Naslov
The Neuromuscular Junction in the Amphioxus Myotomes

Autori
Bočina, Ivana ; Saraga-Babić, Mirna

Izvornik
Imaging and Microscopy (1439-4243) 12 (2010); 36-39

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
amphioxus ; locomotion ; myosepta ; neuromuscular junction

Sažetak
Amphioxus myotomes are similar to those of vertebrates in having two distinct muscle fibre types: deep fibres and smaller, mitochondria-rich superficial fibres (Flood, 1968 ; Lacalli and Kelly, 1999). Each of these fibre types in amphioxus has its own innervation (Flood, 1966).Axial undulatory locomotion is the primary and most widespread mode of locomotion in aquatic vertebrates (Gemballa and Vogel, 2002). Muscular forces that generate bending movements for undulatory locomotion can be transmitted to the axis via muscle fibers that directly attach to the axis, or via myoseptal collagen fibers or tendons that link muscle fibers to the axis (Gemballa and Vogel, 2002 ; Gemballa et al., 2003). In amphioxus, muscle fibers never attach directly to the axial structures such as the notochord or median septum, whereas they do attach to axial structures in all Craniata (Gemballa and Vogel, 2002). So, the important role in transmission of muscular forces to the notochord in amphioxus is taken by the myosepta. Using light microscopy, it was found, in the semi-thin sections, that each myosepta contains two round-shaped structures resembling the peripheral nerves surrounded by the connective tissue. When observed under transmission electron microscope, the smaller, oval structure resembled very much the neuromuscular spindle containing nerve and muscle fibers encircled by collagen fibers. The nearby structure within the septa resembled the peripheral nerve made of neural fibers encircled by perineurium. Some epithelial cells and collagen fibers could be seen in perineurium. In order to confirm neural fibers in this region, antibodies to neurofilament and β-tubulin were applied. In all sections used for immunohistochemical study, applied antibodies to neurofilament and β-tubulin have shown positive reaction in the described area, as well.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

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