Tyramide Amplification Allows Anterograde Tracing by Horseradish Peroxidase-conjugated Lectins in Conjunction with Simultaneous ImmunohistochemistryMichael Kresselaa Institute of Anatomy, Friedrich-Alexander University of Erlangen, Erlangen, Germany Correspondence to: Michael Kressel, Inst. of Anatomy, University of Erlangen, Krankenhausstr. 9, D-91054 Erlangen, Germany. Current protocols for a combined approach of anterograde tracing with carbocyanine dyes or horseradish peroxidase (HRP) conjugates and immunohistochemistry represent a compromise between sensitive detection of the tracer and the immunohistochemical procedure. Therefore, it was investigated whether the use of tyramide amplification allows sensitive anterograde tracing with wheat-germ agglutinin conjugated to horseradish peroxidase (WGAHRP) in conjunction with simultaneous immunohistochemistry. Vagal afferents were anterogradely labeled by injection of WGAHRP into the nodose ganglion of rats. By use of tyramidebiotin amplification, a dense fiber plexus of vagal afferents was visualized centrally in the nucleus of the solitary tract and in retrogradely labeled neurons in the dorsal vagal nucleus. In the esophagus and duodenum, large- and small-caliber vagal fibers and terminals could be demonstrated comparably to conventional tracing techniques using carbocyanine dyes or WGAHRP and TMB histochemistry. Combination with immunohistochemistry could easily be done, requiring only one more incubation step, and did not result in loss of sensitivity of the tracing. With this method and confocal microscopy, the presence of Ca binding proteins in vagal afferent terminals could be demonstrated. Tyramide amplification allows sensitive anterograde tracing with low background staining in conjunction with immunohistochemistry of intra-axonal markers. (J Histochem Cytochem 46:527533, 1998) Key Words: tyramides, carbocyanine dyes, anterograde tracing, calretinin, calbindin, wheat-germ agglutinin, confocal microscopy
This article has been cited by other articles:
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||