Ultrastructural localization of immunolabeled substance P and methionine-enkephalin-octapeptide in the surface layer of the dorsal horn of rat spinal cord.
A preembedding dual immunolabeling technique and electron microscopy were utilized to demonstrate the localization of immunoreactive substance P and methionine-enkephalin-octapeptide (Enk-8) in ultrathin sections of the surface layer (laminae I and II) of rat spinal dorsal horn. The immunoreaction of Enk-8 was visualized as gold-toned silver particles and that of substance P as diaminobenzidine reaction products. Axonal terminals with immunoreactive substance P, and also unlabeled axonal terminals, formed synaptic junctions with the perikarya and dendritic processes of Enk-8-containing neurons. Dendritic profiles immunolabeled for substance P were synaptically linked with unlabeled axons but not with Enk-8-positive ones. Furthermore, it was found that Enk-8 axons and substance P axons terminated synaptically in juxtaposition to one another on the same immunonegative dendrites. Among the Enk-8-containing neurons axonal profiles also appeared to be synaptically associated with immunoreactive Enk-8 dendritic processes.
Katoh
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Department of Anatomy, School of Medicine, University of Tokushima, Japan.
Hisano
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Daikoku
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D000818:Animals; D001369:Axons / Q000648:ultrastructure; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives* / Q000032:analysis / Q000276:immunology; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron / Q000379:methods; D009474:Neurons / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains / Q000033:anatomy & histology*; D013116:Spinal Cord / Q000166:cytology*; D013373:Substance P / Q000032:analysis / Q000276:immunology*; D013569:Synapses / Q000648:ultrastructure
D013373:Substance P; D004744:Enkephalin, Methionine; C033453:enkephalin-Met, Arg(6)-Gly(7)-Leu(8)-