title: Control of planula migration by LWamide and RFamide neuropeptides in Hydractinia echinata.
abstract: Planula larvae of Hydractinia echinata (Cnidaria) settled on a substratum migrate toward light. We observed that planula migration is not a continuous process. Instead, it consists of repeating cycles of active migration (about 8 min on average) and inactive resting periods (about 26 min on average). This pattern of periodic migration is regulated by LWamide and RFamide neuropeptides. LWamide (10(-8) mol l(-1)) stimulates migration primarily by making the active periods longer, whereas RFamide (10(-7) mol l(-1)) inhibits migration by blocking the initiation and also shortening the length of the active periods. Since sensory neurons containing LWamides and RFamides are present in planula larvae, it appears likely that planula migration is regulated by the release of endogenous neuropeptides in response to environmental cues.
authors.affiliation: Ishinomaki Senshu University, Ishinomaki 986-8580, Japan Hachinohe Institute of Technology, Hachinohe 031-8501, Japan. katsukura@zoo.uni-heidelberg.de
authors.forename: Yuki
authors.initials: Y
authors.lastname: Katsukura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ando
authors.forename: Charles N
authors.initials: CN
authors.lastname: David
authors.forename: Cornelis J P
authors.initials: CJ
authors.lastname: Grimmelikhuijzen
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Sugiyama
mesh_terms: D025041:Animal Migration / Q000187:drug effects*; D000818:Animals; D037402:Hydrozoa / Q000502:physiology*; D007814:Larva / Q000502:physiology; D008027:Light; D009479:Neuropeptides / Q000493:pharmacokinetics / Q000494:pharmacology*; D012623:Seawater; D013997:Time Factors; D014741:Video Recording
chemical_list: D009479:Neuropeptides; C058047:arginylphenylalaninamide