担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

Perineuronal nets are extracellular matrix structures that surround neuronal cell bodies and their proximal dendrites in the central nervous system. Chondroitin sulfate proteoglycans, which contain chondroitin sulfates (CSs) are major components of perineuronal nets. CSs are considered to have inhibitory roles in neural plasticity, although the effects differ according to their sulfation pattern. In the present study, we investigated the expression of the CS subtypes CS-A and CS-C surrounding spinal motoneurons in different postnatal periods to explore the potential influence of altered CS sulfation patterns on spinal development. CS-A-positive structures were observed around motoneurons in the cervical, thoracic, and lumbar segments as early as postnatal day (P) 5. Most motoneurons were covered with CS-A-positive structures during the first 2 postnatal weeks. The percentage of motoneurons covered with CS-A-positive structures decreased after P20, becoming lower than 70% in the cervical, and lumber segments after P35. CS-C-positive structures were occasionally observed around motoneurons during the first 2 postnatal weeks. The percentage of motoneurons covered with CS-C-positive structures increased after P20, becoming significantly higher after P25 than before P20. The expression pattern of Wisteria Floribunda agglutinin-positive structures around motoneurons was similar to that of the CS-C-positive structures. The present findings revealed that CS-A and CS-C are differentially expressed in the extracellular matrix surrounding motoneurons. The altered sulfation pattern with increased CS-C expression is associated with the maturation of perineuronal nets and might lead to changes in the motoneuron plasticity.

DOI： 10.1016/j.brainres.2020.147252

PubMed

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier Ltd  

Complete spinal transection in adult rats results in poor recovery of hind limb function and severe urinary bladder dysfunction. Neonatal rats with spinal cord transection, however, exhibit spontaneous and significant recovery of micturition control. A previous study in which biotinylated-dextran amine (BDA) was used as an anterograde tracer demonstrated that primary afferent fibers from the fifth lumbar dorsal root ganglion (DRG) project more strongly and make more terminals in the ventral horn after neonatal spinal cord transection at the mid-thoracic level. In the present study, we injected BDA into the sixth lumbar (L6) DRG of neonatally spinalized rats to label primary afferent fibers that include visceral afferents. The labeled fibers projected to the intermediolateral nucleus (IML) in the intermediate zone on ipsilateral side of the L6 spinal segment, whereas no projections to the IML were observed in sham-operated or intact rats. The BDA-labeled fibers of neonatally spinalized rats formed varicose terminals on parasympathetic preganglionic neurons in the IML. These findings suggest that some primary afferent projections from the L6 DRG to the IML appear after neonatal spinal cord transection, and these de novo projections might contribute to the recovery of autonomic function such as micturition following spinal cord injury in the neonatal stage.

DOI： 10.1016/j.ibror.2017.11.002

Scopus

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1016/j.bbrc.2018.09.151

Scopus

researchmap

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

Complete spinal transection in adult rats results in poor recovery of hind limb function, whereas significant spontaneous recovery can occur following spinal cord transection in rat neonates. The mechanisms underlying the recovery, however, are poorly understood. Recent studies in rodents suggested that the recovery is not due to axonal regeneration, but rather due to reorganization of the neural circuits in the spinal cord below the injury site, including central pattern generators. Few studies have reported histological evidence for changes in the primary sensory fibers or terminals. Thus, in the present study, we transected spinal cords of rats at thoracic level 8 at postnatal day 5. Four weeks after the injury, biotinylated-dextran amine (BDA), an anterograde tracer, was injected into the dorsal root ganglion of the lumbar spinal cord to examine the localization of sensory fibers and their terminal buttons in the spinal cord. BDA-positive axons in the rat spinal cord following neonatal spinal transection (neo ST) were longer than those in sham-operated or normal rats. The number of terminal buttons was also higher in spinal cords of neo ST rats compared with sham-operated or normal rats. These findings suggest that sensory fibers project more strongly and make more synapses following neo ST to compensate for the lack of supraspinal projections. (C) 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.neuroscience.2015.07.046

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：BIOMED CENTRAL LTD  

Background: The descending antinociceptive system (DAS) is thought to play crucial roles in the antinociceptive effect of spinal cord stimulation (SCS), especially through its serotonergic pathway. The nucleus raphe magnus (NRM) in the rostral ventromedial medulla is a major source of serotonin [5-hydroxytryptamine (5-HT)] to the DAS, but the role of the dorsal raphe nucleus (DRN) in the ventral periaqueductal gray matter is still unclear. Moreover, the influence of the noradrenergic pathway is largely unknown. In this study, we evaluated the involvement of these serotonergic and noradrenergic pathways in SCS-induced antinociception by behavioral analysis of spinal nerve-ligated (SNL) rats. We also investigated immunohistochemical changes in the DRN and locus coeruleus (LC), regarded as the adrenergic center of the DAS, and expression changes of synthetic enzymes of 5-HT [tryptophan hydroxylase (TPH)] and norepinephrine [dopamine beta-hydroxylase (D beta H)] in the spinal dorsal horn.
Results: Intrathecally administered methysergide, a 5-HT1-and 5-HT2-receptor antagonist, and idazoxan, an alpha(2)-adrenergic receptor antagonist, equally abolished the antinociceptive effect of SCS. The numbers of TPH-positive serotonergic and phosphorylated cyclic AMP response element binding protein (pCREB)-positive neurons and percentage of pCREB-positive serotonergic neurons in the DRN significantly increased after 3-h SCS. Further, the ipsilateral-to-contralateral immunoreactivity ratio of D beta H increased in the LC of SNL rats and reached the level seen in naive rats, even though the number of pCREB-positive neurons in the LC was unchanged by SNL and SCS. Moreover, 3-h SCS did not increase the expression levels of TPH and D beta H in the spinal dorsal horn.
Conclusions: The serotonergic and noradrenergic pathways of the DAS are involved in the antinociceptive effect of SCS, but activation of the DRN might primarily be responsible for this effect, and the LC may have a smaller contribution. SCS does not potentiate the synthetic enzymes of 5HT and norepinephrine in the neuropathic spinal cord.

DOI： 10.1186/s12990-015-0039-9

Web of Science

researchmap

記述言語：日本語   出版者・発行元：日本アフェレシス学会  

フィルター無使用で白血球除去装置ポータブル化が可能か,基礎的検討を行った.基礎となる理論は,(1)白血球系細胞は細血管では壁面を転がるように流れる特性を持つこと,(2)細管では液体は中心流や壁流などの層流を形成して流れ,中心流は回路抵抗が低いこと,(3)白血球の様な自走能を持つ細胞は極めて細い繊維に寄り添うように付着する接触走性の特性を持つこと,である.平均内径3mmの血液回路の一部に断面直径3.3μの極細ポリエステル繊維UFPFsと通常の太さ16μのポリエステル繊維RPFsの2種類の筒状布帛を配置し,白血球系細胞が回路壁面で繊維に捕捉される設計とした.ヘパリン化した犬を用いた血液ポンプ無使用の静脈-静脈回路2時間では160ml/minの血流量を維持し,UFPFsの白血球捕捉数はRPFsの5倍強であった.この結果はUFPFsを用いた回路壁面白血球捕捉法は効果的であり,その手法を用いた装置ポータブル化の可能性を示唆している.

CiNii Books

researchmap

その他リンク： http://id.nii.ac.jp/1141/00152217/

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ELSEVIER SCIENCE BV  

Cyclin E, a member of the G1 cyclins, is essential for the G1/S transition of the cell cycle in cultured cells, but its roles in vivo are not fully defined. The present study characterized the spatiotemporal expression profile of cyclin E in two representative brain regions in the mouse, the cerebral and cerebellar cortices. Western blotting showed that the levels of cyclin E increased towards adulthood. In situ hybridization and immunohistochemistry showed the distributions of cyclin E mRNA and protein were comparable in the cerebral cortex and the cerebellum. Immunohistochemistry for the proliferating cell marker, proliferating cell nuclear antigen (PCNA) revealed that cyclin E was expressed by both proliferating and non-proliferating cells in the cerebral cortex at embryonic day 12.5 (E12.5) and in the cerebellum at postnatal day 1 (P1). Subcellular localization in neurons was examined using immunofluorescence and western blotting. Cyclin E expression was nuclear in proliferating neuronal precursor cells but cytoplasmic in postmitotic neurons during embryonic development. Nuclear cyclin E expression in neurons remained faint in newborns, increased during postnatal development and was markedly decreased in adults. In various adult brain regions, cyclin E staining was more intense in the cytoplasm than in the nucleus in most neurons. These data suggest a role for cyclin E in the development and function of the mammalian central nervous system and that its subcellular localization in neurons is important. Our report presents the first detailed analysis of cyclin E expression in postmitotic neurons during development and in the adult mouse brain. (c) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.gep.2010.09.004

Web of Science

researchmap

記述言語：英語   掲載種別：研究論文（学術雑誌）  

To examine the compensatory mechanisms in rats that underwent left decortication at postnatal day 7 (P7), we injected the retrograde tracers fluorescein isothiocyanate-cholera toxin B subunit (FITC-CTB) and Fast Blue (FB) into the right and left upper cervical spinal cord, respectively, at postoperative weeks 2, 3, 4, and 5 and counted the number of retrogradely labeled corticospinal neurons in the right cerebral cortex compared with that in normally developed rats. Significantly more ipsilaterally projecting neurons were labeled with FITC-CTB in the decorticated rats compared with normal rats at all time points examined. The number of labeled neurons was similar to that at P7 in normal rats. There were also some FITC-CTB and FB double-labeled neurons in both decorticated and normal rats. The number of double-labeled neurons in the decorticated rats increased each week and was significantly greater than that in normal rats at postoperative weeks 4 and 5. The present results suggest that the elimination of ipsilaterally projecting axons observed in normal rats was prevented in the decorticated rats, so that the cerebral cortex neurons on the unlesioned side projected corticospinal tracts to the ipsilateral spinal cord. Furthermore, the collaterals of the corticospinal tracts originating from the cerebral cortex on the unlesioned side also project to the ipsilateral spinal cord. These compensatory mechanisms might underlie the acquisition of motor function in these animals.

DOI： 10.1159/000335526

PubMed

researchmap