title: Modulation of pumping rate by two species of marine bivalve molluscs in response to neurotransmitters: Comparison of in vitro and in vivo results.
abstract: Most studies regarding the neuroanatomy and neurophysiology of molluscan ctenidia have focused on isolated ctenidial tissue preparations. This study investigated how bivalve molluscs modulate their feeding rates by examining the effects of a variety of neurotransmitters, including serotonin, dopamine, and the dopamine agonist apomorphine on both isolated ctenidial tissue and in intact members of two commercially important bivalve species: the blue mussel, Mytilus edulis; and the bay scallop Argopecten irradians. In particular, we examined the effect of changes in: 1) beat of the lateral cilia (in vitro), 2) distance between ctenidial filaments and/or plicae (in vivo), and 3) diameter of the siphonal openings (in vivo) on alteration of bulk water flow through the mantle cavity. Important differences were found between isolated tissue and whole animals, and between species. Drugs that stimulated ciliary beat in vitro did not increase water processing rate in vivo. None of the treatments increased water flow through the mantle cavity of intact animals. Results suggest that A. irradians was primarily modulating lateral ciliary activity, while M. edulis appeared to have a number of ways to control water processing activity, signifying that the two species may have different compensatory and regulatory mechanisms controlling feeding activity.
authors.affiliation: Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, Groton, CT 06340, USA. Electronic address: dana.frank@uconn.edu.
authors.forename: Dana M
authors.initials: DM
authors.lastname: Frank
authors.affiliation: Department of Biology, University of Louisiana at Lafayette, PO Box 42451, Lafayette, LA 70504, USA.
authors.forename: Lewis
authors.initials: L
authors.lastname: Deaton
authors.affiliation: Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, Groton, CT 06340, USA.
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Shumway
authors.affiliation: Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, Groton, CT 06340, USA.
authors.forename: Bridget A
authors.initials: BA
authors.lastname: Holohan
authors.affiliation: Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Road, Groton, CT 06340, USA.
authors.forename: J Evan
authors.initials: JE
authors.lastname: Ward
mesh_terms: D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001692:Biological Transport; D002923:Cilia / Q000187:drug effects / Q000502:physiology; D004298:Dopamine / Q000494:pharmacology / Q000502:physiology; D018491:Dopamine Agonists / Q000494:pharmacology; D049880:Mytilus edulis / Q000187:drug effects / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000494:pharmacology / Q000502:physiology*; D049897:Pectinidae / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology / Q000502:physiology; D018490:Serotonin Agents / Q000494:pharmacology
chemical_list: D018491:Dopamine Agonists; D018377:Neurotransmitter Agents; D018490:Serotonin Agents; D012701:Serotonin; D001058:Apomorphine; D004298:Dopamine
keywords: Argopecten irradians; Bivalve; Mollusc; Mussel; Mytilus edulis; Neurotransmitter; PIV; Pumping rate; Scallop; Suspension feeding