Fig. 4

Representative raw records of fluorescence changes. A–F From top to bottom, the fluorescence signal in regions 1 to 6 (R1 to R6) shown in Fig. 2A, respectively, at each focal depth. The lowest trace (C4) represents the leaky integrated wave of electrical activity in C4VR. Vertical scale bar: 4% of the baseline fluorescence intensity for R1 to R6. The strong (R1 and R2), weak (R3 and R4), and no (R5 and R6) inspiratory modulation groups are shown