure 5

The local Ca²⁺ responses elicited by brief depolarization at an Mb1 bipolar cell synaptic ribbon were altered in older-aged zebrafish. (A,B) Average Cal520-2LA fluorescence at ribbon locations in response to 10 ms depolarization in Mb1 bipolar cells isolated from middle-aged (MA; left panels; n = 3 ribbons from 3 cells and fish) and older-aged (OA; right panels; n = 3 ribbons from 3 cells and fish) zebrafish with pipette solution containing 2 mM EGTA. Shown is the change in fluorescence (ΔF) from baseline before stimulation, divided by the baseline fluorescence (F_min). (C,D) Same as in (A,B), except that the pipette solution contained 10 mM EGTA. (E,F) Same as in A-B, except that the pipette solution contained 2 mM BAPTA. Red arrows indicate the time of pulse stimulation.