The Experts below are selected from a list of 36 Experts worldwide ranked by ideXlab platform
Zhang Y. - One of the best experts on this subject based on the ideXlab platform.
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The development and molecular characterization of muscle spindles from wildtype and mutant mice.
Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014Co-Authors: Zhang Y.Abstract:Muscle spindles are complex stretch-sensitive mechanoreceptors that consist of 4-12 specialized muscle fibers. These intrafusal muscle fibers are innervated in the central (equatorial) region by an afferent Sensory axon and in both peripheral (polar) regions by efferent γ-motoneurons. Until now little is known about muscle spindle development at the molecular level, especially about the development of cholinergic specializations. My study shows that nicotinic acetylcholine receptors (AChR) are concentrated at the γ-motoneuron endplate as well as in the equatorial region. Moreover, enzymes required for the synthesis and removal of acetylcholine, including choline acetyltransferase (ChAT) and acetylcholinesterase (AChE), as well as vesicular acetylcholine transporter (VAChT) and the AChR-associated protein rapsyn are all concentrated at the polar γ-motoneuron endplate and (with the exception of AChE) also at the equatorial region. Finally, the presynaptic protein bassoon, involved in synaptic vesicle exocytosis, is also present at the γ-motoneuron endplate and at the annulospiral Sensory Nerve Ending. During postnatal development, the AChR subunit composition at the γ-motoneuron endplate changes from the γ-subunit containing fetal AChR to the ε-subunit containing adult AChR. This is similar to the postnatal change at the neuromuscular junction. In the equatorial region the ε-subunit expression starts around postnatal week two; however the γ-subunit persists in the central region despite the onset of the ε-subunit expression. Therefore, the γ- and ε-subunits are simultaneously present in the equatorial region. This result was confirmed using a mouse line in which the AChR γ-subunit was genetically labelled by green fluorescence protein (GFP). In this mouse, the GFP-labelled AChR γ-subunits are concentrated at the contact site of the intrafusal fiber with the Sensory Nerve Ending. This result indicates different AChR maturation occurs within two areas of the same intrafusal fiber. I also show that agrin and the agrin receptor complex (consisting of LRP4 and MuSK) are present in muscle spindles in the region of the Sensory and motor innervation. Moreover, agrin, MuSK, and LRP4 are expressed by proprioceptive neurons in dorsal root ganglia but only agrin and LRP4 were detected in the cell body of γ-motoneurons in the spinal cord. In mice with a targeted deletion of agrin, AChR aggregates are absent from the polar region and γ-motoneuron endplates do not form. By contrast, AChR aggregates remain detectable in the central part of intrafusal fibers. Moreover, muscle-specific re-expression of mini-agrin is sufficient to restore the formation of synaptic specializations at γ-motoneuron endplates. These results show an unusual AChR maturation at the annulospiral Endings and confirm that agrin is a major determinant for the formation of γ-motoneuron endplates. Agrin on the other hand appears dispensable for the aggregation of AChRs in the central region of intrafusal fibers
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Formation of cholinergic synapse-like specializations at developing murine muscle spindles.
Academic Press Inc Elsevier Science, 2014Co-Authors: Zhang Y., Karakatsani A., Wesolowski M., Kröger S.Abstract:Muscle spindles are complex stretch-sensitive mechanoreceptors. They consist of specialized skeletal muscle fibers, called intrafusal fibers, which are innervated in the central (equatorial) region by afferent Sensory axons and in both polar regions by efferent γ-motoneurons. We show that AChRs are concentrated at the γ-motoneuron endplate as well as in the equatorial region where they colocalize with the Sensory Nerve Ending. In addition to the AChRs, the contact site between Sensory Nerve Ending and intrafusal muscle fiber contains a high concentration of choline acetyltransferase, vesicular acetylcholine transporter and the AChR-associated protein rapsyn. Moreover, bassoon, a component of the presynaptic cytomatrix involved in synaptic vesicle exocytosis, is present in γ-motoneuron endplates but also in the Sensory Nerve terminal. Finally, we demonstrate that during postnatal development of the γ-motoneuron endplate, the AChR subunit stoichiometry changes from the γ-subunit-containing fetal AChRs to the ε-subunit-containing adult AChRs, similar and approximately in parallel to the postnatal subunit maturation at the neuromuscular junction. In contrast, despite the onset of ε-subunit expression during postnatal development the γ-subunit remains detectable in the equatorial region by subunit-specific antibodies as well as by analysis of muscle spindles from mice with genetically-labeled AChR γ-subunits. These results demonstrate an unusual maturation of the AChR subunit composition at the annulospiral Endings and suggest that in addition to the recently described glutamatergic secretory system, the Sensory Nerve terminals are also specialized for cholinergic synaptic transmission, synaptic vesicle storage and exocytosis
Zhang Yina - One of the best experts on this subject based on the ideXlab platform.
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The development and molecular characterization of muscle spindles from wildtype and mutant mice
Ludwig-Maximilians-Universität München, 2014Co-Authors: Zhang YinaAbstract:Muscle spindles are complex stretch-sensitive mechanoreceptors that consist of 4-12 specialized muscle fibers. These intrafusal muscle fibers are innervated in the central (equatorial) region by an afferent Sensory axon and in both peripheral (polar) regions by efferent γ-motoneurons. Until now little is known about muscle spindle development at the molecular level, especially about the development of cholinergic specializations. My study shows that nicotinic acetylcholine receptors (AChR) are concentrated at the γ-motoneuron endplate as well as in the equatorial region. Moreover, enzymes required for the synthesis and removal of acetylcholine, including choline acetyltransferase (ChAT) and acetylcholinesterase (AChE), as well as vesicular acetylcholine transporter (VAChT) and the AChR-associated protein rapsyn are all concentrated at the polar γ-motoneuron endplate and (with the exception of AChE) also at the equatorial region. Finally, the presynaptic protein bassoon, involved in synaptic vesicle exocytosis, is also present at the γ-motoneuron endplate and at the annulospiral Sensory Nerve Ending. During postnatal development, the AChR subunit composition at the γ-motoneuron endplate changes from the γ-subunit containing fetal AChR to the ε-subunit containing adult AChR. This is similar to the postnatal change at the neuromuscular junction. In the equatorial region the ε-subunit expression starts around postnatal week two; however the γ-subunit persists in the central region despite the onset of the ε-subunit expression. Therefore, the γ- and ε-subunits are simultaneously present in the equatorial region. This result was confirmed using a mouse line in which the AChR γ-subunit was genetically labelled by green fluorescence protein (GFP). In this mouse, the GFP-labelled AChR γ-subunits are concentrated at the contact site of the intrafusal fiber with the Sensory Nerve Ending. This result indicates different AChR maturation occurs within two areas of the same intrafusal fiber. I also show that agrin and the agrin receptor complex (consisting of LRP4 and MuSK) are present in muscle spindles in the region of the Sensory and motor innervation. Moreover, agrin, MuSK, and LRP4 are expressed by proprioceptive neurons in dorsal root ganglia but only agrin and LRP4 were detected in the cell body of γ-motoneurons in the spinal cord. In mice with a targeted deletion of agrin, AChR aggregates are absent from the polar region and γ-motoneuron endplates do not form. By contrast, AChR aggregates remain detectable in the central part of intrafusal fibers. Moreover, muscle-specific re-expression of mini-agrin is sufficient to restore the formation of synaptic specializations at γ-motoneuron endplates. These results show an unusual AChR maturation at the annulospiral Endings and confirm that agrin is a major determinant for the formation of γ-motoneuron endplates. Agrin on the other hand appears dispensable for the aggregation of AChRs in the central region of intrafusal fibers.Muskelspindeln sind komplexe, dehnungsempfindliche Mechanorezeptoren, die aus vier bis zwölf spezialisierten Muskelfasern bestehen. Diese intrafusalen Muskelfasern werden im zentralen (äquatorialen) Bereich durch afferente Axone und in beiden peripheren (polaren) Regionen von efferenten γ-Motoneuronen innerviert. Über die Entwicklung von Muskelspindeln auf molekularer Ebene ist kaum etwas bekannt, vor allem was cholinerge Spezialisierung angeht. In meiner Doktorarbeit konnte ich zeigen, dass nikotinische Azetylcholinrezeptoren (AChR) an der neuromusklären Endplatte von γ-Motoneuronen sowie in der äquatorialen Region konzentriert sind. Auch die Enzyme, die für die Synthese, den Transport und den Abbau von Acetylcholin verantwortlich sind, (Cholinazetyltransferase (ChAT), Azetylcholinesterase (AChE) und vesikuläre Azetylcholintransporter (VAChT) wurden in der polaren und der äquatorialen Region gefunden. Diese Ergebnisse zeigen, dass sowohl die sensorischen afferenten- als auch die motorischen efferenten Neurone im Bereich des Kontaktes mit den Intrafusalfasern cholinerg spezialisiert sind. Während der postnatalen Entwicklung der neuromuskulären Endplatte verändert sich die Zusammensetzung der AChR Untereinheiten. Aus den γ-Untereinheit enthaltenden embryonalen AChRen werden ε-Untereinheit enthaltende adulte AChRen gebildet. Vergleichbare postnatale Veränderungen findet man auch an der neuromuskulären Endplatte der Extrafusalfasern. Im Gegensatz zu diesen Synapsen bleibt in den Intrafusalfasern die Expression der γ-Untereinheit im zentralen Bereich der Nervenfaser neben der Expression der ε-Untereinheit während der postnatalen Entwicklung erhalten. Diese fehlende gamma-zu-epsilon-Umschaltung wurde mit Hilfe von transgenen Mäusen bestätigt, bei denen die AChR γ-Untereinheiten mittels GFP genetisch markiert waren. Diese Ergebnisse zeigen, dass AChR γ-Untereinheiten in adulten intrafusalen Fasern dort konzentriert sind, wo sie Kontakt zu sensorischen Nervenendigungen haben. Agrin und der Agrin Rezeptor-Komplex - bestehend aus MuSK und LRP4 (LDL Rezeptor-beziehend Protein) - konnten in Muskelspindeln im Bereich der sensorischen und motorischen Innervation nachgewiesen werden. Außerdem sind Agrin und sein Rezeptor-Komplex in propriozeptiven Neuronen der Spinalganglien exprimiert, während nur Agrin und LRP4 in γ-Motoneuronen im Rückenmark zu finden sind. In Agrin knock-out Mäusen ist keine AChR Aggregation in der Polarregion zu finden, was zu Defekten in der Ausbildung der gamma-Motoeneuronen Endplatten führt. Im Gegensatz dazu sind die AChR Aggregate im zentralen Teil der intrafusalen Fasern nicht betroffen. Muskelspezifische Überexpression von Mini-Agrin reicht aus, um die Bildung von synaptischen Spezialisierungen in den Endplatten von γ-Motoneuronen wiederherzustellen. Diese Ergebnisse zeigen eine ungewöhnliche AChR Reifung an den annulospiralen sensorischen Endigungen und bestätigen, dass Agrin, ein essenzieller Faktor für die Bildung der Endplatten von γ-Motoneuronen ist, während er nicht notwendig für die Aggregation von AChRs in der zentralen Region von intrafusalen Fasern zu sein scheint
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Formation of cholinergic synapse-like specializations at developing murine muscle spindles
Elsevier Inc., 2014Co-Authors: Zhang Yina, Wesolowski Marta, Karakatsani Andromachi, Witzemann Veit, Kröger StephanAbstract:AbstractMuscle spindles are complex stretch-sensitive mechanoreceptors. They consist of specialized skeletal muscle fibers, called intrafusal fibers, which are innervated in the central (equatorial) region by afferent Sensory axons and in both polar regions by efferent γ-motoneurons. We show that AChRs are concentrated at the γ-motoneuron endplate as well as in the equatorial region where they colocalize with the Sensory Nerve Ending. In addition to the AChRs, the contact site between Sensory Nerve Ending and intrafusal muscle fiber contains a high concentration of choline acetyltransferase, vesicular acetylcholine transporter and the AChR-associated protein rapsyn. Moreover, bassoon, a component of the presynaptic cytomatrix involved in synaptic vesicle exocytosis, is present in γ-motoneuron endplates but also in the Sensory Nerve terminal. Finally, we demonstrate that during postnatal development of the γ-motoneuron endplate, the AChR subunit stoichiometry changes from the γ-subunit-containing fetal AChRs to the ε-subunit-containing adult AChRs, similar and approximately in parallel to the postnatal subunit maturation at the neuromuscular junction. In contrast, despite the onset of ε-subunit expression during postnatal development the γ-subunit remains detectable in the equatorial region by subunit-specific antibodies as well as by analysis of muscle spindles from mice with genetically-labeled AChR γ-subunits. These results demonstrate an unusual maturation of the AChR subunit composition at the annulospiral Endings and suggest that in addition to the recently described glutamatergic secretory system, the Sensory Nerve terminals are also specialized for cholinergic synaptic transmission, synaptic vesicle storage and exocytosis
Tsuneo Takebayashi - One of the best experts on this subject based on the ideXlab platform.
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friday september 28 2018 1 00 pm 2 30 pm abstracts a new look at imaging 203 analysis of chronic low back pain with magnetic resonance imaging t2 mapping of lumbar intervertebral disc
The Spine Journal, 2018Co-Authors: Izaya Ogon, Hiroyuki Takashima, Katsumasa Tanimoto, Tsuneo TakebayashiAbstract:BACKGROUND CONTEXT Intervertebral disc degeneration (IVDD) is considered to be the principal tissue as a source of low back pain (LBP). There are many reports concerning discogenic LBP from the aspect of pathology, diagnosis, and treatment, however the mechanism and treatment still remain to be unclear. Magnetic resonance imaging (MRI) is an important modality for diagnosis of degenerative intervertebral disc (IVD). Signal variation of the discs on T2-weighted images reflects age and degeneration and allows for the determination of disc degeneration. Specifically, since signal strength in the MRI is related to water and proteoglycan content, changes in MRI signal strength in the nucleus pulposus can indicate IVDD. IVDD has been classified by T2-weighted images using the system described by Pfirrmann et al., but since this classification is based on visual evaluation, the quantification of degeneration using this strategy is unclear. In recent years, there have been several reported attempts using MRI T2 mapping and MRI T1p mapping to quantify lumbar disc degeneration. MRI T2 mapping utilizes the T2 relaxation time for quantification of moisture contents and the collagen sequence breakdown. In our previous work, we used MRI T2 mapping to quantify the extent of IVDD and reported a correlation with Pfirrmann classifications. Recently, there are a few reports regarding the quantitative evaluation of discogenic LBP with MRI T2 mapping and MRI T1p mapping, but the number is small. PURPOSE In this study, we used MRI T2 mapping to quantify IVDD and investigate possible correlations between these quantified values and the low back pain visual analog scale (VAS) scores and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) scores. STUDY DESIGN/SETTING Cross sectional study. PATIENT SAMPLE Twenty-eight (15 males, 13 females; mean age, 48.9±9.6 years; range, 22–60 years) patients whose visual analog scale scores were >30mm for CLBP were included. Further, 25 asymptomatic control participants matched with the CLBP group subjects for gender and age (13 males, 12 females; mean age, 43.8±14.5 years; range, 23–60 years) who had no low back pain, constituted the control group. OUTCOME MEASURES VAS scores and JOABPEQ scores (low back pain and lumbar function). METHODS We screened the subjects whose disc degeneration at L4-5 level was Pfirrmann grade III–V, but another discs were Pfirrmanngrade I–II. For measurement, disc was divided into five equal areas, designating the front fifth of the anterior annulus fibrosus (AF), the middle fifth of the nucleus pulposus (NP), and the last fifth of the posterior AF, referring to past report. The mean values in the region of interest (ROI) were measured. T2 values were measured with MedCalc (version 10.2.0.0, MedCalc Software, Mariakerke, Belgium). We compared T2 values of the CLBP group to the control group. We also investigated possible correlations between these quantified values at the L4-5 level (a total of 28 lumbar discs) and the VAS scores and JOABPEQ scores (low back pain and lumbar function) in the CLBP group. Differences among groups were compared using the Mann–Whitney U test. The relationship between T2 values of IVD and CLBP were analyzed by the Spearman's rank-correlation coefficient. A P value of less than .05 was considered statistically significant. RESULTS T2 values for the control and CLBP groups were 70.2±14.4ms and 63.4±20.1ms, respectively, for the anterior AF, 80.8±31.3ms and 71.7±16.7ms, respectively, for NP, 70.3±15.8ms and 54.4±9.7ms, respectively, for the posterior AF. T2 values for IVD tended to be lower in the CLBP group than in the control group, and these values were significantly different (p CONCLUSIONS Conventionally, IVDD has been characterized by MRI findings according to the classifications reported by Pfirrmann. However, there are problems with this technique, such as difficulty with assessments of early degeneration and the AF as well as poor reproducibility and objectivity because the classifications are visually performed. In the present study, we used MRI T2 mapping to quantitatively investigate a possible correlation between the degree of IVDD and CLBP. The results indicated a correlation between posterior AF degeneration and CLBP. Sinuvertebral Nerves, which originate from spinal Nerve roots, are distributed around the posterior AF region; therefore, this area is rich innervated. IVD with myelomeres are controlled through sinuvertebral Nerves and those without myelomeres are controlled through paravertebral sympathetic Nerves. We think that these changes which so rich afferent fibers around the posterior AF grow into disc provide an explanation for the induction of discogenic LBP in patients with IVDD. In addition, Sensory Nerve Ending had differences of the sensitivity against noxious stimuli. The mechanical threshold of front part in IVD were 241g (164–279g), in contrast that of back side part (longitudinal ligament) were 80.3g (20.9–164g) . We speculated about a possibility that CLBP did not show correlations with T2 value of anterior AF or that of NP, but with that of posterior AF, because of low sensitivity against noxious stimuli at front part in IVD. Invasive discography has been conventionally used to examine discogenic LBP. This technique, which can cause pain due to the injection of contrast fluid between intervertebral discs, has a high false-positive rate; therefore, it has been reported to be not entirely suitable as an index for identifying the source of pain. Moreover, discography has been reported to cause progression of intervertebral disc degeneration. MRI T2 mapping is a noninvasive quantitative evaluation method that offers high reproducibility in contrast to discography. The results of the present study suggest that MRI T2 mapping could be used instead of invasive discography as a quantitative method for diagnosing discogenic pain.
Kröger S. - One of the best experts on this subject based on the ideXlab platform.
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Formation of cholinergic synapse-like specializations at developing murine muscle spindles.
Academic Press Inc Elsevier Science, 2014Co-Authors: Zhang Y., Karakatsani A., Wesolowski M., Kröger S.Abstract:Muscle spindles are complex stretch-sensitive mechanoreceptors. They consist of specialized skeletal muscle fibers, called intrafusal fibers, which are innervated in the central (equatorial) region by afferent Sensory axons and in both polar regions by efferent γ-motoneurons. We show that AChRs are concentrated at the γ-motoneuron endplate as well as in the equatorial region where they colocalize with the Sensory Nerve Ending. In addition to the AChRs, the contact site between Sensory Nerve Ending and intrafusal muscle fiber contains a high concentration of choline acetyltransferase, vesicular acetylcholine transporter and the AChR-associated protein rapsyn. Moreover, bassoon, a component of the presynaptic cytomatrix involved in synaptic vesicle exocytosis, is present in γ-motoneuron endplates but also in the Sensory Nerve terminal. Finally, we demonstrate that during postnatal development of the γ-motoneuron endplate, the AChR subunit stoichiometry changes from the γ-subunit-containing fetal AChRs to the ε-subunit-containing adult AChRs, similar and approximately in parallel to the postnatal subunit maturation at the neuromuscular junction. In contrast, despite the onset of ε-subunit expression during postnatal development the γ-subunit remains detectable in the equatorial region by subunit-specific antibodies as well as by analysis of muscle spindles from mice with genetically-labeled AChR γ-subunits. These results demonstrate an unusual maturation of the AChR subunit composition at the annulospiral Endings and suggest that in addition to the recently described glutamatergic secretory system, the Sensory Nerve terminals are also specialized for cholinergic synaptic transmission, synaptic vesicle storage and exocytosis
Izaya Ogon - One of the best experts on this subject based on the ideXlab platform.
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friday september 28 2018 1 00 pm 2 30 pm abstracts a new look at imaging 203 analysis of chronic low back pain with magnetic resonance imaging t2 mapping of lumbar intervertebral disc
The Spine Journal, 2018Co-Authors: Izaya Ogon, Hiroyuki Takashima, Katsumasa Tanimoto, Tsuneo TakebayashiAbstract:BACKGROUND CONTEXT Intervertebral disc degeneration (IVDD) is considered to be the principal tissue as a source of low back pain (LBP). There are many reports concerning discogenic LBP from the aspect of pathology, diagnosis, and treatment, however the mechanism and treatment still remain to be unclear. Magnetic resonance imaging (MRI) is an important modality for diagnosis of degenerative intervertebral disc (IVD). Signal variation of the discs on T2-weighted images reflects age and degeneration and allows for the determination of disc degeneration. Specifically, since signal strength in the MRI is related to water and proteoglycan content, changes in MRI signal strength in the nucleus pulposus can indicate IVDD. IVDD has been classified by T2-weighted images using the system described by Pfirrmann et al., but since this classification is based on visual evaluation, the quantification of degeneration using this strategy is unclear. In recent years, there have been several reported attempts using MRI T2 mapping and MRI T1p mapping to quantify lumbar disc degeneration. MRI T2 mapping utilizes the T2 relaxation time for quantification of moisture contents and the collagen sequence breakdown. In our previous work, we used MRI T2 mapping to quantify the extent of IVDD and reported a correlation with Pfirrmann classifications. Recently, there are a few reports regarding the quantitative evaluation of discogenic LBP with MRI T2 mapping and MRI T1p mapping, but the number is small. PURPOSE In this study, we used MRI T2 mapping to quantify IVDD and investigate possible correlations between these quantified values and the low back pain visual analog scale (VAS) scores and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) scores. STUDY DESIGN/SETTING Cross sectional study. PATIENT SAMPLE Twenty-eight (15 males, 13 females; mean age, 48.9±9.6 years; range, 22–60 years) patients whose visual analog scale scores were >30mm for CLBP were included. Further, 25 asymptomatic control participants matched with the CLBP group subjects for gender and age (13 males, 12 females; mean age, 43.8±14.5 years; range, 23–60 years) who had no low back pain, constituted the control group. OUTCOME MEASURES VAS scores and JOABPEQ scores (low back pain and lumbar function). METHODS We screened the subjects whose disc degeneration at L4-5 level was Pfirrmann grade III–V, but another discs were Pfirrmanngrade I–II. For measurement, disc was divided into five equal areas, designating the front fifth of the anterior annulus fibrosus (AF), the middle fifth of the nucleus pulposus (NP), and the last fifth of the posterior AF, referring to past report. The mean values in the region of interest (ROI) were measured. T2 values were measured with MedCalc (version 10.2.0.0, MedCalc Software, Mariakerke, Belgium). We compared T2 values of the CLBP group to the control group. We also investigated possible correlations between these quantified values at the L4-5 level (a total of 28 lumbar discs) and the VAS scores and JOABPEQ scores (low back pain and lumbar function) in the CLBP group. Differences among groups were compared using the Mann–Whitney U test. The relationship between T2 values of IVD and CLBP were analyzed by the Spearman's rank-correlation coefficient. A P value of less than .05 was considered statistically significant. RESULTS T2 values for the control and CLBP groups were 70.2±14.4ms and 63.4±20.1ms, respectively, for the anterior AF, 80.8±31.3ms and 71.7±16.7ms, respectively, for NP, 70.3±15.8ms and 54.4±9.7ms, respectively, for the posterior AF. T2 values for IVD tended to be lower in the CLBP group than in the control group, and these values were significantly different (p CONCLUSIONS Conventionally, IVDD has been characterized by MRI findings according to the classifications reported by Pfirrmann. However, there are problems with this technique, such as difficulty with assessments of early degeneration and the AF as well as poor reproducibility and objectivity because the classifications are visually performed. In the present study, we used MRI T2 mapping to quantitatively investigate a possible correlation between the degree of IVDD and CLBP. The results indicated a correlation between posterior AF degeneration and CLBP. Sinuvertebral Nerves, which originate from spinal Nerve roots, are distributed around the posterior AF region; therefore, this area is rich innervated. IVD with myelomeres are controlled through sinuvertebral Nerves and those without myelomeres are controlled through paravertebral sympathetic Nerves. We think that these changes which so rich afferent fibers around the posterior AF grow into disc provide an explanation for the induction of discogenic LBP in patients with IVDD. In addition, Sensory Nerve Ending had differences of the sensitivity against noxious stimuli. The mechanical threshold of front part in IVD were 241g (164–279g), in contrast that of back side part (longitudinal ligament) were 80.3g (20.9–164g) . We speculated about a possibility that CLBP did not show correlations with T2 value of anterior AF or that of NP, but with that of posterior AF, because of low sensitivity against noxious stimuli at front part in IVD. Invasive discography has been conventionally used to examine discogenic LBP. This technique, which can cause pain due to the injection of contrast fluid between intervertebral discs, has a high false-positive rate; therefore, it has been reported to be not entirely suitable as an index for identifying the source of pain. Moreover, discography has been reported to cause progression of intervertebral disc degeneration. MRI T2 mapping is a noninvasive quantitative evaluation method that offers high reproducibility in contrast to discography. The results of the present study suggest that MRI T2 mapping could be used instead of invasive discography as a quantitative method for diagnosing discogenic pain.
