Figure 3. In vivo measurements.

In vivo application of pH sensor. Two-photon pH imaging was performed. Dyes were simultaneously excited at 820 nm by a pulsed laser and detected using green and red filters. (a) Ratiometric imaging in the brain extracellular matrix. (b) pH ratio values recorded in the ECM during hypercapnia. (c) Simultaneous acquisition of pH ratiometric imaging (top) and electrophysiology (ef) field trace (bottom) during hypercapnia in an bicucullin-administered mouse. The typical interictal activity observed in the ef trace following pharmacological treatment was suppressed during hypercapnia.