Fig. 7 | Nature Communications

Fig. 7

From: Deep 2-photon imaging and artifact-free optogenetics through transparent graphene microelectrode arrays

Fig. 7

Combination of macroscopic hemodynamic optical imaging with electrical recordings. Light absorption at six wavelength ranges (560–610 nm, 10 nm step size) was recorded with a CCD camera at an acquisition frequency of ca. 18 Hz. Absorption at these wavelengths was converted to concentrations of oxyhemoglobin (HbO), deoxyhemoglobin (Hb), and total hemoglobin (HbT) measured as changes relative to pre-stimulus baseline. A train of six electric pulses (1 mV for 2 s at 3 Hz, pulse width: 300 µs) was delivered to the whisker pad. a Image of the exposure and graphene microelectrode array with region of interest (yellow line) used for evaluation of hemodynamic signals. b Image of the exposure with location and numbering of graphene electrodes. Scale bars for a and b, 500 µm. c Changes in HbO, Hb, and HbT in response to electrical whisker pad stimulation (average of 10 trials across the region of interest shown in a). d Corresponding recordings from the graphene microelectrode array; voltage traces recorded during stimulation period are shown (average of 10 trials; channel positions as indicated in b). e Spatiotemporal analysis of the electrical response to one electrical stimulus (red highlight in d). The sequence of 24 images covers a recording period of 42 ms (time between two images: 2 ms); the yellow rectangle indicates stimulus delivery. fh Spatiotemporal analysis of changes in HbO, Hb, HbT in response to whisker pad stimulation. The sequence of 24 images covers a recording period of 8.4 s (time between two images: 400 ms); red rectangles indicate stimulation onset

Back to article page