小脑-下丘脑投射在小脑顶核调节淋巴细胞数量与功能中的介导作用

目的:探讨小脑顶核对淋巴细胞功能的调节作用及其作用途径。方法:用海人酸(KA)损毁大鼠双侧小脑顶核,术后第8d用血细胞计数法和酶联免疫吸附试验(ELISA)分别检测动物外周血中淋巴细胞数和血清中抗绵羊红细胞(SRBC)特异性IgM抗体水平。用电损毁小脑上脚交叉中顶核投射至下丘脑的神经纤维,检测动物淋巴细胞数和抗SRBC特异性IgM抗体水平的变化。结果:KA注入双侧小脑顶核后第8d,在Nissl染色的小脑切片,呈现双侧顶核内神经元胞体破坏。作为对照,在生理盐水注入顶核的动物脑片上,可见正常的Nissl小体。小脑顶核损毁后第8d,动物外周血中淋巴细胞数占白细胞总数的百分比以及血清中抗SRBC特异性IgM抗体水平均明显高于顶核注射生理盐水的对照动物。电损毁小脑上脚交叉处顶核投射至下丘脑的神经纤维后第8d,外周血中淋巴细胞的百分比及抗SRBC特异性IgM抗体水平均明显高于假损毁小脑上脚交叉的对照动物。结论:小脑顶核的神经元胞体损毁导致淋巴细胞功能增强,小脑顶核投射至下丘脑的神经纤维损毁同样引起淋巴细胞功能增强,这些结果提示小脑顶核至下丘脑的神经投射参与介导小脑顶核对淋巴细胞功能的调节作用。

Involvement of cerebellohypothalamic projections in the modulation of lymphocyte function by cerebellar fastigial nuclei

Aim:To explore the effect of cerebellar fastigial nuclei(FN)on lymphocyte function and the pathway mediating the effect.Methods:Kainic acid(KA)was microinjected into bilateral FN of rats to destroy neuronal bodies in the FN.On the eighth day after the surgery,lymphocyte percentage in the peripheral blood and level of sheep red blood cell(SRBC)-specific IgM antibody in the serum were measured by using blood corpuscle counter and enzyme-linked immunosorbent assay(ELISA),respectively.A technology of electrolytic lesion was used to destroy the projections of cerebellar FN neurons to hypothalamus in decussation of superior cerebellar peduncle(xscp).Results:On the eighth day after the microinjection of KA into the bilateral FN of rats,the Nissl-stained neuronal bodies in the FN disappeared and glia could proliferated within the damaged FN.In the nuclei close to FN,the interposed nuclei and the dentate nuclei,Nissl-stained neurons still could be seen.On the control cerebellar sections,in which FN was infused with saline,we could see the normal Nissl-stained neurons in the FN and the other two nuclei.On day 8 following the effective FN lesions,both the lymphocyte percentage in the peripheral blood and the level of anti-SRBC IgM antibody in the serum were significantly increased in comparison with those of control rats infused with saline in the FN.On the eighth day after electrolytic lesion of the fibres in xscp,the FN-hypothalamic projections were damaged and there were no visible BDA-positive endings in hypothalamus.Meanwhile,both the lymphocyte percentage in the peripheral blood and the level of anti-SRBC IgM antibody in the serum were remarkably enhanced relative to those of control rats with sham lesion of xscp.Conclusion:The electrolytic lesion of the FN-hypothalamic projections in xscp causes an enhancement of lymphocyte function similar to that of KA lesions of neuronal soma in the FN.These findings suggest that the cerebellohypothalamic projections participate in mediating the modulation of lymphocyte function by the cerebellum.