Label-free identification of the microstructure of rat spinal cords based on nonlinear optical microscopy.
The spinal cord is a vital link between the brain and the body and mainly comprises neurons, glial cells and nerve fibres. In this work, nonlinear optical (NLO) microscopy based on intrinsic tissue properties was employed to label-freely analyze the cells and matrix in spinal cords at a molecular level. The high-resolution and high-contrast NLO images of unstained spinal cords demonstrate that NLO microscopy has the ability to show the microstructure of white and grey matter including ventral horn, intermediate area, dorsal horns, ventral column, lateral column and dorsal column. Neurons with various sizes were identified in grey matter by dark spots of nonfluorescent nuclei encircled by cytoplasm-emitting two-photon excited fluorescence signals. Nerve fibres and neuroglias were observed in white matter. Besides, the spinal arteries were clearly presented by NLO microscopy. Using spectral and morphological information, this technique was proved to be an effective tool for label-freely imaging spinal cord tissues, based on endogenous signals in biological tissue. With future development, we foresee promising applications of the NLO technique for in vivo, real-time assessment of spinal cord diseases or injures.
Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou, 350007, P. R. China.
C X
CX
Liao
Department of Orthopedics, Affiliated Union Hospital of Fujian Medical University, Fuzhou, P. R. China.
Z Y
ZY
Wang
Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou, 350007, P. R. China.
Y
Y
Zhou
Department of Orthopedics, Affiliated Union Hospital of Fujian Medical University, Fuzhou, P. R. China.
L Q
LQ
Zhou
Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou, 350007, P. R. China.
X Q
XQ
Zhu
Department of Orthopedics, Affiliated Union Hospital of Fujian Medical University, Fuzhou, P. R. China.
W G
WG
Liu
Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, Fujian Provincial Key Laboratory of Photonics Technology, Fujian Normal University, Fuzhou, 350007, P. R. China.
J X
JX
Chen
D000818:Animals; D009457:Neuroglia / Q000166:cytology*; D009474:Neurons / Q000166:cytology*; D000073758:Nonlinear Optical Microscopy / Q000379:methods*; D051381:Rats; D013116:Spinal Cord / Q000033:anatomy & histology*
Nonlinear optical microscopy; second harmonic generation; spinal cord; two-photon excited fluorescence