Biomedical Engineering Reference
In-Depth Information
FIgurE 14.11
The structures of somites (S), notochords (N), and muscle fibers obtained from embryos at differ-
ent development stages. (a) THG image of somites of a three-somite-stage embryo with dorsal side to the top and
the pitching-off of the fourth somite (arrow) can be observed through THG; (b) THG image of a five-somite-stage
embryo with left side to the top; (c) THG image of a 18-somite-stage embryo with left side to the top and the small
vacuoles (arrow) within the notochord cells can be observed; (d) SHG/THG image of a 20-somite-stage embryos
with dorsal side to the top, and the newborn muscle fibers in the somites are revealed by SHG; (e) In a 48-hpf
embryo, matured muscle fibers are by SHG with the sarcomere clearly resolved. Scale bar: 100 μm. SHG images
corresponding to (d)-(f) are shown in (d-S)-(f-S), respectively.
structures of the matured muscle fibers can be revealed by SHG and the sarcomere are also clearly
resolved (Figure 14.11f). By applying SHG/THG microscopy, both the morphological changes of the
somites and notochord and the development of the muscle fibers can be recorded at different stages and
this can greatly help to study the somite development of the zebrafish embryo.
14.3.3 Animal Models: Mouse
Mouse is a popularly used standard animal model of mammals for many biomedical studies. Applying
SHG/THG microscopy to mouse tissues can help to identify various image contrasts of SHG and THG
modalities and find the imaging capability of SHG/THG microscopy in mammal tissues. According to
previous studies of mouse tissues like skin, oral mucosa, and eye, SHG contrasts are found to be mainly
provided by collagen fibers, especially type I collagen, which is the most widespread structural protein
in mammals and is the main component of connective tissues. The strong SHG signals arising from
the collagen fibers can be utilized to investigate the fibril structures in the connective tissues like the
