title: Horseradish peroxidase retrograde labeling of primary sensory neurons: a comparison of four intraspinal application methods.
abstract: The purpose of this study was to optimize the methods of retrograde labeling of sensory neurons in demonstrating the continuity of post-ganglionic primary sensory axons. This was accomplished by comparing four different methods of horseradish peroxidase (HRP) application into the lower thoracic spinal cord of adult rats (level T11). HRP application with a piece of Gelfoam via a dorsal myelotomy (group 1, n = 8), stereotactic injections with a 0.72-mm tip diameter needle (group 2, n = 8), with a 0.24-mm tip needle (group 3, n = 8), and with a 0.08-mm tip glass micropipette (group 4, n = 5). Histological examination of the application site showed that the extent of spinal cord injury was directly proportional to the diameter of the needle tip. The mean number of dorsal root ganglia (DRG) sensory neurons retrogradely stained by HRP differed among the four experimental groups: 77 +/- 45 (SEM) per DRG in group 1, 106 +/- 24 in group 2, 652 +/- 90 in group 3, and 238 +/- 60 in group 4. A significant difference was found between group 3 and the other ones (P < 0.05). Intraspinal injection of HRP with a fine needle (0.24-mm tip diameter) using a stereotactic approach can achieve effective and reliable retrograde labeling of primary sensory neurons. This reproducible method may be useful in studies dealing with regeneration of post-ganglionic primary sensory axons.
authors.affiliation: Laboratory of Experimental Neurosurgery, Bicêtre University Hospital, University of Paris-Sud, Le Kremlin-Bicêtre, France. phongdamhieu@hotmail.com
authors.forename: P
authors.initials: P
authors.lastname: Dam-Hieu
authors.forename: S
authors.initials: S
authors.lastname: Liu
authors.forename: A S
authors.initials: AS
authors.lastname: Bonnard
authors.forename: M
authors.initials: M
authors.lastname: Tadie
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004195:Disease Models, Animal; D006735:Horseradish Peroxidase / Q000032:analysis*; D007278:Injections, Spinal; D008297:Male; D008866:Microsurgery / Q000379:methods; D009475:Neurons, Afferent / Q000187:drug effects*; D011336:Probability; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D013116:Spinal Cord / Q000473:pathology* / Q000601:surgery; D013119:Spinal Cord Injuries / Q000473:pathology* / Q000601:surgery; D013194:Staining and Labeling / Q000379:methods*; D013904:Thoracic Vertebrae
chemical_list: D006735:Horseradish Peroxidase