title: Cyclic AMP modulates fast axonal transport in Aplysia bag cell neurons by increasing the probability of single organelle movement.
abstract: Stimulation of Aplysia bag cell neurons triggers elevation of cAMP and prolonged secretion of ELH neuropeptide. Using video-enhanced microscopy to track individual organelle movements in bag cell neurons, we find that organelle translocation consists of periods of movement interrupted by stationary episodes. cAMP elevation leads to a 2- to 3-fold enhancement of the average rate of organelle transport in both anterograde and retrograde directions. This effect does not result from alteration of the instantaneous velocity of organelle transport along microtubules, but rather from an increase in the proportion of time individual organelles spend in motion. Biochemical measurements also provided evidence that cAMP elevation promotes ELH peptide translocation from the somata into axons. Enhanced transport of ELH as a result of these effects may contribute to the replenishment of neuropeptide-containing vesicles at release sites during prolonged periods of secretion.
authors.affiliation: Department of Pharmacology, Yale University, New Haven, Connecticut 06510.
authors.forename: E M
authors.initials: EM
authors.lastname: Azhderian
authors.forename: D
authors.initials: D
authors.lastname: Hefner
authors.forename: C H
authors.initials: CH
authors.lastname: Lin
authors.forename: L K
authors.initials: LK
authors.lastname: Kaczmarek
authors.forename: P
authors.initials: P
authors.lastname: Forscher
mesh_terms: D000818:Animals; D001048:Aplysia; D001370:Axonal Transport; D001369:Axons / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D017952:Ganglia, Invertebrate / Q000502:physiology*; D007447:Invertebrate Hormones / Q000378:metabolism*; D008870:Microtubules / Q000502:physiology* / Q000648:ultrastructure; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D015388:Organelles / Q000502:physiology* / Q000648:ultrastructure; D011336:Probability; D013806:Theophylline / Q000494:pharmacology; D013873:Thionucleotides / Q000494:pharmacology
chemical_list: D007447:Invertebrate Hormones; D013873:Thionucleotides; C026880:egg-laying hormone, Mollusca; D005576:Colforsin; C015929:8-((4-chlorophenyl)thio)cyclic-3',5'-AMP; D013806:Theophylline; D000242:Cyclic AMP