Validation of the imaging contrast enhancement [37]. (A, B) A mouse brain slice imaged using OR-PAM and GR-PAM, respectively. (C, D) The magnifications of the square regions marked as 1 and 2 in (A) and (B), respectively; here, the internal structures of the cell nuclei are unclear in OR-PAM (C) but resolved in GR-PAM (D). (E, F) A-line profiles of the dot-cross sections marked as 3 and 4 in (A) and (B), respectively. Figures reproduced with publisher’s permission [37].