Research Article

Endogenous Two-Photon Excited Fluorescence Provides Label-Free Visualization of the Inflammatory Response in the Rodent Spinal Cord

Figure 1

Multiphoton images of spinal cord tissue and immunohistochemistry of microglial markers on the identical section. Control (top) and representative samples 7 d (left) and 21 d (right) after SCI are shown. Images of unlabeled cryosection of spinal cord tissue were obtained by combining second harmonic generation (SHG, blue channel), endogenous two-photon excited fluorescence (TPEF, green channel), and coherent anti-Stokes Raman scattering (CARS, red channel). (a–d) RGB image and single channels of uninjured control spinal cord tissue. (e, f) Multiphoton image of spinal cord 7 d and 21 d after injury. (g, h) Immunohistochemical staining of the same tissue section, overlay of nuclear DAPI staining (blue channel), CD68 (green channel), and Iba1 (red channel). (i–n) Single channel information of endogenous fluorescence and immunohistochemical staining as indicated. The dotted line indicates the region of the lesion. # marks the position of strong endogenous TPEF in peripheral regions. Scale bars: 1 mm.
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