Neural tract tracing is used to study neural pathways and evaluate neuronal regeneration following nerve injuries.However,it is not always clear which tracer should be used to yield optimal results.In this study,we ex...Neural tract tracing is used to study neural pathways and evaluate neuronal regeneration following nerve injuries.However,it is not always clear which tracer should be used to yield optimal results.In this study,we examined the use of Alexa Fluor 488-conjugated cholera toxin subunit B(AF488-CTB).This was injected into the gastrocnemius muscle of rats,and it was found that motor,sensory,and sympathetic neurons were labeled in the spinal ventral horn,dorsal root ganglia,and sympathetic chain,respectively.Similar results were obtained when we injected AF594-CTB into the tibialis anterior muscle.The morphology and number of neurons were evaluated at different time points following the AF488-CTB injection.It was found that labeled motor and sensory neurons could be observed 12 hours post-injection.The intensity was found to increase over time,and the morphology appeared clear and complete 3-7 days post-injection,with clearly distinguishable motor neuron axons and dendrites.However,14 days after the injection,the quality of the images decreased and the neurons appeared blurred and incomplete.Nissl and immunohistochemical staining showed that the AF488-CTB-labeled neurons retained normal neurochemical and morphological features,and the surrounding microglia were also found to be unaltered.Overall,these results imply that the cholera toxin subunit B,whether unconjugated or conjugated with Alexa Fluor,is effective for retrograde tracing in muscular tissues and that it would also be suitable for evaluating the regeneration or degeneration of injured nerves.展开更多
基金supported by the CACMS Innovation Fund,No.CI2021A03407(to WZB)the Project of National Key R&D Program of China,No.2019YFC1709103(to WZB)+1 种基金the National Natural Science Foundation of China,Nos.81774432(to JJC),81774211(to WZB),82004492(to JW),81801561(to DSX)the Fundamental Research Funds for the Central Public Welfare Research Institutes of China,Nos.ZZ13-YQ-068(to JJC),ZZ14-YQ-032(to JW),ZZ14-YQ-034(to DSX).
文摘Neural tract tracing is used to study neural pathways and evaluate neuronal regeneration following nerve injuries.However,it is not always clear which tracer should be used to yield optimal results.In this study,we examined the use of Alexa Fluor 488-conjugated cholera toxin subunit B(AF488-CTB).This was injected into the gastrocnemius muscle of rats,and it was found that motor,sensory,and sympathetic neurons were labeled in the spinal ventral horn,dorsal root ganglia,and sympathetic chain,respectively.Similar results were obtained when we injected AF594-CTB into the tibialis anterior muscle.The morphology and number of neurons were evaluated at different time points following the AF488-CTB injection.It was found that labeled motor and sensory neurons could be observed 12 hours post-injection.The intensity was found to increase over time,and the morphology appeared clear and complete 3-7 days post-injection,with clearly distinguishable motor neuron axons and dendrites.However,14 days after the injection,the quality of the images decreased and the neurons appeared blurred and incomplete.Nissl and immunohistochemical staining showed that the AF488-CTB-labeled neurons retained normal neurochemical and morphological features,and the surrounding microglia were also found to be unaltered.Overall,these results imply that the cholera toxin subunit B,whether unconjugated or conjugated with Alexa Fluor,is effective for retrograde tracing in muscular tissues and that it would also be suitable for evaluating the regeneration or degeneration of injured nerves.
文摘目的探讨黏膜佐剂霍乱毒素B 亚单位（CT-B ）在激发旋毛虫感染的黏膜免疫中的作用。方法24只NI H 小鼠随机分为4 组，每组6 只。CT-B 免疫组：每只小鼠于0 、7 、14 d 用含幼虫抗原100 μg 、C T-B 10 μg 的免疫原200 μl 经口灌服；正常对照组；免疫后感染组：免疫方法同CT-B 免疫组，末次免疫后第7 天，每只小鼠用200 条旋毛虫进行感染；单纯感染组：不免疫，与免疫后感染组同时进行感染。CT 蛳B 免疫组与正常对照组在免疫后第7 天、免疫后感染组与单纯感染组在感染后第7 天分别取血检测Ig A 、Ig G 1 、Ig G 2 b ，刮取肠黏液检测sIgA ，检测肠道成虫数，并收集每鼠雌虫，在体外检查其生殖力。结果与单纯感染组相比，CT-B 免疫后感染组肠道成虫数明显减少，雌虫生殖力明显降低，成虫与新生幼虫减虫率分别为88.2%和72.4%。CT-B 免疫组小鼠肠黏液sIg A 、血清Ig A 较对照组小鼠明显提高(0 .2 9 ±0 .04 vs 0.09 ±0.02，0.21 ±0.06 vs 0.08 ±0.01，P <0.001)；而两组Ig G 1 和Ig G 2 b 水平无显著性差异(P>0.05)。CT-B 免疫后感染组小鼠肠黏液sIg A 、血清Ig A 较单纯感染组小鼠相比有显著性差异(0 .5 5 ±0 .28 vs0.08 ±0.15，0.33 ±0.06 vs 0.10 ±0.10，P <0.001)。
