Anatomical study of the innervation of different parts of the posterior ligamentous region of the sacroiliac joint

Background and objectivesThe periarticular sacroiliac joint (SIJ) technique has become an important area of focus, and the quartering of the SIJ posterior ligamentous region has been proposed as a way to refine this technique. However, detailed nerve distribution combined with the division of the SIJ posterior ligamentous region is lacking. We aimed to explore the innervation of the SIJ posteriorly based on the quartering of the SIJ posterior ligamentous region.MethodsSixteen SIJs from eight embalmed cadavers were studied. Each SIJ posterior ligamentous region was equally divided into areas 0–3 from top to bottom. The origin, distribution, quantity, transverse diameter, spatial orientation, relation with bony structures, and the number of identifiable terminal nerve branches in each area were examined.ResultsAreas 0–1 were innervated by the lateral branches of the dorsal rami of L4−L5 directly in all specimens. Areas 2–3 were innervated by that of both lumbar and sacral nerves via the posterior sacral network (PSN), with L5 contributing to the PSN in all specimens and L4 in 68.75%. The number of identifiable terminal nerve branches were significantly higher in areas 2–3 than in areas 0–1.ConclusionsThe inferior part of the SIJ posterior ligamentous region seems to be the main source of SIJ-related pain and is innervated by lumbar and sacral nerves via the PSN. However, the superior part directly innervated by lumbar nerves should not be neglected, and further clinical verification is needed.

Identifying Isl1 genetic lineage in the developing olfactory system and in GnRH-1 neurons

During embryonic development, symmetric ectodermal thickenings (olfactory placodes) give rise to several cell types that comprise the olfactory system, such as those that form the terminal nerve ganglion (TN), gonadotropin releasing hormone-1 (GnRH-1) neurons and other migratory neurons in rodents. Even though the genetic heterogeneity among these cell types are documented, unidentified cell populations arising from the olfactory placode remain. One candidate to identify placodal derived neurons in the developing nasal area is the transcription factor Isl1, which was recently identified in GnRH-3 neurons of the terminal nerve in fish, as well as expression in neurons of the nasal migratory mass. Here, we analyzed the Isl1 genetic lineage in chemosensory neuronal populations in the nasal area and migratory GnRH-1 neurons in mice using in-situ hybridization, immunolabeling a Tamoxifen inducible Isl1CreERT and a constitutive Isl1Cre knock-in mouse lines. In addition, we also performed conditional Isl1 ablation in developing GnRH neurons. We found Isl1 lineage across non sensory cells of the respiratory epithelium and sustentacular cells of OE and VNO. We identified a population of transient embryonic Isl1+ neurons in the olfactory epithelium and sparse Isl1+ neurons in postnatal VNO. Isl1 is expressed in almost all GnRH neurons and in approximately half of the other neuron populations in the Migratory Mass. However, Isl1 conditional ablation alone does not significantly compromise GnRH-1 neuronal migration or GnRH-1 expression, suggesting compensatory mechanisms. Further studies will elucidate the functional and mechanistic role of Isl1 in development of migratory endocrine neurons.

SV40T reprograms Schwann cells into stem-like cells that can re-differentiate into terminal nerve cells.

Background : The effects of Simian virus 40 T antigen (SV40T) on various kinds of cells are different. Previous researchers failed to use SV40T immortalized nerve cells. However, they argued that SV40T caused nerve cell transformation. No one further study what is the specific effect of SV40T on nerve cells. We transfected Schwann cells (SCs) that did not have differentiation ability with MPH 86 plasmid containing SV40T in order to explore the effects of SV40T on Schwann cells. Methods : SCs were transfected with MPH 86 plasmid carrying the SV40T gene and cultured in different media, as well as co-cultured with neural stem cells (NSCs). In our study, SCs overexpressing SV40T were defined as SV40T-SCs. The proliferation of these cells was detected by WST-1, and the expression of different biomarkers was analyzed by qPCR and immunohistochemistry. Results: SV40T induced the characteristics of NSCs, such as the ability to grow in suspension, form spheroid colonies and proliferate rapidly, in the SCs, which were reversed by knocking out SV40T by the Flip-adenovirus . In addition, SV40T up-regulated the neurocrest markers Nestin, Pax3 and Slug, and down-regulated S100b as well as the late differentiation markers MBP, GFAP and Olig1/2. These cells also expressed NSC markers like Nestin, Sox2, CD133 and SSEA-1, as well as early development markers of embryonic stem cells (ESCs) like BMP4, c-Myc, OCT4 and Gbx2. Co-culturing with NSCs induced differentiation of the SV40T-SCs into neuronal and glial cells. Conclusions: SV40T reprograms Schwann cells to stem-like cells at the stage of neural crest cells that can differentiate to terminal nerve cells.

SV40T reprograms Schwann cells into stem-like cells that can re-differentiate into terminal nerve cells.

Background : The effects of Simian virus 40 T antigen (SV40T) on various kinds of cells are different. Previous researchers failed to use SV40T immortalized nerve cells. However, they argued that SV40T caused nerve cell transformation. No one further study what is the specific effect of SV40T on nerve cells. We transfected Schwann cells (SCs) that did not have differentiation ability with MPH 86 plasmid containing SV40T in order to explore the effects of SV40T on Schwann cells. Methods: SCs were transfected with MPH 86 plasmid carrying the SV40T gene and cultured in different media, as well as co-cultured with neural stem cells (NSCs). In our study, SCs overexpressing SV40T were defined as SV40T-SCs. The proliferation of these cells was detected by WST-1, and the expression of different biomarkers was analyzed by qPCR and immunohistochemistry. Results: SV40T induced the characteristics of NSCs, such as the ability to grow in suspension, form spheroid colonies and proliferate rapidly, in the SCs, which were reversed by knocking out SV40T by the Flip-adenovirus . In addition, SV40T up-regulated the neurocrest markers Nestin, Pax3 and Slug, and down-regulated S100b as well as the late differentiation markers MBP, GFAP and Olig1/2. These cells also expressed NSC markers like Nestin, SOX2, CD133 and SSEA-1, as well as early development markers of embryonic stem cells (ESCs) like BMP4, C-myc, OCT4 and Gbx2. Co-culturing with NSCs induced differentiation of the SV40T-SCs into neuronal and glial cells. Conclusions: SV40T reprograms Schwann cells to stem-like cells at the stage of neural crest cells that can differentiate to terminal nerve cells. Background : The effects of Simian virus 40 T antigen (SV40T) on various kinds of cells are different. Previous researchers failed to use SV40T immortalized nerve cells. However, they argued that SV40T caused nerve cell transformation. No one further study what is the specific effect of SV40T on nerve cells.