植块联合培养法探讨备用背根猫脊髓背核组织对鸡胚背根节神经突起生长的影响

EFFECT OF CLARKE'S NUCLEUS OF SPARED DORSAL ROOT CAT ON THE NEURITE-OUTGROWTH OF DORSAL ROOT GANGLION FROM CHICKEN EMBRYO IN VITRO

５只单侧备用背根猫，于术后第５ｄ分别切取手术侧、非手术侧脊髓Ｌ_３节段背核组织植块，与Ｈａｍｂｕｒｇｅｒ３５期鸡胚背根节（ＤＲＧ）进行植块联合悬滴培养，以单独ＤＲＧ培养作为参照。于培养２４ｈ、４８ｈ观察ＤＲＧ神经突起的生长情况并测量其长度。结果发现：１．所有ＤＲＧ从培养２４ｈ到４８ｈ其神经突起都有明显增长；２：同一观察时间内，参照组与对照组（ＤＲＧ与非手术侧背核植块联合培养组）神经突起的生长状况较为相似，神经突起少而短，从ＤＲＧ迁移出的细胞多。而实验组（ＤＲＧ与手术侧背核植块联合培养组）神经突起多且长，从ＤＲＧ迁移出的细胞少；３：在分别求出每批培养物的实验组、对照组ＤＲＧ神经突起平均长度与参照组者的比值及５批培养物的平均比值后，发现两个观测时间实验组的平均比值都明显大于对照组者。本研究结果提示，猫脊髓在部分腰骶背根切除后，背核组织的促神经突起生长作用增强。

Five adult cats which were subjected to unilateral lumbosacral posterior rhizotomy with L_6 dorsal root spared and allowed to survive for 5 days were used in this study, Tissue explants of Clarke's nucleus from both operated and unoperated side of L_3 spinal segments were taken and co-cultured individually with a dorsal root ganglion(DRG)of chicken embryo at Hamburger stage 35 by hanging drop culture technique. The co-cultured group of a DRG with an operated side Clarke's nucleus explant was named as the experimental group and that with an unoperated side Clarke's nucleus explant as the control group, another group of DRG cultured alone as the reference one, Tissue explants from one cat were used for one batch of cultures. The average neurite length of every DRG cultured for 24h and 48 h was measured. Our findings demonstrated that:(1)There was a significant neurite extension from 24 h to 48 h of the cultured DRG in all groups.(2)As compared with the control and the reference groups, DRG of the experimental group displayed much more and longer neurites with less cells migrated out. (3)By calculating respectively the ratio of the average neurite length of the experimental group or the control group to the reference one for each batch of cultures as well as the mean ratio value for 5 batches,we found that the mean ratio value of the experimental group was statistically higher than that of the control group at the same test time. Our results indicated that an increased neurite-outgrowth promoting effect appeared in Clarke's nucleus of cat spinal cord with unilateral lumbosacral posterior rhizotomy.