title: Extracellularly applied horseradish peroxidase increases the number of dense core vesicles in leech sensory neurons.
abstract: The uptake of horseradish peroxidase (HRP), applied as an extracellular tracer, is a classical method for studying endo/exocytosis of synaptic vesicles at the ultrastructural level. It is generally not considered that HRP may affect neuronal function. Reported here is the finding that extracellularly applied HRP (0.1%) perturbs dense core vesicles in the synaptic processes of leech neurons. The strength of the effect varies with neuronal class. In sensory afferents, the number of dense core vesicles increases 5-fold, while there is only a 2-fold increase in central neurons.
authors.affiliation: Department of Pediatrics and Human Development, Michigan State University, East Lansing 48824, USA.
authors.forename: Mei-Hui
authors.initials: MH
authors.lastname: Tai
authors.forename: Birgit
authors.initials: B
authors.lastname: Zipser
mesh_terms: D000818:Animals; D002452:Cell Count / Q000379:methods; D005110:Extracellular Space / Q000187:drug effects*; D006735:Horseradish Peroxidase / Q000494:pharmacology*; D007865:Leeches / Q000187:drug effects* / Q000648:ultrastructure; D009475:Neurons, Afferent / Q000187:drug effects* / Q000648:ultrastructure; D013572:Synaptic Vesicles / Q000187:drug effects* / Q000648:ultrastructure
chemical_list: D006735:Horseradish Peroxidase