Figure 6. Effects of bicuculline application on the evoked [Ca²⁺]_i transients.

Dose-response curves of the evoked [Ca²⁺]_i transients to bicuculline administration in each of the regions. The normalized ΔF/F values (solid circle) were obtained from the maximum amplitudes of ΔF/F from the 16×16-pixel binned area indicated in the leftmost panel of Figure 5A (red square). The ΔF/F values were normalized by the amplitude in the stimulus position (region b) under the control condition. The values obtained from each slice were averaged (n = 4 slices). The stimulus intensity was 80 µA. The alphabetical index of each panel corresponds to the region indicated in leftmost panel of Figure 5A. The normalized ΔF/F values were fitted into the following equation (solid line): Base + A_max/(1+ (EC₅₀/[bicuculline])^nH). The fitted A_max, EC₅₀, and nH values were as follows: region a, A_max = 2.4, EC₅₀ = 2.0 µM, and nH = 2.2; region b, A_max = 1.1, EC₅₀ = 2.3 µM, and nH = 2.3; region c, A_max = 2.1, EC₅₀ = 2.6 µM, and nH = 1.6; region d, A_max = 3.1, EC₅₀ = 1.8 µM, and nH = 2.5; region e, A_max = 2.4, EC₅₀ = 2.1 µM, and nH = 2.1; and region f, A_max = 2.6, EC₅₀ = 2.8 µM, and nH = 1.4. Error bars are represented as SEM.