Histological differences between lumbar and tail intervertebral discs in mice
Autor: | Angela Schulz, Karsten Winter, Jana Brendler, Paul Lochhead, Albert M. Ricken |
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Rok vydání: | 2021 |
Předmět: |
vertebral column
Tail musculoskeletal diseases Nucleus Pulposus Histology age‐related changes Intervertebral Disc Degeneration Biology Degenerative disc disease Mice endplate Lumbar medicine Animals Molecular Biology Ecology Evolution Behavior and Systematics Original Paper spinal column Lumbar Vertebrae Soft tissue Intervertebral disc Cell Biology Anatomy musculoskeletal system medicine.disease Original Papers Spinal column animal models Mice Inbred C57BL medicine.anatomical_structure Coronal plane intervertebral disc vertebral body Vertebral column Developmental Biology |
Zdroj: | Journal of Anatomy |
ISSN: | 1469-7580 0021-8782 |
Popis: | Both the lumbar and tail intervertebral discs (IVD) of mice serve as models for the pathogenesis and histologic progression of degenerative disc disease. Recent studies in mature mice, however, demonstrate that the mechanics and physical attributes of lumbar and tail IVD‐endplate (EP)‐interfaces are strikingly different. We hypothesized that these structural disparities are associated with differences in the composition and organization of soft tissue elements that influence the biomechanical properties of the spine. Lumbar and tail vertebral segments and discs were collected from the same C57BL/6N and C57BL/6JRj mice, respectively for histological comparison of coronal sections at the ages of 4 weeks (weaned, both strains, C57BL/6N: n = 7; C57BL/6JRj: n = 4), three (mature, C57BL/6N: n = 7; C57BL/6JRj: n = 4), twelve (middle aged, C57BL/6JRj only: n = 3) and eighteen (old, C57BL/6JRj only: n = 3) months old. The histology of lumbar and tail IVD‐EP‐interfaces of mature mice differed markedly. The lumbar IVD‐EP‐interphase was characterized by a broad cartilaginous EP, while the tail IVD‐EP‐interphase comprised a thin layer of cartilage cells adjacent to a broad bony layer abutting the vertebral growth plate. Furthermore, the composition of the nuclei pulposi (NP) of lumbar and tail IVD in mature mice differed greatly. Lumbar NP consisted of a compact cluster of mainly large, uni‐vacuolated cells centered in an amorphous matrix, while tail NP were composed of a loose aggregate of vacuolated and non‐vacuolated cells. The anuli fibrosi also differed, with more abundant and sharply defined lamellae in tail compared to lumbar discs. The observed histological differences in the EP were even most prominent in weaned mice but were still discernible in middle‐aged and old mice. An appreciation of the histological differences between lumbar and tail IVD components in mice, including nucleus pulposus, annulus fibrosus, and endplates, is essential to our understanding of spinal biomechanics in these animals and should inform the design and interpretation of future IVD‐studies. In mice, cartilaginous intervertebral disc‐endplate‐ (IVD‐EP‐) segments co‐exist with bony IVD‐EP‐segments. This observation expands existing knowledge on mechanical and gross anatomical differences between lumbar and tail IVD‐EP‐segments in these quadrupeds. Our findings suggest that considerable attention should be given to spinal level‐related anatomic variation when using mice and other quadrupeds as models for IVD‐degeneration and its surgical management. Scale bars equal 50 µm. |
Databáze: | OpenAIRE |
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