@article{oai:sapmed.repo.nii.ac.jp:00014769,
 author = {今井, 富裕},
 issue = {4},
 journal = {札幌医学雑誌 = The Sapporo medical journal, The Sapporo medical journal},
 month = {Aug},
 note = {The aim of this study was to determine if biocytin, a low molecular weight analog of biotin, would reliably label details of corticospinal fibers at the lumbar level in the rat. All surgi- cal procedures were performed aseptically under Nembutal anesthesia. Biocytin （5%） was injected extracellularly by pressure into the hindlimb motor cortex. Rats were per fused following survival periods of 1-7 days. After fixation, frozen sections （40μm thick） of the injection sites and the lum- bar segments were incubated with avidin-horseradish peroxidase （HRP） containing 0.3% Triton-X 100. The reaction was enhanced with heavy metals. To elucidate the advantages of this technique with biocytin, wheat germ agglutinin （WGA）-HRP was compared with biocytin for its use in cor- ticospinal fiber tracing. The results are summarized as follows. 1） Biocytin was transported rapidly, at a speed of 20-40 mm/day outward from the injection site. Terminal labeling of corticospinal fibers at the lumber segment was observed within 2 to 3 days of the injection. 2） With an injection volume of 300nl, there was no apparent difference in labeling quality between animals with survival times of 24-72 h. The labeling was weaker with longer survival times （>5days）. 3） Although the reason for the decrease in labeling with survival time is unknown, possible expla- nations are that biocytin could be degraded by intracellular enzymes, such as biotinidase, or that it might have been expelled from the terminals into the extracellular space. 4）The number of axons labeled by biocytin was smaller than by WGA-HRP. However, biocytin stain provides a view of a higher level of detail than WGA-HRP. These results indicate that anterograde tracing with biocytin can be applied to label axons in a long tract such as the corticospinal tract. Biocytin can be especially recommended as a useful anter- ograde neuronal tracer to reveal fine details in labeled axons.},
 pages = {257--266},
 title = {Biocytinによるラット皮質脊髄路の順行性標識法 : WGA-HRP法との比較},
 volume = {61},
 year = {1992}
}