title: Cholera Toxin B Subunit Shows Transneuronal Tracing after Injection in an Injured Sciatic Nerve.
abstract: Cholera toxin B subunit (CTB) has been extensively used in the past for monosynaptic mapping. For decades, it was thought to lack the ability of transneuronal tracing. In order to investigate whether biotin conjugates of CTB (b-CTB) would pass through transneurons in the rat spinal cord, it was injected into the crushed left sciatic nerve. For experimental control, the first order afferent neuronal projections were defined by retrograde transport of fluorogold (FG, a non-transneuronal labeling marker as an experimental control) injected into the crushed right sciatic nerve in the same rat. Neurons containing b-CTB or FG were observed in the dorsal root ganglia (DRG) at the L4-L6 levels ipsilateral to the tracer injection. In the spinal cord, b-CTB labeled neurons were distributed in all laminae ipsilaterally between C7 and S1 segments, but labeling of neurons at the cervical segment was abolished when the T10 segment was transected completely. The interneurons, distributed in the intermediate gray matter and identified as gamma-aminobutyric acid-ergic (GABAergic), were labeled by b-CTB. In contrast, FG labeling was confined to the ventral horn neurons at L4-L6 spinal segments ipsilateral to the injection. b-CTB immunoreactivity remained to be restricted to the soma of neurons and often appeared as irregular patches detected by light and electron microscopy. Detection of monosialoganglioside (GM1) in b-CTB labeled neurons suggests that GM1 ganglioside may specifically enhance the uptake and transneuronal passage of b-CTB, thus supporting the notion that it may be used as a novel transneuronal tracer.
authors.affiliation: Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China.
authors.forename: Bi-Qin
authors.initials: BQ
authors.lastname: Lai
authors.affiliation: Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China.
authors.forename: Xue-Chen
authors.initials: XC
authors.lastname: Qiu
authors.affiliation: Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
authors.forename: Rong-Yi
authors.initials: RY
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Jin
authors.affiliation: Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China.
authors.forename: Ge
authors.initials: G
authors.lastname: Li
authors.affiliation: Institute of Spinal Cord Injury, Sun Yat-sen University, Guangzhou, 510120, China.|Department of Orthopedics of Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, China.
authors.forename: Hui-Yong
authors.initials: HY
authors.lastname: Shen
authors.affiliation: Department of Electron Microscope, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
authors.forename: Jin-Lang
authors.initials: JL
authors.lastname: Wu
authors.affiliation: Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore.
authors.forename: Eng-Ang
authors.initials: EA
authors.lastname: Ling
authors.affiliation: Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China.|Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.|Institute of Spinal Cord Injury, Sun Yat-sen University, Guangzhou, 510120, China.|Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.|Guangdong Provincial Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
authors.forename: Yuan-Shan
authors.initials: YS
authors.lastname: Zeng
mesh_terms: D000818:Animals; D002772:Cholera Toxin / Q000493:pharmacokinetics / Q000494:pharmacology; D005260:Female; D005677:G(M1) Ganglioside / Q000378:metabolism; D059330:GABAergic Neurons / Q000166:cytology* / Q000378:metabolism; D005727:Ganglia, Spinal / Q000166:cytology* / Q000378:metabolism; D066128:Gray Matter / Q000166:cytology* / Q000378:metabolism; D056347:Neuroanatomical Tract-Tracing Techniques / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000166:cytology* / Q000378:metabolism
chemical_list: D005677:G(M1) Ganglioside; D002772:Cholera Toxin