Roles of cytokines and trophic factors on the plastic changes of dendritic morphology

1.内源性凝集素和免疫抑制剂FK506对感觉神经元的影响1)半乳糖凝集素-1（Gal-1）参与多种功能，包括神经突生长。约20%的DRG神经元表现出强烈的gal -1免疫反应性，大部分为c- ret阳性。鞘内注射抗rhgal -1抗体可显著减轻周围神经损伤引起的机械超敏反应，提示内源性Gal-1可增强神经性疼痛。2)FK506在神经元上表现出多种作用，尽管确切的机制尚不清楚。我们研究了FK506是否直接激活感觉神经元。Ca^<2+>对培养大鼠DRG神经元的影响显示fk506诱导小DRG神经元亚群细胞内Ca^<2+>升高（3.1%）。当使用炎症大鼠的DRGs时，发生率增加到7.4%。FK506敏感神经元也对辣椒素和缓激素有反应。在神经-皮肤准备中，FK506增强了单个c -纤维的神经元放电，这些c -纤维对热和缓激素的反应更强，表明FK506激活了伤害性c -纤维（提交给期刊）。慢性应激动物海马神经元树突形态的调节因素重复抑制应激3周可诱导海马锥体细胞树突萎缩。在这些动物中，我们研究了海马BDNF mRNA水平、血浆糖corliocid （CC）水平、海马/下丘脑GC受体和中颚核5-HT合成，发现CC和5-HT诱导的海马BDNF合成下调在树突形态的调节中起关键作用（已提交期刊）。肿瘤坏死因子受体超家族新成员TROY在神经系统发育中的作用我们研究了TROY mRNA在发育中的小鼠大脑中的表达模式。TROYmRNA在胚胎发育过程中，在含有神经元和胶质前体的通气带和通气下带强烈表达，表明TROY在神经系统发育中起重要作用。少

1.Effects of endogenous lectin and immunosuppressant FK506 on sensory neurons1)Galectin-1(Gal-1) is involved in a variety of functions, including neurite outgrowth. About 20% of DRG neurons showed intense Gal-1-immunoreactivity, and most of them were c-Ret-positive. Intrathecal administration of anti-rhGal-1 antibody significantly attenuated the mechanical hypersensitivity induced by peripheral nerve injury, suggesting that endogenous Gal-1 potentiates neuropathic pain.2)FK506 shows multiple actions on neurons, although precise mechanisms are obscure. We addressed if FK506 directly activates sensory neurons or not. Ca^<2+> on cultured rat DRG neurons revealed FK506-induced increase in intracellular Ca^<2+> in a subpopulation of small DRG neurons (3.1%). When DRGs from inflamed rats were used, the incidence increased to 7.4%. FK506 sensitive neurons also responded to capsaicin and bradykinin. In the nerve-skin preparation, FK506 enhanced neuronal discharges of single C-fibers that are r … More esponsive to heat and bradykinin, indicating that FK506 activates nociceptive C-fibers (submitted to a journal).2.Factors that regulate dendritic morphology of hippocampal neurons in chronically stressed animalsRepetitive restrain stress for 3 weeks was shown to induce dendritic atrophy of pyramical cells in the hippocampus. We investigated BDNF mRNA levels in the hippocampus, together with plasma glucocorliocid (CC) levels, GC receptors in the hippocampus/hypothalamus and 5-HT synthesis in the raphe nuclei, in these animals, and suggested that CC-and 5-HT-induced down regulation of BDNF synthesis in the hippocampus plays a pivotal role in the regulation of dendritic morphology (submitted to a journal).3.Roles of a new member of TNF receptor superfamily TROY on the development of nervous systemWe investigated the expression pattern of TROY mRNA in the developing mice brain. TROYmRNA was strongly expressed in the ventiicular zone and subventiicular zone, which contain neuronal and glial precursors during embryogenesis, indicating that TROY plays important roles in the development of nervous system. Less