Figure 2
From: Photoacoustic imaging of voltage responses beyond the optical diffusion limit
In vivo mouse brain response before and during electrical stimulation at a minimally vascularized point. (a) The exact M-mode imaging location is identified by the yellow cross in the depth-coded maximum amplitude projection image of the DPA-stained mouse cranial window. (b) A 63 second stimulation sequence comprises 189 electrical stimulation pulses with a pulse width of 300 μs and a pulse period of 333 ms. (c) Baseline (before electrical stimulation) and response (during stimulation) of voltage and hemodynamic signals in the frequency domain. Both the voltage response signal (red) and hemodynamic response signal (black) have observable frequency components at 3.1 Hz and 6.2 Hz. The SNRs of the voltage and hemodynamic response peaks are respectively labeled with red and black text.
