Existence and features of the myodural bridge in Gallus domesticus: indication of its important physiological function
The myodural bridge (MDB) is a dense connective tissue that connects muscles with the cervical spinal dura mater via the posterior atlanto-occipital and atlato-axial interspaces. To date, the physiological function of the MDB has not been fully elucidated. Recent studies have identified the presence of the MDB in mammals, but very little information is available on the existence of the MDB in avifauna. We selected Gallus domesticus to explore the existence and the fiber property of the MDB in avifauna. We found that in this species, fibers originating from the ventral aspect of the rectus capitis dorsal minor are fused with the dorsal atlanto-occipital membrane and that numerous trabeculae connect the dorsal atlanto-occipital membrane with the cervical spinal dura mater. Furthermore, the occipital venous sinus is located between the trabeculae. The MDB is mainly composed of collagen type I fibers. Our results show that the MDB is present in G. domesticus and lead us to infer that the MDB is a highly conservative evolutionary structure which may play essential physiological roles.
KeywordsMyodural bridge Cerebrospinal fluid circulation Collagen fiber Gallus domesticus
We would like to thank Ye-Xian Fan and Bing-Yi Luan in Dalian Hoffen Preservation Technique Institution for helping with preparing the sagittal sections.
YRD conceived the study, performed the study, interpreted the data, prepared the figures, and wrote the manuscript. NZ supervised the research, performed the macroscopic analysis, and edited the manuscript. JG performed the scanning electron microscopy examination. TW performed the thick Sagittal section examination. OCS edited the manuscript. YZ, YZ, YXC, SYP, LCQ performed the anatomical dissections. SBY, HJS collected the research material, supervised the research, and edited the manuscript. All authors approved the last version of manuscript.
This work was supported by Natural Science Foundation of China (NSFC31600972, NSFC31571234), Liaoning Province Department of Education Funds (L2016012).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no competing interests.
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