title: Retrograde loading of nerves, tracts, and spinal roots with fluorescent dyes.
abstract: Retrograde labeling of neurons is a standard anatomical method(1,2) that has also been used to load calcium and voltage-sensitive dyes into neurons(3-6). Generally, the dyes are applied as solid crystals or by local pressure injection using glass pipettes. However, this can result in dilution of the dye and reduced labeling intensity, particularly when several hours are required for dye diffusion. Here we demonstrate a simple and low-cost technique for introducing fluorescent and ion-sensitive dyes into neurons using a polyethylene suction pipette filled with the dye solution. This method offers a reliable way for maintaining a high concentration of the dye in contact with axons throughout the loading procedure.
authors.affiliation: Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA. blivisd@ninds.nih.gov
authors.forename: Dvir
authors.initials: D
authors.lastname: Blivis
authors.forename: Michael J
authors.initials: MJ
authors.lastname: O'Donovan
mesh_terms: D000818:Animals; D001369:Axons / Q000737:chemistry*; D003911:Dextrans / Q000737:chemistry; D005452:Fluoresceins / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D009474:Neurons / Q000737:chemistry* / Q000166:cytology; D013126:Spinal Nerve Roots / Q000033:anatomy & histology / Q000737:chemistry* / Q000166:cytology; D013127:Spinal Nerves / Q000033:anatomy & histology / Q000737:chemistry* / Q000166:cytology; D013194:Staining and Labeling / Q000295:instrumentation / Q000379:methods*
chemical_list: D003911:Dextrans; D005452:Fluoresceins; D005456:Fluorescent Dyes